[FFmpeg-devel] [PATCH 2/3] avformat/av1: Add a parameter to av1c to omit seq header

[James Almer]

On 2/17/2022 2:51 AM, Vignesh Venkatasubramanian wrote:
> Add a parameter to omit seq header when generating the av1C atom.
> 
> For now, this does not change any behavior. This will be used by a
> follow-up patch to add AVIF support.
> 
> Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
> ---
>   libavformat/av1.c         | 7 +++++--
>   libavformat/av1.h         | 4 +++-
>   libavformat/matroskaenc.c | 4 ++--
>   libavformat/movenc.c      | 2 +-
>   4 files changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/libavformat/av1.c b/libavformat/av1.c
> index 1fcfac2356..95ca7cc47f 100644
> --- a/libavformat/av1.c
> +++ b/libavformat/av1.c
> @@ -361,7 +361,8 @@ int ff_av1_parse_seq_header(AV1SequenceParameters *seq, const uint8_t *buf, int
>       return AVERROR_INVALIDDATA;
>   }
>   
> -int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size)
> +int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size,
> +                       int write_seq_header)
>   {
>       AVIOContext *meta_pb;
>       AV1SequenceParameters seq_params;
> @@ -451,7 +452,9 @@ int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size)
>       flush_put_bits(&pbc);
>   
>       avio_write(pb, header, sizeof(header));
> -    avio_write(pb, seq, seq_size);
> +    if (write_seq_header) {
> +        avio_write(pb, seq, seq_size);
> +    }
>   
>       meta_size = avio_get_dyn_buf(meta_pb, &meta);
>       if (meta_size)
> diff --git a/libavformat/av1.h b/libavformat/av1.h
> index f57dabe986..a393fbb78f 100644
> --- a/libavformat/av1.h
> +++ b/libavformat/av1.h
> @@ -96,9 +96,11 @@ int ff_av1_parse_seq_header(AV1SequenceParameters *seq, const uint8_t *buf, int
>    * @param pb pointer to the AVIOContext where the av1C box shall be written
>    * @param buf input data buffer
>    * @param size size in bytes of the input data buffer
> + * @param write_seq_header If 1, Sequence Header OBU will be written inside the
> + *           av1C box. Otherwise, Sequence Header OBU will be omitted.
>    *
>    * @return >= 0 in case of success, a negative AVERROR code in case of failure
>    */
> -int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size);
> +int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size, int write_seq_header);
>   
>   #endif /* AVFORMAT_AV1_H */
> diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
> index 38d9485288..5061961283 100644
> --- a/libavformat/matroskaenc.c
> +++ b/libavformat/matroskaenc.c
> @@ -1087,7 +1087,7 @@ static int mkv_write_native_codecprivate(AVFormatContext *s, AVIOContext *pb,
>       case AV_CODEC_ID_AV1:
>           if (par->extradata_size)
>               return ff_isom_write_av1c(dyn_cp, par->extradata,
> -                                      par->extradata_size);
> +                                      par->extradata_size, 1);
>           else
>               put_ebml_void(pb, 4 + 3);
>           break;
> @@ -2663,7 +2663,7 @@ static int mkv_check_new_extra_data(AVFormatContext *s, const AVPacket *pkt)
>               ret = avio_open_dyn_buf(&dyn_cp);
>               if (ret < 0)
>                   return ret;
> -            ff_isom_write_av1c(dyn_cp, side_data, side_data_size);
> +            ff_isom_write_av1c(dyn_cp, side_data, side_data_size, 1);
>               codecpriv_size = avio_get_dyn_buf(dyn_cp, &codecpriv);
>               if ((ret = dyn_cp->error) < 0 ||
>                   !codecpriv_size && (ret = AVERROR_INVALIDDATA)) {
> diff --git a/libavformat/movenc.c b/libavformat/movenc.c
> index 4c868919ae..1a746a67fd 100644
> --- a/libavformat/movenc.c
> +++ b/libavformat/movenc.c
> @@ -1303,7 +1303,7 @@ static int mov_write_av1c_tag(AVIOContext *pb, MOVTrack *track)
>   
>       avio_wb32(pb, 0);
>       ffio_wfourcc(pb, "av1C");
> -    ff_isom_write_av1c(pb, track->vos_data, track->vos_len);
> +    ff_isom_write_av1c(pb, track->vos_data, track->vos_len, 1);
>       return update_size(pb, pos);
>   }
>   

This patch no longer applies.