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

[aviad rozenhek]

On Tue, Dec 14, 2010 at 20:29, JULIAN GARDNER <joolzg at btinternet.com> 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.
>
> 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?
>
> Anybody hekp and would a patch file be os use to anybody
>
> joolzg
>
>
>
The 64k socket buffer asked for by ffmpeg is too small, especially when
using higher bitrate streams like 10mbps and up.
using 250k is much more reasonable IMHO and works much better.
using a tight loop to read from the socket improves on the current
situation, but does not fix it.
increasing the buffer size solves it completely, and requires no code.