[FFmpeg-devel] [PATCH 1/3] mjpegdec: Add hwaccel hooks

[Philip Langdale]

From: Mark Thompson <sw at jkqxz.net>

Also adds some extra fields to the main context structure that may
be needed by a hwaccel decoder.

(Modified by philipl to remove a YUVJ mapping hack that isn't required
 by nvdec and would otherwise block merging the rest of the change.)
---
 libavcodec/mjpegdec.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++--
 libavcodec/mjpegdec.h | 11 +++++++++
 2 files changed, 77 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 5055ee2826..9a7a329b19 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -36,6 +36,7 @@
 #include "avcodec.h"
 #include "blockdsp.h"
 #include "copy_block.h"
+#include "hwaccel.h"
 #include "idctdsp.h"
 #include "internal.h"
 #include "jpegtables.h"
@@ -147,6 +148,7 @@ av_cold int ff_mjpeg_decode_init(AVCodecContext *avctx)
     s->org_height    = avctx->coded_height;
     avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
     avctx->colorspace = AVCOL_SPC_BT470BG;
+    s->hwaccel_pix_fmt = s->hwaccel_sw_pix_fmt = AV_PIX_FMT_NONE;
 
     if ((ret = build_basic_mjpeg_vlc(s)) < 0)
         return ret;
@@ -279,6 +281,11 @@ int ff_mjpeg_decode_dht(MJpegDecodeContext *s)
                                  code_max + 1, 0, 0)) < 0)
                 return ret;
         }
+
+        for (i = 0; i < 16; i++)
+            s->raw_huffman_lengths[class][index][i] = bits_table[i + 1];
+        for (i = 0; i < 256; i++)
+            s->raw_huffman_values[class][index][i] = val_table[i];
     }
     return 0;
 }
@@ -636,6 +643,24 @@ unk_pixfmt:
         return AVERROR_BUG;
     }
 
+    // TODO: Handle the fact that YUVJ pix_fmts are not recognised by hwaccels and
+    // might impact the ability to allocate hw frames.
+
+    if (s->avctx->pix_fmt == s->hwaccel_sw_pix_fmt) {
+        s->avctx->pix_fmt = s->hwaccel_pix_fmt;
+    } else {
+        enum AVPixelFormat pix_fmts[] = {
+            s->avctx->pix_fmt,
+            AV_PIX_FMT_NONE,
+        };
+        s->hwaccel_pix_fmt = ff_get_format(s->avctx, pix_fmts);
+        if (s->hwaccel_pix_fmt < 0)
+            return AVERROR(EINVAL);
+
+        s->hwaccel_sw_pix_fmt = s->avctx->pix_fmt;
+        s->avctx->pix_fmt = s->hwaccel_pix_fmt;
+    }
+
     if (s->avctx->skip_frame == AVDISCARD_ALL) {
         s->picture_ptr->pict_type = AV_PICTURE_TYPE_I;
         s->picture_ptr->key_frame = 1;
@@ -683,6 +708,19 @@ unk_pixfmt:
         }
         memset(s->coefs_finished, 0, sizeof(s->coefs_finished));
     }
+
+    if (s->avctx->hwaccel) {
+        s->hwaccel_picture_private =
+            av_mallocz(s->avctx->hwaccel->frame_priv_data_size);
+        if (!s->hwaccel_picture_private)
+            return AVERROR(ENOMEM);
+
+        ret = s->avctx->hwaccel->start_frame(s->avctx, s->raw_buffer,
+                                             s->raw_buffer_size);
+        if (ret < 0)
+            return ret;
+    }
+
     return 0;
 }
 
@@ -1510,7 +1548,7 @@ int ff_mjpeg_decode_sos(MJpegDecodeContext *s, const uint8_t *mb_bitmask,
         }
     }
 
-    av_assert0(s->picture_ptr->data[0]);
+    //av_assert0(s->picture_ptr->data[0]);
     /* XXX: verify len field validity */
     len = get_bits(&s->gb, 16);
     nb_components = get_bits(&s->gb, 8);
@@ -1600,7 +1638,18 @@ next_field:
     for (i = 0; i < nb_components; i++)
         s->last_dc[i] = (4 << s->bits);
 
-    if (s->lossless) {
+    if (s->avctx->hwaccel) {
+        int bytes_to_start = get_bits_count(&s->gb) / 8;
+        av_assert0(bytes_to_start >= 0 &&
+                   s->raw_buffer_size >= bytes_to_start);
+
+        ret = s->avctx->hwaccel->decode_slice(s->avctx,
+                                              s->raw_buffer      + bytes_to_start,
+                                              s->raw_buffer_size - bytes_to_start);
+        if (ret < 0)
+            return ret;
+
+    } else if (s->lossless) {
         av_assert0(s->picture_ptr == s->picture);
         if (CONFIG_JPEGLS_DECODER && s->ls) {
 //            for () {
@@ -2226,6 +2275,9 @@ int ff_mjpeg_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
             goto fail;
         }
 
+        s->raw_buffer      = buf_ptr;
+        s->raw_buffer_size = buf_end - buf_ptr;
+
         s->start_code = start_code;
         if (s->avctx->debug & FF_DEBUG_STARTCODE)
             av_log(avctx, AV_LOG_DEBUG, "startcode: %X\n", start_code);
@@ -2342,6 +2394,13 @@ eoi_parser:
                 s->got_picture = 0;
                 goto the_end_no_picture;
             }
+            if (s->avctx->hwaccel) {
+                ret = s->avctx->hwaccel->end_frame(s->avctx);
+                if (ret < 0)
+                    return ret;
+
+                av_freep(&s->hwaccel_picture_private);
+            }
             if ((ret = av_frame_ref(frame, s->picture_ptr)) < 0)
                 return ret;
             *got_frame = 1;
@@ -2666,6 +2725,8 @@ av_cold int ff_mjpeg_decode_end(AVCodecContext *avctx)
 
     reset_icc_profile(s);
 
+    av_freep(&s->hwaccel_picture_private);
+
     return 0;
 }
 
@@ -2706,6 +2767,9 @@ AVCodec ff_mjpeg_decoder = {
     .priv_class     = &mjpegdec_class,
     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
                       FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
+    .hw_configs     = (const AVCodecHWConfigInternal*[]) {
+                        NULL
+                    },
 };
 #endif
 #if CONFIG_THP_DECODER
diff --git a/libavcodec/mjpegdec.h b/libavcodec/mjpegdec.h
index c36fba5f22..11dfdbf62b 100644
--- a/libavcodec/mjpegdec.h
+++ b/libavcodec/mjpegdec.h
@@ -137,6 +137,17 @@ typedef struct MJpegDecodeContext {
     int *iccdatalens;
     int iccnum;
     int iccread;
+
+    // Raw stream data for hwaccel use.
+    const uint8_t *raw_buffer;
+    size_t         raw_buffer_size;
+
+    uint8_t raw_huffman_lengths[2][4][16];
+    uint8_t raw_huffman_values[2][4][256];
+
+    enum AVPixelFormat hwaccel_sw_pix_fmt;
+    enum AVPixelFormat hwaccel_pix_fmt;
+    void *hwaccel_picture_private;
 } MJpegDecodeContext;
 
 int ff_mjpeg_decode_init(AVCodecContext *avctx);
-- 
2.14.1