[FFmpeg-devel] [PATCH 1/2] avformat/demux: use io_close2 when closing avfromat

[Andreas Rheinhardt]

Kacper Michajłow:
> It's not valid to call avio_close() on context that has not been open
> with avio_open().
> 
> This fixes use of custom IO. (io_open / io_close2 callbacks)
> 
> Note that by default io_close2 is set to io_close2_default() which calls
> avio_close(), so default case will work the same as before.
> 
> Signed-off-by: Kacper Michajłow <kasper93 at gmail.com>
> ---
>  libavformat/demux.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/libavformat/demux.c b/libavformat/demux.c
> index 2795863567..ecd4f40da9 100644
> --- a/libavformat/demux.c
> +++ b/libavformat/demux.c
> @@ -383,11 +383,10 @@ void avformat_close_input(AVFormatContext **ps)
>          if (ffifmt(s->iformat)->read_close)
>              ffifmt(s->iformat)->read_close(s);
>  
> +    ff_format_io_close(s, &pb);
>      avformat_free_context(s);
>  
>      *ps = NULL;
> -
> -    avio_close(pb);
>  }
>  
>  static void force_codec_ids(AVFormatContext *s, AVStream *st)

avformat_open_input() sets AVFMT_FLAG_CUSTOM_IO when using custom IO and
avformat_close_input() checks for this and does not free the
AVFormatContext's AVIOContext in this case (but does avio_close(NULL) in
this case).
Your patch furthermore presumes that the custom IO context is compatible
with io_close2, which need not be true at all (one can use custom IO
without ever touching io_open/io_close2 pointers; I expect users that
use custom IO, but not formats that open new AVIOContexts to do so).

- Andreas