[FFmpeg-devel] [PATCH] avformat/demux: Fix segfault due to avcodec_open2 failure (v2)

[Pavel Koshevoy]

ping

On Mon, Jun 9, 2025 at 9:45 PM Pavel Koshevoy <pkoshevoy at gmail.com> wrote:

> Fixes 'ffprobe 1_poc.mp4' segfault introduced with
> commit 0021484d05f9b0f032fa319399de6e24eea0c04f
>
> codec_close should not assume that the codec_id did not change.
> ---
>  libavformat/demux.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/libavformat/demux.c b/libavformat/demux.c
> index ecd4f40da9..3749ab67a3 100644
> --- a/libavformat/demux.c
> +++ b/libavformat/demux.c
> @@ -1292,9 +1292,15 @@ static int codec_close(FFStream *sti)
>  {
>      AVCodecContext *avctx_new = NULL;
>      AVCodecParameters *par_tmp = NULL;
> +    const AVCodec *new_codec = NULL;
>      int ret;
>
> -    avctx_new = avcodec_alloc_context3(sti->avctx->codec);
> +    new_codec =
> +      (sti->avctx->codec_id != sti->pub.codecpar->codec_id) ?
> +      avcodec_find_decoder(sti->pub.codecpar->codec_id) :
> +      sti->avctx->codec;
> +
> +    avctx_new = avcodec_alloc_context3(new_codec);
>      if (!avctx_new) {
>          ret = AVERROR(ENOMEM);
>          goto fail;
> --
> 2.43.0
>
>