[FFmpeg-devel] [PATCH 3/3] avcodec/avpacket: Don't write into non-writable buffer

[Andreas Rheinhardt]

Andreas Rheinhardt:
> The data of an AVPacket may be a part of the data of an AVBufferRef;
> Therefore av_grow_packet() doesn't reallocate if the available space in
> the actual buffer is sufficient for the enlargement. But given that it
> also zeroes the padding it also needs to make sure that the buffer is
> actually writable; this commit implements this.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavcodec/avpacket.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
> index 0d9ddeee07..a7b0b6bd5d 100644
> --- a/libavcodec/avpacket.c
> +++ b/libavcodec/avpacket.c
> @@ -127,7 +127,8 @@ int av_grow_packet(AVPacket *pkt, int grow_by)
>                  return AVERROR(ENOMEM);
>          }
>  
> -        if (new_size + data_offset > pkt->buf->size) {
> +        if (new_size + data_offset > pkt->buf->size ||
> +            !av_buffer_is_writable(pkt->buf)) {
>              int ret = av_buffer_realloc(&pkt->buf, new_size + data_offset);
>              if (ret < 0) {
>                  pkt->data = old_data;
> 
Will apply tomorrow if there are no objections.

- Andreas