Rename ffserver to avserver.

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+\input texinfo @c -*- texinfo -*-
+
+@settitle avserver Documentation
+@titlepage
+@center @titlefont{avserver Documentation}
+@end titlepage
+
+@top
+
+@contents
+
+@chapter Synopsys
+
+The generic syntax is:
+
+@example
+@c man begin SYNOPSIS
+avserver [options]
+@c man end
+@end example
+
+@chapter Description
+@c man begin DESCRIPTION
+
+avserver is a streaming server for both audio and video. It supports
+several live feeds, streaming from files and time shifting on live feeds
+(you can seek to positions in the past on each live feed, provided you
+specify a big enough feed storage in avserver.conf).
+
+avserver runs in daemon mode by default; that is, it puts itself in
+the background and detaches from its TTY, unless it is launched in
+debug mode or a NoDaemon option is specified in the configuration
+file.
+
+This documentation covers only the streaming aspects of avserver /
+ffmpeg. All questions about parameters for ffmpeg, codec questions,
+etc. are not covered here. Read @file{ffmpeg-doc.html} for more
+information.
+
+@section How does it work?
+
+avserver receives prerecorded files or FFM streams from some ffmpeg
+instance as input, then streams them over RTP/RTSP/HTTP.
+
+An avserver instance will listen on some port as specified in the
+configuration file. You can launch one or more instances of ffmpeg and
+send one or more FFM streams to the port where avserver is expecting
+to receive them. Alternately, you can make avserver launch such ffmpeg
+instances at startup.
+
+Input streams are called feeds, and each one is specified by a <Feed>
+section in the configuration file.
+
+For each feed you can have different output streams in various
+formats, each one specified by a <Stream> section in the configuration
+file.
+
+@section Status stream
+
+avserver supports an HTTP interface which exposes the current status
+of the server.
+
+Simply point your browser to the address of the special status stream
+specified in the configuration file.
+
+For example if you have:
+@example
+<Stream status.html>
+Format status
+
+# Only allow local people to get the status
+ACL allow localhost
+ACL allow 192.168.0.0 192.168.255.255
+</Stream>
+@end example
+
+then the server will post a page with the status information when
+the special stream @file{status.html} is requested.
+
+@section What can this do?
+
+When properly configured and running, you can capture video and audio in real
+time from a suitable capture card, and stream it out over the Internet to
+either Windows Media Player or RealAudio player (with some restrictions).
+
+It can also stream from files, though that is currently broken. Very often, a
+web server can be used to serve up the files just as well.
+
+It can stream prerecorded video from .ffm files, though it is somewhat tricky
+to make it work correctly.
+
+@section What do I need?
+
+I use Linux on a 900 MHz Duron with a cheapo Bt848 based TV capture card. I'm
+using stock Linux 2.4.17 with the stock drivers. [Actually that isn't true,
+I needed some special drivers for my motherboard-based sound card.]
+
+I understand that FreeBSD systems work just fine as well.
+
+@section How do I make it work?
+
+First, build the kit. It *really* helps to have installed LAME first. Then when
+you run the avserver ./configure, make sure that you have the
+@code{--enable-libmp3lame} flag turned on.
+
+LAME is important as it allows for streaming audio to Windows Media Player.
+Don't ask why the other audio types do not work.
+
+As a simple test, just run the following two command lines where INPUTFILE
+is some file which you can decode with ffmpeg:
+
+@example
+./avserver -f doc/avserver.conf &
+./ffmpeg -i INPUTFILE http://localhost:8090/feed1.ffm
+@end example
+
+At this point you should be able to go to your Windows machine and fire up
+Windows Media Player (WMP). Go to Open URL and enter
+
+@example
+    http://<linuxbox>:8090/test.asf
+@end example
+
+You should (after a short delay) see video and hear audio.
+
+WARNING: trying to stream test1.mpg doesn't work with WMP as it tries to
+transfer the entire file before starting to play.
+The same is true of AVI files.
+
+@section What happens next?
+
+You should edit the avserver.conf file to suit your needs (in terms of
+frame rates etc). Then install avserver and ffmpeg, write a script to start
+them up, and off you go.
+
+@section Troubleshooting
+
+@subsection I don't hear any audio, but video is fine.
+
+Maybe you didn't install LAME, or got your ./configure statement wrong. Check
+the ffmpeg output to see if a line referring to MP3 is present. If not, then
+your configuration was incorrect. If it is, then maybe your wiring is not
+set up correctly. Maybe the sound card is not getting data from the right
+input source. Maybe you have a really awful audio interface (like I do)
+that only captures in stereo and also requires that one channel be flipped.
+If you are one of these people, then export 'AUDIO_FLIP_LEFT=1' before
+starting ffmpeg.
+
+@subsection The audio and video loose sync after a while.
+
+Yes, they do.
+
+@subsection After a long while, the video update rate goes way down in WMP.
+
+Yes, it does. Who knows why?
+
+@subsection WMP 6.4 behaves differently to WMP 7.
+
+Yes, it does. Any thoughts on this would be gratefully received. These
+differences extend to embedding WMP into a web page. [There are two
+object IDs that you can use: The old one, which does not play well, and
+the new one, which does (both tested on the same system). However,
+I suspect that the new one is not available unless you have installed WMP 7].
+
+@section What else can it do?
+
+You can replay video from .ffm files that was recorded earlier.
+However, there are a number of caveats, including the fact that the
+avserver parameters must match the original parameters used to record the
+file. If they do not, then avserver deletes the file before recording into it.
+(Now that I write this, it seems broken).
+
+You can fiddle with many of the codec choices and encoding parameters, and
+there are a bunch more parameters that you cannot control. Post a message
+to the mailing list if there are some 'must have' parameters. Look in
+avserver.conf for a list of the currently available controls.
+
+It will automatically generate the ASX or RAM files that are often used
+in browsers. These files are actually redirections to the underlying ASF
+or RM file. The reason for this is that the browser often fetches the
+entire file before starting up the external viewer. The redirection files
+are very small and can be transferred quickly. [The stream itself is
+often 'infinite' and thus the browser tries to download it and never
+finishes.]
+
+@section Tips
+
+* When you connect to a live stream, most players (WMP, RA, etc) want to
+buffer a certain number of seconds of material so that they can display the
+signal continuously. However, avserver (by default) starts sending data
+in realtime. This means that there is a pause of a few seconds while the
+buffering is being done by the player. The good news is that this can be
+cured by adding a '?buffer=5' to the end of the URL. This means that the
+stream should start 5 seconds in the past -- and so the first 5 seconds
+of the stream are sent as fast as the network will allow. It will then
+slow down to real time. This noticeably improves the startup experience.
+
+You can also add a 'Preroll 15' statement into the avserver.conf that will
+add the 15 second prebuffering on all requests that do not otherwise
+specify a time. In addition, avserver will skip frames until a key_frame
+is found. This further reduces the startup delay by not transferring data
+that will be discarded.
+
+* You may want to adjust the MaxBandwidth in the avserver.conf to limit
+the amount of bandwidth consumed by live streams.
+
+@section Why does the ?buffer / Preroll stop working after a time?
+
+It turns out that (on my machine at least) the number of frames successfully
+grabbed is marginally less than the number that ought to be grabbed. This
+means that the timestamp in the encoded data stream gets behind realtime.
+This means that if you say 'Preroll 10', then when the stream gets 10
+or more seconds behind, there is no Preroll left.
+
+Fixing this requires a change in the internals of how timestamps are
+handled.
+
+@section Does the @code{?date=} stuff work.
+
+Yes (subject to the limitation outlined above). Also note that whenever you
+start avserver, it deletes the ffm file (if any parameters have changed),
+thus wiping out what you had recorded before.
+
+The format of the @code{?date=xxxxxx} is fairly flexible. You should use one
+of the following formats (the 'T' is literal):
+
+@example
+* YYYY-MM-DDTHH:MM:SS     (localtime)
+* YYYY-MM-DDTHH:MM:SSZ    (UTC)
+@end example
+
+You can omit the YYYY-MM-DD, and then it refers to the current day. However
+note that @samp{?date=16:00:00} refers to 16:00 on the current day -- this
+may be in the future and so is unlikely to be useful.
+
+You use this by adding the ?date= to the end of the URL for the stream.
+For example:   @samp{http://localhost:8080/test.asf?date=2002-07-26T23:05:00}.
+@c man end
+
+@chapter Options
+@c man begin OPTIONS
+
+@include fftools-common-opts.texi
+
+@section Main options
+
+@table @option
+@item -f @var{configfile}
+Use @file{configfile} instead of @file{/etc/avserver.conf}.
+@item -n
+Enable no-launch mode. This option disables all the Launch directives
+within the various <Stream> sections. Since avserver will not launch
+any ffmpeg instances, you will have to launch them manually.
+@item -d
+Enable debug mode. This option increases log verbosity, directs log
+messages to stdout and causes avserver to run in the foreground
+rather than as a daemon.
+@end table
+@c man end
+
+@ignore
+
+@setfilename avserver
+@settitle avserver video server
+
+@c man begin SEEALSO
+
+ffmpeg(1), avplay(1), avprobe(1), the @file{ffmpeg/doc/avserver.conf}
+example and the Libav HTML documentation
+@c man end
+
+@c man begin AUTHORS
+The Libav developers
+@c man end
+
+@end ignore
+
+@bye