[FFmpeg-devel] [PATCH] mpeg12enc: Use all Closed Captions side data

[Mathieu Duponchelle]

Anyone? :)

On 3/23/19 12:22 AM, Mathieu Duponchelle wrote:
> It is perfectly valid to have multiple CC Picture User Data
> for the same frame. Instead of using the first side_data
> potentially present with the A53_CC type, iterate over all
> side_data.
> ---
>  libavcodec/mpeg12enc.c | 56 +++++++++++++++++++++++-------------------
>  1 file changed, 31 insertions(+), 25 deletions(-)
>
> diff --git a/libavcodec/mpeg12enc.c b/libavcodec/mpeg12enc.c
> index 2bc5289d63..0162939399 100644
> --- a/libavcodec/mpeg12enc.c
> +++ b/libavcodec/mpeg12enc.c
> @@ -547,31 +547,37 @@ void ff_mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
>      }
>  
>      if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->a53_cc) {
> -        side_data = av_frame_get_side_data(s->current_picture_ptr->f,
> -            AV_FRAME_DATA_A53_CC);
> -        if (side_data) {
> -            if (side_data->size <= A53_MAX_CC_COUNT * 3 && side_data->size % 3 == 0) {
> -                int i = 0;
> -
> -                put_header (s, USER_START_CODE);
> -
> -                put_bits(&s->pb, 8, 'G');                   // user_identifier
> -                put_bits(&s->pb, 8, 'A');
> -                put_bits(&s->pb, 8, '9');
> -                put_bits(&s->pb, 8, '4');
> -                put_bits(&s->pb, 8, 3);                     // user_data_type_code
> -                put_bits(&s->pb, 8,
> -                    (side_data->size / 3 & A53_MAX_CC_COUNT) | 0x40); // flags, cc_count
> -                put_bits(&s->pb, 8, 0xff);                  // em_data
> -
> -                for (i = 0; i < side_data->size; i++)
> -                    put_bits(&s->pb, 8, side_data->data[i]);
> -
> -                put_bits(&s->pb, 8, 0xff);                  // marker_bits
> -            } else {
> -                av_log(s->avctx, AV_LOG_WARNING,
> -                    "Warning Closed Caption size (%d) can not exceed 93 bytes "
> -                    "and must be a multiple of 3\n", side_data->size);
> +        int i;
> +
> +        for (i = 0; i < s->current_picture_ptr->f->nb_side_data; i++) {
> +            side_data = s->current_picture_ptr->f->side_data[i];
> +            if (side_data->type != AV_FRAME_DATA_A53_CC)
> +              continue;
> +
> +            if (side_data) {
> +                if (side_data->size <= A53_MAX_CC_COUNT * 3 && side_data->size % 3 == 0) {
> +                    int i = 0;
> +
> +                    put_header (s, USER_START_CODE);
> +
> +                    put_bits(&s->pb, 8, 'G');                   // user_identifier
> +                    put_bits(&s->pb, 8, 'A');
> +                    put_bits(&s->pb, 8, '9');
> +                    put_bits(&s->pb, 8, '4');
> +                    put_bits(&s->pb, 8, 3);                     // user_data_type_code
> +                    put_bits(&s->pb, 8,
> +                        (side_data->size / 3 & A53_MAX_CC_COUNT) | 0x40); // flags, cc_count
> +                    put_bits(&s->pb, 8, 0xff);                  // em_data
> +
> +                    for (i = 0; i < side_data->size; i++)
> +                        put_bits(&s->pb, 8, side_data->data[i]);
> +
> +                    put_bits(&s->pb, 8, 0xff);                  // marker_bits
> +                } else {
> +                    av_log(s->avctx, AV_LOG_WARNING,
> +                        "Warning Closed Caption size (%d) can not exceed 93 bytes "
> +                        "and must be a multiple of 3\n", side_data->size);
> +                }
>              }
>          }
>      }