[FFmpeg-devel] [PATCH] lavc/libaomenc: Add a maximum constraint of 64 encoder threads.

[Carl Eugen Hoyos]

2018-11-28 1:54 GMT+01:00, mypopy at gmail.com <mypopy at gmail.com>:
> On Wed, Nov 28, 2018 at 4:47 AM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>
>> 2018-11-27 10:18 GMT+01:00, Jun Zhao <mypopydev at gmail.com>:
>> > fixed the error in Intel(R) Xeon(R) Gold 6152 CPU like:
>> > [libaom-av1 @ 0x469f340] Failed to initialize encoder: Invalid parameter
>> > [libaom-av1 @ 0x469f340]   Additional information: g_threads out of
>> > range
>> > [..MAX_NUM_THREADS]
>> >
>> > Signed-off-by: Jun Zhao <mypopydev at gmail.com>
>> > ---
>> >  libavcodec/libaomenc.c |    3 ++-
>> >  1 files changed, 2 insertions(+), 1 deletions(-)
>> >
>> > diff --git a/libavcodec/libaomenc.c b/libavcodec/libaomenc.c
>> > index cb31c55..ccb0cf9 100644
>> > --- a/libavcodec/libaomenc.c
>> > +++ b/libavcodec/libaomenc.c
>> > @@ -504,7 +504,8 @@ static av_cold int aom_init(AVCodecContext *avctx,
>> >      enccfg.g_h            = avctx->height;
>> >      enccfg.g_timebase.num = avctx->time_base.num;
>> >      enccfg.g_timebase.den = avctx->time_base.den;
>> > -    enccfg.g_threads      = avctx->thread_count ? avctx->thread_count :
>> > av_cpu_count();
>> > +    enccfg.g_threads      =
>> > +     FFMIN(avctx->thread_count ? avctx->thread_count : av_cpu_count(),
>> 64);
>>
>> Is there a limitation in libaom's api that requires users to never set
>> g_threads >64 that we missed so far?
>> Or is there a bug in libaom that you would like to fix in FFmpeg?
>>
>> Please explain, Carl Eugen
>>
>> I  belive this is a libaom's limitation

Then why isn't the limitation fixed in libaom?
Or is it documented?

> and we missed the check in FFmpeg part,

In which way did we "miss" it, where is it defined that it is invalid
to pass large positive numbers to this option?

> libvpx have the same issue and the commit d6b1248fc
> try to fix the same issue.

Two wrong commits don't make a correct one;-)

Carl Eugen