[FFmpeg-devel] [PATCH]Improved message for bitrate tolerance too small

Michel Bardiaux mbardiaux
Fri Feb 1 16:02:42 CET 2008

Michael Niedermayer wrote:
> On Fri, Feb 01, 2008 at 11:01:17AM +0100, Michel Bardiaux wrote:
>> Michael Niedermayer wrote:
>>> On Thu, Jan 31, 2008 at 04:26:57PM +0100, Michel Bardiaux wrote:
>>>>> Note that if someone could explain *why* tol must be > bitrate/fps...
>>>>> Cheers,
>>>> Ping?
>>> IIRC the test is a heuristic, thus the minimum the patch would print isnt much
>>> better than 2* of that or 0.5* of it. Values that small cause problems.
>>> So i dont want to make it easy to select the smallest value, because that
>>> is almost certainly too small.
>> Does that mean you forbid the patch? Because as things stand, we have an 
>> error condition that can be understood only by looking in the code, talk 
>> about obfuscated behaviour...
> No, your patch obfuscates the code, making the user belive that there would
> be a minimum which would be ok and below which was not.

Uh? Basic users are not supposed to see the code. My patch might 
obfuscate the doc, but not the code. On the contrary, it makes explicit 
what the code does. That's scruitability, not obfuscation.

Non-expert users have no alternative to trying higher and higher 
tolerance values until the error message goes away. Which is exactly 
equivalent to using the value suggested by my patch. Expert users will 
never see the message.

>> Besides I have another issues with the current code: It is 
>> mathematically very dubious since it compares a bitrate*timebase with a 
>> bitrate!
> This is not true, as the tolerance is not in bit/sec.

Not according to ffmpeg-doc.texi ca. line 388.

Michel Bardiaux
R&D Director
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