[FFmpeg-devel] [PATCH] ffmpeg: Update muxer extradata after flushing encoders

[Paul B Mahol]

On 8/17/16, Michael Niedermayer <michael at niedermayer.cc> wrote:
> This is needed for encoders which store a final sample count or checksum in
> extradata
>
> alternatively every encoder as well as muxer can implement
> AV_PKT_DATA_NEW_EXTRADATA support
> to update the extradata at the end.
>
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  ffmpeg.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/ffmpeg.c b/ffmpeg.c
> index bae515d..9d972d0 100644
> --- a/ffmpeg.c
> +++ b/ffmpeg.c
> @@ -1772,6 +1772,23 @@ static void flush_encoders(void)
>              if (stop_encoding)
>                  break;
>          }
> +        if (ost->enc_ctx->extradata_size) {
> +            void *ptr  = av_mallocz(ost->enc_ctx->extradata_size +
> AV_INPUT_BUFFER_PADDING_SIZE);
> +            void *ptr2 = av_mallocz(ost->enc_ctx->extradata_size +
> AV_INPUT_BUFFER_PADDING_SIZE);
> +            if (ptr && ptr2) {
> +                av_free(ost->st->codec->extradata);
> +                av_free(ost->st->codecpar->extradata);
> +                ost->st->codec->extradata    = ptr;
> +                ost->st->codecpar->extradata = ptr2;
> +                memcpy(ost->st->codec->extradata   ,
> ost->enc_ctx->extradata, ost->enc_ctx->extradata_size);
> +                memcpy(ost->st->codecpar->extradata,
> ost->enc_ctx->extradata, ost->enc_ctx->extradata_size);
> +                ost->st->codec   ->extradata_size =
> ost->enc_ctx->extradata_size;
> +                ost->st->codecpar->extradata_size =
> ost->enc_ctx->extradata_size;
> +            } else {
> +                av_free(ptr);
> +                av_free(ptr2);
> +            }
> +        }
>      }
>  }

I'm against this patch. Use API already available, don't add hacks on
top of hacks.