Provided by: ffmpeg_3.3.4-2_amd64 bug

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 intput 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 folling 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 lastest
           occurrence overrides previous if multiple definitions.

   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)