[Ffmpeg-devel] [PATCH] DVR-MS probe audio format - was DVR-MS bug (MP2 decoding)

Justin Ruggles justinruggles
Fri Mar 16 07:16:30 CET 2007


Michael Niedermayer wrote:
> Hi
> 
> On Thu, Mar 15, 2007 at 09:56:52PM -0500, John Donaghy wrote:
> 
>>>trying the same check everywhere in a buffer, lets say its 2kb large will
>>>cause 1 out of 50 random files to be misdetected as ac3, thats not going
>>>to
>>>work ...
>>
>>
>>OK, I see your point. I can think of three approaches then:
>>
>>1) Improve the ac3_probe function which I think is probably the best way -
>>but unfortunately I've no idea how to do it.
> 
> 
> search for several valid frames in a row, the AVParser for AC3 can find the
> size of each, there should be a matching header immedeatly after that AFAIK
> see mp3_read_probe()

If nobody else beats me to it, I'll try this tomorrow.  I was going to
do some tweaking to ac3_probe anyway because I still have some AC-3
files which are not auto-detected.  I like the idea of making it work
like mp3_read_probe much better though.

-Justin





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