[FFmpeg-devel] [PATCH] DPX image encoder

Peter Ross pross at xvid.org
Mon Mar 28 14:26:40 CEST 2011


---

1. HEADER_SIZE is the length of the DPX Generic header.

2. Have updated to use accurate header descriptions, per SMPTE-268M-2003. 
   Thanks Kieran for picking up on this.

 Changelog              |    1 +
 doc/general.texi       |    2 +-
 libavcodec/Makefile    |    1 +
 libavcodec/allcodecs.c |    2 +-
 libavcodec/dpxenc.c    |  136 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 140 insertions(+), 2 deletions(-)
 create mode 100644 libavcodec/dpxenc.c

diff --git a/Changelog b/Changelog
index c91faab..761f790 100644
--- a/Changelog
+++ b/Changelog
@@ -81,6 +81,7 @@ version <next>:
 - Linux framebuffer input device added
 - Apple HTTP Live Streaming protocol handler
 - sndio support for playback and record
+- DPX image encoder
 
 
 version 0.6:
diff --git a/doc/general.texi b/doc/general.texi
index 23ffb0d..29fb997 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -275,7 +275,7 @@ following image formats are supported:
     @tab Only uncompressed GIFs are generated.
 @item BMP          @tab X @tab X
     @tab Microsoft BMP image
- at item DPX          @tab   @tab X
+ at item DPX          @tab X @tab X
     @tab Digital Picture Exchange
 @item JPEG         @tab X @tab X
     @tab Progressive JPEG is not supported.
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 2dc9f93..7ee7035 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -110,6 +110,7 @@ OBJS-$(CONFIG_DNXHD_ENCODER)           += dnxhdenc.o dnxhddata.o       \
                                           ratecontrol.o mpeg12data.o   \
                                           mpegvideo.o
 OBJS-$(CONFIG_DPX_DECODER)             += dpx.o
+OBJS-$(CONFIG_DPX_ENCODER)             += dpxenc.o
 OBJS-$(CONFIG_DSICINAUDIO_DECODER)     += dsicinav.o
 OBJS-$(CONFIG_DSICINVIDEO_DECODER)     += dsicinav.o
 OBJS-$(CONFIG_DVBSUB_DECODER)          += dvbsubdec.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 695b25b..833ad3c 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -89,7 +89,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (CSCD, cscd);
     REGISTER_DECODER (CYUV, cyuv);
     REGISTER_ENCDEC  (DNXHD, dnxhd);
-    REGISTER_DECODER (DPX, dpx);
+    REGISTER_ENCDEC  (DPX, dpx);
     REGISTER_DECODER (DSICINVIDEO, dsicinvideo);
     REGISTER_ENCDEC  (DVVIDEO, dvvideo);
     REGISTER_DECODER (DXA, dxa);
diff --git a/libavcodec/dpxenc.c b/libavcodec/dpxenc.c
new file mode 100644
index 0000000..416a346
--- /dev/null
+++ b/libavcodec/dpxenc.c
@@ -0,0 +1,136 @@
+/*
+ * DPX (.dpx) image encoder
+ * Copyright (c) 2011 Peter Ross <pross at xvid.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 "libavutil/intreadwrite.h"
+#include "libavutil/imgutils.h"
+#include "avcodec.h"
+
+typedef struct DPXContext {
+    AVFrame picture;
+    int big_endian;
+    int bits_per_component;
+    int descriptor;
+} DPXContext;
+
+static av_cold int encode_init(AVCodecContext *avctx)
+{
+    DPXContext *s = avctx->priv_data;
+
+    avctx->coded_frame = &s->picture;
+    avctx->coded_frame->pict_type = FF_I_TYPE;
+    avctx->coded_frame->key_frame = 1;
+
+    s->big_endian         = 1;
+    s->bits_per_component = 8;
+    s->descriptor         = 50; /* RGB */
+
+    switch (avctx->pix_fmt) {
+    case PIX_FMT_RGB24:
+        break;
+    case PIX_FMT_RGBA:
+        s->descriptor = 51; /* RGBA */
+        break;
+    case PIX_FMT_RGB48LE:
+        s->big_endian = 0;
+    case PIX_FMT_RGB48BE:
+        s->bits_per_component = avctx->bits_per_raw_sample ? avctx->bits_per_raw_sample : 16;
+        break;
+    default:
+        av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+#define write16(p, value) \
+do { \
+    if (s->big_endian) AV_WB16(p, value); \
+    else               AV_WL16(p, value); \
+} while(0)
+
+#define write32(p, value) \
+do { \
+    if (s->big_endian) AV_WB32(p, value); \
+    else               AV_WL32(p, value); \
+} while(0)
+
+static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data)
+{
+    DPXContext *s = avctx->priv_data;
+    int size;
+
+#define HEADER_SIZE 0x680  /* DPX Generic header size */
+    if (buf_size < HEADER_SIZE)
+        return -1;
+
+    memset(buf, 0, HEADER_SIZE);
+
+    /* File information header */
+    write32(buf,         MKBETAG('S','D','P','X'));
+    write32(buf +     4, HEADER_SIZE);
+    memcpy (buf +     8, "V1.0", 4);
+    write32(buf +  0x14, 1); /* new image */
+    write32(buf +  0x18, HEADER_SIZE);
+    memcpy (buf +  0xA0, LIBAVCODEC_IDENT, FFMIN(sizeof(LIBAVCODEC_IDENT), 100));
+    write32(buf + 0x294, 0xFFFFFFFF); /* unencrypted */
+
+    /* Image information header */
+    write16(buf + 0x300, 0); /* orientation; left to right, top to bottom */
+    write16(buf + 0x302, 1); /* number of elements */
+    write32(buf + 0x304, avctx->width);
+    write32(buf + 0x308, avctx->height);
+    buf[0x320] = s->descriptor;
+    buf[0x321] = 2; /* linear transfer */
+    buf[0x322] = 2; /* linear colorimetric */
+    buf[0x323] = s->bits_per_component;
+
+    /* Image source information header */
+    write32(buf + 0x540, avctx->sample_aspect_ratio.num);
+    write32(buf + 0x544, avctx->sample_aspect_ratio.den);
+
+    size = avpicture_layout((AVPicture*)data, avctx->pix_fmt,
+                            avctx->width, avctx->height,
+                            buf + HEADER_SIZE, buf_size - HEADER_SIZE);
+    if (size < 0)
+        return size;
+
+    size += HEADER_SIZE;
+
+    write32(buf + 0x10, size); /* file size */
+    return size;
+}
+
+AVCodec ff_dpx_encoder = {
+    "dpx",
+    AVMEDIA_TYPE_VIDEO,
+    CODEC_ID_DPX,
+    sizeof(DPXContext),
+    encode_init,
+    encode_frame,
+    .pix_fmts= (const enum PixelFormat[]){
+        PIX_FMT_RGB24,
+        PIX_FMT_RGBA,
+        PIX_FMT_RGB48LE,
+        PIX_FMT_RGB48BE,
+        PIX_FMT_NONE},
+    .long_name = NULL_IF_CONFIG_SMALL("DPX image"),
+};
-- 
1.7.4.1


-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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