[FFmpeg-devel] [RFC] per format probe buffer sizes

[Benjamin Larsson]

Hello, while trying to work out how to get dts in wav detection to work 
properly I found out that there was a problem with the size of the probe 
buffer. Right now it starts from 2048 and increases the size until a 
format is detected. And when the wav format is used with a command line 
like "ffmpeg -i dts.wav test.wav" the format is detected in the first 
try. And reliable dts detection in a test file I had will need more. It 
found the first SYNC word after 3072 bytes. So for this to work we need 
to increase this buffer, one could either do it globally or just for the 
needed format. Before the actual probing that finds the wav format 
(utils.c:447) there is another probe (utils:433). My suggestion is that 
we add a flag and size parameter to the format struct and let this probe 
call fetch this value so it can be used later in the real 
probe(utils.c:447). This way we can add per format probe sizes which 
might useful.

So what do you think of this idea ?


MvH
Benjamin Larsson