[FFmpeg-devel] MAX_THREADS for ffmpeg-mt mp4

fbarchard fbarchard
Thu Sep 24 18:29:43 CEST 2009

On Thu, Sep 24, 2009 at 3:49 AM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Wed, Sep 23, 2009 at 12:41:05PM -0700, Frank Barchard wrote:
>> Threads vs Time/Frame (ms)
>> 8 ? ? 2.93
>> 16 ? 1.70
> well, if that helps that much then ok

It does for ffmpeg-mt anyway.  For normal ffmpeg, it wont help unless
you create content with 16 slices.
ffmpeg-mt uses the same thread context arrays.
This is for 1080p content, and its decoding in 2.93 ms (341 fps) with
8 cores.... plenty fast enough.
quicktime creates 8 slices for 1080p.

It also avoids the crash for now, because it makes sense to initialize
a thread per core on a multicore machine, and 16 is state of the art.
Longer term it would be good to remove the limitation.

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