[FFmpeg-devel] udp.c comments/thoughts

Roger Pack rogerdpack2 at gmail.com
Mon Jan 6 20:37:50 CET 2014


On 1/6/14, Roger Pack <rogerdpack2 at gmail.com> wrote:
> Hello.  I noticed that in udp.c sometimes (with pthread cancel
> enabled) it says "Part of datagram lost due to insufficient buffer
> size" (I think what it meant to say is due to insufficient read
> request size?)
> Also it's quite confusing that fifo_size is in multiples of 188.
> Unless you an MPEG engineer, nobody anticipates this.  I might suggest
> adding another setting of "fifo_size_bytes" or something so that
> people realize there's a difference.
>
> Also I've noticed that the default RECV buffer size is 64K by default
> for udp packets.  I might suggest increasing this substantially, as
> this is far too little for many streams, and the OS can typically
> handle far higher (1M-10MB at least).

Also as a follow-up, perhaps overrun_nonfatal should be default, since
it's basically just dropping packets, which UDP by default can do and
does anyway (so currently it behaves slightly differently with pthread
cancel enabled than otherwise, which is somewhat confusing).

Also is av_fifo_peek stable?  Might it not accidentally return you a
memory address that allows you to read past the end of the circular
buffer, if you read too far?

-roger-


More information about the ffmpeg-devel mailing list