cab85051c0
In particular, add some markup, fix empty line, and merge it with "How does it work?" section.
295 lines
10 KiB
Plaintext
295 lines
10 KiB
Plaintext
\input texinfo @c -*- texinfo -*-
|
|
|
|
@settitle ffserver Documentation
|
|
@titlepage
|
|
@center @titlefont{ffserver Documentation}
|
|
@end titlepage
|
|
|
|
@top
|
|
|
|
@contents
|
|
|
|
@chapter Synopsis
|
|
|
|
ffserver [@var{options}]
|
|
|
|
@chapter Description
|
|
@c man begin DESCRIPTION
|
|
|
|
@command{ffserver} 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
|
|
@file{ffserver.conf}).
|
|
|
|
This documentation covers only the streaming aspects of ffserver /
|
|
ffmpeg. All questions about parameters for ffmpeg, codec questions,
|
|
etc. are not covered here. Read @file{ffmpeg.html} for more
|
|
information.
|
|
|
|
@command{ffserver} receives prerecorded files or FFM streams from some
|
|
@command{ffmpeg} instance as input, then streams them over
|
|
RTP/RTSP/HTTP.
|
|
|
|
An @command{ffserver} instance will listen on some port as specified
|
|
in the configuration file. You can launch one or more instances of
|
|
@command{ffmpeg} and send one or more FFM streams to the port where
|
|
ffserver is expecting to receive them. Alternately, you can make
|
|
@command{ffserver} launch such @command{ffmpeg} instances at startup.
|
|
|
|
Input streams are called feeds, and each one is specified by a
|
|
@code{<Feed>} section in the configuration file.
|
|
|
|
For each feed you can have different output streams in various
|
|
formats, each one specified by a @code{<Stream>} section in the
|
|
configuration file.
|
|
|
|
@section Status stream
|
|
|
|
ffserver 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 cheap 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 ffserver ./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
|
|
ffserver -f doc/ffserver.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 ffserver.conf file to suit your needs (in terms of
|
|
frame rates etc). Then install ffserver 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 lose 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
|
|
ffserver parameters must match the original parameters used to record the
|
|
file. If they do not, then ffserver 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
|
|
ffserver.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, ffserver (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 ffserver.conf that will
|
|
add the 15 second prebuffering on all requests that do not otherwise
|
|
specify a time. In addition, ffserver 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 ffserver.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 ffserver, 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
|
|
|
|
@section What is FFM, FFM2
|
|
|
|
FFM and FFM2 are formats used by ffserver. They allow storing a wide variety of
|
|
video and audio streams and encoding options, and can store a moving time segment
|
|
of an infinite movie or a whole movie.
|
|
|
|
FFM is version specific, and there is limited compatibility of FFM files
|
|
generated by one version of ffmpeg/ffserver and another version of
|
|
ffmpeg/ffserver. It may work but its not guaranteed to work.
|
|
|
|
FFM2 is extensible while maintaining compatibility and should work between
|
|
differing versions of tools. FFM2 is the default.
|
|
|
|
@chapter Options
|
|
@c man begin OPTIONS
|
|
|
|
@include avtools-common-opts.texi
|
|
|
|
@section Main options
|
|
|
|
@table @option
|
|
@item -f @var{configfile}
|
|
Use @file{configfile} instead of @file{/etc/ffserver.conf}.
|
|
@item -n
|
|
Enable no-launch mode. This option disables all the Launch directives
|
|
within the various <Stream> sections. Since ffserver 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.
|
|
@end table
|
|
@c man end
|
|
|
|
@chapter See Also
|
|
|
|
@ifhtml
|
|
The @file{doc/ffserver.conf} example,
|
|
@url{ffmpeg.html,ffmpeg}, @url{ffplay.html,ffplay}, @url{ffprobe.html,ffprobe},
|
|
@url{ffmpeg-utils.html,ffmpeg-utils},
|
|
@url{ffmpeg-scaler.html,ffmpeg-scaler},
|
|
@url{ffmpeg-resampler.html,ffmpeg-resampler},
|
|
@url{ffmpeg-codecs.html,ffmpeg-codecs},
|
|
@url{ffmpeg-bitstream-filters,ffmpeg-bitstream-filters},
|
|
@url{ffmpeg-formats.html,ffmpeg-formats},
|
|
@url{ffmpeg-devices.html,ffmpeg-devices},
|
|
@url{ffmpeg-protocols.html,ffmpeg-protocols},
|
|
@url{ffmpeg-filters.html,ffmpeg-filters}
|
|
@end ifhtml
|
|
|
|
@ifnothtml
|
|
The @file{doc/ffserver.conf} example, ffmpeg(1), ffplay(1), ffprobe(1),
|
|
ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1),
|
|
ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1),
|
|
ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1)
|
|
@end ifnothtml
|
|
|
|
@include authors.texi
|
|
|
|
@ignore
|
|
|
|
@setfilename ffserver
|
|
@settitle ffserver video server
|
|
|
|
@end ignore
|
|
|
|
@bye
|