[FFmpeg-devel] [PATCH] Yield on AVERROR(EAGAIN).

[Michael Niedermayer]

On Fri, Mar 05, 2010 at 11:58:06AM +0100, Luca Abeni wrote:
> Michael Niedermayer wrote:
>> On Fri, Mar 05, 2010 at 11:46:03AM +0100, Luca Abeni wrote:
>>> Michael Niedermayer wrote:
>>>> On Fri, Mar 05, 2010 at 08:23:07AM +0100, Reimar D?ffinger wrote:
>>>>> On Fri, Mar 05, 2010 at 03:48:52AM +0100, Michael Niedermayer wrote:
>>>>>> What you suggest needs a select() like system that works with files,
>>>>>> network protocols, audio and video grab APIs as well as screen capture
>>>>>> APIs needs to work on all platforms
>>>>>> that support yield()/sleep() of some kind and needs to work with
>>>>>> any set of supported protocols on that platform and needs protocols
>>>>>> to pass thier file/object handle(s) through demuxers to the user app 
>>>>>> so
>>>>>> it can do that select() call
>>>>> Actually... No, it would be enough for the devices to just do a select 
>>>>> themselves.
>>>>> After all, our networking code does not just do a non-blocking read and 
>>>>> then
>>>>> just returns EAGAIN if it didn't get anything.
>>>> this should be fixed of course
>>> The networking code does not support the AVFMT_FLAG_NONBLOCK flag.
>>> I tried adding support for it in the UDP and RTP protocols some
>>> time ago (this is actually quite trivial), but then I had issues with
>>> some other code in libavformat (av_find_stream_info(), if I remember
>>> well - but I might be wrong) that is not prepared to it...
>>> Then, I ran out of time :)
>> av_find_stream_info() will block from the users point of view, unless the
>> user stops it through url_interrupt_cb()
>> is there some other problem with it?
>
> I might be wrong (maybe I remember the wrong problem :), but I seem to
> remember that it consumed 100% of the CPU if the network returned EAGAIN
> because of AVFMT_FLAG_NONBLOCK.

question is, even if so, why would this hold adding nonblock support to
tcp/udp up?
Its not as if av_find_stream_info() didnt consume 100% now in that case

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I know you won't believe me, but the highest form of Human Excellence is
to question oneself and others. -- Socrates
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