[FFmpeg-devel] [PATCH] libx264: copy A53 closed captions from source

[Michael Niedermayer]

On Sat, Sep 26, 2015 at 07:41:32AM -0400, DeHackEd wrote:
> Assumes 'GA94' format (ATSC standard)
> 
> Signed-off-by: DHE <git at dehacked.net>
> ---
>  doc/encoders.texi    |  5 +++++
>  libavcodec/libx264.c | 37 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 42 insertions(+)
> 
> diff --git a/doc/encoders.texi b/doc/encoders.texi
> index 3550bcc..aabbda0 100644
> --- a/doc/encoders.texi
> +++ b/doc/encoders.texi
> @@ -2069,6 +2069,11 @@ For example to specify libx264 encoding options with @command{ffmpeg}:
>  ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
>  @end example
>  
> + at item a53cc @var{boolean}
> +Import closed captions (which must be ATSC compatible format) into output.
> +Only the mpeg2 and h264 decoders provide these. Default is 0 (off).
> +
> +
>  @item x264-params (N.A.)
>  Override the x264 configuration using a :-separated list of key=value
>  parameters.
> diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
> index 58fcfb0..8540ff9 100644
> --- a/libavcodec/libx264.c
> +++ b/libavcodec/libx264.c
> @@ -83,6 +83,7 @@ typedef struct X264Context {
>      int avcintra_class;
>      int motion_est;
>      int forced_idr;
> +    int a53_cc;
>      char *x264_params;
>  } X264Context;
>  
> @@ -256,6 +257,7 @@ static int X264_frame(AVCodecContext *ctx, AVPacket *pkt, const AVFrame *frame,
>      int nnal, i, ret;
>      x264_picture_t pic_out = {0};
>      int pict_type;
> +    AVFrameSideData *side_data;
>  
>      x264_picture_init( &x4->pic );
>      x4->pic.img.i_csp   = x4->params.i_csp;
> @@ -278,6 +280,40 @@ static int X264_frame(AVCodecContext *ctx, AVPacket *pkt, const AVFrame *frame,
>                                              X264_TYPE_AUTO;
>  
>          reconfig_encoder(ctx, frame);
> +
> +        if (x4->a53_cc) {
> +            side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC);
> +            if (side_data) {
> +                x4->pic.extra_sei.num_payloads = 1;
> +                x4->pic.extra_sei.payloads = av_mallocz(sizeof(x4->pic.extra_sei.payloads[0]));

missing malloc failure check


> +                x4->pic.extra_sei.sei_free = av_free;
> +
> +                x4->pic.extra_sei.payloads[0].payload_size = side_data->size + 11;
> +                x4->pic.extra_sei.payloads[0].payload = av_mallocz(x4->pic.extra_sei.payloads[0].payload_size);

missing malloc failure check


> +                x4->pic.extra_sei.payloads[0].payload_type = 4;
> +                memcpy(x4->pic.extra_sei.payloads[0].payload + 10, side_data->data, side_data->size);
> +                x4->pic.extra_sei.payloads[0].payload[0] = 181;
> +                x4->pic.extra_sei.payloads[0].payload[1] = 0;
> +                x4->pic.extra_sei.payloads[0].payload[2] = 49;
> +
> +                /**
> +                 * 'GA94' is standard in North America for ATSC, but hard coding
> +                 * this style may not be the right thing to do -- other formats
> +                 * do exist. This information is not available in the side_data
> +                 * so we are going with this right now.
> +                 */
> +                x4->pic.extra_sei.payloads[0].payload[3] = 'G';
> +                x4->pic.extra_sei.payloads[0].payload[4] = 'A';
> +                x4->pic.extra_sei.payloads[0].payload[5] = '9';
> +                x4->pic.extra_sei.payloads[0].payload[6] = '4';
> +                x4->pic.extra_sei.payloads[0].payload[7] = 3;
> +                x4->pic.extra_sei.payloads[0].payload[8] =
> +                    ((side_data->size/3) & 0x1f) | 0x40;
> +                x4->pic.extra_sei.payloads[0].payload[9] = 0;
> +                x4->pic.extra_sei.payloads[0].payload[side_data->size+10] = 255;
> +            }
> +        }
> +
>      }
>      do {
>          if (x264_encoder_encode(x4->enc, &nal, &nnal, frame? &x4->pic: NULL, &pic_out) < 0)
> @@ -821,6 +857,7 @@ static const AVOption options[] = {
>      {"level", "Specify level (as defined by Annex A)", OFFSET(level), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, VE},
>      {"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_INT,    {.i64 = 0}, 0, 1, VE},

AV_OPT_TYPE_BOOL

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

If you think the mosad wants you dead since a long time then you are either
wrong or dead since a long time.
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