[FFmpeg-devel] [RFC] unix socket protocol and our proto situation

[Luca Barbato]

On 12/14/2010 07:29 PM, JULIAN GARDNER wrote:
> 
> 
> --- On Tue, 14/12/10, aviad rozenhek <aviadr1 at gmail.com> wrote:
> 
>> From: aviad rozenhek <aviadr1 at gmail.com>
>> Subject: Re: [FFmpeg-devel] [RFC] unix socket protocol and our proto situation
>> To: "FFmpeg development discussions and patches" <ffmpeg-devel at mplayerhq.hu>
>> Date: Tuesday, 14 December, 2010, 16:43
>> On Sun, Sep 19, 2010 at 15:40, Luca
>> Barbato <lu_zero at gentoo.org>
>> wrote:
>>
>>> On 09/18/2010 11:39 AM, Howard Chu wrote:
>>>> Lowering the send buffer size sounds like a
>> reasonable solution for
>>>> local sockets. That really should be all that's
>> necessary to deal with
>>>> unix domain sockets.
>>>
>>> Changing the defaults to be the same as udp fixed the
>> issue indeed.
>>> I exposed both buffer_size and pkt_size, now.
>>>
>>> Comments and test welcome as usual =)
>>>
>>> lu
>>>
>>>
>> I still have a lot of loss on windows when streaming from
>> ffmpeg to ffplay.
>> I found out that all this problems go away when the receive
>> buffer is
>> bigger.
>> I don't know how big the buffer can be set on other
>> platforms, but on
>> windows, a buffer size of 0x3FFFF [262143 bytes] works like
>> a charm without
>> any losses.
>>
>> would it be possible to increase the default receive buffer
>> size for udp to
>> 0x3FFFF, at least on windows systems?
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at mplayerhq.hu
>> https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
>>
> 
> I am having the same problem, i receive a multicast stream from a hardware encoder
> in MPEG2 and using ffmpeg i then encode the stream in x264.
> 
> Now my problem was/is that ffplay works fine, no errors, but ffmpeg gives lots of errors.

> I added a circular buffer into the udp.c file which allocates a 2Mb buffer and this is
> controlled by a seperate task.

May we see that code? for now a too long time I'm drafting ideas to
provide ffmpeg with a poll+enqueue infrastructure for network protocols...

> I have validated that the buffer is working and sometime i see a max level of 800k
> but it is normally around 450k.
> 
> But i am still getting decode errors on the input, so if i am receiving the data and not
> losing any why do i get decode errors?

udp isn't reliable at all. Our implementation of network protocols
relies too much on the OS buffers and exacerbates the situation.

lu

-- 

Luca Barbato
Gentoo/linux
http://dev.gentoo.org/~lu_zero