[Ffmpeg-devel] [BUG] "too many threads" with brd_scale >= 5

Loren Merritt lorenm
Sun Jan 29 11:51:33 CET 2006

On Sat, 28 Jan 2006, Corey Hickey wrote:

> Loren Merritt wrote:
>> On Thu, 26 Jan 2006, Corey Hickey wrote:
>>> I've been testing vb_stategy=2 and brd_scale, and I ran into a bug.
>>> Whenever brd_scale is set to 5 or higher, libavcodec reports:
>>> [mpeg4 @ 0xb93650]too many threads
>>> ...and mencoder segfaults.
>> fixed. (though it'll still fail if you really are using too many threads
>> for the downscaled encode.)
> Thank you. ...I'm a little confused, though: I thought, from Michael's
> response, that the problem was due to the width being 22.5 (not an
> integer) rather than the height being 15 (less than 16). Did I draw the
> wrong conclusion, or were they separate issues?

Odd dimensions aren't the problem here. It's true that in general YV12 
they're ugly / not well defined. But in the case of brd_scale, the result 
is padded up to a multiple of 16, not just even.
OTOH, scaling a whole frame down to 2 macroblocks is bound to be 
inaccurate no matter what you do with it.

--Loren Merritt

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