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

[James Almer]

On 12/29/2019 9:32 PM, Carl Eugen Hoyos wrote:
> 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

Alright, then -1 is fine. It can always be changed to something else if
needed.