@chapter Protocols
@c man begin PROTOCOLS
-Protocols are configured elements in FFmpeg which allow to access
+Protocols are configured elements in Libav which allow to access
resources which require the use of a particular protocol.
-When you configure your FFmpeg build, all the supported protocols
-are enabled by default. You can list them using the configure option
-"--list-protocols".
+When you configure your Libav build, all the supported protocols are
+enabled by default. You can list all available ones using the
+configure option "--list-protocols".
You can disable all the protocols using the configure option
"--disable-protocols", and selectively enable a protocol using the
particular protocol using the option
"--disable-protocol=@var{PROTOCOL}".
-The option "-protocols" of the ff* tools will display the list of
-the supported protocols.
+The option "-protocols" of the av* tools will display the list of
+supported protocols.
A description of the currently available protocols follows.
Physical concatenation protocol.
-Allow to read and seek from many resource in sequence as they were an
-unique resource.
+Allow to read and seek from many resource in sequence as if they were
+a unique resource.
-An url accepted by this protocol has the syntax:
+A URL accepted by this protocol has the syntax:
@example
concat:@var{URL1}|@var{URL2}|...|@var{URLN}
@end example
protocol.
For example to read a sequence of files @file{split1.mpeg},
-@file{split2.mpeg}, @file{split3.mpeg} with @file{ffplay} use the
+@file{split2.mpeg}, @file{split3.mpeg} with @command{avplay} use the
command:
@example
-ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
+avplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
@end example
Note that you may need to escape the character "|" which is special for
Allow to read from or read to a file.
-For example to read from a file @file{input.mpeg} with @file{ffmpeg}
+For example to read from a file @file{input.mpeg} with @command{avconv}
use the command:
@example
-ffmpeg -i file:input.mpeg output.mpeg
+avconv -i file:input.mpeg output.mpeg
@end example
-Note that if not specified otherwise, the ff* tools will use the file
-protocol by default, that is a resource specified with the name
-"FILE.mpeg" is interpreted as it were the url "file:FILE.mpeg".
+The av* tools default to the file protocol, that is a resource
+specified with the name "FILE.mpeg" is interpreted as the URL
+"file:FILE.mpeg".
@section gopher
Gopher protocol.
+@section hls
+
+Read Apple HTTP Live Streaming compliant segmented stream as
+a uniform one. The M3U8 playlists describing the segments can be
+remote HTTP resources or local files, accessed using the standard
+file protocol.
+The nested protocol is declared by specifying
+"+@var{proto}" after the hls URI scheme name, where @var{proto}
+is either "file" or "http".
+
+@example
+hls+http://host/path/to/remote/resource.m3u8
+hls+file://path/to/local/resource.m3u8
+@end example
+
+Using this protocol is discouraged - the hls demuxer should work
+just as well (if not, please report the issues) and is more complete.
+To use the hls demuxer instead, simply use the direct URLs to the
+m3u8 files.
+
@section http
-HTTP (Hyper Text Trasfer Protocol).
+HTTP (Hyper Text Transfer Protocol).
@section mmst
MMS (Microsoft Media Server) protocol over TCP.
+@section mmsh
+
+MMS (Microsoft Media Server) protocol over HTTP.
+
+The required syntax is:
+@example
+mmsh://@var{server}[:@var{port}][/@var{app}][/@var{playpath}]
+@end example
+
@section md5
MD5 output protocol.
-Computes the MD5 hash of data written, and on close writes this to the
-designated output or stdout if none is specified. It can be used to
-test muxers without writing an actual file.
+Computes the MD5 hash of the data to be written, and on close writes
+this to the designated output or stdout if none is specified. It can
+be used to test muxers without writing an actual file.
Some examples follow.
@example
-# write the MD5 hash of the encoded AVI file in the file output.avi.md5
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
+# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
+avconv -i input.flv -f avi -y md5:output.avi.md5
-# write the MD5 hash of the encoded AVI file to stdout
-ffmpeg -i input.flv -f avi -y md5:
+# Write the MD5 hash of the encoded AVI file to stdout.
+avconv -i input.flv -f avi -y md5:
@end example
-Note that some formats (typically mov) require the output protocol to
+Note that some formats (typically MOV) require the output protocol to
be seekable, so they will fail with the MD5 output protocol.
@section pipe
@end example
@var{number} is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr).
-If @var{number} is not specified will use by default stdout if the
-protocol is used for writing, stdin if the protocol is used for
-reading.
+pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If @var{number}
+is not specified, by default the stdout file descriptor will be used
+for writing, stdin for reading.
-For example to read from stdin with @file{ffmpeg}:
+For example to read from stdin with @command{avconv}:
@example
-cat test.wav | ffmpeg -i pipe:0
-# this is the same as
-cat test.wav | ffmpeg -i pipe:
+cat test.wav | avconv -i pipe:0
+# ...this is the same as...
+cat test.wav | avconv -i pipe:
@end example
-For writing to stdout with @file{ffmpeg}:
+For writing to stdout with @command{avconv}:
@example
-ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# this is the same as
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
+avconv -i test.wav -f avi pipe:1 | cat > test.avi
+# ...this is the same as...
+avconv -i test.wav -f avi pipe: | cat > test.avi
@end example
-Note that some formats (typically mov), require the output protocol to
+Note that some formats (typically MOV), require the output protocol to
be seekable, so they will fail with the pipe output protocol.
@section rtmp
Real-Time Messaging Protocol.
-The Real-Time Messaging Protocol (RTMP) is used for streaming multime‐
-dia content across a TCP/IP network.
+The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
+content across a TCP/IP network.
The required syntax is:
@example
-rtmp://@var{server}[:@var{port}][/@var{app}][/@var{playpath}]
+rtmp://@var{server}[:@var{port}][/@var{app}][/@var{instance}][/@var{playpath}]
@end example
-Follows the description of the accepted parameters.
+The accepted parameters are:
@table @option
@item server
-It is the address of the RTMP server.
+The address of the RTMP server.
@item port
-It is the number of the TCP port to use (by default is 1935).
+The number of the TCP port to use (by default is 1935).
@item app
-It is the name of the application to acces. It usually corresponds to
-the the path where the application is installed on the RTMP server
-(e.g. @file{/ondemand/}, @file{/flash/live/}, etc.).
+It is the name of the application to access. It usually corresponds to
+the path where the application is installed on the RTMP server
+(e.g. @file{/ondemand/}, @file{/flash/live/}, etc.). You can override
+the value parsed from the URI through the @code{rtmp_app} option, too.
@item playpath
It is the path or name of the resource to play with reference to the
-application specified in @var{app}, may be prefixed by "mp4:".
+application specified in @var{app}, may be prefixed by "mp4:". You
+can override the value parsed from the URI through the @code{rtmp_playpath}
+option, too.
+
+@item listen
+Act as a server, listening for an incoming connection.
+@item timeout
+Maximum time to wait for the incoming connection. Implies listen.
@end table
-For example to read with @file{ffplay} a multimedia resource named
+Additionally, the following parameters can be set via command line options
+(or in code via @code{AVOption}s):
+@table @option
+
+@item rtmp_app
+Name of application to connect on the RTMP server. This option
+overrides the parameter specified in the URI.
+
+@item rtmp_buffer
+Set the client buffer time in milliseconds. The default is 3000.
+
+@item rtmp_conn
+Extra arbitrary AMF connection parameters, parsed from a string,
+e.g. like @code{B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0}.
+Each value is prefixed by a single character denoting the type,
+B for Boolean, N for number, S for string, O for object, or Z for null,
+followed by a colon. For Booleans the data must be either 0 or 1 for
+FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
+1 to end or begin an object, respectively. Data items in subobjects may
+be named, by prefixing the type with 'N' and specifying the name before
+the value (i.e. @code{NB:myFlag:1}). This option may be used multiple
+times to construct arbitrary AMF sequences.
+
+@item rtmp_flashver
+Version of the Flash plugin used to run the SWF player. The default
+is LNX 9,0,124,2.
+
+@item rtmp_flush_interval
+Number of packets flushed in the same request (RTMPT only). The default
+is 10.
+
+@item rtmp_live
+Specify that the media is a live stream. No resuming or seeking in
+live streams is possible. The default value is @code{any}, which means the
+subscriber first tries to play the live stream specified in the
+playpath. If a live stream of that name is not found, it plays the
+recorded stream. The other possible values are @code{live} and
+@code{recorded}.
+
+@item rtmp_pageurl
+URL of the web page in which the media was embedded. By default no
+value will be sent.
+
+@item rtmp_playpath
+Stream identifier to play or to publish. This option overrides the
+parameter specified in the URI.
+
+@item rtmp_subscribe
+Name of live stream to subscribe to. By default no value will be sent.
+It is only sent if the option is specified or if rtmp_live
+is set to live.
+
+@item rtmp_swfhash
+SHA256 hash of the decompressed SWF file (32 bytes).
+
+@item rtmp_swfsize
+Size of the decompressed SWF file, required for SWFVerification.
+
+@item rtmp_swfurl
+URL of the SWF player for the media. By default no value will be sent.
+
+@item rtmp_swfverify
+URL to player swf file, compute hash/size automatically.
+
+@item rtmp_tcurl
+URL of the target stream. Defaults to proto://host[:port]/app.
+
+@end table
+
+For example to read with @command{avplay} a multimedia resource named
"sample" from the application "vod" from an RTMP server "myserver":
@example
-ffplay rtmp://myserver/vod/sample
+avplay rtmp://myserver/vod/sample
@end example
+@section rtmpe
+
+Encrypted Real-Time Messaging Protocol.
+
+The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
+streaming multimedia content within standard cryptographic primitives,
+consisting of Diffie-Hellman key exchange and HMACSHA256, generating
+a pair of RC4 keys.
+
+@section rtmps
+
+Real-Time Messaging Protocol over a secure SSL connection.
+
+The Real-Time Messaging Protocol (RTMPS) is used for streaming
+multimedia content across an encrypted connection.
+
+@section rtmpt
+
+Real-Time Messaging Protocol tunneled through HTTP.
+
+The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
+for streaming multimedia content within HTTP requests to traverse
+firewalls.
+
+@section rtmpte
+
+Encrypted Real-Time Messaging Protocol tunneled through HTTP.
+
+The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
+is used for streaming multimedia content within HTTP requests to traverse
+firewalls.
+
+@section rtmpts
+
+Real-Time Messaging Protocol tunneled through HTTPS.
+
+The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
+for streaming multimedia content within HTTPS requests to traverse
+firewalls.
+
@section rtmp, rtmpe, rtmps, rtmpt, rtmpte
Real-Time Messaging Protocol and its variants supported through
librtmp.
-Require the presence of the headers and library of librtmp during
-configuration. You need to explicitely configure the build with
+Requires the presence of the librtmp headers and library during
+configuration. You need to explicitly configure the build with
"--enable-librtmp". If enabled this will replace the native RTMP
protocol.
where @var{rtmp_proto} is one of the strings "rtmp", "rtmpt", "rtmpe",
"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
@var{server}, @var{port}, @var{app} and @var{playpath} have the same
-meaning has specified for the RTMP native protocol.
+meaning as specified for the RTMP native protocol.
@var{options} contains a list of space-separated options of the form
@var{key}=@var{val}.
-See the manual page of librtmp (man 3 librtmp) for more information.
+See the librtmp manual page (man 3 librtmp) for more information.
For example, to stream a file in real-time to an RTMP server using
-@file{ffmpeg}:
+@command{avconv}:
@example
-ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
+avconv -re -i myfile -f flv rtmp://myserver/live/mystream
@end example
-To play the same stream using @file{ffplay}:
+To play the same stream using @command{avplay}:
@example
-ffplay "rtmp://myserver/live/mystream live=1"
+avplay "rtmp://myserver/live/mystream live=1"
@end example
@section rtp
Real-Time Protocol.
+@section rtsp
+
+RTSP is not technically a protocol handler in libavformat, it is a demuxer
+and muxer. The demuxer supports both normal RTSP (with data transferred
+over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
+data transferred over RDT).
+
+The muxer can be used to send a stream using RTSP ANNOUNCE to a server
+supporting it (currently Darwin Streaming Server and Mischa Spiegelmock's
+@uref{http://github.com/revmischa/rtsp-server, RTSP server}).
+
+The required syntax for a RTSP url is:
+@example
+rtsp://@var{hostname}[:@var{port}]/@var{path}
+@end example
+
+The following options (set on the @command{avconv}/@command{avplay} command
+line, or set in code via @code{AVOption}s or in @code{avformat_open_input}),
+are supported:
+
+Flags for @code{rtsp_transport}:
+
+@table @option
+
+@item udp
+Use UDP as lower transport protocol.
+
+@item tcp
+Use TCP (interleaving within the RTSP control channel) as lower
+transport protocol.
+
+@item udp_multicast
+Use UDP multicast as lower transport protocol.
+
+@item http
+Use HTTP tunneling as lower transport protocol, which is useful for
+passing proxies.
+@end table
+
+Multiple lower transport protocols may be specified, in that case they are
+tried one at a time (if the setup of one fails, the next one is tried).
+For the muxer, only the @code{tcp} and @code{udp} options are supported.
+
+Flags for @code{rtsp_flags}:
+
+@table @option
+@item filter_src
+Accept packets only from negotiated peer address and port.
+@item listen
+Act as a server, listening for an incoming connection.
+@end table
+
+When receiving data over UDP, the demuxer tries to reorder received packets
+(since they may arrive out of order, or packets may get lost totally). This
+can be disabled by setting the maximum demuxing delay to zero (via
+the @code{max_delay} field of AVFormatContext).
+
+When watching multi-bitrate Real-RTSP streams with @command{avplay}, the
+streams to display can be chosen with @code{-vst} @var{n} and
+@code{-ast} @var{n} for video and audio respectively, and can be switched
+on the fly by pressing @code{v} and @code{a}.
+
+Example command lines:
+
+To watch a stream over UDP, with a max reordering delay of 0.5 seconds:
+
+@example
+avplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
+@end example
+
+To watch a stream tunneled over HTTP:
+
+@example
+avplay -rtsp_transport http rtsp://server/video.mp4
+@end example
+
+To send a stream in realtime to a RTSP server, for others to watch:
+
+@example
+avconv -re -i @var{input} -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
+@end example
+
+To receive a stream in realtime:
+
+@example
+avconv -rtsp_flags listen -i rtsp://ownaddress/live.sdp @var{output}
+@end example
+
+@section sap
+
+Session Announcement Protocol (RFC 2974). This is not technically a
+protocol handler in libavformat, it is a muxer and demuxer.
+It is used for signalling of RTP streams, by announcing the SDP for the
+streams regularly on a separate port.
+
+@subsection Muxer
+
+The syntax for a SAP url given to the muxer is:
+@example
+sap://@var{destination}[:@var{port}][?@var{options}]
+@end example
+
+The RTP packets are sent to @var{destination} on port @var{port},
+or to port 5004 if no port is specified.
+@var{options} is a @code{&}-separated list. The following options
+are supported:
+
+@table @option
+
+@item announce_addr=@var{address}
+Specify the destination IP address for sending the announcements to.
+If omitted, the announcements are sent to the commonly used SAP
+announcement multicast address 224.2.127.254 (sap.mcast.net), or
+ff0e::2:7ffe if @var{destination} is an IPv6 address.
+
+@item announce_port=@var{port}
+Specify the port to send the announcements on, defaults to
+9875 if not specified.
+
+@item ttl=@var{ttl}
+Specify the time to live value for the announcements and RTP packets,
+defaults to 255.
+
+@item same_port=@var{0|1}
+If set to 1, send all RTP streams on the same port pair. If zero (the
+default), all streams are sent on unique ports, with each stream on a
+port 2 numbers higher than the previous.
+VLC/Live555 requires this to be set to 1, to be able to receive the stream.
+The RTP stack in libavformat for receiving requires all streams to be sent
+on unique ports.
+@end table
+
+Example command lines follow.
+
+To broadcast a stream on the local subnet, for watching in VLC:
+
+@example
+avconv -re -i @var{input} -f sap sap://224.0.0.255?same_port=1
+@end example
+
+Similarly, for watching in avplay:
+
+@example
+avconv -re -i @var{input} -f sap sap://224.0.0.255
+@end example
+
+And for watching in avplay, over IPv6:
+
+@example
+avconv -re -i @var{input} -f sap sap://[ff0e::1:2:3:4]
+@end example
+
+@subsection Demuxer
+
+The syntax for a SAP url given to the demuxer is:
+@example
+sap://[@var{address}][:@var{port}]
+@end example
+
+@var{address} is the multicast address to listen for announcements on,
+if omitted, the default 224.2.127.254 (sap.mcast.net) is used. @var{port}
+is the port that is listened on, 9875 if omitted.
+
+The demuxers listens for announcements on the given address and port.
+Once an announcement is received, it tries to receive that particular stream.
+
+Example command lines follow.
+
+To play back the first stream announced on the normal SAP multicast address:
+
+@example
+avplay sap://
+@end example
+
+To play back the first stream announced on one the default IPv6 SAP multicast address:
+
+@example
+avplay sap://[ff0e::2:7ffe]
+@end example
+
@section tcp
Trasmission Control Protocol.
+The required syntax for a TCP url is:
+@example
+tcp://@var{hostname}:@var{port}[?@var{options}]
+@end example
+
+@table @option
+
+@item listen
+Listen for an incoming connection
+
+@example
+avconv -i @var{input} -f @var{format} tcp://@var{hostname}:@var{port}?listen
+avplay tcp://@var{hostname}:@var{port}
+@end example
+
+@end table
+
@section udp
User Datagram Protocol.
+The required syntax for a UDP url is:
+@example
+udp://@var{hostname}:@var{port}[?@var{options}]
+@end example
+
+@var{options} contains a list of &-seperated options of the form @var{key}=@var{val}.
+Follow the list of supported options.
+
+@table @option
+
+@item buffer_size=@var{size}
+set the UDP buffer size in bytes
+
+@item localport=@var{port}
+override the local UDP port to bind with
+
+@item localaddr=@var{addr}
+Choose the local IP address. This is useful e.g. if sending multicast
+and the host has multiple interfaces, where the user can choose
+which interface to send on by specifying the IP address of that interface.
+
+@item pkt_size=@var{size}
+set the size in bytes of UDP packets
+
+@item reuse=@var{1|0}
+explicitly allow or disallow reusing UDP sockets
+
+@item ttl=@var{ttl}
+set the time to live value (for multicast only)
+
+@item connect=@var{1|0}
+Initialize the UDP socket with @code{connect()}. In this case, the
+destination address can't be changed with ff_udp_set_remote_url later.
+If the destination address isn't known at the start, this option can
+be specified in ff_udp_set_remote_url, too.
+This allows finding out the source address for the packets with getsockname,
+and makes writes return with AVERROR(ECONNREFUSED) if "destination
+unreachable" is received.
+For receiving, this gives the benefit of only receiving packets from
+the specified peer address/port.
+
+@item sources=@var{address}[,@var{address}]
+Only receive packets sent to the multicast group from one of the
+specified sender IP addresses.
+
+@item block=@var{address}[,@var{address}]
+Ignore packets sent to the multicast group from the specified
+sender IP addresses.
+@end table
+
+Some usage examples of the udp protocol with @command{avconv} follow.
+
+To stream over UDP to a remote endpoint:
+@example
+avconv -i @var{input} -f @var{format} udp://@var{hostname}:@var{port}
+@end example
+
+To stream in mpegts format over UDP using 188 sized UDP packets, using a large input buffer:
+@example
+avconv -i @var{input} -f mpegts udp://@var{hostname}:@var{port}?pkt_size=188&buffer_size=65535
+@end example
+
+To receive over UDP from a remote endpoint:
+@example
+avconv -i udp://[@var{multicast-address}]:@var{port}
+@end example
+
@c man end PROTOCOLS
projects / ffmpeg / blobdiff