FFSERVER(1)							   FFSERVER(1)

NAME
       ffserver - ffserver video server

SYNOPSIS
       ffserver [options]

DESCRIPTION
       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.

       ffserver is configured through a configuration file, which is read at
       startup. If not explicitly specified, it will read from
       /etc/ffserver.conf.

       ffserver receives prerecorded files or FFM streams from some ffmpeg
       instance as input, then streams them over RTP/RTSP/HTTP.

       An ffserver 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 ffserver is expecting to
       receive them. Alternately, you can make ffserver 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.

DETAILED DESCRIPTION
       ffserver works by forwarding streams encoded by ffmpeg, or pre-recorded
       streams which are read from disk.

       Precisely, ffserver acts as an HTTP server, accepting POST requests
       from ffmpeg to acquire the stream to publish, and serving RTSP clients
       or HTTP clients GET requests with the stream media content.

       A feed is an FFM stream created by ffmpeg, and sent to a port where
       ffserver is listening.

       Each feed is identified by a unique name, corresponding to the name of
       the resource published on ffserver, and is configured by a dedicated
       "Feed" section in the configuration file.

       The feed publish URL is given by:

	       http://<ffserver_ip_address>:<http_port>/<feed_name>

       where ffserver_ip_address is the IP address of the machine where
       ffserver is installed, http_port is the port number of the HTTP server
       (configured through the HTTPPort option), and feed_name is the name of
       the corresponding feed defined in the configuration file.

       Each feed is associated to a file which is stored on disk. This stored
       file is used to send pre-recorded data to a player as fast as possible
       when new content is added in real-time to the stream.

       A "live-stream" or "stream" is a resource published by ffserver, and
       made accessible through the HTTP protocol to clients.

       A stream can be connected to a feed, or to a file. In the first case,
       the published stream is forwarded from the corresponding feed generated
       by a running instance of ffmpeg, in the second case the stream is read
       from a pre-recorded file.

       Each stream is identified by a unique name, corresponding to the name
       of the resource served by ffserver, and is configured by a dedicated
       "Stream" section in the configuration file.

       The stream access HTTP URL is given by:

	       http://<ffserver_ip_address>:<http_port>/<stream_name>[<options>]

       The stream access RTSP URL is given by:

	       http://<ffserver_ip_address>:<rtsp_port>/<stream_name>[<options>]

       stream_name is the name of the corresponding stream defined in the
       configuration file. options is a list of options specified after the
       URL which affects how the stream is served by ffserver. http_port and
       rtsp_port are the HTTP and RTSP ports configured with the options
       HTTPPort and RTSPPort respectively.

       In case the stream is associated to a feed, the encoding parameters
       must be configured in the stream configuration. They are sent to ffmpeg
       when setting up the encoding. This allows ffserver to define the
       encoding parameters used by the ffmpeg encoders.

       The ffmpeg override_ffserver commandline option allows one to override
       the encoding parameters set by the server.

       Multiple streams can be connected to the same feed.

       For example, you can have a situation described by the following graph:

			      _________       __________
			     |	       |     |		|
	       ffmpeg 1 -----| feed 1  |-----| stream 1 |
		   \	     |_________|\    |__________|
		    \			 \
		     \			  \   __________
		      \ 		   \ |		|
		       \		    \| stream 2 |
			\		     |__________|
			 \
			  \   _________       __________
			   \ |	       |     |		|
			    \| feed 2  |-----| stream 3 |
			     |_________|     |__________|

			      _________       __________
			     |	       |     |		|
	       ffmpeg 2 -----| feed 3  |-----| stream 4 |
			     |_________|     |__________|

			      _________       __________
			     |	       |     |		|
			     | file 1  |-----| stream 5 |
			     |_________|     |__________|

   FFM, FFM2 formats
       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 it is not guaranteed to work.

       FFM2 is extensible while maintaining compatibility and should work
       between differing versions of tools. FFM2 is the default.

   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:

	       <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>

       then the server will post a page with the status information when the
       special stream status.html is requested.

   How do I make it work?
       As a simple test, just run the following two command lines where
       INPUTFILE is some file which you can decode with ffmpeg:

	       ffserver -f doc/ffserver.conf &
	       ffmpeg -i INPUTFILE http://localhost:8090/feed1.ffm

       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

		   http://<linuxbox>:8090/test.asf

       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.

       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.

   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.]

   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.

   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.

   Does the "?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 "?date=xxxxxx" is fairly flexible. You should use one
       of the following formats (the 'T' is literal):

	       * YYYY-MM-DDTHH:MM:SS	 (localtime)
	       * YYYY-MM-DDTHH:MM:SSZ	 (UTC)

       You can omit the YYYY-MM-DD, and then it refers to the current day.
       However note that ?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:   http://localhost:8080/test.asf?date=2002-07-26T23:05:00.

OPTIONS
       All the numerical options, if not specified otherwise, accept a string
       representing a number as input, which may be followed by one of the SI
       unit prefixes, for example: 'K', 'M', or 'G'.

       If 'i' is appended to the SI unit prefix, the complete prefix will be
       interpreted as a unit prefix for binary multiples, which are based on
       powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit
       prefix multiplies the value by 8. This allows using, for example: 'KB',
       'MiB', 'G' and 'B' as number suffixes.

       Options which do not take arguments are boolean options, and set the
       corresponding value to true. They can be set to false by prefixing the
       option name with "no". For example using "-nofoo" will set the boolean
       option with name "foo" to false.

   Stream specifiers
       Some options are applied per-stream, e.g. bitrate or codec. Stream
       specifiers are used to precisely specify which stream(s) a given option
       belongs to.

       A stream specifier is a string generally appended to the option name
       and separated from it by a colon. E.g. "-codec:a:1 ac3" contains the
       "a:1" stream specifier, which matches the second audio stream.
       Therefore, it would select the ac3 codec for the second audio stream.

       A stream specifier can match several streams, so that the option is
       applied to all of them. E.g. the stream specifier in "-b:a 128k"
       matches all audio streams.

       An empty stream specifier matches all streams. For example, "-codec
       copy" or "-codec: copy" would copy all the streams without reencoding.

       Possible forms of stream specifiers are:

       stream_index
	   Matches the stream with this index. E.g. "-threads:1 4" would set
	   the thread count for the second stream to 4.

       stream_type[:stream_index]
	   stream_type is one of following: 'v' or 'V' for video, 'a' for
	   audio, 's' for subtitle, 'd' for data, and 't' for attachments. 'v'
	   matches all video streams, 'V' only matches video streams which are
	   not attached pictures, video thumbnails or cover arts.  If
	   stream_index is given, then it matches stream number stream_index
	   of this type. Otherwise, it matches all streams of this type.

       p:program_id[:stream_index]
	   If stream_index is given, then it matches the stream with number
	   stream_index in the program with the id program_id. Otherwise, it
	   matches all streams in the program.

       #stream_id or i:stream_id
	   Match the stream by stream id (e.g. PID in MPEG-TS container).

       m:key[:value]
	   Matches streams with the metadata tag key having the specified
	   value. If value is not given, matches streams that contain the
	   given tag with any value.

       u   Matches streams with usable configuration, the codec must be
	   defined and the essential information such as video dimension or
	   audio sample rate must be present.

	   Note that in ffmpeg, matching by metadata will only work properly
	   for input files.

   Generic options
       These options are shared amongst the ff* tools.

       -L  Show license.

       -h, -?, -help, --help [arg]
	   Show help. An optional parameter may be specified to print help
	   about a specific item. If no argument is specified, only basic (non
	   advanced) tool options are shown.

	   Possible values of arg are:

	   long
	       Print advanced tool options in addition to the basic tool
	       options.

	   full
	       Print complete list of options, including shared and private
	       options for encoders, decoders, demuxers, muxers, filters, etc.

	   decoder=decoder_name
	       Print detailed information about the decoder named
	       decoder_name. Use the -decoders option to get a list of all
	       decoders.

	   encoder=encoder_name
	       Print detailed information about the encoder named
	       encoder_name. Use the -encoders option to get a list of all
	       encoders.

	   demuxer=demuxer_name
	       Print detailed information about the demuxer named
	       demuxer_name. Use the -formats option to get a list of all
	       demuxers and muxers.

	   muxer=muxer_name
	       Print detailed information about the muxer named muxer_name.
	       Use the -formats option to get a list of all muxers and
	       demuxers.

	   filter=filter_name
	       Print detailed information about the filter name filter_name.
	       Use the -filters option to get a list of all filters.

       -version
	   Show version.

       -formats
	   Show available formats (including devices).

       -demuxers
	   Show available demuxers.

       -muxers
	   Show available muxers.

       -devices
	   Show available devices.

       -codecs
	   Show all codecs known to libavcodec.

	   Note that the term 'codec' is used throughout this documentation as
	   a shortcut for what is more correctly called a media bitstream
	   format.

       -decoders
	   Show available decoders.

       -encoders
	   Show all available encoders.

       -bsfs
	   Show available bitstream filters.

       -protocols
	   Show available protocols.

       -filters
	   Show available libavfilter filters.

       -pix_fmts
	   Show available pixel formats.

       -sample_fmts
	   Show available sample formats.

       -layouts
	   Show channel names and standard channel layouts.

       -colors
	   Show recognized color names.

       -sources device[,opt1=val1[,opt2=val2]...]
	   Show autodetected sources of the input device.  Some devices may
	   provide system-dependent source names that cannot be autodetected.
	   The returned list cannot be assumed to be always complete.

		   ffmpeg -sources pulse,server=192.168.0.4

       -sinks device[,opt1=val1[,opt2=val2]...]
	   Show autodetected sinks of the output device.  Some devices may
	   provide system-dependent sink names that cannot be autodetected.
	   The returned list cannot be assumed to be always complete.

		   ffmpeg -sinks pulse,server=192.168.0.4

       -loglevel [repeat+]loglevel | -v [repeat+]loglevel
	   Set the logging level used by the library.  Adding "repeat+"
	   indicates that repeated log output should not be compressed to the
	   first line and the "Last message repeated n times" line will be
	   omitted. "repeat" can also be used alone.  If "repeat" is used
	   alone, and with no prior loglevel set, the default loglevel will be
	   used. If multiple loglevel parameters are given, using 'repeat'
	   will not change the loglevel.  loglevel is a string or a number
	   containing one of the following values:

	   quiet, -8
	       Show nothing at all; be silent.

	   panic, 0
	       Only show fatal errors which could lead the process to crash,
	       such as an assertion failure. This is not currently used for
	       anything.

	   fatal, 8
	       Only show fatal errors. These are errors after which the
	       process absolutely cannot continue.

	   error, 16
	       Show all errors, including ones which can be recovered from.

	   warning, 24
	       Show all warnings and errors. Any message related to possibly
	       incorrect or unexpected events will be shown.

	   info, 32
	       Show informative messages during processing. This is in
	       addition to warnings and errors. This is the default value.

	   verbose, 40
	       Same as "info", except more verbose.

	   debug, 48
	       Show everything, including debugging information.

	   trace, 56

	   By default the program logs to stderr. If coloring is supported by
	   the terminal, colors are used to mark errors and warnings. Log
	   coloring can be disabled setting the environment variable
	   AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting the
	   environment variable AV_LOG_FORCE_COLOR.  The use of the
	   environment variable NO_COLOR is deprecated and will be dropped in
	   a future FFmpeg version.

       -report
	   Dump full command line and console output to a file named
	   "program-YYYYMMDD-HHMMSS.log" in the current directory.  This file
	   can be useful for bug reports.  It also implies "-loglevel
	   verbose".

	   Setting the environment variable FFREPORT to any value has the same
	   effect. If the value is a ':'-separated key=value sequence, these
	   options will affect the report; option values must be escaped if
	   they contain special characters or the options delimiter ':' (see
	   the ``Quoting and escaping'' section in the ffmpeg-utils manual).

	   The following options are recognized:

	   file
	       set the file name to use for the report; %p is expanded to the
	       name of the program, %t is expanded to a timestamp, "%%" is
	       expanded to a plain "%"

	   level
	       set the log verbosity level using a numerical value (see
	       "-loglevel").

	   For example, to output a report to a file named ffreport.log using
	   a log level of 32 (alias for log level "info"):

		   FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output

	   Errors in parsing the environment variable are not fatal, and will
	   not appear in the report.

       -hide_banner
	   Suppress printing banner.

	   All FFmpeg tools will normally show a copyright notice, build
	   options and library versions. This option can be used to suppress
	   printing this information.

       -cpuflags flags (global)
	   Allows setting and clearing cpu flags. This option is intended for
	   testing. Do not use it unless you know what you're doing.

		   ffmpeg -cpuflags -sse+mmx ...
		   ffmpeg -cpuflags mmx ...
		   ffmpeg -cpuflags 0 ...

	   Possible flags for this option are:

	   x86
	       mmx
	       mmxext
	       sse
	       sse2
	       sse2slow
	       sse3
	       sse3slow
	       ssse3
	       atom
	       sse4.1
	       sse4.2
	       avx
	       avx2
	       xop
	       fma3
	       fma4
	       3dnow
	       3dnowext
	       bmi1
	       bmi2
	       cmov
	   ARM
	       armv5te
	       armv6
	       armv6t2
	       vfp
	       vfpv3
	       neon
	       setend
	   AArch64
	       armv8
	       vfp
	       neon
	   PowerPC
	       altivec
	   Specific Processors
	       pentium2
	       pentium3
	       pentium4
	       k6
	       k62
	       athlon
	       athlonxp
	       k8
       -opencl_bench
	   This option is used to benchmark all available OpenCL devices and
	   print the results. This option is only available when FFmpeg has
	   been compiled with "--enable-opencl".

	   When FFmpeg is configured with "--enable-opencl", the options for
	   the global OpenCL context are set via -opencl_options. See the
	   "OpenCL Options" section in the ffmpeg-utils manual for the
	   complete list of supported options. Amongst others, these options
	   include the ability to select a specific platform and device to run
	   the OpenCL code on. By default, FFmpeg will run on the first device
	   of the first platform. While the options for the global OpenCL
	   context provide flexibility to the user in selecting the OpenCL
	   device of their choice, most users would probably want to select
	   the fastest OpenCL device for their system.

	   This option assists the selection of the most efficient
	   configuration by identifying the appropriate device for the user's
	   system. The built-in benchmark is run on all the OpenCL devices and
	   the performance is measured for each device. The devices in the
	   results list are sorted based on their performance with the fastest
	   device listed first. The user can subsequently invoke ffmpeg using
	   the device deemed most appropriate via -opencl_options to obtain
	   the best performance for the OpenCL accelerated code.

	   Typical usage to use the fastest OpenCL device involve the
	   following steps.

	   Run the command:

		   ffmpeg -opencl_bench

	   Note down the platform ID (pidx) and device ID (didx) of the first
	   i.e. fastest device in the list.  Select the platform and device
	   using the command:

		   ffmpeg -opencl_options platform_idx=<pidx>:device_idx=<didx> ...

       -opencl_options options (global)
	   Set OpenCL environment options. This option is only available when
	   FFmpeg has been compiled with "--enable-opencl".

	   options must be a list of key=value option pairs separated by ':'.
	   See the ``OpenCL Options'' section in the ffmpeg-utils manual for
	   the list of supported options.

   AVOptions
       These options are provided directly by the libavformat, libavdevice and
       libavcodec libraries. To see the list of available AVOptions, use the
       -help option. They are separated into two categories:

       generic
	   These options can be set for any container, codec or device.
	   Generic options are listed under AVFormatContext options for
	   containers/devices and under AVCodecContext options for codecs.

       private
	   These options are specific to the given container, device or codec.
	   Private options are listed under their corresponding
	   containers/devices/codecs.

       For example to write an ID3v2.3 header instead of a default ID3v2.4 to
       an MP3 file, use the id3v2_version private option of the MP3 muxer:

	       ffmpeg -i input.flac -id3v2_version 3 out.mp3

       All codec AVOptions are per-stream, and thus a stream specifier should
       be attached to them.

       Note: the -nooption syntax cannot be used for boolean AVOptions, use
       -option 0/-option 1.

       Note: the old undocumented way of specifying per-stream AVOptions by
       prepending v/a/s to the options name is now obsolete and will be
       removed soon.

   Main options
       -f configfile
	   Read configuration file configfile. If not specified it will read
	   by default from /etc/ffserver.conf.

       -n  Enable no-launch mode. This option disables all the "Launch"
	   directives within the various "<Feed>" sections. Since ffserver
	   will not launch any ffmpeg instances, you will have to launch them
	   manually.

       -d  Enable debug mode. This option increases log verbosity, and directs
	   log messages to stdout. When specified, the CustomLog option is
	   ignored.

CONFIGURATION FILE SYNTAX
       ffserver reads a configuration file containing global options and
       settings for each stream and feed.

       The configuration file consists of global options and dedicated
       sections, which must be introduced by "<SECTION_NAME ARGS>" on a
       separate line and must be terminated by a line in the form
       "</SECTION_NAME>". ARGS is optional.

       Currently the following sections are recognized: Feed, Stream,
       Redirect.

       A line starting with "#" is ignored and treated as a comment.

       Name of options and sections are case-insensitive.

   ACL syntax
       An ACL (Access Control List) specifies the address which are allowed to
       access a given stream, or to write a given feed.

       It accepts the following forms

       ·   Allow/deny access to address.

		   ACL ALLOW <address>
		   ACL DENY <address>

       ·   Allow/deny access to ranges of addresses from first_address to
	   last_address.

		   ACL ALLOW <first_address> <last_address>
		   ACL DENY <first_address> <last_address>

       You can repeat the ACL allow/deny as often as you like. It is on a per
       stream basis. The first match defines the action. If there are no
       matches, then the default is the inverse of the last ACL statement.

       Thus 'ACL allow localhost' only allows access from localhost.  'ACL
       deny 1.0.0.0 1.255.255.255' would deny the whole of network 1 and allow
       everybody else.

   Global options
       HTTPPort port_number
       Port port_number
       RTSPPort port_number
	   HTTPPort sets the HTTP server listening TCP port number, RTSPPort
	   sets the RTSP server listening TCP port number.

	   Port is the equivalent of HTTPPort and is deprecated.

	   You must select a different port from your standard HTTP web server
	   if it is running on the same computer.

	   If not specified, no corresponding server will be created.

       HTTPBindAddress ip_address
       BindAddress ip_address
       RTSPBindAddress ip_address
	   Set address on which the HTTP/RTSP server is bound. Only useful if
	   you have several network interfaces.

	   BindAddress is the equivalent of HTTPBindAddress and is deprecated.

       MaxHTTPConnections n
	   Set number of simultaneous HTTP connections that can be handled. It
	   has to be defined before the MaxClients parameter, since it defines
	   the MaxClients maximum limit.

	   Default value is 2000.

       MaxClients n
	   Set number of simultaneous requests that can be handled. Since
	   ffserver is very fast, it is more likely that you will want to
	   leave this high and use MaxBandwidth.

	   Default value is 5.

       MaxBandwidth kbps
	   Set the maximum amount of kbit/sec that you are prepared to consume
	   when streaming to clients.

	   Default value is 1000.

       CustomLog filename
	   Set access log file (uses standard Apache log file format). '-' is
	   the standard output.

	   If not specified ffserver will produce no log.

	   In case the commandline option -d is specified this option is
	   ignored, and the log is written to standard output.

       NoDaemon
	   Set no-daemon mode. This option is currently ignored since now
	   ffserver will always work in no-daemon mode, and is deprecated.

       UseDefaults
       NoDefaults
	   Control whether default codec options are used for the all streams
	   or not.  Each stream may overwrite this setting for its own.
	   Default is UseDefaults.  The last occurrence overrides the previous
	   if multiple definitions exist.

   Feed section
       A Feed section defines a feed provided to ffserver.

       Each live feed contains one video and/or audio sequence coming from an
       ffmpeg encoder or another ffserver. This sequence may be encoded
       simultaneously with several codecs at several resolutions.

       A feed instance specification is introduced by a line in the form:

	       <Feed FEED_FILENAME>

       where FEED_FILENAME specifies the unique name of the FFM stream.

       The following options are recognized within a Feed section.

       File filename
       ReadOnlyFile filename
	   Set the path where the feed file is stored on disk.

	   If not specified, the /tmp/FEED.ffm is assumed, where FEED is the
	   feed name.

	   If ReadOnlyFile is used the file is marked as read-only and it will
	   not be deleted or updated.

       Truncate
	   Truncate the feed file, rather than appending to it. By default
	   ffserver will append data to the file, until the maximum file size
	   value is reached (see FileMaxSize option).

       FileMaxSize size
	   Set maximum size of the feed file in bytes. 0 means unlimited. The
	   postfixes "K" (2^10), "M" (2^20), and "G" (2^30) are recognized.

	   Default value is 5M.

       Launch args
	   Launch an ffmpeg command when creating ffserver.

	   args must be a sequence of arguments to be provided to an ffmpeg
	   instance. The first provided argument is ignored, and it is
	   replaced by a path with the same dirname of the ffserver instance,
	   followed by the remaining argument and terminated with a path
	   corresponding to the feed.

	   When the launched process exits, ffserver will launch another
	   program instance.

	   In case you need a more complex ffmpeg configuration, e.g. if you
	   need to generate multiple FFM feeds with a single ffmpeg instance,
	   you should launch ffmpeg by hand.

	   This option is ignored in case the commandline option -n is
	   specified.

       ACL spec
	   Specify the list of IP address which are allowed or denied to write
	   the feed. Multiple ACL options can be specified.

   Stream section
       A Stream section defines a stream provided by ffserver, and identified
       by a single name.

       The stream is sent when answering a request containing the stream name.

       A stream section must be introduced by the line:

	       <Stream STREAM_NAME>

       where STREAM_NAME specifies the unique name of the stream.

       The following options are recognized within a Stream section.

       Encoding options are marked with the encoding tag, and they are used to
       set the encoding parameters, and are mapped to libavcodec encoding
       options. Not all encoding options are supported, in particular it is
       not possible to set encoder private options. In order to override the
       encoding options specified by ffserver, you can use the ffmpeg
       override_ffserver commandline option.

       Only one of the Feed and File options should be set.

       Feed feed_name
	   Set the input feed. feed_name must correspond to an existing feed
	   defined in a "Feed" section.

	   When this option is set, encoding options are used to setup the
	   encoding operated by the remote ffmpeg process.

       File filename
	   Set the filename of the pre-recorded input file to stream.

	   When this option is set, encoding options are ignored and the input
	   file content is re-streamed as is.

       Format format_name
	   Set the format of the output stream.

	   Must be the name of a format recognized by FFmpeg. If set to
	   status, it is treated as a status stream.

       InputFormat format_name
	   Set input format. If not specified, it is automatically guessed.

       Preroll n
	   Set this to the number of seconds backwards in time to start. Note
	   that most players will buffer 5-10 seconds of video, and also you
	   need to allow for a keyframe to appear in the data stream.

	   Default value is 0.

       StartSendOnKey
	   Do not send stream until it gets the first key frame. By default
	   ffserver will send data immediately.

       MaxTime n
	   Set the number of seconds to run. This value set the maximum
	   duration of the stream a client will be able to receive.

	   A value of 0 means that no limit is set on the stream duration.

       ACL spec
	   Set ACL for the stream.

       DynamicACL spec
       RTSPOption option
       MulticastAddress address
       MulticastPort port
       MulticastTTL integer
       NoLoop
       FaviconURL url
	   Set favicon (favourite icon) for the server status page. It is
	   ignored for regular streams.

       Author value
       Comment value
       Copyright value
       Title value
	   Set metadata corresponding to the option. All these options are
	   deprecated in favor of Metadata.

       Metadata key value
	   Set metadata value on the output stream.

       UseDefaults
       NoDefaults
	   Control whether default codec options are used for the stream or
	   not.  Default is UseDefaults unless disabled globally.

       NoAudio
       NoVideo
	   Suppress audio/video.

       AudioCodec codec_name (encoding,audio)
	   Set audio codec.

       AudioBitRate rate (encoding,audio)
	   Set bitrate for the audio stream in kbits per second.

       AudioChannels n (encoding,audio)
	   Set number of audio channels.

       AudioSampleRate n (encoding,audio)
	   Set sampling frequency for audio. When using low bitrates, you
	   should lower this frequency to 22050 or 11025. The supported
	   frequencies depend on the selected audio codec.

       AVOptionAudio [codec:]option value (encoding,audio)
	   Set generic or private option for audio stream.  Private option
	   must be prefixed with codec name or codec must be defined before.

       AVPresetAudio preset (encoding,audio)
	   Set preset for audio stream.

       VideoCodec codec_name (encoding,video)
	   Set video codec.

       VideoBitRate n (encoding,video)
	   Set bitrate for the video stream in kbits per second.

       VideoBitRateRange range (encoding,video)
	   Set video bitrate range.

	   A range must be specified in the form minrate-maxrate, and
	   specifies the minrate and maxrate encoding options expressed in
	   kbits per second.

       VideoBitRateRangeTolerance n (encoding,video)
	   Set video bitrate tolerance in kbits per second.

       PixelFormat pixel_format (encoding,video)
	   Set video pixel format.

       Debug integer (encoding,video)
	   Set video debug encoding option.

       Strict integer (encoding,video)
	   Set video strict encoding option.

       VideoBufferSize n (encoding,video)
	   Set ratecontrol buffer size, expressed in KB.

       VideoFrameRate n (encoding,video)
	   Set number of video frames per second.

       VideoSize (encoding,video)
	   Set size of the video frame, must be an abbreviation or in the form
	   WxH.  See the Video size section in the ffmpeg-utils(1) manual.

	   Default value is "160x128".

       VideoIntraOnly (encoding,video)
	   Transmit only intra frames (useful for low bitrates, but kills
	   frame rate).

       VideoGopSize n (encoding,video)
	   If non-intra only, an intra frame is transmitted every VideoGopSize
	   frames. Video synchronization can only begin at an intra frame.

       VideoTag tag (encoding,video)
	   Set video tag.

       VideoHighQuality (encoding,video)
       Video4MotionVector (encoding,video)
       BitExact (encoding,video)
	   Set bitexact encoding flag.

       IdctSimple (encoding,video)
	   Set simple IDCT algorithm.

       Qscale n (encoding,video)
	   Enable constant quality encoding, and set video qscale
	   (quantization scale) value, expressed in n QP units.

       VideoQMin n (encoding,video)
       VideoQMax n (encoding,video)
	   Set video qmin/qmax.

       VideoQDiff integer (encoding,video)
	   Set video qdiff encoding option.

       LumiMask float (encoding,video)
       DarkMask float (encoding,video)
	   Set lumi_mask/dark_mask encoding options.

       AVOptionVideo [codec:]option value (encoding,video)
	   Set generic or private option for video stream.  Private option
	   must be prefixed with codec name or codec must be defined before.

       AVPresetVideo preset (encoding,video)
	   Set preset for video stream.

	   preset must be the path of a preset file.

       Server status stream

       A server status stream is a special stream which is used to show
       statistics about the ffserver operations.

       It must be specified setting the option Format to status.

   Redirect section
       A redirect section specifies where to redirect the requested URL to
       another page.

       A redirect section must be introduced by the line:

	       <Redirect NAME>

       where NAME is the name of the page which should be redirected.

       It only accepts the option URL, which specify the redirection URL.

STREAM EXAMPLES
       ·   Multipart JPEG

		   <Stream test.mjpg>
		   Feed feed1.ffm
		   Format mpjpeg
		   VideoFrameRate 2
		   VideoIntraOnly
		   NoAudio
		   Strict -1
		   </Stream>

       ·   Single JPEG

		   <Stream test.jpg>
		   Feed feed1.ffm
		   Format jpeg
		   VideoFrameRate 2
		   VideoIntraOnly
		   VideoSize 352x240
		   NoAudio
		   Strict -1
		   </Stream>

       ·   Flash

		   <Stream test.swf>
		   Feed feed1.ffm
		   Format swf
		   VideoFrameRate 2
		   VideoIntraOnly
		   NoAudio
		   </Stream>

       ·   ASF compatible

		   <Stream test.asf>
		   Feed feed1.ffm
		   Format asf
		   VideoFrameRate 15
		   VideoSize 352x240
		   VideoBitRate 256
		   VideoBufferSize 40
		   VideoGopSize 30
		   AudioBitRate 64
		   StartSendOnKey
		   </Stream>

       ·   MP3 audio

		   <Stream test.mp3>
		   Feed feed1.ffm
		   Format mp2
		   AudioCodec mp3
		   AudioBitRate 64
		   AudioChannels 1
		   AudioSampleRate 44100
		   NoVideo
		   </Stream>

       ·   Ogg Vorbis audio

		   <Stream test.ogg>
		   Feed feed1.ffm
		   Metadata title "Stream title"
		   AudioBitRate 64
		   AudioChannels 2
		   AudioSampleRate 44100
		   NoVideo
		   </Stream>

       ·   Real with audio only at 32 kbits

		   <Stream test.ra>
		   Feed feed1.ffm
		   Format rm
		   AudioBitRate 32
		   NoVideo
		   </Stream>

       ·   Real with audio and video at 64 kbits

		   <Stream test.rm>
		   Feed feed1.ffm
		   Format rm
		   AudioBitRate 32
		   VideoBitRate 128
		   VideoFrameRate 25
		   VideoGopSize 25
		   </Stream>

       ·   For stream coming from a file: you only need to set the input
	   filename and optionally a new format.

		   <Stream file.rm>
		   File "/usr/local/httpd/htdocs/tlive.rm"
		   NoAudio
		   </Stream>

		   <Stream file.asf>
		   File "/usr/local/httpd/htdocs/test.asf"
		   NoAudio
		   Metadata author "Me"
		   Metadata copyright "Super MegaCorp"
		   Metadata title "Test stream from disk"
		   Metadata comment "Test comment"
		   </Stream>

SEE ALSO
       ffserver-all(1), the 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)

AUTHORS
       The FFmpeg developers.

       For details about the authorship, see the Git history of the project
       (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command git log in
       the FFmpeg source directory, or browsing the online repository at
       <http://source.ffmpeg.org>.

       Maintainers for the specific components are listed in the file
       MAINTAINERS in the source code tree.

								   FFSERVER(1)
