=head1 NAME

ffprobe - FFprobe media prober

=head1 SYNOPSIS

ffprobe [options] [F<input_file>]

=head1 DESCRIPTION


FFprobe gathers information from multimedia streams and prints it in
human- and machine-readable fashion.

For example it can be used to check the format of the container used
by a multimedia stream and the format and type of each media stream
contained in it.

If a filename is specified in input, ffprobe will try to open and
probe the file content. If the file cannot be opened or recognized as
a multimedia file, a positive exit code is returned.

FFprobe may be employed both as a standalone application or in
combination with a textual filter, which may perform more
sophisticated processing, e.g. statistical processing or plotting.

Options are used to list some of the formats supported by ffprobe or
for specifying which information to display, and for setting how
ffprobe will show it.

FFprobe output is designed to be easily parsable by a textual filter,
and consists of one or more sections of the form:
	
	[SECTION]
	key1=val1
	...
	keyN=valN
	[/SECTION]


Metadata tags stored in the container or in the streams are recognized
and printed in the corresponding "FORMAT" or "STREAM" section, and
are prefixed by the string "TAG:".


=head1 OPTIONS


All the numerical options, if not specified otherwise, accept in input
a string representing a number, which may contain one of the
International System number postfixes, for example 'K', 'M', 'G'.
If 'i' is appended after the postfix, powers of 2 are used instead of
powers of 10. The 'B' postfix multiplies the value for 8, and can be
appended after another postfix or used alone. This allows using for
example 'KB', 'MiB', 'G' and 'B' as postfix.

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


=head2 Generic options


These options are shared amongst the ff* tools.


=over 4



=item B<-L>

Show license.


=item B<-h, -?, -help, --help>

Show help.


=item B<-version>

Show version.


=item B<-formats>

Show available formats.

The fields preceding the format names have the following meanings:

=over 4


=item B<D>

Decoding available

=item B<E>

Encoding available

=back



=item B<-codecs>

Show available codecs.

The fields preceding the codec names have the following meanings:

=over 4


=item B<D>

Decoding available

=item B<E>

Encoding available

=item B<V/A/S>

Video/audio/subtitle codec

=item B<S>

Codec supports slices

=item B<D>

Codec supports direct rendering

=item B<T>

Codec can handle input truncated at random locations instead of only at frame boundaries

=back



=item B<-bsfs>

Show available bitstream filters.


=item B<-protocols>

Show available protocols.


=item B<-filters>

Show available libavfilter filters.


=item B<-pix_fmts>

Show available pixel formats.


=item B<-loglevel> I<loglevel>

Set the logging level used by the library.
I<loglevel> is a number or a string containing one of the following values:

=over 4


=item B<quiet>


=item B<panic>


=item B<fatal>


=item B<error>


=item B<warning>


=item B<info>


=item B<verbose>


=item B<debug>


=back


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 B<NO_COLOR>.


=back



=head2 Main options



=over 4



=item B<-convert_tags>

Convert the tag names in the format container to the generic FFmpeg tag names.


=item B<-f> I<format>

Force format to use.


=item B<-unit>

Show the unit of the displayed values.


=item B<-prefix>

Use SI prefixes for the displayed values.
Unless the "-byte_binary_prefix" option is used all the prefixes
are decimal.


=item B<-byte_binary_prefix>

Force the use of binary prefixes for byte values.


=item B<-sexagesimal>

Use sexagesimal format HH:MM:SS.MICROSECONDS for time values.


=item B<-pretty>

Prettify the format of the displayed values, it corresponds to the
options "-unit -prefix -byte_binary_prefix -sexagesimal".


=item B<-show_format>

Show information about the container format of the input multimedia
stream.

All the container format information is printed within a section with
name "FORMAT".


=item B<-show_packets>

Show information about each packet contained in the input multimedia
stream.

The information for each single packet is printed within a dedicated
section with name "PACKET".


=item B<-show_streams>

Show information about each media stream contained in the input
multimedia stream.

Each media stream information is printed within a dedicated section
with name "STREAM".


=back


=head1 PROTOCOLS


Protocols are configured elements in FFmpeg 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 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
option "--enable-protocol=I<PROTOCOL>", or you can disable a
particular protocol using the option
"--disable-protocol=I<PROTOCOL>".

The option "-protocols" of the ff* tools will display the list of
supported protocols.

A description of the currently available protocols follows.


=head2 concat


Physical concatenation protocol.

Allow to read and seek from many resource in sequence as if they were
a unique resource.

A URL accepted by this protocol has the syntax:
	
	concat:<URL1>|<URL2>|...|<URLN>


where I<URL1>, I<URL2>, ..., I<URLN> are the urls of the
resource to be concatenated, each one possibly specifying a distinct
protocol.

For example to read a sequence of files F<split1.mpeg>,
F<split2.mpeg>, F<split3.mpeg> with F<ffplay> use the
command:
	
	ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg


Note that you may need to escape the character "|" which is special for
many shells.


=head2 file


File access protocol.

Allow to read from or read to a file.

For example to read from a file F<input.mpeg> with F<ffmpeg>
use the command:
	
	ffmpeg -i file:input.mpeg output.mpeg


The ff* tools default to the file protocol, that is a resource
specified with the name "FILE.mpeg" is interpreted as the URL
"file:FILE.mpeg".


=head2 gopher


Gopher protocol.


=head2 http


HTTP (Hyper Text Transfer Protocol).


=head2 mmst


MMS (Microsoft Media Server) protocol over TCP.


=head2 mmsh


MMS (Microsoft Media Server) protocol over HTTP.

The required syntax is:
	
	mmsh://<server>[:<port>][/<app>][/<playpath>]



=head2 md5


MD5 output protocol.

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.
	
	# 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
	
	# Write the MD5 hash of the encoded AVI file to stdout.
	ffmpeg -i input.flv -f avi -y md5:


Note that some formats (typically MOV) require the output protocol to
be seekable, so they will fail with the MD5 output protocol.


=head2 pipe


UNIX pipe access protocol.

Allow to read and write from UNIX pipes.

The accepted syntax is:
	
	pipe:[<number>]


I<number> is the number corresponding to the file descriptor of the
pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr).  If I<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 F<ffmpeg>:
	
	cat test.wav | ffmpeg -i pipe:0
	# ...this is the same as...
	cat test.wav | ffmpeg -i pipe:


For writing to stdout with F<ffmpeg>:
	
	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


Note that some formats (typically MOV), require the output protocol to
be seekable, so they will fail with the pipe output protocol.


=head2 rtmp


Real-Time Messaging Protocol.

The Real-Time Messaging Protocol (RTMP) is used for streaming multime‐
dia content across a TCP/IP network.

The required syntax is:
	
	rtmp://<server>[:<port>][/<app>][/<playpath>]


The accepted parameters are:

=over 4



=item B<server>

The address of the RTMP server.


=item B<port>

The number of the TCP port to use (by default is 1935).


=item B<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. F</ondemand/>, F</flash/live/>, etc.).


=item B<playpath>

It is the path or name of the resource to play with reference to the
application specified in I<app>, may be prefixed by "mp4:".


=back


For example to read with F<ffplay> a multimedia resource named
"sample" from the application "vod" from an RTMP server "myserver":
	
	ffplay rtmp://myserver/vod/sample



=head2 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
"--enable-librtmp". If enabled this will replace the native RTMP
protocol.

This protocol provides most client functions and a few server
functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
variants of these encrypted types (RTMPTE, RTMPTS).

The required syntax is:
	
	<rtmp_proto>://<server>[:<port>][/<app>][/<playpath>] <options>


where I<rtmp_proto> is one of the strings "rtmp", "rtmpt", "rtmpe",
"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
I<server>, I<port>, I<app> and I<playpath> have the same
meaning as specified for the RTMP native protocol.
I<options> contains a list of space-separated options of the form
I<key>=I<val>.

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
F<ffmpeg>:
	
	ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream


To play the same stream using F<ffplay>:
	
	ffplay "rtmp://myserver/live/mystream live=1"



=head2 rtp


Real-Time Protocol.


=head2 tcp


Trasmission Control Protocol.


=head2 udp


User Datagram Protocol.


=head1 INPUT DEVICES


Input devices are configured elements in FFmpeg which allow to access
the data coming from a multimedia device attached to your system.

When you configure your FFmpeg build, all the supported input devices
are enabled by default. You can list all available ones using the
configure option "--list-indevs".

You can disable all the input devices using the configure option
"--disable-indevs", and selectively enable an input device using the
option "--enable-indev=I<INDEV>", or you can disable a particular
input device using the option "--disable-indev=I<INDEV>".

The option "-formats" of the ff* tools will display the list of
supported input devices (amongst the demuxers).

A description of the currently available input devices follows.


=head2 alsa


ALSA (Advanced Linux Sound Architecture) input device.

To enable this input device during configuration you need libasound
installed on your system.

This device allows capturing from an ALSA device. The name of the
device to capture has to be an ALSA card identifier.

An ALSA identifier has the syntax:
	
	hw:<CARD>[,<DEV>[,<SUBDEV>]]


where the I<DEV> and I<SUBDEV> components are optional.

The three arguments (in order: I<CARD>,I<DEV>,I<SUBDEV>)
specify card number or identifier, device number and subdevice number
(-1 means any).

To see the list of cards currently recognized by your system check the
files F</proc/asound/cards> and F</proc/asound/devices>.

For example to capture with F<ffmpeg> from an ALSA device with
card id 0, you may run the command:
	
	ffmpeg -f alsa -i hw:0 alsaout.wav


For more information see:
E<lt>B<http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html>E<gt>


=head2 bktr


BSD video input device.


=head2 dv1394


Linux DV 1394 input device.


=head2 jack


JACK input device.

To enable this input device during configuration you need libjack
installed on your system.

A JACK input device creates one or more JACK writable clients, one for
each audio channel, with name I<client_name>:input_I<N>, where
I<client_name> is the name provided by the application, and I<N>
is a number which identifies the channel.
Each writable client will send the acquired data to the FFmpeg input
device.

Once you have created one or more JACK readable clients, you need to
connect them to one or more JACK writable clients.

To connect or disconnect JACK clients you can use the
F<jack_connect> and F<jack_disconnect> programs, or do it
through a graphical interface, for example with F<qjackctl>.

To list the JACK clients and their properties you can invoke the command
F<jack_lsp>.

Follows an example which shows how to capture a JACK readable client
with F<ffmpeg>.
	
	# Create a JACK writable client with name "ffmpeg".
	$ ffmpeg -f jack -i ffmpeg -y out.wav
	
	# Start the sample jack_metro readable client.
	$ jack_metro -b 120 -d 0.2 -f 4000
	
	# List the current JACK clients.
	$ jack_lsp -c
	system:capture_1
	system:capture_2
	system:playback_1
	system:playback_2
	ffmpeg:input_1
	metro:120_bpm
	
	# Connect metro to the ffmpeg writable client.
	$ jack_connect metro:120_bpm ffmpeg:input_1


For more information read:
E<lt>B<http://jackaudio.org/>E<gt>


=head2 libdc1394


IIDC1394 input device, based on libdc1394 and libraw1394.


=head2 oss


Open Sound System input device.

The filename to provide to the input device is the device node
representing the OSS input device, and is usually set to
F</dev/dsp>.

For example to grab from F</dev/dsp> using F<ffmpeg> use the
command:
	
	ffmpeg -f oss -i /dev/dsp /tmp/oss.wav


For more information about OSS see:
E<lt>B<http://manuals.opensound.com/usersguide/dsp.html>E<gt>


=head2 video4linux and video4linux2


Video4Linux and Video4Linux2 input video devices.

The name of the device to grab is a file device node, usually Linux
systems tend to automatically create such nodes when the device
(e.g. an USB webcam) is plugged into the system, and has a name of the
kind F</dev/videoI<N>>, where I<N> is a number associated to
the device.

Video4Linux and Video4Linux2 devices only support a limited set of
I<width>xI<height> sizes and framerates. You can check which are
supported for example with the command F<dov4l> for Video4Linux
devices and the command F<v4l-info> for Video4Linux2 devices.

If the size for the device is set to 0x0, the input device will
try to autodetect the size to use.

Video4Linux support is deprecated since Linux 2.6.30, and will be
dropped in later versions.

Follow some usage examples of the video4linux devices with the ff*
tools.
	
	# Grab and show the input of a video4linux device.
	ffplay -s 320x240 -f video4linux /dev/video0
	
	# Grab and show the input of a video4linux2 device, autoadjust size.
	ffplay -f video4linux2 /dev/video0
	
	# Grab and record the input of a video4linux2 device, autoadjust size.
	ffmpeg -f video4linux2 -i /dev/video0 out.mpeg



=head2 vfwcap


VfW (Video for Windows) capture input device.


=head2 x11grab


X11 video input device.

This device allows to capture a region of an X11 display.

The filename passed as input has the syntax:
	
	[<hostname>]:<display_number>.<screen_number>[+<x_offset>,<y_offset>]


I<hostname>:I<display_number>.I<screen_number> specifies the
X11 display name of the screen to grab from. I<hostname> can be
ommitted, and defaults to "localhost". The environment variable
B<DISPLAY> contains the default display name.

I<x_offset> and I<y_offset> specify the offsets of the grabbed
area with respect to the top-left border of the X11 screen. They
default to 0.

Check the X11 documentation (e.g. man X) for more detailed information.

Use the F<dpyinfo> program for getting basic information about the
properties of your X11 display (e.g. grep for "name" or "dimensions").

For example to grab from F<:0.0> using F<ffmpeg>:
	
	ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg
	
	# Grab at position 10,20.
	ffmpeg -f x11grab -25 -s cif -i :0.0+10,20 out.mpg



=head1 SEE ALSO

ffmpeg(1), ffplay(1), ffserver(1) and the FFmpeg HTML documentation

=head1 AUTHORS

The FFmpeg developers

