[FFmpeg-devel] [PATCH 1/3] avcodec/avcodec: Add codec_tags array to AVCodec

[Carl Eugen Hoyos]

Am Mo., 30. Dez. 2019 um 01:19 Uhr schrieb James Almer <jamrial at gmail.com>:
>
> On 12/29/2019 8:38 PM, Michael Niedermayer wrote:
> > This allows the fuzzer to target meaningfull codec tags instead
> > of hunting the 4gb space, which it seems to have problems with.
> >
> > Suggested-by: James
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavcodec/avcodec.h | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> > index 119b32dc1f..b0c6a8f2e3 100644
> > --- a/libavcodec/avcodec.h
> > +++ b/libavcodec/avcodec.h
> > @@ -3634,6 +3634,12 @@ typedef struct AVCodec {
> >       * The user can only access this field via avcodec_get_hw_config().
> >       */
> >      const struct AVCodecHWConfigInternal **hw_configs;
> > +
> > +    /**
> > +     * List of supported codec_tags, terminated by CODEC_TAGS_END.
> > +     */
> > +    const uint32_t *codec_tags;
> > +#define CODEC_TAGS_END -1
>
> Why not zero? 0xFFFFFFFF could very well be a valid tag (even if
> unlikely), and we always terminate arrays with 0.

0 is a valid codec tag in avi.

Carl Eugen