[FFmpeg-devel] [PATCH 4/4] libavcodec/dev: v4l2: add support for v4l2 mem2mem codecs

Jorge Ramirez-Ortiz jorge.ramirez-ortiz at linaro.org
Mon Jul 24 22:08:49 EEST 2017


From: Alexis Ballier <aballier at gentoo.org>

This patchset enhances Alexis Ballier's original patch and validates
it using Qualcomm's Venus hardware (driver recently landed upstream
[1]).

This has been tested on Qualcomm's DragonBoard 410c and 820c

ffplay tested video decoders:
- h264,
- vp8
- mpeg4

Some of the changes introduced:
- v4l2: some cleanup of the code.
- v4l2: some cleaup before upstreaming.
- v4l2: follow the new decode api.
- v4l2: fix display size for NV12 output pool.
- v4l2: handle EOS.
- v4l2: fix vp8 and mpeg4 decoding.
- v4l2: generate EOF on dequeue errors.
- v4l2: h264_mp4toannexb filtering.

[1] https://lwn.net/Articles/697956/

Reviewed-by: Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
Reviewed-by: Alexis Ballier <aballier at gentoo.org>
Tested-by: Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
---
 Changelog                     |   3 +-
 configure                     |  17 +-
 libavcodec/Makefile           |  15 +-
 libavcodec/allcodecs.c        |   7 +
 libavcodec/v4l2-buffers.c     | 633 ++++++++++++++++++++++++++++++++++++++++++
 libavcodec/v4l2-buffers.h     | 247 ++++++++++++++++
 libavcodec/v4l2-common.c      |  48 ++--
 libavcodec/v4l2-common.h      |   4 +-
 libavcodec/v4l2_m2m.c         | 358 ++++++++++++++++++++++++
 libavcodec/v4l2_m2m.h         |  69 +++++
 libavcodec/v4l2_m2m_avcodec.h |  32 +++
 libavcodec/v4l2_m2m_dec.c     | 244 ++++++++++++++++
 libavcodec/v4l2_m2m_enc.c     | 251 +++++++++++++++++
 13 files changed, 1897 insertions(+), 31 deletions(-)
 create mode 100644 libavcodec/v4l2-buffers.c
 create mode 100644 libavcodec/v4l2-buffers.h
 create mode 100644 libavcodec/v4l2_m2m.c
 create mode 100644 libavcodec/v4l2_m2m.h
 create mode 100644 libavcodec/v4l2_m2m_avcodec.h
 create mode 100644 libavcodec/v4l2_m2m_dec.c
 create mode 100644 libavcodec/v4l2_m2m_enc.c

diff --git a/Changelog b/Changelog
index 187ae79..d31de07 100644
--- a/Changelog
+++ b/Changelog
@@ -29,6 +29,7 @@ version <next>:
 - limiter video filter
 - libvmaf video filter
 - Dolby E decoder and SMPTE 337M demuxer
+- V4L2 mem2mem HW accelerated codecs support
 
 version 3.3:
 - CrystalHD decoder moved to new decode API
@@ -65,7 +66,6 @@ version 3.3:
 - Intel QSV-accelerated VP8 video decoding
 - VAAPI-accelerated deinterlacing
 
-
 version 3.2:
 - libopenmpt demuxer
 - tee protocol
@@ -105,7 +105,6 @@ version 3.2:
 - Changed mapping of rtp MIME type G726 to codec g726le.
 - spec compliant VAAPI/DXVA2 VC-1 decoding of slices in frame-coded images
 
-
 version 3.1:
 - DXVA2-accelerated HEVC Main10 decoding
 - fieldhint filter
diff --git a/configure b/configure
index 0ebc022..9762f32 100755
--- a/configure
+++ b/configure
@@ -10,7 +10,6 @@
 # Prevent locale nonsense from breaking basic text processing.
 LC_ALL=C
 export LC_ALL
-
 # make sure we are running under a compatible shell
 # try to make this part work with most shells
 
@@ -149,6 +148,7 @@ Component options:
   --disable-pixelutils     disable pixel utils in libavutil
 
 Individual component options:
+  --disable-v4l2_m2m       disable V4L2 mem2mem code [autodetect]
   --disable-everything     disable all components listed below
   --disable-encoder=NAME   disable encoder NAME
   --enable-encoder=NAME    enable encoder NAME
@@ -1432,6 +1432,7 @@ AVCODEC_COMPONENTS="
 
 AVDEVICE_COMPONENTS="
     indevs
+    v4l2_m2m
     outdevs
 "
 AVFILTER_COMPONENTS="
@@ -2269,10 +2270,12 @@ map 'eval ${v}_inline_deps=inline_asm' $ARCH_EXT_LIST_ARM
 loongson2_deps="mips"
 loongson3_deps="mips"
 v4l2_deps_any="linux_videodev2_h sys_videoio_h"
+v4l2_m2m_select="v4l2"
 mipsfpu_deps="mips"
 mipsdsp_deps="mips"
 mipsdspr2_deps="mips"
 mips32r2_deps="mips"
+vc1_v4l2m2m_decoder_deps="v4l2_m2m"
 mips32r5_deps="mips"
 mips32r6_deps="mips"
 mips64r2_deps="mips"
@@ -2283,6 +2286,8 @@ mmi_deps="mips"
 altivec_deps="ppc"
 dcbzl_deps="ppc"
 ldbrx_deps="ppc"
+vp8_v4l2m2m_decoder_deps="v4l2_m2m"
+vp8_v4l2m2m_encoder_deps="v4l2_m2m"
 ppc4xx_deps="ppc"
 vsx_deps="altivec"
 power8_deps="vsx"
@@ -2436,11 +2441,15 @@ h261_decoder_select="mpegvideo"
 h261_encoder_select="aandcttables mpegvideoenc"
 h263_decoder_select="h263_parser h263dsp mpegvideo qpeldsp"
 h263_encoder_select="aandcttables h263dsp mpegvideoenc"
+h263_v4l2m2m_decoder_deps="v4l2_m2m"
+h263_v4l2m2m_encoder_deps="v4l2_m2m"
 h263i_decoder_select="h263_decoder"
 h263p_decoder_select="h263_decoder"
 h263p_encoder_select="h263_encoder"
 h264_decoder_select="cabac golomb h264chroma h264dsp h264parse h264pred h264qpel videodsp"
 h264_decoder_suggest="error_resilience"
+h264_v4l2m2m_decoder_deps="v4l2_m2m"
+h264_v4l2m2m_encoder_deps="v4l2_m2m"
 hap_decoder_select="snappy texturedsp"
 hap_encoder_deps="libsnappy"
 hap_encoder_select="texturedspenc"
@@ -2481,6 +2490,7 @@ mpc7_decoder_select="bswapdsp mpegaudiodsp"
 mpc8_decoder_select="mpegaudiodsp"
 mpeg_xvmc_decoder_deps="X11_extensions_XvMClib_h"
 mpeg_xvmc_decoder_select="mpeg2video_decoder"
+mpeg1_v4l2m2m_decoder_deps="v4l2_m2m"
 mpegvideo_decoder_select="mpegvideo"
 mpeg1video_decoder_select="mpegvideo"
 mpeg1video_encoder_select="aandcttables mpegvideoenc h263dsp"
@@ -2488,6 +2498,8 @@ mpeg2video_decoder_select="mpegvideo"
 mpeg2video_encoder_select="aandcttables mpegvideoenc h263dsp"
 mpeg4_decoder_select="h263_decoder mpeg4video_parser"
 mpeg4_encoder_select="h263_encoder"
+mpeg4_v4l2m2m_decoder_deps="v4l2_m2m"
+mpeg4_v4l2m2m_encoder_deps="v4l2_m2m"
 msa1_decoder_select="mss34dsp"
 mscc_decoder_select="zlib"
 msmpeg4v1_decoder_select="h263_decoder"
@@ -3590,7 +3602,7 @@ done
 enable_weak audiotoolbox
 
 # Enable hwaccels by default.
-enable_weak d3d11va dxva2 vaapi vda vdpau videotoolbox_hwaccel xvmc
+enable_weak d3d11va dxva2 vaapi v4l2_m2m vda vdpau videotoolbox_hwaccel xvmc
 enable_weak xlib
 
 enable_weak cuda cuvid nvenc vda_framework videotoolbox videotoolbox_encoder
@@ -6059,6 +6071,7 @@ check_header linux/fb.h
 check_header linux/videodev.h
 check_header linux/videodev2.h
 check_code cc linux/videodev2.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete
+check_code cc linux/videodev2.h "int i = V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_VIDEO_M2M;" || disable v4l2_m2m
 
 check_header sys/videoio.h
 check_code cc sys/videoio.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index a594b23..12be85b 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -6,6 +6,7 @@ HEADERS = avcodec.h                                                     \
           avfft.h                                                       \
           d3d11va.h                                                     \
           dirac.h                                                       \
+          v4l2.h                                                        \
           dv_profile.h                                                  \
           dxva2.h                                                       \
           jni.h                                                         \
@@ -101,7 +102,8 @@ OBJS-$(CONFIG_LZF)                     += lzf.o
 OBJS-$(CONFIG_MDCT)                    += mdct_fixed.o mdct_float.o mdct_fixed_32.o
 OBJS-$(CONFIG_ME_CMP)                  += me_cmp.o
 OBJS-$(CONFIG_MEDIACODEC)              += mediacodecdec_common.o mediacodec_surface.o mediacodec_wrapper.o mediacodec_sw_buffer.o
-OBJS-$(CONFIG_V4L2)                    += v4l2-common.o
+OBJS-$(CONFIG_V4L2)                    += v4l2-common.o v4l2-buffers.o
+OBJS-$(CONFIG_V4L2_M2M)                += v4l2_m2m.o
 OBJS-$(CONFIG_MPEG_ER)                 += mpeg_er.o
 OBJS-$(CONFIG_MPEGAUDIO)               += mpegaudio.o
 OBJS-$(CONFIG_MPEGAUDIODSP)            += mpegaudiodsp.o                \
@@ -320,6 +322,8 @@ OBJS-$(CONFIG_H261_ENCODER)            += h261enc.o h261data.o h261.o
 OBJS-$(CONFIG_H263_DECODER)            += h263dec.o h263.o ituh263dec.o        \
                                           mpeg4video.o mpeg4videodec.o flvdec.o\
                                           intelh263dec.o h263data.o
+OBJS-$(CONFIG_H263_V4L2M2M_DECODER)    += v4l2_m2m_dec.o
+OBJS-$(CONFIG_H263_V4L2M2M_ENCODER)    += v4l2_m2m_enc.o
 OBJS-$(CONFIG_H263_ENCODER)            += mpeg4videoenc.o mpeg4video.o  \
                                           h263.o ituh263enc.o flvenc.o h263data.o
 OBJS-$(CONFIG_H264_DECODER)            += h264dec.o h264_cabac.o h264_cavlc.o \
@@ -327,6 +331,8 @@ OBJS-$(CONFIG_H264_DECODER)            += h264dec.o h264_cabac.o h264_cavlc.o \
                                           h264_mb.o h264_picture.o \
                                           h264_refs.o h264_sei.o \
                                           h264_slice.o h264data.o
+OBJS-$(CONFIG_H264_V4L2M2M_DECODER)    += v4l2_m2m_dec.o
+OBJS-$(CONFIG_H264_V4L2M2M_ENCODER)    += v4l2_m2m_enc.o
 OBJS-$(CONFIG_H264_CUVID_DECODER)      += cuvid.o
 OBJS-$(CONFIG_H264_MEDIACODEC_DECODER) += mediacodecdec.o
 OBJS-$(CONFIG_H264_MMAL_DECODER)       += mmaldec.o
@@ -419,11 +425,13 @@ OBJS-$(CONFIG_MP3ON4FLOAT_DECODER)     += mpegaudiodec_float.o mpeg4audio.o
 OBJS-$(CONFIG_MPC7_DECODER)            += mpc7.o mpc.o
 OBJS-$(CONFIG_MPC8_DECODER)            += mpc8.o mpc.o
 OBJS-$(CONFIG_MPEGVIDEO_DECODER)       += mpeg12dec.o mpeg12.o mpeg12data.o
+OBJS-$(CONFIG_MPEG1_V4L2M2M_DECODER)   += v4l2_m2m_dec.o
 OBJS-$(CONFIG_MPEG1VIDEO_DECODER)      += mpeg12dec.o mpeg12.o mpeg12data.o
 OBJS-$(CONFIG_MPEG1VIDEO_ENCODER)      += mpeg12enc.o mpeg12.o
 OBJS-$(CONFIG_MPEG2_MMAL_DECODER)      += mmaldec.o
 OBJS-$(CONFIG_MPEG2_QSV_DECODER)       += qsvdec_other.o
 OBJS-$(CONFIG_MPEG2_QSV_ENCODER)       += qsvenc_mpeg2.o
+OBJS-$(CONFIG_MPEG2_V4L2M2M_DECODER)   += v4l2_m2m_dec.o
 OBJS-$(CONFIG_MPEG2VIDEO_DECODER)      += mpeg12dec.o mpeg12.o mpeg12data.o
 OBJS-$(CONFIG_MPEG2VIDEO_ENCODER)      += mpeg12enc.o mpeg12.o
 OBJS-$(CONFIG_MPEG2_MEDIACODEC_DECODER) += mediacodecdec.o
@@ -431,6 +439,8 @@ OBJS-$(CONFIG_MPEG2_VAAPI_ENCODER)     += vaapi_encode_mpeg2.o
 OBJS-$(CONFIG_MPEG4_DECODER)           += xvididct.o
 OBJS-$(CONFIG_MPEG4_MEDIACODEC_DECODER) += mediacodecdec.o
 OBJS-$(CONFIG_MPEG4_OMX_ENCODER)       += omx.o
+OBJS-$(CONFIG_MPEG4_V4L2M2M_DECODER)   += v4l2_m2m_dec.o
+OBJS-$(CONFIG_MPEG4_V4L2M2M_ENCODER)   += v4l2_m2m_enc.o
 OBJS-$(CONFIG_MPL2_DECODER)            += mpl2dec.o ass.o
 OBJS-$(CONFIG_MSA1_DECODER)            += mss3.o
 OBJS-$(CONFIG_MSCC_DECODER)            += mscc.o
@@ -503,6 +513,7 @@ OBJS-$(CONFIG_RALF_DECODER)            += ralf.o
 OBJS-$(CONFIG_RAWVIDEO_DECODER)        += rawdec.o
 OBJS-$(CONFIG_RAWVIDEO_ENCODER)        += rawenc.o
 OBJS-$(CONFIG_REALTEXT_DECODER)        += realtextdec.o ass.o
+OBJS-$(CONFIG_VC1_V4L2M2M_DECODER)     += v4l2_m2m_dec.o
 OBJS-$(CONFIG_RL2_DECODER)             += rl2.o
 OBJS-$(CONFIG_ROQ_DECODER)             += roqvideodec.o roqvideo.o
 OBJS-$(CONFIG_ROQ_ENCODER)             += roqvideoenc.o roqvideo.o elbg.o
@@ -518,6 +529,8 @@ OBJS-$(CONFIG_RV30_DECODER)            += rv30.o rv34.o rv30dsp.o
 OBJS-$(CONFIG_RV40_DECODER)            += rv40.o rv34.o rv40dsp.o
 OBJS-$(CONFIG_SAMI_DECODER)            += samidec.o ass.o htmlsubtitles.o
 OBJS-$(CONFIG_S302M_DECODER)           += s302m.o
+OBJS-$(CONFIG_VP8_V4L2M2M_DECODER)     += v4l2_m2m_dec.o
+OBJS-$(CONFIG_VP8_V4L2M2M_ENCODER)     += v4l2_m2m_enc.o
 OBJS-$(CONFIG_S302M_ENCODER)           += s302menc.o
 OBJS-$(CONFIG_SANM_DECODER)            += sanm.o
 OBJS-$(CONFIG_SCPR_DECODER)            += scpr.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 4712592..12af5bd 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -207,8 +207,10 @@ static void register_all(void)
     REGISTER_ENCDEC (H263,              h263);
     REGISTER_DECODER(H263I,             h263i);
     REGISTER_ENCDEC (H263P,             h263p);
+    REGISTER_ENCDEC (H263_V4L2M2M,      h263_v4l2m2m);
     REGISTER_DECODER(H264,              h264);
     REGISTER_DECODER(H264_CRYSTALHD,    h264_crystalhd);
+    REGISTER_ENCDEC (H264_V4L2M2M,      h264_v4l2m2m);
     REGISTER_DECODER(H264_MEDIACODEC,   h264_mediacodec);
     REGISTER_DECODER(H264_MMAL,         h264_mmal);
     REGISTER_DECODER(H264_QSV,          h264_qsv);
@@ -253,6 +255,7 @@ static void register_all(void)
     REGISTER_ENCDEC (MPEG2VIDEO,        mpeg2video);
     REGISTER_ENCDEC (MPEG4,             mpeg4);
     REGISTER_DECODER(MPEG4_CRYSTALHD,   mpeg4_crystalhd);
+    REGISTER_ENCDEC (MPEG4_V4L2M2M,     mpeg4_v4l2m2m);
     REGISTER_DECODER(MPEG4_MMAL,        mpeg4_mmal);
 #if FF_API_VDPAU
     REGISTER_DECODER(MPEG4_VDPAU,       mpeg4_vdpau);
@@ -262,8 +265,10 @@ static void register_all(void)
     REGISTER_DECODER(MPEG_VDPAU,        mpeg_vdpau);
     REGISTER_DECODER(MPEG1_VDPAU,       mpeg1_vdpau);
 #endif
+    REGISTER_DECODER(MPEG1_V4L2M2M,     mpeg1_v4l2m2m);
     REGISTER_DECODER(MPEG2_MMAL,        mpeg2_mmal);
     REGISTER_DECODER(MPEG2_CRYSTALHD,   mpeg2_crystalhd);
+    REGISTER_DECODER(MPEG2_V4L2M2M,     mpeg2_v4l2m2m);
     REGISTER_DECODER(MPEG2_QSV,         mpeg2_qsv);
     REGISTER_DECODER(MPEG2_MEDIACODEC,  mpeg2_mediacodec);
     REGISTER_DECODER(MSA1,              msa1);
@@ -361,6 +366,7 @@ static void register_all(void)
     REGISTER_DECODER(VC1IMAGE,          vc1image);
     REGISTER_DECODER(VC1_MMAL,          vc1_mmal);
     REGISTER_DECODER(VC1_QSV,           vc1_qsv);
+    REGISTER_DECODER(VC1_V4L2M2M,       vc1_v4l2m2m);
     REGISTER_ENCODER(VC2,               vc2);
     REGISTER_DECODER(VCR1,              vcr1);
     REGISTER_DECODER(VMDVIDEO,          vmdvideo);
@@ -372,6 +378,7 @@ static void register_all(void)
     REGISTER_DECODER(VP6F,              vp6f);
     REGISTER_DECODER(VP7,               vp7);
     REGISTER_DECODER(VP8,               vp8);
+    REGISTER_ENCDEC (VP8_V4L2M2M,       vp8_v4l2m2m);
     REGISTER_DECODER(VP9,               vp9);
     REGISTER_DECODER(VQA,               vqa);
     REGISTER_DECODER(BITPACKED,         bitpacked);
diff --git a/libavcodec/v4l2-buffers.c b/libavcodec/v4l2-buffers.c
new file mode 100644
index 0000000..bc6ef28
--- /dev/null
+++ b/libavcodec/v4l2-buffers.c
@@ -0,0 +1,633 @@
+/*
+ * V4L2 buffer{,pool} helper functions.
+ *
+ * Copyright (C) 2017 Alexis Ballier <aballier at gentoo.org>
+ * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <poll.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "avcodec.h"
+#include "internal.h"
+#include "v4l2-buffers.h"
+#include "v4l2-common.h"
+
+#if 0
+#define V4L_BUFFER_DEBUG */
+#endif
+
+#define IS_BP_SUPPORTED(bp) ((bp->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) || \
+                             (bp->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)  || \
+                             (bp->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)        || \
+                             (bp->type == V4L2_BUF_TYPE_VIDEO_OUTPUT))
+
+enum V4LBuffer_status {
+    V4LBUF_AVAILABLE,
+    V4LBUF_IN_DRIVER,
+    V4LBUF_RET_USER,
+};
+
+struct V4LBuffer {
+    AVBufferRef *bufrefs[VIDEO_MAX_PLANES];
+    struct V4LBufferPool *pool;
+    struct v4l2_plane planes[VIDEO_MAX_PLANES];
+    struct v4l2_buffer buf;
+
+    void * mm_addr[VIDEO_MAX_PLANES];
+    size_t lengths[VIDEO_MAX_PLANES];
+    enum V4LBuffer_status status;
+    int bytesperline[4];
+    int num_planes;
+    int num_lines;
+    int index;
+    int flags;
+    struct timeval timestamp;
+    int ref_cnt;
+};
+
+static int enqueue_v4lbuf(V4LBuffer* avbuf)
+{
+    int ret;
+
+    memset(&avbuf->buf, 0, sizeof(avbuf->buf));
+    avbuf->buf.memory = avbuf->pool->memory;
+    avbuf->buf.type = avbuf->pool->type;
+    avbuf->buf.index = avbuf->index;
+
+    if (V4L2_TYPE_IS_MULTIPLANAR(avbuf->pool->type)) {
+        avbuf->buf.length   = avbuf->num_planes;
+        avbuf->buf.m.planes = avbuf->planes;
+    } else {
+        avbuf->buf.bytesused = avbuf->planes[avbuf->index].bytesused;
+        avbuf->buf.m.userptr = avbuf->planes[avbuf->index].m.userptr;
+        avbuf->buf.length    = avbuf->planes[avbuf->index].length;
+    }
+
+    avbuf->buf.flags = avbuf->pool->default_flags | avbuf->flags;
+    avbuf->buf.timestamp = avbuf->timestamp;
+
+    ret = ioctl(avbuf->pool->fd, VIDIOC_QBUF, &avbuf->buf);
+    if (ret < 0)
+        return AVERROR(errno);
+
+    avbuf->status = V4LBUF_IN_DRIVER;
+    avbuf->pool->num_queued++;
+
+#ifdef V4L_BUFFER_DEBUG
+    av_log(avbuf->pool->log_ctx, AV_LOG_DEBUG, " buffer enqueued on %s\n", avbuf->pool->name);
+#endif
+
+    return 0;
+}
+
+static V4LBuffer* dequeue_v4lbuf(V4LBufferPool *bp)
+{
+    struct v4l2_plane planes[VIDEO_MAX_PLANES];
+    struct v4l2_buffer buf = { 0 };
+    V4LBuffer* avbuf = NULL;
+    struct pollfd pfd;
+    int ret;
+    int i;
+
+    if (bp->num_queued < bp->min_queued_buffers) {
+        return NULL;
+    }
+
+    if (bp->blocking_dequeue) {
+        pfd.fd = bp->fd;
+        switch (bp->type) {
+        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
+        case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
+            pfd.events = POLLIN | POLLERR;
+            break;
+        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+        case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
+            pfd.events = POLLOUT | POLLERR | POLLWRNORM;
+            break;
+        default:
+            pfd.events = POLLIN | POLLERR | POLLRDNORM;
+        }
+
+        ret = poll(&pfd, 1, bp->blocking_dequeue);
+        if (ret<= 0) {
+            av_log(bp->log_ctx, AV_LOG_WARNING, "%s: timeout (%d ms)\n", bp->name, bp->blocking_dequeue);
+            return NULL;
+        }
+    }
+
+    memset(&buf, 0, sizeof(buf));
+    buf.memory = bp->memory;
+    buf.type = bp->type;
+    if (V4L2_TYPE_IS_MULTIPLANAR(bp->type)) {
+        memset(planes, 0, sizeof(planes));
+        buf.length = VIDEO_MAX_PLANES;
+        buf.m.planes = planes;
+    }
+
+    ret = ioctl(bp->fd, VIDIOC_DQBUF, &buf);
+    if (ret) {
+        if (errno != EAGAIN) {
+            av_log(bp->log_ctx, AV_LOG_DEBUG, "%s: VIDIOC_DQBUF, errno (%d)\n", bp->name, errno);
+            bp->broken = errno;
+        }
+        return NULL;
+    }
+
+    avbuf = &(bp->buffers[buf.index]);
+    if (V4L2_TYPE_IS_MULTIPLANAR(bp->type)) {
+        memcpy(avbuf->planes, planes, sizeof(planes));
+        avbuf->buf.m.planes = avbuf->planes;
+    }
+    avbuf->status = V4LBUF_AVAILABLE;
+    avbuf->pool->num_queued--;
+    avbuf->buf = buf;
+
+    if (V4L2_TYPE_IS_OUTPUT(avbuf->pool->type)) {
+        for (i = 0; i < avbuf->num_planes; i++) {
+            if (avbuf->bufrefs[i]) {
+                av_buffer_unref(&avbuf->bufrefs[i]);
+            }
+        }
+    }
+
+#ifdef V4L_BUFFER_DEBUG
+    av_log(bp->log_ctx, AV_LOG_DEBUG, "dequeued buffer on %s\n", bp->name);
+#endif
+
+    return avbuf;
+}
+
+static void buffer_callback(void *opaque, uint8_t *unused)
+{
+    V4LBuffer* avbuf = opaque;
+
+    if (--avbuf->ref_cnt <= 0) {
+        if (V4LBUF_IN_DRIVER != avbuf->status) {
+            if (!V4L2_TYPE_IS_OUTPUT(avbuf->pool->type)) {
+                enqueue_v4lbuf(avbuf);
+            } else {
+                avbuf->status = V4LBUF_AVAILABLE;
+            }
+        }
+    }
+}
+
+static inline int init_buffer(V4LBuffer* avbuf)
+{
+    int ret, i;
+
+    avbuf->buf.memory = avbuf->pool->memory;
+    avbuf->buf.type = avbuf->pool->type;
+    avbuf->buf.index = avbuf->index;
+
+    if (V4L2_TYPE_IS_MULTIPLANAR(avbuf->pool->type)) {
+        avbuf->buf.length = VIDEO_MAX_PLANES;
+        avbuf->buf.m.planes = avbuf->planes;
+    }
+
+    ret = ioctl(avbuf->pool->fd, VIDIOC_QUERYBUF, &avbuf->buf);
+    if (ret < 0)
+        return AVERROR(errno);
+
+    if (V4L2_TYPE_IS_MULTIPLANAR(avbuf->pool->type)) {
+        avbuf->num_planes = 0;
+        for (;;) {
+            if (avbuf->num_planes < avbuf->buf.length) {
+                if (avbuf->buf.m.planes[avbuf->num_planes].length) {
+                    avbuf->num_planes++;
+                    continue;
+                }
+            }
+            break;
+        }
+    } else {
+        avbuf->num_planes = 1;
+    }
+
+    avbuf->num_lines = avbuf->pool->format.fmt.pix_mp.height;
+    for (i = 0; i < avbuf->num_planes; i++) {
+        if (V4L2_TYPE_IS_MULTIPLANAR(avbuf->pool->type)) {
+            avbuf->bytesperline[i] = avbuf->pool->format.fmt.pix_mp.plane_fmt[i].bytesperline;
+        } else {
+            avbuf->bytesperline[i] = avbuf->pool->format.fmt.pix.bytesperline;
+        }
+
+        switch (avbuf->pool->memory) {
+        case V4L2_MEMORY_MMAP:
+            if (V4L2_TYPE_IS_MULTIPLANAR(avbuf->pool->type)) {
+                avbuf->lengths[i] = avbuf->buf.m.planes[i].length;
+                avbuf->mm_addr[i] = mmap(NULL, avbuf->buf.m.planes[i].length,
+                                         PROT_READ | PROT_WRITE, MAP_SHARED,
+                                         avbuf->pool->fd, avbuf->buf.m.planes[i].m.mem_offset);
+            } else {
+                avbuf->lengths[i] = avbuf->buf.length;
+                avbuf->mm_addr[i] = mmap(NULL, avbuf->buf.length,
+                                         PROT_READ | PROT_WRITE, MAP_SHARED,
+                                         avbuf->pool->fd, avbuf->buf.m.offset);
+            }
+            if (avbuf->mm_addr[i] == MAP_FAILED) {
+                return AVERROR(ENOMEM);
+            }
+            break;
+        case V4L2_MEMORY_USERPTR:
+            /* Nothing to do */
+            break;
+        default:
+            av_log(avbuf->pool->log_ctx, AV_LOG_ERROR, "memory type %i not supported\n", avbuf->pool->memory);
+            return AVERROR_PATCHWELCOME;
+        }
+    }
+    avbuf->status = V4LBUF_AVAILABLE;
+
+    if (!V4L2_TYPE_IS_OUTPUT(avbuf->pool->type)) {
+        if (avbuf->pool->memory != V4L2_MEMORY_USERPTR) {
+            return enqueue_v4lbuf(avbuf);
+        }
+    }
+
+    return 0;
+}
+
+int avpriv_init_v4lbufpool(V4LBufferPool* bufs)
+{
+    struct v4l2_requestbuffers req;
+    int ret, i;
+
+    if (!IS_BP_SUPPORTED(bufs)) {
+        av_log(bufs->log_ctx, AV_LOG_ERROR, "%type %i not supported\n", bufs->type);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    memset(&req, 0, sizeof(req));
+    req.count = bufs->num_buffers + bufs->min_queued_buffers;
+    req.memory = bufs->memory;
+    req.type = bufs->type;
+
+    ret = ioctl(bufs->fd, VIDIOC_REQBUFS, &req);
+    if (ret< 0)
+        return AVERROR(errno);
+
+    bufs->num_buffers = req.count;
+    bufs->num_queued  = 0;
+    bufs->buffers = av_mallocz(bufs->num_buffers * sizeof(V4LBuffer));
+
+    for (i = 0; i < req.count; i++) {
+        V4LBuffer *avbuf = &bufs->buffers[i];
+
+        avbuf->pool = bufs;
+        avbuf->index = i;
+        ret = init_buffer(avbuf);
+        if (ret < 0) {
+            av_log(bufs->log_ctx, AV_LOG_ERROR, "%s buffer initialization (%s)\n", bufs->name, av_err2str(ret));
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+static void release_buf(V4LBuffer* b)
+{
+    int i;
+
+    for (i = 0; i < b->num_planes; i++) {
+        if (b->mm_addr[i] && b->lengths[i]) {
+            munmap(b->mm_addr[i], b->lengths[i]);
+        }
+    }
+}
+
+void avpriv_release_buffer_pool(V4LBufferPool* bp)
+{
+    if (bp->buffers) {
+        int i;
+
+        for (i = 0; i < bp->num_buffers; i++)
+            release_buf(&bp->buffers[i]);
+
+        av_free(bp->buffers);
+    }
+}
+
+static inline void set_pts(V4LBuffer *out, int64_t pts)
+{
+    out->timestamp.tv_sec  = pts / INT64_C(1000000);
+    out->timestamp.tv_usec = pts % INT64_C(1000000);
+}
+
+static inline uint64_t get_pts(V4LBuffer *avbuf)
+{
+    if (avbuf->buf.timestamp.tv_sec || avbuf->buf.timestamp.tv_usec)
+        return (avbuf->buf.timestamp.tv_sec * INT64_C(1000000) + avbuf->buf.timestamp.tv_usec);
+
+    return AV_NOPTS_VALUE;
+}
+
+static int buf2v4l(V4LBuffer *out, int plane, const uint8_t* data, int size, AVBufferRef* bref)
+{
+    if (plane >= out->num_planes)
+        return AVERROR(EINVAL);
+
+    switch (out->pool->memory) {
+    case V4L2_MEMORY_MMAP:
+            memcpy(out->mm_addr[plane], data, FFMIN(size, out->lengths[plane]));
+            break;
+    case V4L2_MEMORY_USERPTR:
+        if (!bref) {
+            av_log(out->pool->log_ctx, AV_LOG_ERROR,
+                   "needs to be set with an AVBufferRef for USERPTR memory type\n");
+            return AVERROR_PATCHWELCOME;
+        }
+
+        if (out->bufrefs[plane]) {
+            av_log(out->pool->log_ctx, AV_LOG_WARNING,
+                   "V4L buffer already had a buffer referenced\n");
+            av_buffer_unref(&out->bufrefs[plane]);
+        }
+
+        out->bufrefs[plane] = av_buffer_ref(bref);
+        if (!out->bufrefs[plane])
+            return AVERROR(ENOMEM);
+
+        out->planes[plane].m.userptr = (unsigned long)out->bufrefs[plane]->data;
+        out->lengths[plane] = out->bufrefs[plane]->size;
+
+        break;
+    default:
+        av_log(out->pool->log_ctx, AV_LOG_ERROR,
+               "memory type %i not supported", out->pool->memory);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    out->planes[plane].bytesused = FFMIN(size ? size : 1, out->lengths[plane]);
+    out->planes[plane].length    = out->lengths[plane];
+
+    return 0;
+}
+
+static int avframe_to_v4lbuf(const AVFrame *pict, V4LBuffer* out) {
+    int i, ret;
+
+    for (i = 0; i < out->num_planes; i++) {
+        ret = buf2v4l(out, i, pict->buf[i]->data, pict->buf[i]->size, pict->buf[i]);
+        if (ret)
+            return ret;
+    }
+    set_pts(out, pict->pts);
+
+    return 0;
+}
+
+static int avpkt_to_v4lbuf(const AVPacket *pkt, V4LBuffer *out) {
+    int ret;
+
+    ret = buf2v4l(out, 0, pkt->data, pkt->size, pkt->buf);
+    if (ret)
+        return ret;
+
+    if (pkt->pts != AV_NOPTS_VALUE)
+        set_pts(out, pkt->pts);
+
+    if (pkt->flags & AV_PKT_FLAG_KEY)
+        out->flags = V4L2_BUF_FLAG_KEYFRAME;
+
+    if (!pkt->size)
+        out->flags = V4L2_BUF_FLAG_LAST;
+
+    return 0;
+}
+
+static inline int v4l2bufref(V4LBuffer *in, int plane, AVBufferRef **buf)
+{
+#ifdef V4L_BUFFER_DEBUG
+    av_log(in->pool->log_ctx, AV_LOG_DEBUG,
+           "Making an avbuffer from V4L buffer %i[%i] on %s (%i,%i)\n",
+           in->index, plane, in->pool->name, in->pool->type, in->pool->memory);
+#endif
+
+    if (plane >= in->num_planes) {
+        return AVERROR(EINVAL);
+    }
+
+    switch (in->pool->memory) {
+    case V4L2_MEMORY_MMAP:
+        *buf = av_buffer_create(in->mm_addr[plane], in->lengths[plane], buffer_callback, in, 0);
+        if (!*buf)
+            return AVERROR(ENOMEM);
+
+        in->status = V4LBUF_RET_USER;
+        in->ref_cnt++;
+        break;
+    case V4L2_MEMORY_USERPTR:
+        if (!in->bufrefs[plane]) {
+            av_log(in->pool->log_ctx, AV_LOG_ERROR, "AVBufferRef not found\n");
+            return AVERROR(EINVAL);
+        }
+
+        *buf = av_buffer_ref(in->bufrefs[plane]);
+        if (!*buf)
+            return AVERROR(ENOMEM);
+
+        av_buffer_unref(&in->bufrefs[plane]);
+        in->status = V4LBUF_AVAILABLE;
+        break;
+    default:
+        av_log(in->pool->log_ctx, AV_LOG_ERROR, "memory type %i not supported", in->pool->memory);
+        return AVERROR_PATCHWELCOME;
+    }
+    return 0;
+}
+
+static int v4lbuf_to_avpkt(AVPacket *pkt, V4LBuffer *avbuf)
+{
+    int ret;
+
+    av_free_packet(pkt);
+    if (ret = v4l2bufref(avbuf, 0, &pkt->buf))
+        return ret;
+
+    pkt->data = pkt->buf->data;
+    if (V4L2_TYPE_IS_MULTIPLANAR(avbuf->pool->type)) {
+        pkt->size = avbuf->buf.m.planes[0].bytesused;
+    } else {
+        pkt->size = avbuf->buf.bytesused;
+    }
+
+    if (avbuf->buf.flags & V4L2_BUF_FLAG_KEYFRAME) {
+        pkt->flags |= AV_PKT_FLAG_KEY;
+    }
+
+    pkt->pts = get_pts(avbuf);
+
+    return 0;
+}
+
+static int v4lbuf_to_avframe(AVFrame *frame, V4LBuffer *avbuf)
+{
+    int i, ret;
+
+    av_frame_unref(frame);
+
+    for (i = 0; i < avbuf->num_planes; i++) {
+        ret = v4l2bufref(avbuf, i, &frame->buf[i]);
+        if (ret)
+            return ret;
+
+        frame->linesize[i] = avbuf->bytesperline[i];
+        frame->data[i] = frame->buf[i]->data;
+
+        if (avbuf->num_planes == 1) {
+            if (avbuf->pool->av_pix_fmt == AV_PIX_FMT_NV12) {
+                frame->linesize[1] = avbuf->bytesperline[0];
+                frame->data[1] = frame->buf[0]->data + avbuf->bytesperline[0] * avbuf->num_lines;
+            }
+        }
+    }
+
+    frame->key_frame = !!(avbuf->buf.flags & V4L2_BUF_FLAG_KEYFRAME);
+    frame->format = avbuf->pool->av_pix_fmt;
+    frame->height = avbuf->pool->height;
+    frame->width = avbuf->pool->width;
+    frame->pts = get_pts(avbuf);
+
+    return 0;
+}
+
+static V4LBuffer* v4lbufpool_get_from_avframe(const AVFrame* frame, V4LBufferPool *p)
+{
+    int i;
+
+    for (i = 0; i < p->num_buffers; i++) {
+        if (V4LBUF_RET_USER == p->buffers[i].status) {
+            if (p->memory == V4L2_MEMORY_MMAP) {
+                if (p->buffers[i].mm_addr[0] == frame->buf[0]->data)
+                    return &p->buffers[i];
+                continue;
+            }
+            av_log(p->log_ctx, AV_LOG_ERROR, "memory type %i not supported\n", p->memory);
+            return NULL;
+        }
+    }
+
+    return NULL;
+}
+
+V4LBuffer* avpriv_v4lbufpool_getfreebuf(V4LBufferPool *p, const AVFrame *f, const AVPacket* pkt)
+{
+    V4LBuffer* ret;
+    int i;
+
+#ifdef V4L_BUFFER_DEBUG
+    av_log(p->log_ctx, AV_LOG_DEBUG, "Polling for a free buffer on %s\n", p->name);
+#endif
+
+    if (V4L2_TYPE_IS_OUTPUT(p->type)) {
+        for (;;) {
+            if (!dequeue_v4lbuf(p)) {
+                break;
+            }
+        }
+    }
+
+    if (f) {
+        ret = v4lbufpool_get_from_avframe(f, p);
+        if (ret)
+            return ret;
+    }
+
+    for (i = 0; i < p->num_buffers; i++) {
+        if (p->buffers[i].status == V4LBUF_AVAILABLE)
+            return &p->buffers[i];
+    }
+
+    return NULL;
+}
+
+int avpriv_set_stream_status(V4LBufferPool* bp, int cmd)
+{
+    int type = bp->type;
+    int ret;
+
+    ret = ioctl(bp->fd, cmd, &type);
+    if (ret < 0)
+        return AVERROR(errno);
+
+    bp->streamon = (cmd == VIDIOC_STREAMON);
+
+    return 0;
+}
+
+int avpriv_v4l_enqueue_frame_or_pkt_or_buf(V4LBufferPool* bp, const AVFrame* f, const AVPacket* pkt, const uint8_t* buf, int buf_size)
+{
+    V4LBuffer* avbuf;
+    int ret;
+
+    if (!f && !pkt && !buf) {
+        av_log(bp->log_ctx, AV_LOG_ERROR, "either AVFrame*, AVPacket* or buf must valid\n");
+        return AVERROR_BUG;
+    }
+
+    avbuf = avpriv_v4lbufpool_getfreebuf(bp, f, pkt);
+    if (!avbuf)
+        return AVERROR(ENOMEM);
+
+    if (f && (ret = avframe_to_v4lbuf(f, avbuf)))
+        return ret;
+
+    if (pkt && (ret = avpkt_to_v4lbuf(pkt, avbuf)))
+        return ret;
+
+    if (buf && (ret = buf2v4l(avbuf, 0, buf, buf_size, NULL)))
+        return ret;
+
+    if (ret = enqueue_v4lbuf(avbuf))
+        return ret;
+
+    return 0;
+}
+
+int avpriv_v4l_dequeue_frame_or_pkt(V4LBufferPool* bp, AVFrame* f, AVPacket* pkt)
+{
+    V4LBuffer* avbuf = NULL;
+
+    if ((!f && !pkt) || (f && pkt)) {
+        av_log(bp->log_ctx, AV_LOG_ERROR, "either AVFrame* or AVPacket* must be valid\n");
+        return AVERROR_BUG;
+    }
+
+    if (!(avbuf = dequeue_v4lbuf(bp))) {
+        if (bp->broken) {
+            return AVERROR_EOF;
+        }
+        return AVERROR(EAGAIN);
+    }
+
+    if (f)
+        return v4lbuf_to_avframe(f, avbuf);
+
+    if (pkt)
+        return v4lbuf_to_avpkt(pkt, avbuf);
+
+    return AVERROR_BUG;
+}
+
+
diff --git a/libavcodec/v4l2-buffers.h b/libavcodec/v4l2-buffers.h
new file mode 100644
index 0000000..ed0362e
--- /dev/null
+++ b/libavcodec/v4l2-buffers.h
@@ -0,0 +1,247 @@
+/*
+ * V4L2 buffer{,pool} helper functions.
+ *
+ * Copyright (C) 2017 Alexis Ballier <aballier at gentoo.org>
+ * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_V4L2_BUFFERS_H
+#define AVCODEC_V4L2_BUFFERS_H
+
+#include "v4l2-common.h"
+#include "avcodec.h"
+#include "libavutil/pixfmt.h"
+#include "libavutil/frame.h"
+
+struct V4LBuffer;
+typedef struct V4LBuffer V4LBuffer;
+
+struct V4LBufferPool;
+typedef int (*format_f)(struct V4LBufferPool *, int set);
+typedef int (*init_f)(struct V4LBufferPool *);
+
+typedef struct V4LBufferPoolCfg {
+    format_f format;
+    init_f init;
+} V4LBufferPoolCfg;
+
+typedef struct V4LBufferPool {
+    /**
+     * Buffer pool initial configuration.
+     */
+    V4LBufferPoolCfg cfg;
+
+    /**
+     * Log context (for av_log()). Can be NULL.
+     */
+    void *log_ctx;
+
+    /**
+     * Pool's name. Must be set before calling avpriv_init_v4lbufpool().
+     */
+    const char* name;
+
+    /**
+     * File descriptor obtained from opening the associated device.
+     * Must be set before calling avpriv_init_v4lbufpool().
+     * Readonly after init.
+     */
+    int fd;
+
+    /**
+     * Type of this buffer pool.
+     * See V4L2_BUF_TYPE_VIDEO_* in videodev2.h
+     * Must be set before calling avpriv_init_v4lbufpool().
+     * Readonly after init.
+     */
+    enum v4l2_buf_type type;
+
+    /**
+     * Memory type this buffer pool uses.
+     * See V4L2_MEMORY_* in videodev2.h
+     * Must be set before calling avpriv_init_v4lbufpool().
+     * Readonly after init.
+     */
+    enum v4l2_memory memory;
+
+    /**
+     * AVPixelFormat corresponding to this buffer pool.
+     * AV_PIX_FMT_NONE means this is an encoded stream.
+     */
+    enum AVPixelFormat av_pix_fmt;
+
+    /**
+     * AVCodecID corresponding to this buffer pool.
+     * AV_CODEC_ID_RAWVIDEO means this is a raw stream and av_pix_fmt must be set to a valid value.
+     */
+    enum AVCodecID   av_codec_id;
+
+    /**
+     * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
+     * This is used to work around some encoder bugs.
+     * A demuxer should set this to what is stored in the field used to identify the codec.
+     * If there are multiple such fields in a container then the demuxer should choose the one
+     * which maximizes the information about the used codec.
+     * If the codec tag field in a container is larger than 32 bits then the demuxer should
+     * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
+     * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
+     * first.
+     * - encoding: Set by user, if not then the default based on codec_id will be used.
+     * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
+     */
+    unsigned int av_codec_tag;
+
+    /**
+     * Format returned by the driver after initializing the buffer pool.
+     * Must be set before calling avpriv_init_v4lbufpool().
+     * avpriv_set_pool_format() can set it.
+     * Readonly after init.
+     */
+    struct v4l2_format format;
+
+    /**
+     * Width and height of the frames it produces (in case of a capture pool, e.g. when decoding)
+     * or accepts (in case of an output pool, e.g. when encoding).
+     *
+     * For output pools, this must must be set before calling avpriv_init_v4lbufpool().
+     * For capture pools, it will be set after having received the information from the driver.
+     */
+    int width, height;
+
+    /**
+     * Default flags to set on buffers to enqueue.
+     * See V4L2_BUF_FLAG_*.
+     */
+    int default_flags;
+
+    /**
+     * Whether the stream has been started (VIDIOC_STREAMON has been sent).
+     */
+    int streamon;
+
+    /**
+     * Number of queued buffers.
+     */
+    int num_queued;
+
+    /**
+     * Time (in ms) we can wait for a buffer before considering it a failure.
+     */
+    int blocking_dequeue;
+
+    /**
+     * Minimum number of buffers that must be kept queued in this queue.
+     *
+     * E.g. for decoders, the drivers might have such requirements to produce proper output.
+     */
+    int min_queued_buffers;
+
+    /**
+     * The actual number of buffers.
+     *
+     * Before calling avpriv_init_v4lbufpool() this is the number of buffers we would like to have available.
+     * avpriv_init_v4lbufpool() asks for (min_buffers + num_buffers) and sets this value to the actual number
+     * of buffers the driver gave us.
+     * Readonly after init.
+     */
+    int num_buffers;
+
+    /**
+     * Opaque pointers to the actual buffers representations.
+     * After initialization, it is an array of size num_buffers.
+     */
+    V4LBuffer *buffers;
+
+    /**
+     * Pool in unrecoverable error notified by the V4L2 kernel api
+     */
+    int broken;
+
+} V4LBufferPool;
+
+/**
+ * Initializes a V4LBufferPool.
+ *
+ * @param[in] bp A pointer to a V4LBufferPool. See V4LBufferPool description for required variables.
+ * @return 0 in case of success, a negative value representing the error otherwise.
+ */
+int avpriv_init_v4lbufpool(V4LBufferPool* bp);
+
+/**
+ * Releases a V4LBufferPool.
+ *
+ * @param[in] bp A pointer to a V4LBufferPool.
+ *               The caller is reponsible for freeing it.
+ *               It must not be used after calling this function.
+ */
+void avpriv_release_buffer_pool(V4LBufferPool* bp);
+
+/**
+ * Sets the status of a V4LBufferPool.
+ *
+ * @param[in] bp A pointer to a V4LBufferPool.
+ * @param[in] cmd The status to set (VIDIOC_STREAMON or VIDIOC_STREAMOFF).
+ *                Warning: If VIDIOC_STREAMOFF is sent to a buffer pool that still has some frames buffered,
+ *                those frames will be dropped.
+ * @return 0 in case of success, a negative value representing the error otherwise.
+ */
+int avpriv_set_stream_status(V4LBufferPool* bp, int cmd);
+
+/**
+ * Dequeues a buffer from a V4LBufferPool to either an AVFrame or an AVPacket.
+ *
+ * Exactly one of f or pkt must be non NULL.
+ * @param[in] bp The V4LBufferPool to dequeue from.
+ * @param[inout] f The AVFrame to dequeue to.
+ * @param[inout] pkt The AVPacket to dequeue to.
+ * @return 0 in case of success, AVERROR(EAGAIN) if no buffer was ready, another negative error in case of error.
+ */
+int avpriv_v4l_dequeue_frame_or_pkt(V4LBufferPool* bp, AVFrame* f, AVPacket* pkt);
+
+/**
+ * Enqueues a buffer to a V4LBufferPool from either an AVFrame, an AVPacket or a raw buffer.
+ * Exactly one of f, pkt or buf must be non NULL.
+ *
+ * @param[in] bp The V4LBufferPool to enqueue to.
+ * @param[in] f A pointer to an AVFrame to enqueue.
+ * @param[in] pkt A pointer to an AVPacket to enqueue.
+ * @param[in] buf A pointer to a buffer to enqueue.
+ * @param[in] buf_size The size of the buffer pointed by buf.
+ * @return 0 in case of success, a negative error otherwise.
+ */
+int avpriv_v4l_enqueue_frame_or_pkt_or_buf(V4LBufferPool* bp, const AVFrame* f, const AVPacket* pkt, const uint8_t* buf, int buf_size);
+
+/**
+ * Gets a free V4LBuffer from a V4LBufferPool.
+ *
+ * If no matching buffer is found (see below), it tries to dequeue a buffer first
+ * in order to minimize the size of the V4L queue.e
+ *
+ * @param[in] p Pointer to a V4LBufferPool where to get the buffer from.
+ * @param[in] f A pointer to an existing AVFrame:
+ *              If the AVFrame's buffers match a V4LBuffer, this V4LBuffer will be returned.
+ *              Can be NULL.
+ * @param[in] pkt A pointer to an existing AVPacket:
+ *                If the AVPacket's buffers match a V4LBuffer, this V4LBuffer will be returned.
+ *                Can be NULL.
+ * @return A pointer to the V4LBuffer or NULL in case of error.
+ */
+V4LBuffer* avpriv_v4lbufpool_getfreebuf(V4LBufferPool *p, const AVFrame *f, const AVPacket* pkt);
+
+#endif // AVCODEC_V4L2_BUFFERS_H
diff --git a/libavcodec/v4l2-common.c b/libavcodec/v4l2-common.c
index 13744fb..f2f98dc 100644
--- a/libavcodec/v4l2-common.c
+++ b/libavcodec/v4l2-common.c
@@ -19,15 +19,14 @@
 #include "v4l2-common.h"
 
 const struct v4l_fmt_map avpriv_v4l_fmt_conversion_table[] = {
-    //ff_fmt              codec_id              v4l2_fmt                  pack_flags
-    { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420     , FF_V4L_PACK_AVPACKET },
-    { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YVU420     , FF_V4L_PACK_AVPACKET },
-    { AV_PIX_FMT_YUV422P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P    , FF_V4L_PACK_AVPACKET },
+    /* ff_fmt             codec_id              v4l2_fmt                  pack_flags */
+    { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420     , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
+    { AV_PIX_FMT_YUV422P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P    , FF_V4L_PACK_AVPACKET                       },
     { AV_PIX_FMT_YUYV422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV       , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
     { AV_PIX_FMT_UYVY422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY       , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
-    { AV_PIX_FMT_YUV411P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P    , FF_V4L_PACK_AVPACKET },
-    { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410     , FF_V4L_PACK_AVPACKET },
-    { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YVU410     , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_YUV411P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P    , FF_V4L_PACK_AVPACKET                       },
+    { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410     , FF_V4L_PACK_AVPACKET                       },
+    { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YVU410     , FF_V4L_PACK_AVPACKET                       },
     { AV_PIX_FMT_RGB555LE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555     , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
     { AV_PIX_FMT_RGB555BE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555X    , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
     { AV_PIX_FMT_RGB565LE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565     , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
@@ -40,17 +39,17 @@ const struct v4l_fmt_map avpriv_v4l_fmt_conversion_table[] = {
 #ifdef V4L2_PIX_FMT_Y16
     { AV_PIX_FMT_GRAY16LE,AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_Y16        , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
 #endif
-    { AV_PIX_FMT_NV12,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12       , FF_V4L_PACK_AVPACKET },
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_MJPEG      , FF_V4L_PACK_AVPACKET },
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_JPEG       , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NV12,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12       , FF_V4L_PACK_AVPACKET                       },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_MJPEG      , FF_V4L_PACK_AVPACKET                       },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_JPEG       , FF_V4L_PACK_AVPACKET                       },
 #ifdef V4L2_PIX_FMT_H264
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_H264,     V4L2_PIX_FMT_H264       , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_H264,     V4L2_PIX_FMT_H264       , FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_MPEG4
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MPEG4,    V4L2_PIX_FMT_MPEG4      , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MPEG4,    V4L2_PIX_FMT_MPEG4      , FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_CPIA1
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_CPIA,     V4L2_PIX_FMT_CPIA1      , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_CPIA,     V4L2_PIX_FMT_CPIA1      , FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_SRGGB8
     { AV_PIX_FMT_BAYER_BGGR8, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_SBGGR8 , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
@@ -59,36 +58,36 @@ const struct v4l_fmt_map avpriv_v4l_fmt_conversion_table[] = {
     { AV_PIX_FMT_BAYER_RGGB8, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_SRGGB8 , FF_V4L_PACK_AVPACKET | FF_V4L_PACK_AVFRAME },
 #endif
 #ifdef V4L2_PIX_FMT_NV12M
-    { AV_PIX_FMT_NV12,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12M      , FF_V4L_PACK_AVFRAME  },
+    { AV_PIX_FMT_NV12,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12M      , FF_V4L_PACK_AVFRAME                        },
 #endif
 #ifdef V4L2_PIX_FMT_NV21M
-    { AV_PIX_FMT_NV21,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV21M      , FF_V4L_PACK_AVFRAME  },
+    { AV_PIX_FMT_NV21,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV21M      , FF_V4L_PACK_AVFRAME                        },
 #endif
 #ifdef V4L2_PIX_FMT_YUV420M
-    { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420M    , FF_V4L_PACK_AVFRAME  },
+    { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420M    , FF_V4L_PACK_AVFRAME                        },
 #endif
 #ifdef V4L2_PIX_FMT_NV16M
-    { AV_PIX_FMT_NV16,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV16M      , FF_V4L_PACK_AVFRAME  },
+    { AV_PIX_FMT_NV16,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV16M      , FF_V4L_PACK_AVFRAME                        },
 #endif
 #ifdef V4L2_PIX_FMT_DV
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_DVVIDEO,  V4L2_PIX_FMT_DV         , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_DVVIDEO,  V4L2_PIX_FMT_DV         , FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_H263
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_H263,     V4L2_PIX_FMT_H263       , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_H263,     V4L2_PIX_FMT_H263       , FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_MPEG1
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MPEG1VIDEO, V4L2_PIX_FMT_MPEG1    , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MPEG1VIDEO, V4L2_PIX_FMT_MPEG1    , FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_MPEG2
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MPEG2VIDEO, V4L2_PIX_FMT_MPEG2    , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_MPEG2VIDEO, V4L2_PIX_FMT_MPEG2    , FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_VC1_ANNEX_G
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_VC1,      V4L2_PIX_FMT_VC1_ANNEX_G, FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_VC1,      V4L2_PIX_FMT_VC1_ANNEX_G, FF_V4L_PACK_AVPACKET                       },
 #endif
 #ifdef V4L2_PIX_FMT_VP8
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_VP8,      V4L2_PIX_FMT_VP8        , FF_V4L_PACK_AVPACKET },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_VP8,      V4L2_PIX_FMT_VP8        , FF_V4L_PACK_AVPACKET                       },
 #endif
-    { AV_PIX_FMT_NONE,    AV_CODEC_ID_NONE,     0                    },
+    { AV_PIX_FMT_NONE,    AV_CODEC_ID_NONE,     0                       , 0                                          },
 };
 
 uint32_t avpriv_v4l_fmt_ff2v4l(enum AVPixelFormat pix_fmt, enum AVCodecID codec_id, int pack_flags)
@@ -101,6 +100,7 @@ uint32_t avpriv_v4l_fmt_ff2v4l(enum AVPixelFormat pix_fmt, enum AVCodecID codec_
             (pix_fmt == AV_PIX_FMT_NONE ||
              avpriv_v4l_fmt_conversion_table[i].ff_fmt == pix_fmt) &&
              (avpriv_v4l_fmt_conversion_table[i].pack_flags & pack_flags)) {
+
             return avpriv_v4l_fmt_conversion_table[i].v4l2_fmt;
         }
     }
diff --git a/libavcodec/v4l2-common.h b/libavcodec/v4l2-common.h
index 1df64f8..346887c 100644
--- a/libavcodec/v4l2-common.h
+++ b/libavcodec/v4l2-common.h
@@ -33,8 +33,8 @@
 #include "libavutil/imgutils.h"
 #include "libavutil/log.h"
 #include "libavutil/opt.h"
-#include "avdevice.h"
-#include "timefilter.h"
+#include "libavdevice/avdevice.h"
+#include "libavdevice/timefilter.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/time.h"
diff --git a/libavcodec/v4l2_m2m.c b/libavcodec/v4l2_m2m.c
new file mode 100644
index 0000000..a27c637
--- /dev/null
+++ b/libavcodec/v4l2_m2m.c
@@ -0,0 +1,358 @@
+/*
+ * V4L mem2mem wrapper
+ *
+ * Copyright (C) 2017 Alexis Ballier <aballier at gentoo.org>
+ * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include "libavutil/imgutils.h"
+#include "libavutil/pixfmt.h"
+#include "libavutil/pixdesc.h"
+#include "avcodec.h"
+#include "v4l2_m2m_avcodec.h"
+#include "v4l2-buffers.h"
+#include "v4l2-common.h"
+#include "v4l2_m2m.h"
+
+#define V4L_MAX_STREAM_SIZE (3*1024*1024)
+
+static inline int try_raw_format(V4LBufferPool* bp, enum AVPixelFormat pixfmt)
+{
+    struct v4l2_format *fmt = &bp->format;
+    int ret, i, h;
+
+    fmt->type  = bp->type;
+
+    if (V4L2_TYPE_IS_MULTIPLANAR(bp->type)) {
+        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pixfmt);
+
+        fmt->fmt.pix_mp.pixelformat = avpriv_v4l_fmt_ff2v4l(pixfmt, bp->av_codec_id, FF_V4L_PACK_AVFRAME);
+        if (!fmt->fmt.pix_mp.pixelformat)
+            return AVERROR(EINVAL);
+
+        fmt->fmt.pix_mp.num_planes = av_pix_fmt_count_planes(pixfmt);
+        for (i = 0; i < fmt->fmt.pix_mp.num_planes; i++) {
+            fmt->fmt.pix_mp.plane_fmt[i].bytesperline = av_image_get_linesize(pixfmt, bp->width, i);
+            h = (i == 1 || i == 2) ? FF_CEIL_RSHIFT(bp->height, desc->log2_chroma_h) : bp->height;
+            fmt->fmt.pix_mp.plane_fmt[i].sizeimage = fmt->fmt.pix_mp.plane_fmt[i].bytesperline * h;
+        }
+    } else {
+
+        fmt->fmt.pix.pixelformat  = avpriv_v4l_fmt_ff2v4l(pixfmt, bp->av_codec_id, FF_V4L_PACK_AVFRAME);
+        if (!fmt->fmt.pix.pixelformat)
+            return AVERROR(EINVAL);
+
+        fmt->fmt.pix.bytesperline = av_image_get_linesize(pixfmt, bp->width, 0);
+        fmt->fmt.pix.sizeimage = fmt->fmt.pix.bytesperline * bp->height;
+    }
+
+    ret = ioctl(bp->fd, VIDIOC_TRY_FMT, fmt);
+    if (ret)
+        return AVERROR(EINVAL);
+
+    if (V4L2_TYPE_IS_MULTIPLANAR(bp->type)) {
+        fmt->fmt.pix_mp.height = bp->height;
+        fmt->fmt.pix_mp.width = bp->width;
+    } else {
+        fmt->fmt.pix.height = bp->height;
+        fmt->fmt.pix.width = bp->width;
+    }
+
+    return 0;
+}
+
+static int set_raw_format(V4LBufferPool* bp, int set)
+{
+    enum AVPixelFormat pixfmt = bp->av_pix_fmt;
+    struct v4l2_format *fmt = &bp->format;
+    struct v4l2_fmtdesc fmtdesc = { 0 };
+    int ret;
+
+    fmtdesc.type = bp->type;
+    if (pixfmt != AV_PIX_FMT_NONE) {
+        ret = try_raw_format(bp, pixfmt);
+        if (ret)
+            pixfmt = AV_PIX_FMT_NONE;
+    }
+
+    while (AV_PIX_FMT_NONE == pixfmt && !ioctl(bp->fd, VIDIOC_ENUM_FMT, &fmtdesc)) {
+        pixfmt = avpriv_v4l_fmt_v4l2ff(fmtdesc.pixelformat, AV_CODEC_ID_RAWVIDEO);
+
+        ret = try_raw_format(bp, pixfmt);
+        if (ret)
+            pixfmt = AV_PIX_FMT_NONE;
+
+        if (pixfmt != AV_PIX_FMT_NONE && set) {
+            bp->av_pix_fmt = pixfmt;
+        }
+
+        fmtdesc.index++;
+    }
+
+    if (pixfmt == AV_PIX_FMT_NONE)
+        return AVERROR(EINVAL);
+
+    if (set)
+        return ioctl(bp->fd, VIDIOC_S_FMT, fmt);
+
+    return 0;
+}
+
+static int set_coded_format(V4LBufferPool* bp, int set)
+{
+    struct v4l2_format *fmt = &bp->format;
+    struct v4l2_fmtdesc fdesc;
+    uint32_t v4l2_fmt;
+    int found = 0;
+
+    v4l2_fmt = avpriv_v4l_fmt_ff2v4l(bp->av_pix_fmt, bp->av_codec_id, FF_V4L_PACK_AVPACKET);
+    memset(&fdesc, 0, sizeof(fdesc));
+    fdesc.type = bp->type;
+
+    while (!ioctl(bp->fd, VIDIOC_ENUM_FMT, &fdesc)) {
+        if (v4l2_fmt == fdesc.pixelformat) {
+            found = 1;
+            break;
+        }
+        fdesc.index++;
+    }
+
+    if (!found)
+        return AVERROR(EINVAL);
+
+    fmt->type = bp->type;
+
+    if (V4L2_TYPE_IS_MULTIPLANAR(bp->type)) {
+        fmt->fmt.pix_mp.num_planes = VIDEO_MAX_PLANES;
+        fmt->fmt.pix_mp.pixelformat = v4l2_fmt;
+        if (!fmt->fmt.pix_mp.pixelformat) {
+            av_log(bp->log_ctx, AV_LOG_ERROR, "no V4L codec for id %i\n", bp->av_codec_id);
+            return AVERROR(EINVAL);
+        }
+        fmt->fmt.pix_mp.plane_fmt[0].sizeimage = V4L_MAX_STREAM_SIZE;
+        fmt->fmt.pix_mp.height = bp->height;
+        fmt->fmt.pix_mp.width = bp->width;
+
+    } else {
+        fmt->fmt.pix.pixelformat = v4l2_fmt;
+        if (!fmt->fmt.pix.pixelformat) {
+            av_log(bp->log_ctx, AV_LOG_ERROR, "no V4L codec for id %i\n", bp->av_codec_id);
+            return AVERROR(EINVAL);
+        }
+        fmt->fmt.pix.sizeimage = V4L_MAX_STREAM_SIZE;
+        fmt->fmt.pix.height = bp->height;
+        fmt->fmt.pix.width = bp->width;
+    }
+
+    if (set)
+        return ioctl(bp->fd, VIDIOC_S_FMT, fmt);
+
+    return ioctl(bp->fd, VIDIOC_TRY_FMT, fmt);
+}
+
+int avpriv_set_pool_format(V4LBufferPool* bp, int set)
+{
+    if (bp->av_codec_id == AV_CODEC_ID_RAWVIDEO)
+        return set_raw_format(bp, set);
+
+    return set_coded_format(bp, set);
+}
+
+static inline int splane_video(struct v4l2_capability *cap)
+{
+    if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING))
+        return 1;
+
+    if (cap->capabilities & (V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING))
+        return 1;
+
+    return 0;
+}
+
+static inline int mplane_video(struct v4l2_capability *cap)
+{
+    if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_VIDEO_OUTPUT_MPLANE | V4L2_CAP_STREAMING))
+        return 1;
+
+    if (cap->capabilities & (V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_STREAMING))
+        return 1;
+
+    return 0;
+}
+
+static int prepare_pools(V4Lm2mContext* s, void *log_ctx)
+{
+    int ret;
+
+    s->capture_pool.log_ctx = s->output_pool.log_ctx = log_ctx;
+    s->capture_pool.broken = s->output_pool.broken = 0;
+    s->capture_pool.fd = s->output_pool.fd = s->fd;
+    s->capture_pool.name = "capture pool";
+    s->output_pool.name = "output pool";
+
+    memset(&s->cap, 0, sizeof(s->cap));
+    ret = ioctl(s->fd, VIDIOC_QUERYCAP, &s->cap);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (mplane_video(&s->cap)) {
+        s->capture_pool.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+        s->output_pool.type  = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+        return 0;
+    }
+
+    if (splane_video(&s->cap)) {
+        s->capture_pool.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+        s->output_pool.type  = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+        return 0;
+    }
+
+    return AVERROR(EINVAL);
+}
+
+static int probe_and_set(V4Lm2mContext* s, void *log_ctx, int set)
+{
+    int fail_log_level = ( set ? AV_LOG_ERROR : AV_LOG_DEBUG);
+    int ret;
+
+    s->fd = open(s->devname, O_RDWR | O_NONBLOCK, 0);
+    if (s->fd < 0)
+        return AVERROR(errno);
+
+    ret = prepare_pools(s, log_ctx);
+    if (ret < 0)
+        goto error;
+
+    if (s->output_pool.cfg.format) {
+        ret = s->output_pool.cfg.format(&s->output_pool, set);
+        if (ret) {
+            av_log(log_ctx, fail_log_level, "can't set input format\n");
+            goto error;
+        }
+    }
+
+    if (s->capture_pool.cfg.format) {
+        ret = s->capture_pool.cfg.format(&s->capture_pool, set);
+        if (ret) {
+            av_log(log_ctx, fail_log_level, "can't to set output format\n");
+            goto error;
+        }
+    }
+
+    if (s->output_pool.cfg.init && set) {
+        ret = s->output_pool.cfg.init(&s->output_pool);
+        if (ret) {
+            av_log(log_ctx, fail_log_level, "no output pool's buffers\n");
+            goto error;
+        }
+    }
+
+    if (s->capture_pool.cfg.init && set) {
+        ret = s->capture_pool.cfg.init(&s->capture_pool);
+        if (ret) {
+            av_log(log_ctx, fail_log_level, "no capture pool's buffers\n");
+            goto error;
+        }
+    }
+
+    av_log(log_ctx, AV_LOG_INFO, "using driver '%s' on card '%s'\n", s->cap.driver, s->cap.card);
+
+error:
+    if (!set || ret) {
+        close(s->fd);
+        s->fd = 0;
+    }
+
+    return ret;
+}
+
+int avpriv_v4lm2m_init(V4Lm2mContext* s, void* log_ctx)
+{
+    char *devname_save = s->devname;
+    int ret = AVERROR(EINVAL);
+    char tmpbuf[PATH_MAX];
+    struct dirent *dp;
+    DIR *dirp;
+
+    if (s->devname && *s->devname)
+        return probe_and_set(s, log_ctx, 1);
+
+    if (!(dirp = opendir("/dev")))
+        return AVERROR(errno);
+
+    for (dp = readdir(dirp); dp; dp = readdir(dirp)) {
+
+        if (!strncmp(dp->d_name, "video", sizeof("video") - 1)) {
+            snprintf(tmpbuf, sizeof(tmpbuf) - 1, "/dev/%s", dp->d_name);
+            av_log(log_ctx, AV_LOG_DEBUG, "probing %s\n", tmpbuf);
+
+            s->devname = tmpbuf;
+            ret = probe_and_set(s, log_ctx, 0);
+            if (!ret)
+                break;
+        }
+    }
+    closedir(dirp);
+
+    if (ret) {
+        av_log(log_ctx, AV_LOG_ERROR, "Could not find a valid device\n");
+        s->devname = devname_save;
+
+        return ret;
+    }
+
+    av_log(log_ctx, AV_LOG_INFO, "Using device %s\n", tmpbuf);
+    ret = probe_and_set(s, log_ctx, 1);
+    s->devname = devname_save;
+
+    return ret;
+}
+
+int ff_v4lm2m_codec_init(AVCodecContext *avctx)
+{
+    V4Lm2mContext *s = avctx->priv_data;
+
+    return avpriv_v4lm2m_init(s, avctx);
+}
+
+int avpriv_v4lm2m_end(V4Lm2mContext* s)
+{
+    avpriv_release_buffer_pool(&s->output_pool);
+    avpriv_release_buffer_pool(&s->capture_pool);
+    avpriv_set_stream_status(&s->output_pool, VIDIOC_STREAMOFF);
+    avpriv_set_stream_status(&s->capture_pool, VIDIOC_STREAMOFF);
+    close(s->fd);
+
+    return 0;
+}
+
+int ff_v4lm2m_codec_end(AVCodecContext *avctx)
+{
+    V4Lm2mContext *s = avctx->priv_data;
+
+    av_log(avctx, AV_LOG_DEBUG, "Closing context\n");
+
+    return avpriv_v4lm2m_end(s);
+}
diff --git a/libavcodec/v4l2_m2m.h b/libavcodec/v4l2_m2m.h
new file mode 100644
index 0000000..6bfd4c4
--- /dev/null
+++ b/libavcodec/v4l2_m2m.h
@@ -0,0 +1,69 @@
+/*
+ * V4L2 mem2mem helper functions
+ *
+ * Copyright (C) 2017 Alexis Ballier <aballier at gentoo.org>
+ * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_V4L2_M2M_H
+#define AVCODEC_V4L2_M2M_H
+
+#include "v4l2-buffers.h"
+#include "v4l2-common.h"
+
+#define V4L_M2M_DEFAULT_OPTS \
+    { "device",\
+        "Path to the device to use",\
+        OFFSET(devname),\
+        AV_OPT_TYPE_STRING,\
+        {.str = NULL }, 0, 0, FLAGS },\
+    { "input_memory",\
+        "Input memory model: See V4L2_MEMORY_* in videodev2.h. This depends on the HW but default should work with most but would imply useless memcpy()'s if used improperly.",\
+        OFFSET(output_pool.memory),\
+        AV_OPT_TYPE_INT,\
+        {.i64 = V4L2_MEMORY_MMAP},\
+        0, INT_MAX, FLAGS },\
+    { "output_memory",\
+        "Output memory model: See V4L2_MEMORY_* in videodev2.h. This depends on the HW but default should work with most.",\
+        OFFSET(capture_pool.memory),\
+        AV_OPT_TYPE_INT,\
+        {.i64 = V4L2_MEMORY_MMAP},\
+        0, INT_MAX, FLAGS },\
+    { "num_output_pool_buffers",\
+        "Number of buffers in the output pool",\
+        OFFSET(output_pool.num_buffers),\
+        AV_OPT_TYPE_INT,\
+        { .i64 = 16 },\
+        4, INT_MAX, FLAGS }
+
+typedef struct V4Lm2mContext
+{
+    AVClass *class;
+    int fd;
+    char *devname;
+    struct v4l2_capability cap;
+    V4LBufferPool output_pool;
+    V4LBufferPool capture_pool;
+} V4Lm2mContext;
+
+int avpriv_v4lm2m_init(V4Lm2mContext* s, void* log_ctx);
+int avpriv_set_pool_format(V4LBufferPool* bp, int set);
+int avpriv_v4lm2m_end(V4Lm2mContext* ctx);
+
+#endif /* AVCODEC_V4L2_M2M_H */
diff --git a/libavcodec/v4l2_m2m_avcodec.h b/libavcodec/v4l2_m2m_avcodec.h
new file mode 100644
index 0000000..2d0f1b6
--- /dev/null
+++ b/libavcodec/v4l2_m2m_avcodec.h
@@ -0,0 +1,32 @@
+/*
+ * V4L2 mem2mem avcodec helper functions
+ *
+ * Copyright (C) 2017 Alexis Ballier <aballier at gentoo.org>
+ * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_V4L2_M2M_AVCODEC_H
+#define AVCODEC_V4L2_M2M_AVCODEC_H
+
+#include "avcodec.h"
+
+int ff_v4lm2m_codec_init(AVCodecContext *avctx);
+int ff_v4lm2m_codec_end(AVCodecContext *avctx);
+
+#endif
diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c
new file mode 100644
index 0000000..c09ce6a
--- /dev/null
+++ b/libavcodec/v4l2_m2m_dec.c
@@ -0,0 +1,244 @@
+/*
+ * V4L2 mem2mem decoders
+ *
+ * Copyright (C) 2017 Alexis Ballier <aballier at gentoo.org>
+ * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <sys/ioctl.h>
+#include "libavutil/pixfmt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/opt.h"
+#include "v4l2_m2m_avcodec.h"
+#include "v4l2-common.h"
+#include "v4l2-buffers.h"
+#include "v4l2_m2m.h"
+#include "decode.h"
+#include "avcodec.h"
+
+static int try_start(AVCodecContext *avctx)
+{
+    V4Lm2mContext *s = avctx->priv_data;
+    struct v4l2_selection selection;
+    struct v4l2_control ctrl;
+    int ret;
+
+    if (s->output_pool.streamon && s->capture_pool.streamon)
+        return 0;
+
+    /* this will report the size of the frame back (see a4lbuf_to_avframe) */
+    s->capture_pool.height = avctx->coded_height;
+    s->capture_pool.width = avctx->coded_width;
+
+    /* start the output process */
+    if (!s->output_pool.streamon) {
+        ret = avpriv_set_stream_status(&s->output_pool, VIDIOC_STREAMON);
+        if (ret < 0) {
+            av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON on output pool\n");
+            return ret;
+        }
+    }
+
+    /* get the capture format */
+    s->capture_pool.format.type = s->capture_pool.type;
+    ret = ioctl(s->fd, VIDIOC_G_FMT, &s->capture_pool.format);
+    if (ret) {
+        av_log(avctx, AV_LOG_DEBUG, "VIDIOC_G_FMT ioctl\n");
+        return ret;
+    }
+
+    /* store what the decoder gives */
+    avctx->pix_fmt = avpriv_v4l_fmt_v4l2ff(s->capture_pool.format.fmt.pix_mp.pixelformat, AV_CODEC_ID_RAWVIDEO);
+    s->capture_pool.av_pix_fmt = avctx->pix_fmt;
+
+    /* set the crop parameters */
+    selection.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+    selection.r.height = avctx->coded_height;
+    selection.r.width = avctx->coded_width;
+    ret = ioctl(s->fd, VIDIOC_S_SELECTION, &selection);
+    if (!ret) {
+        ret = ioctl(s->fd, VIDIOC_G_SELECTION, &selection);
+        if (ret) {
+            av_log(avctx, AV_LOG_ERROR, "VIDIOC_G_SELECTION ioctl\n");
+        } else {
+            av_log(avctx, AV_LOG_DEBUG, "crop output %dx%d\n", selection.r.width, selection.r.height);
+            /* update the size of the resulting frame */
+            s->capture_pool.height = selection.r.height;
+            s->capture_pool.width  = selection.r.width;
+        }
+    }
+
+    /* get the minimum number of buffers required by capture */
+    memset(&ctrl, 0, sizeof(ctrl));
+    ctrl.id = V4L2_CID_MIN_BUFFERS_FOR_CAPTURE;
+    ret = ioctl(s->fd, VIDIOC_G_CTRL, &ctrl);
+    if (ret) {
+        s->capture_pool.min_queued_buffers = 6;
+    } else {
+        s->capture_pool.min_queued_buffers = ctrl.value;
+    }
+
+    /* init the capture pool */
+    if (!s->capture_pool.buffers) {
+        ret = avpriv_init_v4lbufpool(&s->capture_pool);
+        if (ret) {
+            av_log(avctx, AV_LOG_DEBUG, "can't request output buffers\n");
+            return ret;
+        }
+    }
+
+    /* start the capture process */
+    ret = avpriv_set_stream_status(&s->capture_pool, VIDIOC_STREAMON);
+    if (ret) {
+        av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON, on capture pool\n");
+        return ret;
+    }
+
+
+    return 0;
+}
+
+static av_cold int v4lm2m_decode_init(AVCodecContext *avctx)
+{
+    V4Lm2mContext *s = avctx->priv_data;
+
+    s->output_pool.cfg.format = avpriv_set_pool_format;
+    s->output_pool.cfg.init = avpriv_init_v4lbufpool;
+
+    s->output_pool.av_codec_tag = avctx->codec_tag;
+    s->output_pool.av_codec_id = avctx->codec_id;
+    s->output_pool.av_pix_fmt  = AV_PIX_FMT_NONE;
+    s->output_pool.height = avctx->coded_height;
+    s->output_pool.width = avctx->coded_width;
+    s->output_pool.default_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
+
+    s->capture_pool.cfg.format = avpriv_set_pool_format;
+    s->capture_pool.cfg.init = NULL;
+
+    s->capture_pool.av_codec_tag = 0;
+    s->capture_pool.av_codec_id = AV_CODEC_ID_RAWVIDEO;
+    s->capture_pool.av_pix_fmt = avctx->pix_fmt;
+    s->capture_pool.height = avctx->coded_height;
+    s->capture_pool.width = avctx->coded_width;
+    s->capture_pool.default_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
+
+    return ff_v4lm2m_codec_init(avctx);
+}
+
+static inline void set_dequeue_mode(V4Lm2mContext *s)
+{
+    s->capture_pool.blocking_dequeue = 0;
+
+    if (s->output_pool.num_queued >= s->output_pool.num_buffers - 2)
+        s->capture_pool.blocking_dequeue = 1000;
+}
+
+static int v4lm2m_receive_frame(AVCodecContext *avctx, AVFrame *frame)
+{
+    V4Lm2mContext *s = avctx->priv_data;
+    AVPacket avpkt = {0};
+    int ret;
+
+    ret = ff_decode_get_packet(avctx, &avpkt);
+    if (ret < 0 && ret != AVERROR_EOF)
+        return ret;
+
+    if (avctx->extradata && avctx->extradata_size) {
+            ret = avpriv_v4l_enqueue_frame_or_pkt_or_buf(&s->output_pool, NULL,
+                                NULL, avctx->extradata, avctx->extradata_size);
+            if (ret)
+                return ret;
+
+            (void) try_start(avctx);
+    }
+
+    ret = avpriv_v4l_enqueue_frame_or_pkt_or_buf(&s->output_pool, NULL, &avpkt, NULL, 0);
+    if (ret < 0)
+        return ret;
+
+    ret = try_start(avctx);
+    if (ret)
+        return 0;
+
+    set_dequeue_mode(s);
+
+    return avpriv_v4l_dequeue_frame_or_pkt(&s->capture_pool, frame, NULL);
+}
+
+#define OFFSET(x) offsetof(V4Lm2mContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
+
+        static const AVOption options[] = {
+        V4L_M2M_DEFAULT_OPTS,{ "num_capture_pool_extra_buffers",
+        "Number of extra buffers in the capture pool",
+        OFFSET(capture_pool.num_buffers), AV_OPT_TYPE_INT,{.i64 = 6}, 4, INT_MAX, FLAGS},
+        { NULL},
+        };
+
+#define M2MDEC(NAME, LONGNAME, CODEC, bsf_name) \
+static const AVClass v4l2_m2m_ ## NAME ## _dec_class = {\
+    .class_name = #NAME "_v4l2_m2m_decoder",\
+    .item_name  = av_default_item_name,\
+    .option     = options,\
+    .version    = LIBAVUTIL_VERSION_INT,\
+};\
+\
+AVCodec ff_ ## NAME ## _v4l2m2m_decoder = { \
+    .name           = #NAME "_v4l2m2m" ,\
+    .long_name      = NULL_IF_CONFIG_SMALL("V4L2 mem2mem " LONGNAME " decoder wrapper"),\
+    .type           = AVMEDIA_TYPE_VIDEO,\
+    .id             = CODEC ,\
+    .priv_data_size = sizeof(V4Lm2mContext),\
+    .priv_class     = &v4l2_m2m_ ## NAME ## _dec_class,\
+    .init           = v4lm2m_decode_init,\
+    .receive_frame  = v4lm2m_receive_frame,\
+    .close          = ff_v4lm2m_codec_end,\
+    .capabilities   = CODEC_CAP_DELAY,\
+    .bsfs           = bsf_name, \
+};
+
+#if CONFIG_H263_V4L2M2M_DECODER
+        M2MDEC(h263 , "H.263" , AV_CODEC_ID_H263, NULL);
+#endif
+
+#if CONFIG_H264_V4L2M2M_DECODER
+        M2MDEC(h264 , "H.264" , AV_CODEC_ID_H264, "h264_mp4toannexb");
+#endif
+
+#if CONFIG_MPEG1_V4L2M2M_DECODER
+        M2MDEC(mpeg1, "MPEG1", AV_CODEC_ID_MPEG1VIDEO, NULL);
+#endif
+
+#if CONFIG_MPEG2_V4L2M2M_DECODER
+        M2MDEC(mpeg2, "MPEG2", AV_CODEC_ID_MPEG2VIDEO, NULL);
+#endif
+
+#if CONFIG_MPEG4_V4L2M2M_DECODER
+        M2MDEC(mpeg4, "MPEG4", AV_CODEC_ID_MPEG4, NULL);
+#endif
+
+#if CONFIG_VC1_V4L2M2M_DECODER
+        M2MDEC(vc1  , "VC1"  , AV_CODEC_ID_VC1, NULL);
+#endif
+
+#if CONFIG_VP8_V4L2M2M_DECODER
+        M2MDEC(vp8  , "VP8"  , AV_CODEC_ID_VP8, NULL);
+#endif
+
+
diff --git a/libavcodec/v4l2_m2m_enc.c b/libavcodec/v4l2_m2m_enc.c
new file mode 100644
index 0000000..899a54f
--- /dev/null
+++ b/libavcodec/v4l2_m2m_enc.c
@@ -0,0 +1,251 @@
+/*
+ * V4L2 mem2mem encoders
+ *
+ * Copyright (C) 2017 Alexis Ballier <aballier at gentoo.org>
+ * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz at linaro.org>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <sys/ioctl.h>
+
+#include "libavutil/pixfmt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/opt.h"
+#include "v4l2_m2m_avcodec.h"
+#include "v4l2-buffers.h"
+#include "v4l2-common.h"
+#include "v4l2_m2m.h"
+#include "avcodec.h"
+
+#define SET_V4L_EXT_CTRL(TYPE, ID, VALUE, CLASS, NAME) \
+{ \
+    struct v4l2_ext_control ctrl = { 0 };\
+    struct v4l2_ext_controls ctrls = { 0 };\
+    ctrl.id = ID ;\
+    ctrl.TYPE = VALUE ;\
+    ctrls.ctrl_class = CLASS ;\
+    ctrls.count = 1;\
+    ctrls.controls = &ctrl;\
+\
+    if ((ret = ioctl(s->fd, VIDIOC_S_EXT_CTRLS, &ctrls)) < 0)\
+        av_log(avctx, AV_LOG_WARNING, "Failed to set " NAME "\n");\
+}
+
+static inline int v4l_h264_profile_from_ff(int p)
+{
+    switch(p) {
+        case FF_PROFILE_H264_BASELINE:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE;
+        case FF_PROFILE_H264_CONSTRAINED_BASELINE:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE;
+        case FF_PROFILE_H264_MAIN:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_MAIN;
+        case FF_PROFILE_H264_EXTENDED:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED;
+        case FF_PROFILE_H264_HIGH:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_HIGH;
+        case FF_PROFILE_H264_HIGH_10:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10;
+        case FF_PROFILE_H264_HIGH_10_INTRA:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA;
+        case FF_PROFILE_H264_HIGH_422:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422;
+        case FF_PROFILE_H264_HIGH_422_INTRA:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA;
+        case FF_PROFILE_H264_HIGH_444_PREDICTIVE:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE;
+        case FF_PROFILE_H264_HIGH_444_INTRA:
+            return V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA;
+    }
+
+    return -1;
+}
+
+static inline int v4l_mpeg4_profile_from_ff(int p)
+{
+    switch(p) {
+        case FF_PROFILE_MPEG4_SIMPLE:
+            return V4L2_MPEG_VIDEO_MPEG4_PROFILE_SIMPLE;
+        case FF_PROFILE_MPEG4_ADVANCED_SIMPLE:
+            return V4L2_MPEG_VIDEO_MPEG4_PROFILE_ADVANCED_SIMPLE;
+        case FF_PROFILE_MPEG4_CORE:
+            return V4L2_MPEG_VIDEO_MPEG4_PROFILE_CORE;
+        case FF_PROFILE_MPEG4_SIMPLE_SCALABLE:
+            return V4L2_MPEG_VIDEO_MPEG4_PROFILE_SIMPLE_SCALABLE;
+        case FF_PROFILE_MPEG4_ADVANCED_CODING:
+            return V4L2_MPEG_VIDEO_MPEG4_PROFILE_ADVANCED_CODING_EFFICIENCY;
+    }
+
+    return -1;
+}
+
+static av_cold int v4lm2m_encode_init(AVCodecContext *avctx)
+{
+    V4Lm2mContext *s = avctx->priv_data;
+    int ret, val;
+
+    s->output_pool.cfg.format = avpriv_set_pool_format;
+    s->output_pool.cfg.init = avpriv_init_v4lbufpool;
+    s->output_pool.av_pix_fmt = avctx->pix_fmt;
+    s->output_pool.width = avctx->width;
+    s->output_pool.height = avctx->height;
+    s->output_pool.av_codec_id = AV_CODEC_ID_RAWVIDEO;
+    s->output_pool.default_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
+
+    s->capture_pool.cfg.format = avpriv_set_pool_format;
+    s->capture_pool.cfg.init = avpriv_init_v4lbufpool;
+    s->capture_pool.min_queued_buffers = 1;
+    s->capture_pool.av_pix_fmt  = AV_PIX_FMT_NONE;
+    s->capture_pool.av_codec_id = avctx->codec_id;
+    s->capture_pool.default_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
+
+    if (ret = ff_v4lm2m_codec_init(avctx))
+        return ret;
+
+    SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_GOP_SIZE, avctx->gop_size, V4L2_CTRL_CLASS_MPEG, "gop size");
+    SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_BITRATE , avctx->bit_rate, V4L2_CTRL_CLASS_MPEG, "bit rate");
+    SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_HEADER_MODE, V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME, V4L2_CTRL_CLASS_MPEG, "header mode");
+    SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_B_FRAMES, avctx->max_b_frames, V4L2_CTRL_CLASS_MPEG, "number of B-frames");
+
+    switch(avctx->codec_id) {
+        case AV_CODEC_ID_H264:
+            val = v4l_h264_profile_from_ff(avctx->profile);
+            if (val >= 0) {
+                 SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_H264_PROFILE, val, V4L2_CTRL_CLASS_MPEG, "h264 profile");
+            }
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_H264_MIN_QP, avctx->qmin, V4L2_CTRL_CLASS_MPEG, "minimum video quantizer scale");
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_H264_MAX_QP, avctx->qmax, V4L2_CTRL_CLASS_MPEG, "maximum video quantizer scale");
+            break;
+        case AV_CODEC_ID_MPEG4:
+            val = v4l_mpeg4_profile_from_ff(avctx->profile);
+            if (val >= 0) {
+                 SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE, val, V4L2_CTRL_CLASS_MPEG, "mpeg4 profile");
+            }
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP, avctx->qmin, V4L2_CTRL_CLASS_MPEG, "minimum video quantizer scale");
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP, avctx->qmax, V4L2_CTRL_CLASS_MPEG, "maximum video quantizer scale");
+            if (avctx->flags & CODEC_FLAG_QPEL) {
+                SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_MPEG4_QPEL, 1, V4L2_CTRL_CLASS_MPEG, "qpel");
+            }
+            break;
+        case AV_CODEC_ID_H263:
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_H263_MIN_QP, avctx->qmin, V4L2_CTRL_CLASS_MPEG, "minimum video quantizer scale");
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_H263_MAX_QP, avctx->qmax, V4L2_CTRL_CLASS_MPEG, "maximum video quantizer scale");
+            break;
+        case AV_CODEC_ID_VP8:
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_VPX_MIN_QP, avctx->qmin, V4L2_CTRL_CLASS_MPEG, "minimum video quantizer scale");
+            SET_V4L_EXT_CTRL(value, V4L2_CID_MPEG_VIDEO_VPX_MAX_QP, avctx->qmax, V4L2_CTRL_CLASS_MPEG, "maximum video quantizer scale");
+            break;
+    }
+    return 0;
+}
+
+static int v4lm2m_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
+                              const AVFrame *pict, int *got_packet)
+{
+    V4Lm2mContext *s = avctx->priv_data;
+    int ret;
+
+    if (pict) {
+        ret = avpriv_v4l_enqueue_frame_or_pkt_or_buf(&s->output_pool, pict, NULL, NULL, 0);
+        if (ret < 0)
+            return ret;
+
+        if (!s->output_pool.streamon && (ret = avpriv_set_stream_status(&s->output_pool, VIDIOC_STREAMON))) {
+            av_log(avctx, AV_LOG_ERROR, "VIDIOC_STREAMON failed on output pool\n");
+            return ret;
+        }
+
+        if (!s->capture_pool.streamon && (ret = avpriv_set_stream_status(&s->capture_pool, VIDIOC_STREAMON))) {
+            av_log(avctx, AV_LOG_ERROR, "VIDIOC_STREAMON failed on capture pool\n");
+            return ret;
+        }
+
+    } else if (s->output_pool.streamon) {
+        /* last frame, stop encoder */
+        struct v4l2_encoder_cmd cmd;
+        memset(&cmd, 0, sizeof(cmd));
+        cmd.cmd = V4L2_ENC_CMD_STOP;
+
+        ret = ioctl(s->fd, VIDIOC_ENCODER_CMD, &cmd);
+        if (ret)
+            av_log(avctx, AV_LOG_ERROR, "Failed to stop encoder (%s)\n", av_err2str(AVERROR(errno)));
+
+        s->output_pool.streamon = 0;
+    }
+
+    if (s->output_pool.num_queued >= s->output_pool.num_buffers - 2 || !pict) {
+        s->capture_pool.blocking_dequeue = 100;
+    } else {
+        s->capture_pool.blocking_dequeue = 0;
+    }
+
+    ret = avpriv_v4l_dequeue_frame_or_pkt(&(s->capture_pool), NULL, pkt);
+
+    if (AVERROR(EAGAIN) == ret )
+        return 0;
+
+    if (!ret)
+        *got_packet = 1;
+
+    return ret;
+}
+
+#define OFFSET(x) offsetof(V4Lm2mContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
+
+static const AVOption options[] = {
+    V4L_M2M_DEFAULT_OPTS, { "num_capture_pool_buffers", "Number of buffers in the capture pool",
+      OFFSET(capture_pool.num_buffers), AV_OPT_TYPE_INT, {.i64 = 4 }, 4, INT_MAX, FLAGS }, { NULL },
+};
+
+#define M2MENC(NAME, LONGNAME, CODEC) \
+static const AVClass v4l2_m2m_ ## NAME ## _enc_class = {\
+    .class_name = #NAME "_v4l2_m2m_encoder",\
+    .item_name  = av_default_item_name,\
+    .option     = options,\
+    .version    = LIBAVUTIL_VERSION_INT,\
+};\
+\
+AVCodec ff_ ## NAME ## _v4l2m2m_encoder = { \
+    .name           = #NAME "_v4l2m2m" ,\
+    .long_name      = NULL_IF_CONFIG_SMALL("V4L2 mem2mem " LONGNAME " encoder wrapper"),\
+    .type           = AVMEDIA_TYPE_VIDEO,\
+    .id             = CODEC ,\
+    .priv_data_size = sizeof(V4Lm2mContext),\
+    .priv_class     = &v4l2_m2m_ ## NAME ##_enc_class,\
+    .init           = v4lm2m_encode_init,\
+    .encode2        = v4lm2m_encode_frame,\
+    .close          = ff_v4lm2m_codec_end,\
+    .capabilities   = CODEC_CAP_DELAY,\
+};
+
+#if CONFIG_H263_V4L2M2M_ENCODER
+M2MENC(h263 , "H.263" , AV_CODEC_ID_H263 );
+#endif
+
+#if CONFIG_H264_V4L2M2M_ENCODER
+M2MENC(h264 , "H.264" , AV_CODEC_ID_H264 );
+#endif
+
+#if CONFIG_MPEG4_V4L2M2M_ENCODER
+M2MENC(mpeg4, "MPEG4", AV_CODEC_ID_MPEG4);
+#endif
+
+#if CONFIG_VP8_V4L2M2M_ENCODER
+M2MENC(vp8  , "VP8"  , AV_CODEC_ID_VP8  );
+#endif
-- 
2.7.4



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