@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
+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".
particular protocol using the option
"--disable-protocol=@var{PROTOCOL}".
-The option "-protocols" of the ff* tools will display the list of
+The option "-protocols" of the av* tools will display the list of
supported protocols.
+All protocols accept the following options:
+
+@table @option
+@item rw_timeout
+Maximum time to wait for (network) read/write operations to complete,
+in microseconds.
+@end table
+
A description of the currently available protocols follows.
@section concat
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
-The ff* tools default to the file protocol, that is a resource
+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".
+This protocol accepts the following options:
+
+@table @option
+@item follow
+If set to 1, the protocol will retry reading at the end of the file, allowing
+reading files that still are being written. In order for this to terminate,
+you either need to use the rw_timeout option, or use the interrupt callback
+(for API users).
+
+@end table
+
@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 Transfer Protocol).
+This protocol accepts the following options:
+
+@table @option
+@item chunked_post
+If set to 1 use chunked Transfer-Encoding for posts, default is 1.
+
+@item content_type
+Set a specific content type for the POST messages.
+
+@item headers
+Set custom HTTP headers, can override built in default headers. The
+value must be a string encoding the headers.
+
+@item multiple_requests
+Use persistent connections if set to 1, default is 0.
+
+@item post_data
+Set custom HTTP post data.
+
+@item user_agent
+Override the User-Agent header. If not specified a string of the form
+"Lavf/<version>" will be used.
+
+@item mime_type
+Export the MIME type.
+
+@item icy
+If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
+supports this, the metadata has to be retrieved by the application by reading
+the @option{icy_metadata_headers} and @option{icy_metadata_packet} options.
+The default is 1.
+
+@item icy_metadata_headers
+If the server supports ICY metadata, this contains the ICY-specific HTTP reply
+headers, separated by newline characters.
+
+@item icy_metadata_packet
+If the server supports ICY metadata, and @option{icy} was set to 1, this
+contains the last non-empty metadata packet sent by the server. It should be
+polled in regular intervals by applications interested in mid-stream metadata
+updates.
+
+@item offset
+Set initial byte offset.
+
+@item end_offset
+Try to limit the request to bytes preceding this offset.
+@end table
+
+@section Icecast
+
+Icecast (stream to Icecast servers)
+
+This protocol accepts the following options:
+
+@table @option
+@item ice_genre
+Set the stream genre.
+
+@item ice_name
+Set the stream name.
+
+@item ice_description
+Set the stream description.
+
+@item ice_url
+Set the stream website URL.
+
+@item ice_public
+Set if the stream should be public or not.
+The default is 0 (not public).
+
+@item user_agent
+Override the User-Agent header. If not specified a string of the form
+"Lavf/<version>" will be used.
+
+@item password
+Set the Icecast mountpoint password.
+
+@item content_type
+Set the stream content type. This must be set if it is different from
+audio/mpeg.
+
+@item legacy_icecast
+This enables support for Icecast versions < 2.4.0, that do not support the
+HTTP PUT method but the SOURCE method.
+
+@end table
+
@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.
Some examples follow.
@example
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5: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:
+avconv -i input.flv -f avi -y md5:
@end example
Note that some formats (typically MOV) require the output protocol to
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
+cat test.wav | avconv -i pipe:0
# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
+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
+avconv -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: | cat > test.avi
@end example
Note that some formats (typically MOV), require the output protocol to
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{username}:@var{password}@@]@var{server}[:@var{port}][/@var{app}][/@var{instance}][/@var{playpath}]
@end example
The accepted parameters are:
@table @option
+@item username
+An optional username (mostly for publishing).
+
+@item password
+An optional password (mostly for publishing).
+
@item server
The address of the RTMP server.
@item app
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.).
+(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. (When publishing, the default is FMLE/3.0 (compatible;
+<libavformat version>).)
+
+@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
+
+To publish to a password protected server, passing the playpath and
+app names separately:
+@example
+avconv -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@@myserver/
@end example
-@section rtmp, rtmpe, rtmps, rtmpt, rtmpte
+@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 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte
Real-Time Messaging Protocol and its variants supported through
librtmp.
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitely configure the build with
+configuration. You need to explicitly configure the build with
"--enable-librtmp". If enabled this will replace the native RTMP
protocol.
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.
+Transmission 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 tls
+
+Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
+
+The required syntax for a TLS url is:
+@example
+tls://@var{hostname}:@var{port}
+@end example
+
+The following parameters can be set via command line options
+(or in code via @code{AVOption}s):
+
+@table @option
+
+@item ca_file
+A file containing certificate authority (CA) root certificates to treat
+as trusted. If the linked TLS library contains a default this might not
+need to be specified for verification to work, but not all libraries and
+setups have defaults built in.
+
+@item tls_verify=@var{1|0}
+If enabled, try to verify the peer that we are communicating with.
+Note, if using OpenSSL, this currently only makes sure that the
+peer certificate is signed by one of the root certificates in the CA
+database, but it does not validate that the certificate actually
+matches the host name we are trying to connect to. (With GnuTLS,
+the host name is validated as well.)
+
+This is disabled by default since it requires a CA database to be
+provided by the caller in many cases.
+
+@item cert_file
+A file containing a certificate to use in the handshake with the peer.
+(When operating as server, in listen mode, this is more often required
+by the peer, while client certificates only are mandated in certain
+setups.)
+
+@item key_file
+A file containing the private key for the certificate.
+
+@item listen=@var{1|0}
+If enabled, listen for connections on the provided port, and assume
+the server role in the handshake instead of the client role.
+
+@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 &-separated 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
+
+@section unix
+
+Unix local socket
+
+The required syntax for a Unix socket URL is:
+
+@example
+unix://@var{filepath}
+@end example
+
+The following parameters can be set via command line options
+(or in code via @code{AVOption}s):
+
+@table @option
+@item timeout
+Timeout in ms.
+@item listen
+Create the Unix socket in listening mode.
+@end table
+
@c man end PROTOCOLS
projects / ffmpeg / blobdiff