[FFmpeg-devel] [PATCH] tools/target_dec_fuzzer: add support to fuzz bitstream filters

[James Almer]

On 11/27/2019 5:19 PM, Michael Niedermayer wrote:
> On Wed, Nov 27, 2019 at 01:17:34PM -0300, James Almer wrote:
>> On 11/27/2019 1:09 PM, Michael Niedermayer wrote:
>>> On Wed, Nov 27, 2019 at 11:41:09AM -0300, James Almer wrote:
>>>> On 9/3/2019 10:49 AM, James Almer wrote:
>>>>> On 8/30/2019 1:39 PM, James Almer wrote:
>>>>>> Signed-off-by: James Almer <jamrial at gmail.com>
>>>>>> ---
>>>
>>>>>> Untested.
>>>
>>> i can test if it applies
>>>
>>>
>>>>>> I'm also not sure how to add the FFMPEG_BSF define to tools/Makefile,
>>>>>> and have it coexist with FFMPEG_DECODER. Assuming it's needed.
>>>
>>> maybe something like
>>> tools/target_bsf_%_fuzzer.o: tools/target_dec_fuzzer.c
>>>     $(COMPILE_C) -DFFMPEG_BSF=$*
>>>     
>>> but maybe i misunderdtand ...
>>
>> But then what's the decoder used for it? Where is FFMPEG_CODEC defined
>> in the absence of FFMPEG_DECODER?
> 
> do we need a decoder ?
> the code could take the codec_id from the bsf codec_ids

Not using a decoder would require writing a different tool just for
bsfs, because the way it's implemented in this patch, it processes a
packet with a bsf before passing it to a decoder.

Also, some bsfs support more than one codec, so we still need to pass
two arguments: a bfs, and a codec. We can't just pick the first codec_id
reported by the bsf.
So i again wonder how exactly does the glue work here, and how can we
pass two values to any given fuzzer tool in tools/Makefile.