[FFmpeg-devel] [PATCH 4/6] Support encoding of Active Format Description (AFD) in libx264
Devin Heitmueller
dheitmueller at ltnglobal.com
Thu Nov 16 20:34:15 EET 2017
If AFD side data is present, include it in an H.264 SEI payload when
encoding with libx264.
This is done in the same manner that we currently handle A53 closed
captions (where the business logic for constructing the SEI is in
libavcodec/utils.c), so it should be portable to the other encoder
types (i.e. videotoolbox, etc).
Signed-off-by: Devin Heitmueller <dheitmueller at ltnglobal.com>
---
libavcodec/internal.h | 3 +++
libavcodec/libx264.c | 38 ++++++++++++++++++++++++++++++++++----
libavcodec/utils.c | 36 ++++++++++++++++++++++++++++++++++++
3 files changed, 73 insertions(+), 4 deletions(-)
diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index d47ce0e..a2c7be4 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -408,6 +408,9 @@ int ff_side_data_set_encoder_stats(AVPacket *pkt, int quality, int64_t *error, i
int ff_alloc_a53_sei(const AVFrame *frame, size_t prefix_len,
void **data, size_t *sei_size);
+int ff_alloc_afd_sei(const AVFrame *frame, size_t prefix_len,
+ void **data, size_t *sei_size);
+
/**
* Get an estimated video bitrate based on frame size, frame rate and coded
* bits per pixel.
diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
index 9c67c91..f0f3260 100644
--- a/libavcodec/libx264.c
+++ b/libavcodec/libx264.c
@@ -86,6 +86,7 @@ typedef struct X264Context {
int forced_idr;
int coder;
int a53_cc;
+ int afd;
int b_frame_strategy;
int chroma_offset;
int scenechange_threshold;
@@ -275,6 +276,7 @@ static int X264_frame(AVCodecContext *ctx, AVPacket *pkt, const AVFrame *frame,
x264_nal_t *nal;
int nnal, i, ret;
x264_picture_t pic_out = {0};
+ int num_payloads = 0;
int pict_type;
x264_picture_init( &x4->pic );
@@ -323,10 +325,37 @@ static int X264_frame(AVCodecContext *ctx, AVPacket *pkt, const AVFrame *frame,
} else {
x4->pic.extra_sei.sei_free = av_free;
- x4->pic.extra_sei.payloads[0].payload_size = sei_size;
- x4->pic.extra_sei.payloads[0].payload = sei_data;
- x4->pic.extra_sei.num_payloads = 1;
- x4->pic.extra_sei.payloads[0].payload_type = 4;
+ x4->pic.extra_sei.payloads[num_payloads].payload_size = sei_size;
+ x4->pic.extra_sei.payloads[num_payloads].payload = sei_data;
+ x4->pic.extra_sei.payloads[num_payloads].payload_type = 4;
+ x4->pic.extra_sei.num_payloads++;
+ num_payloads++;
+ }
+ }
+ }
+
+ /* Active Format Description */
+ if (x4->afd) {
+ void *sei_data;
+ size_t sei_size;
+
+ ret = ff_alloc_afd_sei(frame, 0, &sei_data, &sei_size);
+ if (ret < 0) {
+ av_log(ctx, AV_LOG_ERROR, "Not enough memory for AFD, skipping\n");
+ } else if (sei_data) {
+ x4->pic.extra_sei.payloads = av_realloc(x4->pic.extra_sei.payloads,
+ sizeof(x4->pic.extra_sei.payloads[0]) * (num_payloads + 1));
+ if (x4->pic.extra_sei.payloads == NULL) {
+ av_log(ctx, AV_LOG_ERROR, "Not enough memory for AFD, skipping\n");
+ av_free(sei_data);
+ } else {
+ x4->pic.extra_sei.sei_free = av_free;
+
+ x4->pic.extra_sei.payloads[num_payloads].payload_size = sei_size;
+ x4->pic.extra_sei.payloads[num_payloads].payload = sei_data;
+ x4->pic.extra_sei.payloads[num_payloads].payload_type = 4;
+ x4->pic.extra_sei.num_payloads++;
+ num_payloads++;
}
}
}
@@ -892,6 +921,7 @@ static const AVOption options[] = {
{"passlogfile", "Filename for 2 pass stats", OFFSET(stats), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, VE},
{"wpredp", "Weighted prediction for P-frames", OFFSET(wpredp), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, VE},
{"a53cc", "Use A53 Closed Captions (if available)", OFFSET(a53_cc), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, VE},
+ {"afd", "Use Active Format Description (AFD) (if available)",OFFSET(afd), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, VE},
{"x264opts", "x264 options", OFFSET(x264opts), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, VE},
{ "crf", "Select the quality for constant quality mode", OFFSET(crf), AV_OPT_TYPE_FLOAT, {.dbl = -1 }, -1, FLT_MAX, VE },
{ "crf_max", "In CRF mode, prevents VBV from lowering quality beyond this point.",OFFSET(crf_max), AV_OPT_TYPE_FLOAT, {.dbl = -1 }, -1, FLT_MAX, VE },
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index e50de6e..550b030 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -2396,6 +2396,42 @@ int ff_alloc_a53_sei(const AVFrame *frame, size_t prefix_len,
return 0;
}
+/* Defined in SCTE 128-1 2013 Sec 8.1 */
+int ff_alloc_afd_sei(const AVFrame *frame, size_t prefix_len,
+ void **data, size_t *sei_size)
+{
+ AVFrameSideData *side_data = NULL;
+ uint8_t *sei_data;
+
+ if (frame)
+ side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_AFD);
+
+ if (!side_data) {
+ *data = NULL;
+ return 0;
+ }
+
+ *sei_size = 9;
+ *data = av_mallocz(*sei_size + prefix_len);
+ if (!*data)
+ return AVERROR(ENOMEM);
+ sei_data = (uint8_t*)*data + prefix_len;
+
+ /* country code (SCTE 128-1 Sec 8.1.1) */
+ sei_data[0] = 181;
+ sei_data[1] = 0;
+ sei_data[2] = 49;
+
+ /* country code (SCTE 128-1 Sec 8.1.2) */
+ AV_WL32(sei_data + 3, MKTAG('D', 'T', 'G', '1'));
+
+ /* country code (SCTE 128-1 Sec 8.2.5) */
+ sei_data[7] = 0x41;
+ sei_data[8] = 0xf0 | side_data->data[0];
+
+ return 0;
+}
+
int64_t ff_guess_coded_bitrate(AVCodecContext *avctx)
{
AVRational framerate = avctx->framerate;
--
1.8.3.1
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