oasis-root

ffprobe.1 (34397B)

.Dd August 2, 2024
.Dt FFPROBE 7
.Os
.Sh NAME
.Nm ffprobe
.Nd ffprobe Documentation
.Sh 
.Sh  Synopsis
ffprobe [
.Va options
]
.Pa input_url
.Pp
.Sh  Description
ffprobe gathers information from multimedia streams and prints it in human-
and machine-readable fashion.
.Pp
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.
.Pp
If a url is specified in input, ffprobe will try to open and probe the url
content. If the url cannot be opened or recognized as a multimedia file, a
positive exit code is returned.
.Pp
If no output is specified as output with
.Op o
ffprobe will write to stdout.
.Pp
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.
.Pp
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.
.Pp
ffprobe output is designed to be easily parsable by a textual filter, and
consists of one or more sections of a form defined by the selected writer,
which is specified by the
.Op output_format
option.
.Pp
Sections may contain other nested sections, and are identified by a name (which
may be shared by other sections), and an unique name. See the output of
.Op sections .
.Pp
Metadata tags stored in the container or in the streams are recognized and
printed in the corresponding "FORMAT", "STREAM", "STREAM_GROUP_STREAM" or
"PROGRAM_STREAM" section.
.Pp
.Sh  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'.
.Pp
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.
.Pp
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.
.Pp
Options that take arguments support a special syntax where the argument given
on the command line is interpreted as a path to the file from which the actual
argument value is loaded. To use this feature, add a forward slash '/' immediately
before the option name (after the leading dash). E.g.
.Bd -literal -offset indent
ffmpeg -i INPUT -/filter:v filter.script OUTPUT
.Ed
will load a filtergraph description from the file named
.Pa filter.script .
.Pp
.Ss  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.
.Pp
A stream specifier is a string generally appended to the option name and separated
from it by a colon. E.g.
.Li -codec:a:1 ac3
contains the
.Li a:1
stream specifier, which matches the second audio stream. Therefore, it would
select the ac3 codec for the second audio stream.
.Pp
A stream specifier can match several streams, so that the option is applied
to all of them. E.g. the stream specifier in
.Li -b:a 128k
matches all audio streams.
.Pp
An empty stream specifier matches all streams. For example,
.Li -codec copy
or
.Li -codec: copy
would copy all the streams without reencoding.
.Pp
Possible forms of stream specifiers are:
.Bl -tag -width Ds
.It  Va stream_index
Matches the stream with this index. E.g.
.Li -threads:1 4
would set the thread count for the second stream to 4. If
.Va stream_index
is used as an additional stream specifier (see below), then it selects stream
number
.Va stream_index
from the matching streams. Stream numbering is based on the order of the streams
as detected by libavformat except when a stream group specifier or program
ID is also specified. In this case it is based on the ordering of the streams
in the group or program.
.It  Va stream_type[: Va additional_stream_specifier]
.Va 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
.Va additional_stream_specifier
is used, then it matches streams which both have this type and match the
.Va additional_stream_specifier .
Otherwise, it matches all streams of the specified type.
.It  g: Va group_specifier[: Va additional_stream_specifier]
Matches streams which are in the group with the specifier
.Va group_specifier .
if
.Va additional_stream_specifier
is used, then it matches streams which both are part of the group and match
the
.Va additional_stream_specifier .
.Va group_specifier
may be one of the following:
.Bl -tag -width Ds
.It  Va group_index
Match the stream with this group index.
.It  # Va group_id or i: Va group_id
Match the stream with this group id.
.El
.It  p: Va program_id[: Va additional_stream_specifier]
Matches streams which are in the program with the id
.Va program_id .
If
.Va additional_stream_specifier
is used, then it matches streams which both are part of the program and match
the
.Va additional_stream_specifier .
.Pp
.It  # Va stream_id or i: Va stream_id
Match the stream by stream id (e.g. PID in MPEG-TS container).
.It  m: Va key[: Va value]
Matches streams with the metadata tag
.Va key
having the specified value. If
.Va value
is not given, matches streams that contain the given tag with any value.
.It  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.
.Pp
Note that in
.Xr ffmpeg ,
matching by metadata will only work properly for input files.
.El
.Pp
.Ss  Generic options
These options are shared amongst the ff* tools.
.Pp
.Bl -tag -width Ds
.It  -L
Show license.
.Pp
.It  -h, -?, -help, --help [ Va 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.
.Pp
Possible values of
.Va arg
are:
.Bl -tag -width Ds
.It  long
Print advanced tool options in addition to the basic tool options.
.Pp
.It  full
Print complete list of options, including shared and private options for encoders,
decoders, demuxers, muxers, filters, etc.
.Pp
.It  decoder= Va decoder_name
Print detailed information about the decoder named
.Va decoder_name .
Use the
.Op -decoders
option to get a list of all decoders.
.Pp
.It  encoder= Va encoder_name
Print detailed information about the encoder named
.Va encoder_name .
Use the
.Op -encoders
option to get a list of all encoders.
.Pp
.It  demuxer= Va demuxer_name
Print detailed information about the demuxer named
.Va demuxer_name .
Use the
.Op -formats
option to get a list of all demuxers and muxers.
.Pp
.It  muxer= Va muxer_name
Print detailed information about the muxer named
.Va muxer_name .
Use the
.Op -formats
option to get a list of all muxers and demuxers.
.Pp
.It  filter= Va filter_name
Print detailed information about the filter named
.Va filter_name .
Use the
.Op -filters
option to get a list of all filters.
.Pp
.It  bsf= Va bitstream_filter_name
Print detailed information about the bitstream filter named
.Va bitstream_filter_name .
Use the
.Op -bsfs
option to get a list of all bitstream filters.
.Pp
.It  protocol= Va protocol_name
Print detailed information about the protocol named
.Va protocol_name .
Use the
.Op -protocols
option to get a list of all protocols.
.El
.Pp
.It  -version
Show version.
.Pp
.It  -buildconf
Show the build configuration, one option per line.
.Pp
.It  -formats
Show available formats (including devices).
.Pp
.It  -demuxers
Show available demuxers.
.Pp
.It  -muxers
Show available muxers.
.Pp
.It  -devices
Show available devices.
.Pp
.It  -codecs
Show all codecs known to libavcodec.
.Pp
Note that the term 'codec' is used throughout this documentation as a shortcut
for what is more correctly called a media bitstream format.
.Pp
.It  -decoders
Show available decoders.
.Pp
.It  -encoders
Show all available encoders.
.Pp
.It  -bsfs
Show available bitstream filters.
.Pp
.It  -protocols
Show available protocols.
.Pp
.It  -filters
Show available libavfilter filters.
.Pp
.It  -pix_fmts
Show available pixel formats.
.Pp
.It  -sample_fmts
Show available sample formats.
.Pp
.It  -layouts
Show channel names and standard channel layouts.
.Pp
.It  -dispositions
Show stream dispositions.
.Pp
.It  -colors
Show recognized color names.
.Pp
.It  -sources Va device[, Va opt1= Va val1[, Va opt2= Va val2]...]
Show autodetected sources of the input device. Some devices may provide system-dependent
source names that cannot be autodetected. The returned list cannot be assumed
to be always complete.
.Bd -literal -offset indent
ffmpeg -sources pulse,server=192.168.0.4
.Ed
.Pp
.It  -sinks Va device[, Va opt1= Va val1[, Va opt2= Va 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.
.Bd -literal -offset indent
ffmpeg -sinks pulse,server=192.168.0.4
.Ed
.Pp
.It  -loglevel [ Va flags+] Va loglevel | -v [ Va flags+] Va loglevel
Set logging level and flags used by the library.
.Pp
The optional
.Va flags
prefix can consist of the following values:
.Bl -tag -width Ds
.It  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.
.It  level
Indicates that log output should add a
.Li [level]
prefix to each message line. This can be used as an alternative to log coloring,
e.g. when dumping the log to file.
.El
Flags can also be used alone by adding a '+'/'-' prefix to set/reset a single
flag without affecting other
.Va flags
or changing
.Va loglevel .
When setting both
.Va flags
and
.Va loglevel ,
a '+' separator is expected between the last
.Va flags
value and before
.Va loglevel .
.Pp
.Va loglevel
is a string or a number containing one of the following values:
.Bl -tag -width Ds
.It  quiet, -8
Show nothing at all; be silent.
.It  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.
.It  fatal, 8
Only show fatal errors. These are errors after which the process absolutely
cannot continue.
.It  error, 16
Show all errors, including ones which can be recovered from.
.It  warning, 24
Show all warnings and errors. Any message related to possibly incorrect or
unexpected events will be shown.
.It  info, 32
Show informative messages during processing. This is in addition to warnings
and errors. This is the default value.
.It  verbose, 40
Same as
.Li info ,
except more verbose.
.It  debug, 48
Show everything, including debugging information.
.It  trace, 56
.El
.Pp
For example to enable repeated log output, add the
.Li level
prefix, and set
.Va loglevel
to
.Li verbose :
.Bd -literal -offset indent
ffmpeg -loglevel repeat+level+verbose -i input output
.Ed
Another example that enables repeated log output without affecting current
state of
.Li level
prefix flag or
.Va loglevel :
.Bd -literal -offset indent
ffmpeg [...] -loglevel +repeat
.Ed
.Pp
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
.Ev AV_LOG_FORCE_NOCOLOR ,
or can be forced setting the environment variable
.Ev AV_LOG_FORCE_COLOR .
.Pp
.It  -report
Dump full command line and log output to a file named
.Li  Va program- Va YYYYMMDD- Va HHMMSS.log
in the current directory. This file can be useful for bug reports. It also
implies
.Li -loglevel debug .
.Pp
Setting the environment variable
.Ev 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 \(lqQuoting
and escaping\(rq section in the ffmpeg-utils manual).
.Pp
The following options are recognized:
.Bl -tag -width Ds
.It  file
set the file name to use for the report;
.Li %p
is expanded to the name of the program,
.Li %t
is expanded to a timestamp,
.Li %%
is expanded to a plain
.Li %
.It  level
set the log verbosity level using a numerical value (see
.Li -loglevel ) .
.El
.Pp
For example, to output a report to a file named
.Pa ffreport.log
using a log level of
.Li 32
(alias for log level
.Li info ) :
.Pp
.Bd -literal -offset indent
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
.Ed
.Pp
Errors in parsing the environment variable are not fatal, and will not appear
in the report.
.Pp
.It  -hide_banner
Suppress printing banner.
.Pp
All FFmpeg tools will normally show a copyright notice, build options and
library versions. This option can be used to suppress printing this information.
.Pp
.It  -cpuflags flags ( Em global)
Allows setting and clearing cpu flags. This option is intended for testing.
Do not use it unless you know what you're doing.
.Bd -literal -offset indent
ffmpeg -cpuflags -sse+mmx ...
ffmpeg -cpuflags mmx ...
ffmpeg -cpuflags 0 ...
.Ed
Possible flags for this option are:
.Bl -tag -width Ds
.It  x86
.Bl -tag -width Ds
.It  mmx
.It  mmxext
.It  sse
.It  sse2
.It  sse2slow
.It  sse3
.It  sse3slow
.It  ssse3
.It  atom
.It  sse4.1
.It  sse4.2
.It  avx
.It  avx2
.It  xop
.It  fma3
.It  fma4
.It  3dnow
.It  3dnowext
.It  bmi1
.It  bmi2
.It  cmov
.El
.It  ARM
.Bl -tag -width Ds
.It  armv5te
.It  armv6
.It  armv6t2
.It  vfp
.It  vfpv3
.It  neon
.It  setend
.El
.It  AArch64
.Bl -tag -width Ds
.It  armv8
.It  vfp
.It  neon
.El
.It  PowerPC
.Bl -tag -width Ds
.It  altivec
.El
.It  Specific Processors
.Bl -tag -width Ds
.It  pentium2
.It  pentium3
.It  pentium4
.It  k6
.It  k62
.It  athlon
.It  athlonxp
.It  k8
.El
.El
.Pp
.It  -cpucount Va count ( Em global)
Override detection of CPU count. This option is intended for testing. Do not
use it unless you know what you're doing.
.Bd -literal -offset indent
ffmpeg -cpucount 2
.Ed
.Pp
.It  -max_alloc Va bytes
Set the maximum size limit for allocating a block on the heap by ffmpeg's
family of malloc functions. Exercise
.Sy extreme caution
when using this option. Don't use if you do not understand the full consequence
of doing so. Default is INT_MAX.
.El
.Pp
.Ss  AVOptions
These options are provided directly by the libavformat, libavdevice and libavcodec
libraries. To see the list of available AVOptions, use the
.Op -help
option. They are separated into two categories:
.Bl -tag -width Ds
.It  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.
.It  private
These options are specific to the given container, device or codec. Private
options are listed under their corresponding containers/devices/codecs.
.El
.Pp
For example to write an ID3v2.3 header instead of a default ID3v2.4 to an
MP3 file, use the
.Op id3v2_version
private option of the MP3 muxer:
.Bd -literal -offset indent
ffmpeg -i input.flac -id3v2_version 3 out.mp3
.Ed
.Pp
All codec AVOptions are per-stream, and thus a stream specifier should be
attached to them:
.Bd -literal -offset indent
ffmpeg -i multichannel.mxf -map 0:v:0 -map 0:a:0 -map 0:a:0 -c:a:0 ac3 -b:a:0 640k -ac:a:1 2 -c:a:1 aac -b:2 128k out.mp4
.Ed
.Pp
In the above example, a multichannel audio stream is mapped twice for output.
The first instance is encoded with codec ac3 and bitrate 640k. The second
instance is downmixed to 2 channels and encoded with codec aac. A bitrate
of 128k is specified for it using absolute index of the output stream.
.Pp
Note: the
.Op -nooption
syntax cannot be used for boolean AVOptions, use
.Op -option 0
/
.Op -option 1 .
.Pp
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.
.Pp
.Ss  Main options
.Bl -tag -width Ds
.It  -f Va format
Force format to use.
.Pp
.It  -unit
Show the unit of the displayed values.
.Pp
.It  -prefix
Use SI prefixes for the displayed values. Unless the "-byte_binary_prefix"
option is used all the prefixes are decimal.
.Pp
.It  -byte_binary_prefix
Force the use of binary prefixes for byte values.
.Pp
.It  -sexagesimal
Use sexagesimal format HH:MM:SS.MICROSECONDS for time values.
.Pp
.It  -pretty
Prettify the format of the displayed values, it corresponds to the options
"-unit -prefix -byte_binary_prefix -sexagesimal".
.Pp
.It  -output_format, -of, -print_format Va writer_name[= Va writer_options]
Set the output printing format.
.Pp
.Va writer_name
specifies the name of the writer, and
.Va writer_options
specifies the options to be passed to the writer.
.Pp
For example for printing the output in JSON format, specify:
.Bd -literal -offset indent
-output_format json
.Ed
.Pp
For more details on the available output printing formats, see the Writers
section below.
.Pp
.It  -sections
Print sections structure and section information, and exit. The output is
not meant to be parsed by a machine.
.Pp
.It  -select_streams Va stream_specifier
Select only the streams specified by
.Va stream_specifier .
This option affects only the options related to streams (e.g.
.Li show_streams ,
.Li show_packets ,
etc.).
.Pp
For example to show only audio streams, you can use the command:
.Bd -literal -offset indent
ffprobe -show_streams -select_streams a INPUT
.Ed
.Pp
To show only video packets belonging to the video stream with index 1:
.Bd -literal -offset indent
ffprobe -show_packets -select_streams v:1 INPUT
.Ed
.Pp
.It  -show_data
Show payload data, as a hexadecimal and ASCII dump. Coupled with
.Op -show_packets ,
it will dump the packets' data. Coupled with
.Op -show_streams ,
it will dump the codec extradata.
.Pp
The dump is printed as the "data" field. It may contain newlines.
.Pp
.It  -show_data_hash Va algorithm
Show a hash of payload data, for packets with
.Op -show_packets
and for codec extradata with
.Op -show_streams .
.Pp
.It  -show_error
Show information about the error found when trying to probe the input.
.Pp
The error information is printed within a section with name "ERROR".
.Pp
.It  -show_format
Show information about the container format of the input multimedia stream.
.Pp
All the container format information is printed within a section with name
"FORMAT".
.Pp
.It  -show_format_entry Va name
Like
.Op -show_format ,
but only prints the specified entry of the container format information, rather
than all. This option may be given more than once, then all specified entries
will be shown.
.Pp
This option is deprecated, use
.Li show_entries
instead.
.Pp
.It  -show_entries Va section_entries
Set list of entries to show.
.Pp
Entries are specified according to the following syntax.
.Va section_entries
contains a list of section entries separated by
.Li : .
Each section entry is composed by a section name (or unique name), optionally
followed by a list of entries local to that section, separated by
.Li , .
.Pp
If section name is specified but is followed by no
.Li = ,
all entries are printed to output, together with all the contained sections.
Otherwise only the entries specified in the local section entries list are
printed. In particular, if
.Li =
is specified but the list of local entries is empty, then no entries will
be shown for that section.
.Pp
Note that the order of specification of the local section entries is not honored
in the output, and the usual display order will be retained.
.Pp
The formal syntax is given by:
.Bd -literal -offset indent
LOCAL_SECTION_ENTRIES ::= SECTION_ENTRY_NAME[,LOCAL_SECTION_ENTRIES]
SECTION_ENTRY         ::= SECTION_NAME[=[LOCAL_SECTION_ENTRIES]]
SECTION_ENTRIES       ::= SECTION_ENTRY[:SECTION_ENTRIES]
.Ed
.Pp
For example, to show only the index and type of each stream, and the PTS time,
duration time, and stream index of the packets, you can specify the argument:
.Bd -literal -offset indent
packet=pts_time,duration_time,stream_index : stream=index,codec_type
.Ed
.Pp
To show all the entries in the section "format", but only the codec type in
the section "stream", specify the argument:
.Bd -literal -offset indent
format : stream=codec_type
.Ed
.Pp
To show all the tags in the stream and format sections:
.Bd -literal -offset indent
stream_tags : format_tags
.Ed
.Pp
To show only the
.Li title
tag (if available) in the stream sections:
.Bd -literal -offset indent
stream_tags=title
.Ed
.Pp
.It  -show_packets
Show information about each packet contained in the input multimedia stream.
.Pp
The information for each single packet is printed within a dedicated section
with name "PACKET".
.Pp
.It  -show_frames
Show information about each frame and subtitle contained in the input multimedia
stream.
.Pp
The information for each single frame is printed within a dedicated section
with name "FRAME" or "SUBTITLE".
.Pp
.It  -show_log Va loglevel
Show logging information from the decoder about each frame according to the
value set in
.Va loglevel ,
(see
.Li -loglevel ) .
This option requires
.Li -show_frames .
.Pp
The information for each log message is printed within a dedicated section
with name "LOG".
.Pp
.It  -show_streams
Show information about each media stream contained in the input multimedia
stream.
.Pp
Each media stream information is printed within a dedicated section with name
"STREAM".
.Pp
.It  -show_programs
Show information about programs and their streams contained in the input multimedia
stream.
.Pp
Each media stream information is printed within a dedicated section with name
"PROGRAM_STREAM".
.Pp
.It  -show_stream_groups
Show information about stream groups and their streams contained in the input
multimedia stream.
.Pp
Each media stream information is printed within a dedicated section with name
"STREAM_GROUP_STREAM".
.Pp
.It  -show_chapters
Show information about chapters stored in the format.
.Pp
Each chapter is printed within a dedicated section with name "CHAPTER".
.Pp
.It  -count_frames
Count the number of frames per stream and report it in the corresponding stream
section.
.Pp
.It  -count_packets
Count the number of packets per stream and report it in the corresponding
stream section.
.Pp
.It  -read_intervals Va read_intervals
.Pp
Read only the specified intervals.
.Va read_intervals
must be a sequence of interval specifications separated by ",".
.Xr ffprobe
will seek to the interval starting point, and will continue reading from that.
.Pp
Each interval is specified by two optional parts, separated by "%".
.Pp
The first part specifies the interval start position. It is interpreted as
an absolute position, or as a relative offset from the current position if
it is preceded by the "+" character. If this first part is not specified,
no seeking will be performed when reading this interval.
.Pp
The second part specifies the interval end position. It is interpreted as
an absolute position, or as a relative offset from the current position if
it is preceded by the "+" character. If the offset specification starts with
"#", it is interpreted as the number of packets to read (not including the
flushing packets) from the interval start. If no second part is specified,
the program will read until the end of the input.
.Pp
Note that seeking is not accurate, thus the actual interval start point may
be different from the specified position. Also, when an interval duration
is specified, the absolute end time will be computed by adding the duration
to the interval start point found by seeking the file, rather than to the
specified start value.
.Pp
The formal syntax is given by:
.Bd -literal -offset indent
INTERVAL  ::= [START|+START_OFFSET][%[END|+END_OFFSET]]
INTERVALS ::= INTERVAL[,INTERVALS]
.Ed
.Pp
A few examples follow.
.Bl -bullet
.It
Seek to time 10, read packets until 20 seconds after the found seek point,
then seek to position
.Li 01:30
(1 minute and thirty seconds) and read packets until position
.Li 01:45 .
.Bd -literal -offset indent
10%+20,01:30%01:45
.Ed
.Pp
.It
Read only 42 packets after seeking to position
.Li 01:23 :
.Bd -literal -offset indent
01:23%+#42
.Ed
.Pp
.It
Read only the first 20 seconds from the start:
.Bd -literal -offset indent
%+20
.Ed
.Pp
.It
Read from the start until position
.Li 02:30 :
.Bd -literal -offset indent
%02:30
.Ed
.El
.Pp
.It  -show_private_data, -private
Show private data, that is data depending on the format of the particular
shown element. This option is enabled by default, but you may need to disable
it for specific uses, for example when creating XSD-compliant XML output.
.Pp
.It  -show_program_version
Show information related to program version.
.Pp
Version information is printed within a section with name "PROGRAM_VERSION".
.Pp
.It  -show_library_versions
Show information related to library versions.
.Pp
Version information for each library is printed within a section with name
"LIBRARY_VERSION".
.Pp
.It  -show_versions
Show information related to program and library versions. This is the equivalent
of setting both
.Op -show_program_version
and
.Op -show_library_versions
options.
.Pp
.It  -show_pixel_formats
Show information about all pixel formats supported by FFmpeg.
.Pp
Pixel format information for each format is printed within a section with
name "PIXEL_FORMAT".
.Pp
.It  -show_optional_fields Va value
Some writers viz. JSON and XML, omit the printing of fields with invalid or
non-applicable values, while other writers always print them. This option
enables one to control this behaviour. Valid values are
.Li always
/
.Li 1 ,
.Li never
/
.Li 0
and
.Li auto
/
.Li -1 .
Default is
.Va auto .
.Pp
.It  -bitexact
Force bitexact output, useful to produce output which is not dependent on
the specific build.
.Pp
.It  -i Va input_url
Read
.Va input_url .
.Pp
.It  -o Va output_url
Write output to
.Va output_url .
If not specified, the output is sent to stdout.
.Pp
.El
.Sh  Writers
A writer defines the output format adopted by
.Xr ffprobe ,
and will be used for printing all the parts of the output.
.Pp
A writer may accept one or more arguments, which specify the options to adopt.
The options are specified as a list of
.Va key
=
.Va value
pairs, separated by ":".
.Pp
All writers support the following options:
.Pp
.Bl -tag -width Ds
.It  string_validation, sv
Set string validation mode.
.Pp
The following values are accepted.
.Bl -tag -width Ds
.It  fail
The writer will fail immediately in case an invalid string (UTF-8) sequence
or code point is found in the input. This is especially useful to validate
input metadata.
.Pp
.It  ignore
Any validation error will be ignored. This will result in possibly broken
output, especially with the json or xml writer.
.Pp
.It  replace
The writer will substitute invalid UTF-8 sequences or code points with the
string specified with the
.Op string_validation_replacement .
.El
.Pp
Default value is
.Li replace .
.Pp
.It  string_validation_replacement, svr
Set replacement string to use in case
.Op string_validation
is set to
.Li replace .
.Pp
In case the option is not specified, the writer will assume the empty string,
that is it will remove the invalid sequences from the input strings.
.El
.Pp
A description of the currently available writers follows.
.Pp
.Ss  default
Default format.
.Pp
Print each section in the form:
.Bd -literal -offset indent
[SECTION]
key1=val1
\&...
keyN=valN
[/SECTION]
.Ed
.Pp
Metadata tags are printed as a line in the corresponding FORMAT, STREAM, STREAM_GROUP_STREAM
or PROGRAM_STREAM section, and are prefixed by the string "TAG:".
.Pp
A description of the accepted options follows.
.Pp
.Bl -tag -width Ds
.It  nokey, nk
If set to 1 specify not to print the key of each field. Default value is 0.
.Pp
.It  noprint_wrappers, nw
If set to 1 specify not to print the section header and footer. Default value
is 0.
.El
.Pp
.Ss  compact, csv
Compact and CSV format.
.Pp
The
.Li csv
writer is equivalent to
.Li compact ,
but supports different defaults.
.Pp
Each section is printed on a single line. If no option is specified, the output
has the form:
.Bd -literal -offset indent
section|key1=val1| ... |keyN=valN
.Ed
.Pp
Metadata tags are printed in the corresponding "format" or "stream" section.
A metadata tag key, if printed, is prefixed by the string "tag:".
.Pp
The description of the accepted options follows.
.Pp
.Bl -tag -width Ds
.It  item_sep, s
Specify the character to use for separating fields in the output line. It
must be a single printable character, it is "|" by default ("," for the
.Li csv
writer).
.Pp
.It  nokey, nk
If set to 1 specify not to print the key of each field. Its default value
is 0 (1 for the
.Li csv
writer).
.Pp
.It  escape, e
Set the escape mode to use, default to "c" ("csv" for the
.Li csv
writer).
.Pp
It can assume one of the following values:
.Bl -tag -width Ds
.It  c
Perform C-like escaping. Strings containing a newline (
.Li \en ) ,
carriage return (
.Li \er ) ,
a tab (
.Li \et ) ,
a form feed (
.Li \ef ) ,
the escaping character (
.Li \e )
or the item separator character
.Va SEP
are escaped using C-like fashioned escaping, so that a newline is converted
to the sequence
.Li \en ,
a carriage return to
.Li \er ,
.Li \e
to
.Li \e\e
and the separator
.Va SEP
is converted to
.Li \e Va SEP .
.Pp
.It  csv
Perform CSV-like escaping, as described in RFC4180. Strings containing a newline
(
.Li \en ) ,
a carriage return (
.Li \er ) ,
a double quote (
.Li " ) ,
or
.Va SEP
are enclosed in double-quotes.
.Pp
.It  none
Perform no escaping.
.El
.Pp
.It  print_section, p
Print the section name at the beginning of each line if the value is
.Li 1 ,
disable it with value set to
.Li 0 .
Default value is
.Li 1 .
.Pp
.El
.Ss  flat
Flat format.
.Pp
A free-form output where each line contains an explicit key=value, such as
"streams.stream.3.tags.foo=bar". The output is shell escaped, so it can be
directly embedded in sh scripts as long as the separator character is an alphanumeric
character or an underscore (see
.Va sep_char
option).
.Pp
The description of the accepted options follows.
.Pp
.Bl -tag -width Ds
.It  sep_char, s
Separator character used to separate the chapter, the section name, IDs and
potential tags in the printed field key.
.Pp
Default value is
.Li . .
.Pp
.It  hierarchical, h
Specify if the section name specification should be hierarchical. If set to
1, and if there is more than one section in the current chapter, the section
name will be prefixed by the name of the chapter. A value of 0 will disable
this behavior.
.Pp
Default value is 1.
.El
.Pp
.Ss  ini
INI format output.
.Pp
Print output in an INI based format.
.Pp
The following conventions are adopted:
.Pp
.Bl -bullet
.It
all key and values are UTF-8
.It
.Li .
is the subgroup separator
.It
newline,
.Li \et ,
.Li \ef ,
.Li \eb
and the following characters are escaped
.It
.Li \e
is the escape character
.It
.Li #
is the comment indicator
.It
.Li =
is the key/value separator
.It
.Li :
is not used but usually parsed as key/value separator
.El
.Pp
This writer accepts options as a list of
.Va key
=
.Va value
pairs, separated by
.Li : .
.Pp
The description of the accepted options follows.
.Pp
.Bl -tag -width Ds
.It  hierarchical, h
Specify if the section name specification should be hierarchical. If set to
1, and if there is more than one section in the current chapter, the section
name will be prefixed by the name of the chapter. A value of 0 will disable
this behavior.
.Pp
Default value is 1.
.El
.Pp
.Ss  json
JSON based format.
.Pp
Each section is printed using JSON notation.
.Pp
The description of the accepted options follows.
.Pp
.Bl -tag -width Ds
.It  compact, c
If set to 1 enable compact output, that is each section will be printed on
a single line. Default value is 0.
.El
.Pp
For more information about JSON, see
.Lk http://www.json.org/ .
.Pp
.Ss  xml
XML based format.
.Pp
The XML output is described in the XML schema description file
.Pa ffprobe.xsd
installed in the FFmpeg datadir.
.Pp
An updated version of the schema can be retrieved at the url
.Lk http://www.ffmpeg.org/schema/ffprobe.xsd ,
which redirects to the latest schema committed into the FFmpeg development
source code tree.
.Pp
Note that the output issued will be compliant to the
.Pa ffprobe.xsd
schema only when no special global output options (
.Op unit ,
.Op prefix ,
.Op byte_binary_prefix ,
.Op sexagesimal
etc.) are specified.
.Pp
The description of the accepted options follows.
.Pp
.Bl -tag -width Ds
.It  fully_qualified, q
If set to 1 specify if the output should be fully qualified. Default value
is 0. This is required for generating an XML file which can be validated through
an XSD file.
.Pp
.It  xsd_strict, x
If set to 1 perform more checks for ensuring that the output is XSD compliant.
Default value is 0. This option automatically sets
.Op fully_qualified
to 1.
.El
.Pp
For more information about the XML format, see
.Lk https://www.w3.org/XML/ .
.Pp
.Sh  Timecode
.Xr ffprobe
supports Timecode extraction:
.Pp
.Bl -bullet
.It
MPEG1/2 timecode is extracted from the GOP, and is available in the video
stream details (
.Op -show_streams ,
see
.Va timecode ) .
.Pp
.It
MOV timecode is extracted from tmcd track, so is available in the tmcd stream
metadata (
.Op -show_streams ,
see
.Va TAG:timecode ) .
.Pp
.It
DV, GXF and AVI timecodes are available in format metadata (
.Op -show_format ,
see
.Va TAG:timecode ) .
.Pp
.El
.Sh  See Also
ffmpeg(1), ffplay(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)
.Pp
.Sh  Authors
The FFmpeg developers.
.Pp
For details about the authorship, see the Git history of the project (https://git.ffmpeg.org/ffmpeg),
e.g. by typing the command
.Xr git log
in the FFmpeg source directory, or browsing the online repository at
.Lk https://git.ffmpeg.org/ffmpeg .
.Pp
Maintainers for the specific components are listed in the file
.Pa MAINTAINERS
in the source code tree.
.Pp