flvmeta(1)
NAME
flvmeta - manipulate or extract metadata in Adobe Flash Video files
SYNOPSIS
flvmeta INPUT_FILE flvmeta INPUT_FILE OUTPUT_FILE flvmeta -D|--dump [options] INPUT_FILE flvmeta -F|--full-dump [options] INPUT_FILE flvmeta -C|--check [options] INPUT_FILE flvmeta -U|--update [options] INPUT_FILE [OUTPUT_FILE]
DESCRIPTION
flvmeta is a command-line utility aimed at manipulating Adobe(tm) Flash Video files (FLV), through several commands, only one of which can be used for each invocation of the program. It possesses the ability to compute and inject a variety of values in the onMetaData event tag, including keyframe indices used by most video players to allow random-access seeking, notably for HTTP pseudo-streamed files via a server-side module, by having the client send the file offset looked up for the nearest desired keyframe. Tools such as flvmeta must be used in the case the initial encoding process is unable to inject those metadata. It can also optionnally inject the onLastSecond event, used to signal the end of playback, for example to revert the player software to a 'stopped' state. flvmeta also has the ability to dump metadata and full file information to standard output, in a variety of textual output formats, including XML, YAML, and JSON. Finally, the program can analyze FLV files to detect potential problems and errors, and generate a textual report as a raw format, as JSON, or as XML. It has the ability to detect more than a hundred problems, going from harmless to potentially unplayable, using a few real world encountered issues. flvmeta can operate on arbitrarily large files, and can handle FLV files using extended (32-bit) timestamps. It can guess video frame dimensions for all known video codecs supported by the official FLV specification. Its memory usage remains minimal, as it uses a two-pass reading algorithm which permits the computation of all necessary tags without loading anything more than the file's tags headers in memory.
COMMANDS
Only one command can be specified for an invocation of flvmeta. The
chosen command determines the mode of execution of the program.
By default, if no command is specified, flvmeta will implicitly choose
the command to use according to the presence of INPUT_FILE and
OUTPUT_FILE.
If only INPUT_FILE is present, the --dump command will be executed.
If both INPUT_FILE and OUTPUT_FILE are present, the --update command
will be executed.
Here is a list of the supported commands:
-D, --dump
Dump a textual representation of the first onMetaData tag found in
INPUT_FILE to standard output. The default format is XML, unless
specified otherwise.
It is also possible to specify another event via the --event option,
such as onLastSecond.
-F, --full-dump
Dump a textual representation of the whole contents of INPUT_FILE to
standard output. The default format is XML, unless specified
otherwise.
-C, --check
Print a report to standard output listing warnings and errors detected
in INPUT_FILE, as well as potential incompatibilities, and information
about the codecs used in the file. The exit code will be set to a
non-zero value if there is at least one error in the file.
The output format can either be plain text, XML using the --xml option,
or JSON using the --json option. It can also be disabled altogether
using the --quiet option if you are only interested in the exit status.
Messages are divided into four specific levels of increasing
importance:
* info: informational messages that do not pertain to the file validity
* warning: messages that inform of oddities to the flv format but that
might not hamper file reading or playability, this is the default
level
* error: messages that inform of errors that might render the file
impossible to play or stream correctly
* fatal: messages that inform of errors that make further file reading
impossible therefore ending parsing completely
The --level option allows flvmeta to limit the display of messages to a
minimum level among those, for example if the user is only interested
in error messages and above.
Each message or message template presented to the user is identified by
a specific code of the following format:
[level][topic][id]
* level is an upper-case letter that can be either I, W, E, F according
to the aforementioned message levels
* topic is a two-digit integer representing the general topic of the
message
* id is a unique three-digit identifier for the message, or message
template if parameterized
Messages can be related to the following topics :
* 10 general flv file format
* 11 file header
* 12 previous tag size
* 20 tag format
* 30 tag types
* 40 timestamps
* 50 audio data
* 51 audio codecs
* 60 video data
* 61 video codecs
* 70 metadata
* 80 AMF data
* 81 keyframes
* 82 cue points
For example, represents a Warning in topic 51 with the id 050, which
represents a warning message related to audio codecs, in that case to
signal that an audio tag has an unknown codec.
-U, --update
Update the given input file by inserting a computed onMetaData tag. If
OUTPUT_FILE is specified, it will be created or overwritten instead and
the input file will not be modified. If the original file is to be
updated, a temporary file will be created in the default temp directory
of the platform, and it will be copied over the original file at the
end of the operation. This is due to the fact that the output file is
written while the original file is being read due to the two-pass
method.
The computed metadata contains among other data full keyframe
information, in order to allow HTTP pseudo-streaming and random-access
seeking in the file.
By default, an onLastSecond tag will be inserted, unless the
--no-last-second option is specified.
Normally overwritten by the update process, the existing metadata found
in the input file can be preserved by the --preserve option.
It is also possible to insert custom string values with the --add
option, which can be specified multiple times.
By default, the update operation is performed without output, unless
the --verbose option is specified, or the --print-metadata is used to
print the newly written metadata to the standard output.
OPTIONS
DUMP
-d FORMAT, --dump-format=FORMAT
specify dump format where FORMAT is 'xml' (default), 'json',
'raw', or 'yaml'. Also applicable for the --full-dump command.
-j, --json
equivalent to --dump-format=json
-r, --raw
equivalent to --dump-format=raw
-x, --xml
equivalent to --dump-format=xml
-y, --yaml
equivalent to --dump-format=yaml
-e EVENT, --event=EVENT
specify the event to dump instead of onMetaData, for example
onLastSecond
CHECK
-l LEVEL, --level=LEVEL
print only messages where level is at least LEVEL. The levels
are, by ascending importance, 'info', 'warning' (default),
'error', or 'fatal'.
-q, --quiet
do not print messages, only return the status code
-x, --xml
generate an XML report instead of the default
'compiler-friendly' text
-j, --json
generate a JSON report instead of the default
'compiler-friendly' text
UPDATE
-m, --print-metadata
print metadata to stdout after update using the format specified
by the --format option
-a NAME=VALUE, --add=NAME=VALUE
add a metadata string value to the output file. The name/value
pair will be appended at the end of the onMetaData tag.
-s, --no-lastsecond
do not create the onLastSecond tag
-p, --preserve
preserve input file existing onMetadata tags
-f, --fix
fix invalid tags from the input file
-i, --ignore
ignore invalid tags from the input file (the default behaviour
is to stop the update process with an error)
-t, --reset-timestamps
reset timestamps so OUTPUT_FILE starts at zero. This has been
added because some FLV files are produced by cutting bigger
files, and the software doing the cutting does not resets the
timestamps as required by the standard, which can cause playback
issues.
-k, --all-keyframes
index all keyframe tags, including duplicate timestamps
GENERAL
-v, --verbose
display informative messages
-V, --version
print version information and exit
-h, --help
display help on the program usage and exit
FORMATS
The various XML formats used by flvmeta are precisely described by the
following XSD schemas:
* http://schemas.flvmeta.org/flv.xsd: describes the general
organization of FLV files
* http://schemas.flvmeta.org/Amf0.xsd: describes an XML representation
of the Adobe(TM) AMF0 serialization format
* http://schemas.flvmeta.org/report.xsd: describes the XML output
format of the --check --xml command
EXAMPLES
flvmeta example.flv Prints the onMetadata tag contents of example.flv as XML output. flvmeta example.flv out.flv Creates a file named out.flv containing updated metadata and an onLastSecond tag from the exemple.flv file. flvmeta --check --xml --level=error example.flv Checks the validity of the example.flv file and prints the error report to stdout in XML format, displaying only errors and fatal errors. flvmeta --full-dump --yaml example.flv Prints the full contents of example.flv as YAML format to stdout. flvmeta --update --no-last-second --show-metadata --json example.flv Performs an in-place update of example.flv by inserting computed onMetadata without an onLastSecond tag, and prints the newly inserted metadata on stdout as JSON.
EXIT STATUS
* 0 flvmeta exited without error * 1 an error occurred when trying to open an input file * 2 the input file was not recognized as an FLV file * 3 an end-of-file condition was encountered unexpectedly * 4 a memory allocation error occurred during the run of the program * 5 an empty tag was encountered in an input file * 6 an error occurred when trying to open an output file * 7 an invalid tag was encountered in an input file * 8 an error was encountered while writing an output file * 9 the --check command reported an invalid file (one or more errors)
BUGS
flvmeta does not support encrypted FLV files yet.
AUTHOR
Marc Noirot <marc.noirot@gmail.com>
COPYRIGHT
Copyright 2007-2016 Marc Noirot This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
CONTACT
Please report bugs to <flvmeta-discussion@googlegroups.com>
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
