\input texinfo @c -*- texinfo -*-
 
 @settitle Developer Documentation
 @titlepage
 @center @titlefont{Developer Documentation}
 @end titlepage
 

 @top
 
 @contents

 
 @chapter Developers Guide
 

 @section Notes for external developers
 
 This document is mostly useful for internal FFmpeg developers.
 External developers who need to use the API in their application should
 refer to the API doxygen documentation in the public headers, and
 check the examples in @file{doc/examples} and in the source code to
 see how the public API is employed.
 
 You can use the FFmpeg libraries in your commercial program, but you
 are encouraged to @emph{publish any patch you make}. In this case the
 best way to proceed is to send your patches to the ffmpeg-devel
 mailing list following the guidelines illustrated in the remainder of
 this document.
 
 For more detailed legal information about the use of FFmpeg in
 external programs read the @file{LICENSE} file in the source tree and
 consult @url{http://ffmpeg.org/legal.html}.

 @section Contributing
 
 There are 3 ways by which code gets into ffmpeg.
 @itemize @bullet

 @item Submitting Patches to the main developer mailing list

       see @ref{Submitting patches} for details.

 @item Directly committing changes to the main tree.
 @item Committing changes to a git clone, for example on github.com or

       gitorious.org. And asking us to merge these changes.
 @end itemize
 
 Whichever way, changes should be reviewed by the maintainer of the code

 before they are committed. And they should follow the @ref{Coding Rules}.

 The developer making the commit and the author are responsible for their changes
 and should try to fix issues their commit causes.

 @anchor{Coding Rules}

 @section Coding Rules
 

 @subsection Code formatting conventions

 There are the following guidelines regarding the indentation in files:

 @itemize @bullet
 @item
 Indent size is 4.

 @item

 The TAB character is forbidden outside of Makefiles as is any
 form of trailing whitespace. Commits containing either will be

 rejected by the git repository.

 @item

 You should try to limit your code lines to 80 characters; however, do so if
 and only if this improves readability.

 @end itemize
 The presentation is one inspired by 'indent -i4 -kr -nut'.

 The main priority in FFmpeg is simplicity and small code size in order to

 minimize the bug count.
 

 @subsection Comments
 Use the JavaDoc/Doxygen  format (see examples below) so that code documentation

 can be generated automatically. All nontrivial functions should have a comment
 above them explaining what the function does, even if it is just one sentence.
 All structures and their member variables should be documented, too.

 
 Avoid Qt-style and similar Doxygen syntax with @code{!} in it, i.e. replace
 @code{//!} with @code{///} and similar.  Also @@ syntax should be employed
 for markup commands, i.e. use @code{@@param} and not @code{\param}.
 

 @example
 /**

  * @@file

  * MPEG codec.
  * @@author ...
  */
 
 /**
  * Summary sentence.
  * more text ...
  * ...
  */

 typedef struct Foobar @{

     int var1; /**< var1 description */
     int var2; ///< var2 description
     /** var3 description */
     int var3;
 @} Foobar;
 
 /**
  * Summary sentence.
  * more text ...
  * ...
  * @@param my_parameter description of my_parameter
  * @@return return value description
  */
 int myfunc(int my_parameter)
 ...
 @end example
 

 @subsection C language features
 

 FFmpeg is programmed in the ISO C90 language with a few additional

 features from ISO C99, namely:

 @itemize @bullet
 @item
 the @samp{inline} keyword;

 @item
 @samp{//} comments;

 @item
 designated struct initializers (@samp{struct s x = @{ .i = 17 @};})

 @item
 compound literals (@samp{x = (struct s) @{ 17, 23 @};})
 @end itemize
 
 These features are supported by all compilers we care about, so we will not
 accept patches to remove their use unless they absolutely do not impair
 clarity and performance.
 
 All code must compile with recent versions of GCC and a number of other
 currently supported compilers. To ensure compatibility, please do not use
 additional C99 features or GCC extensions. Especially watch out for:

 @itemize @bullet
 @item
 mixing statements and declarations;

 @item
 @samp{long long} (use @samp{int64_t} instead);

 @item
 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;

 @item
 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
 @end itemize
 
 @subsection Naming conventions

 All names should be composed with underscores (_), not CamelCase. For example,
 @samp{avfilter_get_video_buffer} is an acceptable function name and

 @samp{AVFilterGetVideo} is not. The exception from this are type names, like

 for example structs and enums; they should always be in the CamelCase

 There are the following conventions for naming variables and functions:

 @itemize @bullet
 @item
 For local variables no prefix is required.

 @item

 For file-scope variables and functions declared as @code{static}, no prefix
 is required.

 @item

 For variables and functions visible outside of file scope, but only used
 internally by a library, an @code{ff_} prefix should be used,
 e.g. @samp{ff_w64_demuxer}.

 @item

 For variables and functions visible outside of file scope, used internally
 across multiple libraries, use @code{avpriv_} as prefix, for example,
 @samp{avpriv_aac_parse_header}.

 @item

 Each library has its own prefix for public symbols, in addition to the
 commonly used @code{av_} (@code{avformat_} for libavformat,
 @code{avcodec_} for libavcodec, @code{swr_} for libswresample, etc).
 Check the existing code and choose names accordingly.
 Note that some symbols without these prefixes are also exported for
 retro-compatibility reasons. These exceptions are declared in the
 @code{lib<name>/lib<name>.v} files.

 @end itemize
 

 Furthermore, name space reserved for the system should not be invaded.
 Identifiers ending in @code{_t} are reserved by
 @url{http://pubs.opengroup.org/onlinepubs/007904975/functions/xsh_chap02_02.html#tag_02_02_02, POSIX}.
 Also avoid names starting with @code{__} or @code{_} followed by an uppercase
 letter as they are reserved by the C standard. Names starting with @code{_}
 are reserved at the file level and may not be used for externally visible
 symbols. If in doubt, just avoid names starting with @code{_} altogether.
 

 @subsection Miscellaneous conventions

 @itemize @bullet
 @item

 fprintf and printf are forbidden in libavformat and libavcodec,
 please use av_log() instead.

 @item

 Casts should be used only when necessary. Unneeded parentheses
 should also be avoided if they don't make the code easier to understand.

 @end itemize

 @subsection Editor configuration

 In order to configure Vim to follow FFmpeg formatting conventions, paste

 the following snippet into your @file{.vimrc}:
 @example

 " indentation rules for FFmpeg: 4 spaces, no tabs

 set expandtab
 set shiftwidth=4
 set softtabstop=4

 set cindent
 set cinoptions=(0

 " Allow tabs in Makefiles.

 autocmd FileType make,automake set noexpandtab shiftwidth=8 softtabstop=8

 " Trailing whitespace and tabs are forbidden, so highlight them.
 highlight ForbiddenWhitespace ctermbg=red guibg=red
 match ForbiddenWhitespace /\s\+$\|\t/
 " Do not highlight spaces at the end of line while typing on that line.
 autocmd InsertEnter * match ForbiddenWhitespace /\t\|\s\+\%#\@@<!$/
 @end example
 
 For Emacs, add these roughly equivalent lines to your @file{.emacs.d/init.el}:
 @example

 (c-add-style "ffmpeg"

              '("k&r"
                (c-basic-offset . 4)

                (indent-tabs-mode . nil)
                (show-trailing-whitespace . t)

                (c-offsets-alist
                 (statement-cont . (c-lineup-assignments +)))
                )
              )

 (setq c-default-style "ffmpeg")

 @end example
 

 @section Development Policy
 
 @enumerate
 @item

 Contributions should be licensed under the
 @uref{http://www.gnu.org/licenses/lgpl-2.1.html, LGPL 2.1},
 including an "or any later version" clause, or, if you prefer
 a gift-style license, the

 @uref{http://opensource.org/licenses/isc-license.txt, ISC} or

 @uref{http://mit-license.org/, MIT} license.
 @uref{http://www.gnu.org/licenses/gpl-2.0.html, GPL 2} including
 an "or any later version" clause is also acceptable, but LGPL is
 preferred.

 If you add a new file, give it a proper license header. Do not copy and
 paste it from a random place, use an existing file as template.

 
 @item

 You must not commit code which breaks FFmpeg! (Meaning unfinished but
 enabled code which breaks compilation or compiles but does not work or
 breaks the regression tests)
 You can commit unfinished stuff (for testing etc), but it must be disabled
 (#ifdef etc) by default so it does not interfere with other developers'
 work.

 
 @item
 The commit message should have a short first line in the form of
 a @samp{topic: short description} as a header, separated by a newline
 from the body consisting of an explanation of why the change is necessary.
 If the commit fixes a known bug on the bug tracker, the commit message
 should include its bug ID. Referring to the issue on the bug tracker does
 not exempt you from writing an excerpt of the bug in the commit message.
 
 @item

 You do not have to over-test things. If it works for you, and you think it
 should work for others, then commit. If your code has problems
 (portability, triggers compiler bugs, unusual environment etc) they will be
 reported and eventually fixed.

 
 @item
 Do not commit unrelated changes together, split them into self-contained
 pieces. Also do not forget that if part B depends on part A, but A does not
 depend on B, then A can and should be committed first and separate from B.
 Keeping changes well split into self-contained parts makes reviewing and
 understanding them on the commit log mailing list easier. This also helps
 in case of debugging later on.

 Also if you have doubts about splitting or not splitting, do not hesitate to
 ask/discuss it on the developer mailing list.

 
 @item

 Do not change behavior of the programs (renaming options etc) or public
 API or ABI without first discussing it on the ffmpeg-devel mailing list.
 Do not remove functionality from the code. Just improve!
 
 Note: Redundant code can be removed.
 
 @item
 Do not commit changes to the build system (Makefiles, configure script)
 which change behavior, defaults etc, without asking first. The same
 applies to compiler warning fixes, trivial looking fixes and to code
 maintained by other developers. We usually have a reason for doing things
 the way we do. Send your changes as patches to the ffmpeg-devel mailing
 list, and if the code maintainers say OK, you may commit. This does not
 apply to files you wrote and/or maintain.
 
 @item
 We refuse source indentation and other cosmetic changes if they are mixed
 with functional changes, such commits will be rejected and removed. Every
 developer has his own indentation style, you should not change it. Of course
 if you (re)write something, you can use your own style, even though we would
 prefer if the indentation throughout FFmpeg was consistent (Many projects
 force a given indentation style - we do not.). If you really need to make
 indentation changes (try to avoid this), separate them strictly from real
 changes.
 
 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
 then either do NOT change the indentation of the inner part within (do not
 move it to the right)! or do so in a separate commit
 
 @item
 Always fill out the commit log message. Describe in a few lines what you
 changed and why. You can refer to mailing list postings if you fix a
 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
 Recommended format:
 area changed: Short 1 line description
 
 details describing what and why and giving references.
 
 @item
 Make sure the author of the commit is set correctly. (see git commit --author)
 If you apply a patch, send an
 answer to ffmpeg-devel (or wherever you got the patch from) saying that
 you applied the patch.

 
 @item
 When applying patches that have been discussed (at length) on the mailing
 list, reference the thread in the log message.
 
 @item

 Do NOT commit to code actively maintained by others without permission.
 Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
 timeframe (12h for build failures and security fixes, 3 days small changes,
 1 week for big patches) then commit your patch if you think it is OK.
 Also note, the maintainer can simply ask for more time to review!
 
 @item
 Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
 are sent there and reviewed by all the other developers. Bugs and possible
 improvements or general questions regarding commits are discussed there. We
 expect you to react if problems with your code are uncovered.

 
 @item
 Update the documentation if you change behavior or add features. If you are

 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
 maintainer(s) will review and commit your stuff.

 
 @item

 Try to keep important discussions and requests (also) on the public
 developer mailing list, so that all developers can benefit from them.

 
 @item
 Never write to unallocated memory, never write over the end of arrays,
 always check values read from some untrusted source before using them

 as array index or other risky things.

 
 @item

 Remember to check if you need to bump versions for the specific libav*

 parts (libavutil, libavcodec, libavformat) you are changing. You need
 to change the version integer.
 Incrementing the first component means no backward compatibility to
 previous versions (e.g. removal of a function from the public API).
 Incrementing the second component means backward compatible change
 (e.g. addition of a function to the public API or extension of an
 existing data structure).
 Incrementing the third component means a noteworthy binary compatible

 change (e.g. encoder bug fix that matters for the decoder). The third
 component always starts at 100 to distinguish FFmpeg from Libav.

 
 @item

 Compiler warnings indicate potential bugs or code with bad style. If a type of
 warning always points to correct and clean code, that warning should
 be disabled, not the code changed.
 Thus the remaining warnings can either be bugs or correct code.

 If it is a bug, the bug has to be fixed. If it is not, the code should
 be changed to not generate a warning unless that causes a slowdown
 or obfuscates the code.
 

 @item
 Make sure that no parts of the codebase that you maintain are missing from the
 @file{MAINTAINERS} file. If something that you want to maintain is missing add it with
 your name after it.
 If at some point you no longer want to maintain some code, then please help
 finding a new maintainer and also don't forget updating the @file{MAINTAINERS} file.

 @end enumerate
 
 We think our rules are not too hard. If you have comments, contact us.
 

 @anchor{Submitting patches}

 @section Submitting patches
 

 First, read the @ref{Coding Rules} above if you did not yet, in particular

 the rules regarding patch submission.

 When you submit your patch, please use @code{git format-patch} or
 @code{git send-email}. We cannot read other diffs :-)

 
 Also please do not submit a patch which contains several unrelated changes.
 Split it into separate, self-contained pieces. This does not mean splitting
 file by file. Instead, make the patch as small as possible while still
 keeping it as a logical unit that contains an individual change, even
 if it spans multiple files. This makes reviewing your patches much easier
 for us and greatly increases your chances of getting your patch applied.
 

 Use the patcheck tool of FFmpeg to check your patch.

 The tool is located in the tools directory.

 Run the @ref{Regression tests} before submitting a patch in order to verify

 it does not cause unexpected problems.

 
 It also helps quite a bit if you tell us what the patch does (for example
 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
 and has no lrint()')
 
 Also please if you send several patches, send each patch as a separate mail,
 do not attach several unrelated patches to the same mail.
 

 Patches should be posted to the

 @uref{http://lists.ffmpeg.org/mailman/listinfo/ffmpeg-devel, ffmpeg-devel}

 mailing list. Use @code{git send-email} when possible since it will properly
 send patches without requiring extra care. If you cannot, then send patches
 as base64-encoded attachments, so your patch is not trashed during
 transmission.

 Your patch will be reviewed on the mailing list. You will likely be asked
 to make some changes and are expected to send in an improved version that
 incorporates the requests from the review. This process may go through
 several iterations. Once your patch is deemed good enough, some developer

 will pick it up and commit it to the official FFmpeg tree.

 
 Give us a few days to react. But if some time passes without reaction,
 send a reminder by email. Your patch should eventually be dealt with.
 
 

 @section New codecs or formats checklist
 
 @enumerate
 @item

 Did you use av_cold for codec initialization and close functions?
 

 @item

 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
 AVInputFormat/AVOutputFormat struct?
 

 @item

 Did you bump the minor version number (and reset the micro version
 number) in @file{libavcodec/version.h} or @file{libavformat/version.h}?
 

 @item

 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
 

 @item

 Did you add the AVCodecID to @file{avcodec.h}?
 When adding new codec IDs, also add an entry to the codec descriptor
 list in @file{libavcodec/codec_desc.c}.
 

 @item

 If it has a FourCC, did you add it to @file{libavformat/riff.c},
 even if it is only a decoder?
 

 @item

 Did you add a rule to compile the appropriate files in the Makefile?

 Remember to do this even if you're just adding a format to a file that is
 already being compiled by some other rule, like a raw demuxer.

 @item

 Did you add an entry to the table of supported formats or codecs in
 @file{doc/general.texi}?
 

 @item

 Did you add an entry in the Changelog?
 

 @item

 If it depends on a parser or a library, did you add that dependency in
 configure?
 

 @item

 Did you @code{git add} the appropriate files before committing?
 

 @item

 Did you make sure it compiles standalone, i.e. with
 @code{configure --disable-everything --enable-decoder=foo}
 (or @code{--enable-demuxer} or whatever your component is)?

 @end enumerate
 

 @section patch submission checklist
 
 @enumerate
 @item

 Does @code{make fate} pass with the patch applied?
 

 @item

 Was the patch generated with git format-patch or send-email?
 

 @item

 Did you sign off your patch? (git commit -s)
 See @url{http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob_plain;f=Documentation/SubmittingPatches} for the meaning
 of sign off.
 

 @item

 Did you provide a clear git commit log message?

 @item

 Is the patch against latest FFmpeg git master branch?

 @item

 Are you subscribed to ffmpeg-devel?
 (the list is subscribers only due to spam)

 @item

 Have you checked that the changes are minimal, so that the same cannot be
 achieved with a smaller patch and/or simpler final code?
 

 @item

 If the change is to speed critical code, did you benchmark it?
 

 @item

 If you did any benchmarks, did you provide them in the mail?
 

 @item

 Have you checked that the patch does not introduce buffer overflows or
 other security issues?
 

 @item

 Did you test your decoder or demuxer against damaged data? If no, see
 tools/trasher, the noise bitstream filter, and
 @uref{http://caca.zoy.org/wiki/zzuf, zzuf}. Your decoder or demuxer
 should not crash, end in a (near) infinite loop, or allocate ridiculous
 amounts of memory when fed damaged data.
 

 @item

 Does the patch not mix functional and cosmetic changes?
 

 @item

 Did you add tabs or trailing whitespace to the code? Both are forbidden.
 

 @item

 Is the patch attached to the email you send?
 

 @item

 Is the mime type of the patch correct? It should be text/x-diff or
 text/x-patch or at least text/plain and not application/octet-stream.
 

 @item

 If the patch fixes a bug, did you provide a verbose analysis of the bug?
 

 @item

 If the patch fixes a bug, did you provide enough information, including
 a sample, so the bug can be reproduced and the fix can be verified?
 Note please do not attach samples >100k to mails but rather provide a

 URL, you can upload to ftp://upload.ffmpeg.org

 @item

 Did you provide a verbose summary about what the patch does change?
 

 @item

 Did you provide a verbose explanation why it changes things like it does?
 

 @item

 Did you provide a verbose summary of the user visible advantages and
 disadvantages if the patch is applied?
 

 @item

 Did you provide an example so we can verify the new feature added by the
 patch easily?
 

 @item

 If you added a new file, did you insert a license header? It should be

 taken from FFmpeg, not randomly copied and pasted from somewhere else.

 @item

 You should maintain alphabetical order in alphabetically ordered lists as
 long as doing so does not break API/ABI compatibility.
 

 @item

 Lines with similar content should be aligned vertically when doing so
 improves readability.
 

 @item

 Consider to add a regression test for your code.
 

 @item

 If you added YASM code please check that things still work with --disable-yasm
 

 @item

 Make sure you check the return values of function and return appropriate

 error codes. Especially memory allocation functions like @code{av_malloc()}

 are notoriously left unchecked, which is a serious problem.

 @item

 Test your code with valgrind and or Address Sanitizer to ensure it's free
 of leaks, out of array accesses, etc.

 @end enumerate
 
 @section Patch review process
 
 All patches posted to ffmpeg-devel will be reviewed, unless they contain a

 clear note that the patch is not for the git master branch.

 Reviews and comments will be posted as replies to the patch on the
 mailing list. The patch submitter then has to take care of every comment,
 that can be by resubmitting a changed patch or by discussion. Resubmitted
 patches will themselves be reviewed like any other patch. If at some point
 a patch passes review with no comments then it is approved, that can for
 simple and small patches happen immediately while large patches will generally
 have to be changed and reviewed many times before they are approved.
 After a patch is approved it will be committed to the repository.
 
 We will review all submitted patches, but sometimes we are quite busy so
 especially for large patches this can take several weeks.
 

 If you feel that the review process is too slow and you are willing to try to
 take over maintainership of the area of code you change then just clone
 git master and maintain the area of code there. We will merge each area from
 where its best maintained.
 

 When resubmitting patches, please do not make any significant changes
 not related to the comments received during review. Such patches will

 be rejected. Instead, submit significant changes or new features as

 separate patches.
 

 @anchor{Regression tests}

 @section Regression tests
 
 Before submitting a patch (or committing to the repository), you should at least
 test that you did not break anything.
 

 Running 'make fate' accomplishes this, please see @url{fate.html} for details.

 
 [Of course, some patches may change the results of the regression tests. In
 this case, the reference results of the regression tests shall be modified
 accordingly].
 

 @subsection Adding files to the fate-suite dataset
 
 When there is no muxer or encoder available to generate test media for a
 specific test then the media has to be inlcuded in the fate-suite.
 First please make sure that the sample file is as small as possible to test the
 respective decoder or demuxer sufficiently. Large files increase network
 bandwidth and disk space requirements.
 Once you have a working fate test and fate sample, provide in the commit
 message or introductionary message for the patch series that you post to
 the ffmpeg-devel mailing list, a direct link to download the sample media.
 
 

 @subsection Visualizing Test Coverage
 

 The FFmpeg build system allows visualizing the test coverage in an easy

 manner with the coverage tools @code{gcov}/@code{lcov}.  This involves
 the following steps:
 
 @enumerate
 @item
     Configure to compile with instrumentation enabled:
     @code{configure --toolchain=gcov}.

 @item
     Run your test case, either manually or via FATE. This can be either
     the full FATE regression suite, or any arbitrary invocation of any

     front-end tool provided by FFmpeg, in any combination.

 @item
     Run @code{make lcov} to generate coverage data in HTML format.

 @item
     View @code{lcov/index.html} in your preferred HTML viewer.
 @end enumerate
 
 You can use the command @code{make lcov-reset} to reset the coverage
 measurements. You will need to rerun @code{make lcov} after running a
 new test.
 

 @subsection Using Valgrind
 
 The configure script provides a shortcut for using valgrind to spot bugs
 related to memory handling. Just add the option

 @code{--toolchain=valgrind-memcheck} or @code{--toolchain=valgrind-massif}
 to your configure line, and reasonable defaults will be set for running
 FATE under the supervision of either the @strong{memcheck} or the
 @strong{massif} tool of the valgrind suite.

 
 In case you need finer control over how valgrind is invoked, use the
 @code{--target-exec='valgrind <your_custom_valgrind_options>} option in
 your configure line instead.
 

 @anchor{Release process}
 @section Release process
 

 FFmpeg maintains a set of @strong{release branches}, which are the

 recommended deliverable for system integrators and distributors (such as

 Linux distributions, etc.). At regular times, a @strong{release

 manager} prepares, tests and publishes tarballs on the

 @url{http://ffmpeg.org} website.

 
 There are two kinds of releases:
 
 @enumerate
 @item

 @strong{Major releases} always include the latest and greatest
 features and functionality.
 

 @item

 @strong{Point releases} are cut from @strong{release} branches,
 which are named @code{release/X}, with @code{X} being the release
 version number.

 @end enumerate
 

 Note that we promise to our users that shared libraries from any FFmpeg

 release never break programs that have been @strong{compiled} against
 previous versions of @strong{the same release series} in any case!
 
 However, from time to time, we do make API changes that require adaptations
 in applications. Such changes are only allowed in (new) major releases and
 require further steps such as bumping library version numbers and/or
 adjustments to the symbol versioning file. Please discuss such changes

 on the @strong{ffmpeg-devel} mailing list in time to allow forward planning.

 
 @anchor{Criteria for Point Releases}
 @subsection Criteria for Point Releases
 
 Changes that match the following criteria are valid candidates for
 inclusion into a point release:
 
 @enumerate
 @item

 Fixes a security issue, preferably identified by a @strong{CVE
 number} issued by @url{http://cve.mitre.org/}.
 

 @item

 Fixes a documented bug in @url{https://trac.ffmpeg.org}.

 @item

 Improves the included documentation.
 

 @item

 Retains both source code and binary compatibility with previous
 point releases of the same release branch.

 @end enumerate
 
 The order for checking the rules is (1 OR 2 OR 3) AND 4.
 
 
 @subsection Release Checklist
 
 The release process involves the following steps:
 
 @enumerate
 @item

 Ensure that the @file{RELEASE} file contains the version number for
 the upcoming release.
 

 @item

 Add the release at @url{https://trac.ffmpeg.org/admin/ticket/versions}.

 @item

 Announce the intent to do a release to the mailing list.
 

 @item

 Make sure all relevant security fixes have been backported. See
 @url{https://ffmpeg.org/security.html}.

 @item

 Ensure that the FATE regression suite still passes in the release
 branch on at least @strong{i386} and @strong{amd64}

 (cf. @ref{Regression tests}).

 @item

 Prepare the release tarballs in @code{bz2} and @code{gz} formats, and
 supplementing files that contain @code{gpg} signatures

 @item

 Publish the tarballs at @url{http://ffmpeg.org/releases}. Create and
 push an annotated tag in the form @code{nX}, with @code{X}

 containing the version number.
 

 @item

 Propose and send a patch to the @strong{ffmpeg-devel} mailing list

 with a news entry for the website.
 

 @item

 Publish the news entry.
 

 @item

 Send announcement to the mailing list.

 @end enumerate
 

 @bye