[FFmpeg-devel] [FFmpeg-cvslog] avformat/hls: add http_persistent option

[wm4]

On Tue, 26 Dec 2017 05:26:34 +0000
Aman Gupta <ffmpeg at tmm1.net> wrote:

> On Mon, Dec 25, 2017 at 7:55 PM Aman Gupta <ffmpeg at tmm1.net> wrote:
> 
> > On Mon, Dec 25, 2017 at 6:29 PM wm4 <nfxjfg at googlemail.com> wrote:
> >  
> >> On Tue, 26 Dec 2017 02:14:11 +0000
> >> Aman Gupta <ffmpeg at tmm1.net> wrote:
> >>  
> >> > On Mon, Dec 25, 2017 at 1:03 PM Michael Niedermayer  
> >> <michael at niedermayer.cc>  
> >> > wrote:
> >> >  
> >> > > On Mon, Dec 25, 2017 at 06:08:11PM +0000, Aman Gupta wrote:  
> >> > > > On Mon, Dec 25, 2017 at 9:58 AM Michael Niedermayer  
> >> > > <michael at niedermayer.cc>  
> >> > > > wrote:
> >> > > >  
> >> > > > > On Fri, Dec 22, 2017 at 11:00:34PM +0000, Aman Gupta wrote:  
> >> > > > > > ffmpeg | branch: master | Aman Gupta <aman at tmm1.net> | Wed  
> >> Oct  4  
> >> > > > > 14:52:52 2017 -0700| [b7d6c0cd48dac7869b9e6803e2d47d05a4fa373b] |
> >> > > > > committer: Aman Gupta  
> >> > > > > >
> >> > > > > > avformat/hls: add http_persistent option
> >> > > > > >
> >> > > > > > This teaches the HLS demuxer to use the HTTP protocols
> >> > > > > > multiple_requests=1 option, to take advantage of "Connection:
> >> > > > > > Keep-Alive" when downloading playlists and segments from the HLS  
> >> > > server.  
> >> > > > > >
> >> > > > > > With the new option, you can avoid TCP connection and TLS  
> >> negotiation  
> >> > > > > > overhead, which is particularly beneficial when streaming via a
> >> > > > > > high-latency internet connection.
> >> > > > > >
> >> > > > > > Similar to the http_persistent option recently implemented in  
> >> > > hlsenc.c  
> >> > > > > >
> >> > > > > > Signed-off-by: Aman Gupta <aman at tmm1.net>
> >> > > > > > Signed-off-by: Anssi Hannula <anssi.hannula at iki.fi>
> >> > > > > >  
> >> > > > > > >  
> >> > > > >  
> >> > >  
> >> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b7d6c0cd48dac7869b9e6803e2d47d05a4fa373b  
> >> > > > > > ---
> >> > > > > >
> >> > > > > >  doc/demuxers.texi |  4 ++++
> >> > > > > >  libavformat/hls.c | 72  
> >> > > > > +++++++++++++++++++++++++++++++++++++++++++++++++++----  
> >> > > > > >  2 files changed, 72 insertions(+), 4 deletions(-)  
> >> > > > >
> >> > > > > This causes ffmpeg to infinite loop with simplehttpd.py  
> >> > > >
> >> > > >
> >> > > > Is that the same as SimpleHTTPServer.py?
> >> > > >
> >> > > > Sounds like it doesn't support persistent connections, but also  
> >> isn't  
> >> > > > returning "Connection: close" in the response.
> >> > > >
> >> > > > I can investigate if you tell me where to find that httpd server.  
> >> > >
> >> > > Iam not sure where i got it from or its original source but it  
> >> matches the  
> >> > > source here:
> >> > >
> >> > >
> >> > >  
> >> https://www.linuxjournal.com/content/tech-tip-really-simple-http-server-python  
> >> >
> >> >
> >> > Thanks.
> >> >
> >> > I was able to reproduce the issue. It appears to be because the simple  
> >> http  
> >> > server is quite too simple, and can only handle one request at a time.  
> >> The  
> >> > http_multiple option tries to make a second request before the first is
> >> > completed, causing a deadlock.
> >> >
> >> > I guess we could disable http_multiple by default...
> >> >
> >> > Aman
> >> >
> >> > <  
> >> https://www.linuxjournal.com/content/tech-tip-really-simple-http-server-python  
> >> >  
> >>
> >> So I hear this causes some infinite loop. Could this be made adaptive?  
> >
> >
> > I guess we could detect if the server is http/1.1 with the first request
> > and only make multiple connections if it is.
> >  
> 
> I sent a new patchset which only enables http_multiple for http/1.1 servers.
> 
> I tested with simplehttpd.py and it works as expected.

Probably an OK workaround for now.