1 \input texinfo @c -*- texinfo -*-
2 @documentencoding UTF-8
4 @settitle Developer Documentation
6 @center @titlefont{Developer Documentation}
13 @chapter Notes for external developers
15 This document is mostly useful for internal FFmpeg developers.
16 External developers who need to use the API in their application should
17 refer to the API doxygen documentation in the public headers, and
18 check the examples in @file{doc/examples} and in the source code to
19 see how the public API is employed.
21 You can use the FFmpeg libraries in your commercial program, but you
22 are encouraged to @emph{publish any patch you make}. In this case the
23 best way to proceed is to send your patches to the ffmpeg-devel
24 mailing list following the guidelines illustrated in the remainder of
27 For more detailed legal information about the use of FFmpeg in
28 external programs read the @file{LICENSE} file in the source tree and
29 consult @url{https://ffmpeg.org/legal.html}.
33 There are 3 ways by which code gets into FFmpeg.
35 @item Submitting patches to the main developer mailing list.
36 See @ref{Submitting patches} for details.
37 @item Directly committing changes to the main tree.
38 @item Committing changes to a git clone, for example on github.com or
39 gitorious.org. And asking us to merge these changes.
42 Whichever way, changes should be reviewed by the maintainer of the code
43 before they are committed. And they should follow the @ref{Coding Rules}.
44 The developer making the commit and the author are responsible for their changes
45 and should try to fix issues their commit causes.
50 @section Code formatting conventions
52 There are the following guidelines regarding the indentation in files:
59 The TAB character is forbidden outside of Makefiles as is any
60 form of trailing whitespace. Commits containing either will be
61 rejected by the git repository.
64 You should try to limit your code lines to 80 characters; however, do so if
65 and only if this improves readability.
68 K&R coding style is used.
70 The presentation is one inspired by 'indent -i4 -kr -nut'.
72 The main priority in FFmpeg is simplicity and small code size in order to
73 minimize the bug count.
76 Use the JavaDoc/Doxygen format (see examples below) so that code documentation
77 can be generated automatically. All nontrivial functions should have a comment
78 above them explaining what the function does, even if it is just one sentence.
79 All structures and their member variables should be documented, too.
81 Avoid Qt-style and similar Doxygen syntax with @code{!} in it, i.e. replace
82 @code{//!} with @code{///} and similar. Also @@ syntax should be employed
83 for markup commands, i.e. use @code{@@param} and not @code{\param}.
97 typedef struct Foobar @{
98 int var1; /**< var1 description */
99 int var2; ///< var2 description
100 /** var3 description */
108 * @@param my_parameter description of my_parameter
109 * @@return return value description
111 int myfunc(int my_parameter)
115 @section C language features
117 FFmpeg is programmed in the ISO C90 language with a few additional
118 features from ISO C99, namely:
122 the @samp{inline} keyword;
128 designated struct initializers (@samp{struct s x = @{ .i = 17 @};});
131 compound literals (@samp{x = (struct s) @{ 17, 23 @};}).
134 Implementation defined behavior for signed integers is assumed to match the
135 expected behavior for two's complement. Non representable values in integer
136 casts are binary truncated. Shift right of signed values uses sign extension.
139 These features are supported by all compilers we care about, so we will not
140 accept patches to remove their use unless they absolutely do not impair
141 clarity and performance.
143 All code must compile with recent versions of GCC and a number of other
144 currently supported compilers. To ensure compatibility, please do not use
145 additional C99 features or GCC extensions. Especially watch out for:
149 mixing statements and declarations;
152 @samp{long long} (use @samp{int64_t} instead);
155 @samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
158 GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
161 @section Naming conventions
162 All names should be composed with underscores (_), not CamelCase. For example,
163 @samp{avfilter_get_video_buffer} is an acceptable function name and
164 @samp{AVFilterGetVideo} is not. The exception from this are type names, like
165 for example structs and enums; they should always be in CamelCase.
167 There are the following conventions for naming variables and functions:
171 For local variables no prefix is required.
174 For file-scope variables and functions declared as @code{static}, no prefix
178 For variables and functions visible outside of file scope, but only used
179 internally by a library, an @code{ff_} prefix should be used,
180 e.g. @samp{ff_w64_demuxer}.
183 For variables and functions visible outside of file scope, used internally
184 across multiple libraries, use @code{avpriv_} as prefix, for example,
185 @samp{avpriv_report_missing_feature}.
188 Each library has its own prefix for public symbols, in addition to the
189 commonly used @code{av_} (@code{avformat_} for libavformat,
190 @code{avcodec_} for libavcodec, @code{swr_} for libswresample, etc).
191 Check the existing code and choose names accordingly.
192 Note that some symbols without these prefixes are also exported for
193 retro-compatibility reasons. These exceptions are declared in the
194 @code{lib<name>/lib<name>.v} files.
197 Furthermore, name space reserved for the system should not be invaded.
198 Identifiers ending in @code{_t} are reserved by
199 @url{http://pubs.opengroup.org/onlinepubs/007904975/functions/xsh_chap02_02.html#tag_02_02_02, POSIX}.
200 Also avoid names starting with @code{__} or @code{_} followed by an uppercase
201 letter as they are reserved by the C standard. Names starting with @code{_}
202 are reserved at the file level and may not be used for externally visible
203 symbols. If in doubt, just avoid names starting with @code{_} altogether.
205 @section Miscellaneous conventions
209 fprintf and printf are forbidden in libavformat and libavcodec,
210 please use av_log() instead.
213 Casts should be used only when necessary. Unneeded parentheses
214 should also be avoided if they don't make the code easier to understand.
217 @section Editor configuration
218 In order to configure Vim to follow FFmpeg formatting conventions, paste
219 the following snippet into your @file{.vimrc}:
221 " indentation rules for FFmpeg: 4 spaces, no tabs
227 " Allow tabs in Makefiles.
228 autocmd FileType make,automake set noexpandtab shiftwidth=8 softtabstop=8
229 " Trailing whitespace and tabs are forbidden, so highlight them.
230 highlight ForbiddenWhitespace ctermbg=red guibg=red
231 match ForbiddenWhitespace /\s\+$\|\t/
232 " Do not highlight spaces at the end of line while typing on that line.
233 autocmd InsertEnter * match ForbiddenWhitespace /\t\|\s\+\%#\@@<!$/
236 For Emacs, add these roughly equivalent lines to your @file{.emacs.d/init.el}:
238 (c-add-style "ffmpeg"
241 (indent-tabs-mode . nil)
242 (show-trailing-whitespace . t)
244 (statement-cont . (c-lineup-assignments +)))
247 (setq c-default-style "ffmpeg")
250 @chapter Development Policy
252 @section Patches/Committing
253 @subheading Licenses for patches must be compatible with FFmpeg.
254 Contributions should be licensed under the
255 @uref{http://www.gnu.org/licenses/lgpl-2.1.html, LGPL 2.1},
256 including an "or any later version" clause, or, if you prefer
257 a gift-style license, the
258 @uref{http://opensource.org/licenses/isc-license.txt, ISC} or
259 @uref{http://mit-license.org/, MIT} license.
260 @uref{http://www.gnu.org/licenses/gpl-2.0.html, GPL 2} including
261 an "or any later version" clause is also acceptable, but LGPL is
263 If you add a new file, give it a proper license header. Do not copy and
264 paste it from a random place, use an existing file as template.
266 @subheading You must not commit code which breaks FFmpeg!
267 This means unfinished code which is enabled and breaks compilation,
268 or compiles but does not work/breaks the regression tests. Code which
269 is unfinished but disabled may be permitted under-circumstances, like
270 missing samples or an implementation with a small subset of features.
271 Always check the mailing list for any reviewers with issues and test
272 FATE before you push.
274 @subheading Keep the main commit message short with an extended description below.
275 The commit message should have a short first line in the form of
276 a @samp{topic: short description} as a header, separated by a newline
277 from the body consisting of an explanation of why the change is necessary.
278 If the commit fixes a known bug on the bug tracker, the commit message
279 should include its bug ID. Referring to the issue on the bug tracker does
280 not exempt you from writing an excerpt of the bug in the commit message.
282 @subheading Testing must be adequate but not excessive.
283 If it works for you, others, and passes FATE then it should be OK to commit
284 it, provided it fits the other committing criteria. You should not worry about
285 over-testing things. If your code has problems (portability, triggers
286 compiler bugs, unusual environment etc) they will be reported and eventually
289 @subheading Do not commit unrelated changes together.
290 They should be split them into self-contained pieces. Also do not forget
291 that if part B depends on part A, but A does not depend on B, then A can
292 and should be committed first and separate from B. Keeping changes well
293 split into self-contained parts makes reviewing and understanding them on
294 the commit log mailing list easier. This also helps in case of debugging
296 Also if you have doubts about splitting or not splitting, do not hesitate to
297 ask/discuss it on the developer mailing list.
299 @subheading Ask before you change the build system (configure, etc).
300 Do not commit changes to the build system (Makefiles, configure script)
301 which change behavior, defaults etc, without asking first. The same
302 applies to compiler warning fixes, trivial looking fixes and to code
303 maintained by other developers. We usually have a reason for doing things
304 the way we do. Send your changes as patches to the ffmpeg-devel mailing
305 list, and if the code maintainers say OK, you may commit. This does not
306 apply to files you wrote and/or maintain.
308 @subheading Cosmetic changes should be kept in separate patches.
309 We refuse source indentation and other cosmetic changes if they are mixed
310 with functional changes, such commits will be rejected and removed. Every
311 developer has his own indentation style, you should not change it. Of course
312 if you (re)write something, you can use your own style, even though we would
313 prefer if the indentation throughout FFmpeg was consistent (Many projects
314 force a given indentation style - we do not.). If you really need to make
315 indentation changes (try to avoid this), separate them strictly from real
318 NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
319 then either do NOT change the indentation of the inner part within (do not
320 move it to the right)! or do so in a separate commit
322 @subheading Commit messages should always be filled out properly.
323 Always fill out the commit log message. Describe in a few lines what you
324 changed and why. You can refer to mailing list postings if you fix a
325 particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
329 area changed: Short 1 line description
331 details describing what and why and giving references.
334 @subheading Credit the author of the patch.
335 Make sure the author of the commit is set correctly. (see git commit --author)
336 If you apply a patch, send an
337 answer to ffmpeg-devel (or wherever you got the patch from) saying that
338 you applied the patch.
340 @subheading Complex patches should refer to discussion surrounding them.
341 When applying patches that have been discussed (at length) on the mailing
342 list, reference the thread in the log message.
344 @subheading Always wait long enough before pushing changes
345 Do NOT commit to code actively maintained by others without permission.
346 Send a patch to ffmpeg-devel. If no one answers within a reasonable
347 time-frame (12h for build failures and security fixes, 3 days small changes,
348 1 week for big patches) then commit your patch if you think it is OK.
349 Also note, the maintainer can simply ask for more time to review!
352 @subheading API/ABI changes should be discussed before they are made.
353 Do not change behavior of the programs (renaming options etc) or public
354 API or ABI without first discussing it on the ffmpeg-devel mailing list.
355 Do not remove widely used functionality or features (redundant code can be removed).
357 @subheading Remember to check if you need to bump versions for libav*.
358 Depending on the change, you may need to change the version integer.
359 Incrementing the first component means no backward compatibility to
360 previous versions (e.g. removal of a function from the public API).
361 Incrementing the second component means backward compatible change
362 (e.g. addition of a function to the public API or extension of an
363 existing data structure).
364 Incrementing the third component means a noteworthy binary compatible
365 change (e.g. encoder bug fix that matters for the decoder). The third
366 component always starts at 100 to distinguish FFmpeg from Libav.
368 @subheading Warnings for correct code may be disabled if there is no other option.
369 Compiler warnings indicate potential bugs or code with bad style. If a type of
370 warning always points to correct and clean code, that warning should
371 be disabled, not the code changed.
372 Thus the remaining warnings can either be bugs or correct code.
373 If it is a bug, the bug has to be fixed. If it is not, the code should
374 be changed to not generate a warning unless that causes a slowdown
375 or obfuscates the code.
377 @subheading Check untrusted input properly.
378 Never write to unallocated memory, never write over the end of arrays,
379 always check values read from some untrusted source before using them
380 as array index or other risky things.
382 @section Documentation/Other
383 @subheading Subscribe to the ffmpeg-devel mailing list.
384 It is important to be subscribed to the
385 @uref{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-devel, ffmpeg-devel}
386 mailing list. Almost any non-trivial patch is to be sent there for review.
387 Other developers may have comments about your contribution. We expect you see
388 those comments, and to improve it if requested. (N.B. Experienced committers
389 have other channels, and may sometimes skip review for trivial fixes.) Also,
390 discussion here about bug fixes and FFmpeg improvements by other developers may
391 be helpful information for you. Finally, by being a list subscriber, your
392 contribution will be posted immediately to the list, without the moderation
393 hold which messages from non-subscribers experience.
395 However, it is more important to the project that we receive your patch than
396 that you be subscribed to the ffmpeg-devel list. If you have a patch, and don't
397 want to subscribe and discuss the patch, then please do send it to the list
400 @subheading Subscribe to the ffmpeg-cvslog mailing list.
401 Diffs of all commits are sent to the
402 @uref{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-cvslog, ffmpeg-cvslog}
403 mailing list. Some developers read this list to review all code base changes
404 from all sources. Subscribing to this list is not mandatory.
406 @subheading Keep the documentation up to date.
407 Update the documentation if you change behavior or add features. If you are
408 unsure how best to do this, send a patch to ffmpeg-devel, the documentation
409 maintainer(s) will review and commit your stuff.
411 @subheading Important discussions should be accessible to all.
412 Try to keep important discussions and requests (also) on the public
413 developer mailing list, so that all developers can benefit from them.
415 @subheading Check your entries in MAINTAINERS.
416 Make sure that no parts of the codebase that you maintain are missing from the
417 @file{MAINTAINERS} file. If something that you want to maintain is missing add it with
419 If at some point you no longer want to maintain some code, then please help in
420 finding a new maintainer and also don't forget to update the @file{MAINTAINERS} file.
422 We think our rules are not too hard. If you have comments, contact us.
424 @chapter Code of conduct
426 Be friendly and respectful towards others and third parties.
427 Treat others the way you yourself want to be treated.
429 Be considerate. Not everyone shares the same viewpoint and priorities as you do.
430 Different opinions and interpretations help the project.
431 Looking at issues from a different perspective assists development.
433 Do not assume malice for things that can be attributed to incompetence. Even if
434 it is malice, it's rarely good to start with that as initial assumption.
436 Stay friendly even if someone acts contrarily. Everyone has a bad day
438 If you yourself have a bad day or are angry then try to take a break and reply
439 once you are calm and without anger if you have to.
441 Try to help other team members and cooperate if you can.
443 The goal of software development is to create technical excellence, not for any
444 individual to be better and "win" against the others. Large software projects
445 are only possible and successful through teamwork.
447 If someone struggles do not put them down. Give them a helping hand
448 instead and point them in the right direction.
450 Finally, keep in mind the immortal words of Bill and Ted,
451 "Be excellent to each other."
453 @anchor{Submitting patches}
454 @chapter Submitting patches
456 First, read the @ref{Coding Rules} above if you did not yet, in particular
457 the rules regarding patch submission.
459 When you submit your patch, please use @code{git format-patch} or
460 @code{git send-email}. We cannot read other diffs :-).
462 Also please do not submit a patch which contains several unrelated changes.
463 Split it into separate, self-contained pieces. This does not mean splitting
464 file by file. Instead, make the patch as small as possible while still
465 keeping it as a logical unit that contains an individual change, even
466 if it spans multiple files. This makes reviewing your patches much easier
467 for us and greatly increases your chances of getting your patch applied.
469 Use the patcheck tool of FFmpeg to check your patch.
470 The tool is located in the tools directory.
472 Run the @ref{Regression tests} before submitting a patch in order to verify
473 it does not cause unexpected problems.
475 It also helps quite a bit if you tell us what the patch does (for example
476 'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
479 Also please if you send several patches, send each patch as a separate mail,
480 do not attach several unrelated patches to the same mail.
482 Patches should be posted to the
483 @uref{https://lists.ffmpeg.org/mailman/listinfo/ffmpeg-devel, ffmpeg-devel}
484 mailing list. Use @code{git send-email} when possible since it will properly
485 send patches without requiring extra care. If you cannot, then send patches
486 as base64-encoded attachments, so your patch is not trashed during
487 transmission. Also ensure the correct mime type is used
488 (text/x-diff or text/x-patch or at least text/plain) and that only one
489 patch is inline or attached per mail.
490 You can check @url{https://patchwork.ffmpeg.org}, if your patch does not show up, its mime type
493 Your patch will be reviewed on the mailing list. You will likely be asked
494 to make some changes and are expected to send in an improved version that
495 incorporates the requests from the review. This process may go through
496 several iterations. Once your patch is deemed good enough, some developer
497 will pick it up and commit it to the official FFmpeg tree.
499 Give us a few days to react. But if some time passes without reaction,
500 send a reminder by email. Your patch should eventually be dealt with.
503 @chapter New codecs or formats checklist
507 Did you use av_cold for codec initialization and close functions?
510 Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
511 AVInputFormat/AVOutputFormat struct?
514 Did you bump the minor version number (and reset the micro version
515 number) in @file{libavcodec/version.h} or @file{libavformat/version.h}?
518 Did you register it in @file{allcodecs.c} or @file{allformats.c}?
521 Did you add the AVCodecID to @file{avcodec.h}?
522 When adding new codec IDs, also add an entry to the codec descriptor
523 list in @file{libavcodec/codec_desc.c}.
526 If it has a FourCC, did you add it to @file{libavformat/riff.c},
527 even if it is only a decoder?
530 Did you add a rule to compile the appropriate files in the Makefile?
531 Remember to do this even if you're just adding a format to a file that is
532 already being compiled by some other rule, like a raw demuxer.
535 Did you add an entry to the table of supported formats or codecs in
536 @file{doc/general.texi}?
539 Did you add an entry in the Changelog?
542 If it depends on a parser or a library, did you add that dependency in
546 Did you @code{git add} the appropriate files before committing?
549 Did you make sure it compiles standalone, i.e. with
550 @code{configure --disable-everything --enable-decoder=foo}
551 (or @code{--enable-demuxer} or whatever your component is)?
555 @chapter Patch submission checklist
559 Does @code{make fate} pass with the patch applied?
562 Was the patch generated with git format-patch or send-email?
565 Did you sign off your patch? (git commit -s)
566 See @url{http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob_plain;f=Documentation/SubmittingPatches} for the meaning
570 Did you provide a clear git commit log message?
573 Is the patch against latest FFmpeg git master branch?
576 Are you subscribed to ffmpeg-devel?
577 (the list is subscribers only due to spam)
580 Have you checked that the changes are minimal, so that the same cannot be
581 achieved with a smaller patch and/or simpler final code?
584 If the change is to speed critical code, did you benchmark it?
587 If you did any benchmarks, did you provide them in the mail?
590 Have you checked that the patch does not introduce buffer overflows or
591 other security issues?
594 Did you test your decoder or demuxer against damaged data? If no, see
595 tools/trasher, the noise bitstream filter, and
596 @uref{http://caca.zoy.org/wiki/zzuf, zzuf}. Your decoder or demuxer
597 should not crash, end in a (near) infinite loop, or allocate ridiculous
598 amounts of memory when fed damaged data.
601 Did you test your decoder or demuxer against sample files?
602 Samples may be obtained at @url{https://samples.ffmpeg.org}.
605 Does the patch not mix functional and cosmetic changes?
608 Did you add tabs or trailing whitespace to the code? Both are forbidden.
611 Is the patch attached to the email you send?
614 Is the mime type of the patch correct? It should be text/x-diff or
615 text/x-patch or at least text/plain and not application/octet-stream.
618 If the patch fixes a bug, did you provide a verbose analysis of the bug?
621 If the patch fixes a bug, did you provide enough information, including
622 a sample, so the bug can be reproduced and the fix can be verified?
623 Note please do not attach samples >100k to mails but rather provide a
624 URL, you can upload to ftp://upload.ffmpeg.org.
627 Did you provide a verbose summary about what the patch does change?
630 Did you provide a verbose explanation why it changes things like it does?
633 Did you provide a verbose summary of the user visible advantages and
634 disadvantages if the patch is applied?
637 Did you provide an example so we can verify the new feature added by the
641 If you added a new file, did you insert a license header? It should be
642 taken from FFmpeg, not randomly copied and pasted from somewhere else.
645 You should maintain alphabetical order in alphabetically ordered lists as
646 long as doing so does not break API/ABI compatibility.
649 Lines with similar content should be aligned vertically when doing so
650 improves readability.
653 Consider adding a regression test for your code.
656 If you added YASM code please check that things still work with --disable-yasm.
659 Make sure you check the return values of function and return appropriate
660 error codes. Especially memory allocation functions like @code{av_malloc()}
661 are notoriously left unchecked, which is a serious problem.
664 Test your code with valgrind and or Address Sanitizer to ensure it's free
665 of leaks, out of array accesses, etc.
668 @chapter Patch review process
670 All patches posted to ffmpeg-devel will be reviewed, unless they contain a
671 clear note that the patch is not for the git master branch.
672 Reviews and comments will be posted as replies to the patch on the
673 mailing list. The patch submitter then has to take care of every comment,
674 that can be by resubmitting a changed patch or by discussion. Resubmitted
675 patches will themselves be reviewed like any other patch. If at some point
676 a patch passes review with no comments then it is approved, that can for
677 simple and small patches happen immediately while large patches will generally
678 have to be changed and reviewed many times before they are approved.
679 After a patch is approved it will be committed to the repository.
681 We will review all submitted patches, but sometimes we are quite busy so
682 especially for large patches this can take several weeks.
684 If you feel that the review process is too slow and you are willing to try to
685 take over maintainership of the area of code you change then just clone
686 git master and maintain the area of code there. We will merge each area from
687 where its best maintained.
689 When resubmitting patches, please do not make any significant changes
690 not related to the comments received during review. Such patches will
691 be rejected. Instead, submit significant changes or new features as
694 Everyone is welcome to review patches. Also if you are waiting for your patch
695 to be reviewed, please consider helping to review other patches, that is a great
696 way to get everyone's patches reviewed sooner.
698 @anchor{Regression tests}
699 @chapter Regression tests
701 Before submitting a patch (or committing to the repository), you should at least
702 test that you did not break anything.
704 Running 'make fate' accomplishes this, please see @url{fate.html} for details.
706 [Of course, some patches may change the results of the regression tests. In
707 this case, the reference results of the regression tests shall be modified
710 @section Adding files to the fate-suite dataset
712 When there is no muxer or encoder available to generate test media for a
713 specific test then the media has to be included in the fate-suite.
714 First please make sure that the sample file is as small as possible to test the
715 respective decoder or demuxer sufficiently. Large files increase network
716 bandwidth and disk space requirements.
717 Once you have a working fate test and fate sample, provide in the commit
718 message or introductory message for the patch series that you post to
719 the ffmpeg-devel mailing list, a direct link to download the sample media.
721 @section Visualizing Test Coverage
723 The FFmpeg build system allows visualizing the test coverage in an easy
724 manner with the coverage tools @code{gcov}/@code{lcov}. This involves
729 Configure to compile with instrumentation enabled:
730 @code{configure --toolchain=gcov}.
733 Run your test case, either manually or via FATE. This can be either
734 the full FATE regression suite, or any arbitrary invocation of any
735 front-end tool provided by FFmpeg, in any combination.
738 Run @code{make lcov} to generate coverage data in HTML format.
741 View @code{lcov/index.html} in your preferred HTML viewer.
744 You can use the command @code{make lcov-reset} to reset the coverage
745 measurements. You will need to rerun @code{make lcov} after running a
748 @section Using Valgrind
750 The configure script provides a shortcut for using valgrind to spot bugs
751 related to memory handling. Just add the option
752 @code{--toolchain=valgrind-memcheck} or @code{--toolchain=valgrind-massif}
753 to your configure line, and reasonable defaults will be set for running
754 FATE under the supervision of either the @strong{memcheck} or the
755 @strong{massif} tool of the valgrind suite.
757 In case you need finer control over how valgrind is invoked, use the
758 @code{--target-exec='valgrind <your_custom_valgrind_options>} option in
759 your configure line instead.
761 @anchor{Release process}
762 @chapter Release process
764 FFmpeg maintains a set of @strong{release branches}, which are the
765 recommended deliverable for system integrators and distributors (such as
766 Linux distributions, etc.). At regular times, a @strong{release
767 manager} prepares, tests and publishes tarballs on the
768 @url{https://ffmpeg.org} website.
770 There are two kinds of releases:
774 @strong{Major releases} always include the latest and greatest
775 features and functionality.
778 @strong{Point releases} are cut from @strong{release} branches,
779 which are named @code{release/X}, with @code{X} being the release
783 Note that we promise to our users that shared libraries from any FFmpeg
784 release never break programs that have been @strong{compiled} against
785 previous versions of @strong{the same release series} in any case!
787 However, from time to time, we do make API changes that require adaptations
788 in applications. Such changes are only allowed in (new) major releases and
789 require further steps such as bumping library version numbers and/or
790 adjustments to the symbol versioning file. Please discuss such changes
791 on the @strong{ffmpeg-devel} mailing list in time to allow forward planning.
793 @anchor{Criteria for Point Releases}
794 @section Criteria for Point Releases
796 Changes that match the following criteria are valid candidates for
797 inclusion into a point release:
801 Fixes a security issue, preferably identified by a @strong{CVE
802 number} issued by @url{http://cve.mitre.org/}.
805 Fixes a documented bug in @url{https://trac.ffmpeg.org}.
808 Improves the included documentation.
811 Retains both source code and binary compatibility with previous
812 point releases of the same release branch.
815 The order for checking the rules is (1 OR 2 OR 3) AND 4.
818 @section Release Checklist
820 The release process involves the following steps:
824 Ensure that the @file{RELEASE} file contains the version number for
825 the upcoming release.
828 Add the release at @url{https://trac.ffmpeg.org/admin/ticket/versions}.
831 Announce the intent to do a release to the mailing list.
834 Make sure all relevant security fixes have been backported. See
835 @url{https://ffmpeg.org/security.html}.
838 Ensure that the FATE regression suite still passes in the release
839 branch on at least @strong{i386} and @strong{amd64}
840 (cf. @ref{Regression tests}).
843 Prepare the release tarballs in @code{bz2} and @code{gz} formats, and
844 supplementing files that contain @code{gpg} signatures
847 Publish the tarballs at @url{https://ffmpeg.org/releases}. Create and
848 push an annotated tag in the form @code{nX}, with @code{X}
849 containing the version number.
852 Propose and send a patch to the @strong{ffmpeg-devel} mailing list
853 with a news entry for the website.
856 Publish the news entry.
859 Send an announcement to the mailing list.