[FFmpeg-devel] [PATCH V1 3/4] lavf/mpegts: support DOVIVideo Stream Descriptor

[Jan Ekström]

On Mon, Mar 30, 2020 at 11:53 AM Jun Zhao <mypopydev at gmail.com> wrote:
>
> From: vacingfang <vacingfang at tencent.com>
>
> support DOVIVideo Stream Descriptor from Dolby Vision Streams
> Within the MPEG-2 Transport Stream Format V1.2
>
> From the spec: https://www.dolby.com/us/en/technologies/\
> dolby-vision/dolby-vision-bitstreams-in-mpeg-2-transport-\
> stream-multiplex-v1.2.pdf.
>
> export the Dolby Vision profile/level with metadata.
>
> Signed-off-by: vacingfang <vacingfang at tencent.com>
> ---
>  libavformat/mpegts.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> index 7f56bac..e035605 100644
> --- a/libavformat/mpegts.c
> +++ b/libavformat/mpegts.c
> @@ -2135,6 +2135,27 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
>              st->request_probe        = 0;
>          }
>          break;
> +    case 0xb0: /* dolby vision video stream descriptor*/
> +        {
> +            int version_major, version_minor, profile, level;
> +            char str_buf[32];
> +            if (desc_end - *pp < 4) // 8 + 8 + 7 + 6 + 1 + 1 + 1
> +                return AVERROR_INVALIDDATA;
> +
> +            version_major = get8(pp, desc_end);
> +            version_minor = get8(pp, desc_end);
> +            profile = get16(pp, desc_end);
> +            level   = (profile >> 3) & 0x3f;    // 6 bits
> +            profile = (profile >> 9) & 0x7f;    // 7 bits
> +            av_log(fc, AV_LOG_DEBUG, "dolby vision stream, version: %d.%d, profile: %d, level: %d\n",
> +                    version_major, version_minor, profile, level);
> +
> +            snprintf(str_buf, sizeof(str_buf), "%d", profile);
> +            av_dict_set(&st->metadata, "dovi_profile", str_buf, 0);

Ditto for the side data point. Not only would it enable to not have
the whole string<->int conversions out of the way, but also you would
gain the information if the stream has RPUs, or if it's EL/BL etc.

Best regards,
Jan