[FFmpeg-devel] [PATCH 1/2] webmdashenc: Require the 'adaptation_sets' option to be ste

[James Almer]

On 4/20/2017 9:14 AM, Derek Buitenhuis wrote:
> This seems to be non-optional, and if the muxer is run without it,
> strlen() is run on NULL, causing a segfault.
> 
> Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
> ---
>   libavformat/webmdashenc.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/libavformat/webmdashenc.c b/libavformat/webmdashenc.c
> index 602726c..2f5c31e 100644
> --- a/libavformat/webmdashenc.c
> +++ b/libavformat/webmdashenc.c
> @@ -433,6 +433,10 @@ static int parse_adaptation_sets(AVFormatContext *s)
>       char *p = w->adaptation_sets;
>       char *q;
>       enum { new_set, parsed_id, parsing_streams } state;
> +    if (!(w->adaptation_sets)) {
> +        av_log(s, AV_LOG_ERROR, "The 'adaptation_sets' option must be set.\n");
> +        return AVERROR_INVALIDDATA;

EINVAL IMO, since it's an user option.

A non-optional user setting that has no default is in any case weird.
Usually, the user expects a ffmpeg -i INPUT OUTPUT to work even if the 
result is of low quality.

> +    }
>       // syntax id=0,streams=0,1,2 id=1,streams=3,4 and so on
>       state = new_set;
>       while (p < w->adaptation_sets + strlen(w->adaptation_sets)) {
>