[FFmpeg-devel] [PATCH] Fix threaded mpeg*video encoding

[Måns Rullgård]

Michael Niedermayer <michaelni at gmx.at> writes:

> On Thu, Jul 01, 2010 at 12:26:25PM +0100, M?ns Rullg?rd wrote:
>> Michael Niedermayer <michaelni at gmx.at> writes:
>> 
>> > On Thu, Jul 01, 2010 at 04:01:24AM +0100, M?ns Rullg?rd wrote:
>> >> Michael Niedermayer <michaelni at gmx.at> writes:
>> >> 
>> >> > On Wed, Jun 30, 2010 at 03:49:34PM +0100, Mans Rullgard wrote:
>> >> >> This allocates per-thread copies of some buffers which are updated
>> >> >> concurrently from the encoding threads.
>> >> >
>> >> > is this fixing a bug?
>> >> > if so please elaborate what and where. My guess would be toward
>> >> > ac_val being the one causing the issues.
>> >> 
>> >> The threaded regression tests are failing randomly with pthreads enabled:
>> >> 
>> >> http://fate.multimedia.cx/index.php?test_result=66882641
>> >> http://fate.multimedia.cx/index.php?test_result=66852547
>> >> http://fate.multimedia.cx/index.php?test_result=66876769
>> >> 
>> >> Those are just a few examples.  Valgrind complained about most of
>> >> those buffers, particularly ac_val and dc_val, and I add a couple
>> >> since they were written close to the places valgrind identified.  Race
>> >> detection is never exact.
>> >
>> > could you try to just change ac_val and see if this makes the issue
>> > go away?
>> > for ac_val i found ff_mpeg4_clean_buffers() as possible reason for the
>> > race, for the others i am not aware of code that can lead to a race
>> 
>> So OK to commit just the ac_val parts and see what happens?
>
> ok

Done.  Let's keep an eye on FATE.

-- 
M?ns Rullg?rd
mans at mansr.com