@chapter Developers Guide
-@section API
+@section Notes for external developers
-@itemize @bullet
-@item libavcodec is the library containing the codecs (both encoding and
-decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
+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.
-@item libavformat is the library containing the file format handling (mux and
-demux code for several formats). Look at @file{avplay.c} to use it in a
-player. See @file{libavformat/output-example.c} to use it to generate
-audio or video streams.
-@end itemize
+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.
-@section Integrating libav in your program
-
-Shared libraries should be used whenever is possible in order to reduce
-the effort distributors have to pour to support programs and to ensure
-only the public API is used.
-
-You can use Libav in your commercial program, but you must abide to the
-license, LGPL or GPL depending on the specific features used, please refer
-to @uref{http://libav.org/legal.html, our legal page} for a quick checklist and to
-the following links for the exact text of each license:
-@uref{http://git.libav.org/?p=libav.git;a=blob;f=COPYING.GPLv2, GPL version 2},
-@uref{http://git.libav.org/?p=libav.git;a=blob;f=COPYING.GPLv3, GPL version 3},
-@uref{http://git.libav.org/?p=libav.git;a=blob;f=COPYING.LGPLv2.1, LGPL version 2.1},
-@uref{http://git.libav.org/?p=libav.git;a=blob;f=COPYING.LGPLv3, LGPL version 3}.
-Any modification to the source code can be suggested for inclusion.
-The best way to proceed is to send your patches to the
-@uref{https://lists.libav.org/mailman/listinfo/libav-devel, libav-devel}
-mailing list.
+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}.
-@anchor{Coding Rules}
-@section Coding Rules
-
-@subsection Code formatting conventions
-The code is written in K&R C style. That means the following:
+@section Contributing
+There are 3 ways by which code gets into ffmpeg.
@itemize @bullet
-@item
-The control statements are formatted by putting space between the statement
-and parenthesis in the following way:
-@example
-for (i = 0; i < filter->input_count; i++) @{
-@end example
+@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
-@item
-The case statement is always located at the same level as the switch itself:
-@example
-switch (link->init_state) @{
-case AVLINK_INIT:
- continue;
-case AVLINK_STARTINIT:
- av_log(filter, AV_LOG_INFO, "circular filter chain detected");
- return 0;
-@end example
+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.
-@item
-Braces in function declarations are written on the new line:
-@example
-const char *avfilter_configuration(void)
-@{
- return LIBAV_CONFIGURATION;
-@}
-@end example
-
-@item
-Do not check for NULL values by comparison, @samp{if (p)} and
-@samp{if (!p)} are correct; @samp{if (p == NULL)} and @samp{if (p != NULL)}
-are not.
-
-@item
-In case of a single-statement if, no curly braces are required:
-@example
-if (!pic || !picref)
- goto fail;
-@end example
+@anchor{Coding Rules}
+@section Coding Rules
-@item
-Do not put spaces immediately inside parentheses. @samp{if (ret)} is
-a valid style; @samp{if ( ret )} is not.
-@end itemize
+@subsection Code formatting conventions
There are the following guidelines regarding the indentation in files:
+
@itemize @bullet
@item
Indent size is 4.
@subsection C language features
-Libav is programmed in the ISO C90 language with a few additional
+FFmpeg is programmed in the ISO C90 language with a few additional
features from ISO C99, namely:
+
@itemize @bullet
@item
the @samp{inline} keyword;
@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 only exception are structure
-names; they should always be CamelCase.
+@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.
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
-For externally visible symbols, each library has its own prefix. Check
-the existing code and choose names accordingly.
+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.
@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://www.isc.org/software/license/, 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.
- @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
- 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.
+ 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://www.isc.org/software/license/, 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.
+
+ @item
-All the patches MUST be reviewed in the mailing list before they are
-committed.
-
-@item
-The Libav coding style should remain consistent. Changes to
-conform will be suggested during the review or implemented on commit.
-
-@item
-Patches should be generated using @code{git format-patch} or directly sent
-using @code{git send-email}.
-Please make sure you give the proper credit by setting the correct author
-in the commit.
++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.
-If the patch is a bug fix which should be backported to stable releases,
-i.e. a non-API/ABI-breaking bug fix, add @code{CC: libav-stable@@libav.org}
-to the bottom of your commit message, and make sure to CC your patch to
-this address, too. Some git setups will do this automatically.
-
-@item
-Work in progress patches should be sent to the mailing list with the [WIP]
-or the [RFC] tag.
-
-@item
-Branches in public personal repos are advised as way to
-work on issues collaboratively.
+
+ @item
-You do not have to over-test things. If it works for you and you think it
-should work for others, send it to the mailing list for review.
-If you have doubt about portability please state it in the submission so
-people with specific hardware could test it.
++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
-Patches that change behavior of the programs (renaming options etc) or
-public API or ABI should be discussed in depth and possible few days should
-pass between discussion and commit.
-Changes to the build system (Makefiles, configure script) which alter
-the expected behavior should be considered in the same regard.
++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
-Subscribe to the
-@uref{https://lists.libav.org/mailman/listinfo/libav-devel, libav-devel} and
-@uref{https://lists.libav.org/mailman/listinfo/libav-commits, libav-commits}
-mailing lists.
-Bugs and possible improvements or general questions regarding commits
-are discussed on libav-devel. We expect you to react if problems with
-your code are uncovered.
++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 an [RFC] patch to libav-devel.
++unsure how best to do this, send a patch to ffmpeg-devel, the documentation
++maintainer(s) will review and commit your stuff.
+
+ @item
-All discussions and decisions should be reported on the public developer
-mailing list, so that there is a reference to them.
-Other media (e.g. IRC) should be used for coordination and immediate
-collaboration.
++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. Always use valgrind to double-check.
++as array index or other risky things.
+
+ @item
-Remember to check if you need to bump versions for the specific libav
++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).
++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.
++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.
-If a type of warning leads to too many false positives, that warning
-should be disabled, not the code changed.
+
+ @item
+ 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.
@end enumerate
We think our rules are not too hard. If you have comments, contact us.
@enumerate
@item
- Did you use av_cold for codec initialization and close functions?
+ 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?
+ 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}?
+ 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}?
+ 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}.
+ 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?
+ 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.
+ Did you add a rule to compile the appropriate files in the Makefile?
-Remember to do this even if you are just adding a format to a file that
-is already being compiled by some other rule, like a raw demuxer.
++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}?
+ 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?
+ 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?
+ 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?
+ 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)?
+ 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
@enumerate
@item
- Does @code{make fate} pass with the patch applied?
-Does @code{make check} pass with the patch applied?
++Does @code{make fate} pass with the patch applied?
++
+@item
- Was the patch generated with git format-patch or send-email?
++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.
++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?
++Did you provide a clear git commit log message?
+
@item
- Is the patch against latest FFmpeg git master branch?
-Is the patch against latest Libav git master branch?
++Is the patch against latest FFmpeg git master branch?
+
@item
- Are you subscribed to ffmpeg-devel?
- (the list is subscribers only due to spam)
-Are you subscribed to the
-@uref{https://lists.libav.org/mailman/listinfo/libav-devel, libav-devel}
-mailing list? (Only list subscribers are allowed to post.)
++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?
+ 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?
+ 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?
+ 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?
+ 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.
+ 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?
+ Does the patch not mix functional and cosmetic changes?
+
@item
- Did you add tabs or trailing whitespace to the code? Both are forbidden.
+ Did you add tabs or trailing whitespace to the code? Both are forbidden.
+
@item
- Is the patch attached to the email you send?
+ 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.
+ 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?
+ 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
+ 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.libav.org
++URL, you can upload to ftp://upload.ffmpeg.org
+
@item
- Did you provide a verbose summary about what the patch does change?
+ 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?
+ 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?
+ 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?
+ 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.
+ If you added a new file, did you insert a license header? It should be
-taken from Libav, not randomly copied and pasted from somewhere else.
++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.
+ 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.
+ Lines with similar content should be aligned vertically when doing so
+ improves readability.
+
@item
- Consider to add a regression test for your code.
++Consider to add a regression test for your code.
++
+@item
- If you added YASM code please check that things still work with --disable-yasm
++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.
+ Make sure you check the return values of function and return appropriate
-error codes. Especially memory allocation functions like @code{malloc()}
++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.
++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
@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 Libav, in any combination.
+ 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
@enumerate
@item
- @strong{Major releases} always include the latest and greatest
- features and functionality.
+ @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.
+ @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 Libav
+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!
@enumerate
@item
- Fixes a security issue, preferably identified by a @strong{CVE
- number} issued by @url{http://cve.mitre.org/}.
+ 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}.
-Fixes a documented bug in @url{http://bugzilla.libav.org}.
++Fixes a documented bug in @url{https://trac.ffmpeg.org}.
+
@item
- Improves the included documentation.
+ Improves the included documentation.
+
@item
- Retains both source code and binary compatibility with previous
- point releases of the same release branch.
+ 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.
@enumerate
@item
- Ensure that the @file{RELEASE} file contains the version number for
- the upcoming release.
+ 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}.
-File a release tracking bug in @url{http://bugzilla.libav.org}. Make
-sure that the bug has an alias named @code{ReleaseX.Y} for the
-@code{X.Y} release.
++Add the release at @url{https://trac.ffmpeg.org/admin/ticket/versions}.
+
@item
- Announce the intent to do a release to the mailing list.
+ 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}.
-Reassign unresolved blocking bugs from previous release
-tracking bugs to the new bug.
-
-@item
-Review patch nominations that reach the @strong{libav-stable}
-mailing list, and push patches that fulfill the stable release
-criteria to the release branch.
++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}).
+ Ensure that the FATE regression suite still passes in the release
+ branch on at least @strong{i386} and @strong{amd64}
-(cf. @ref{Regression Tests}).
++(cf. @ref{Regression tests}).
+
@item
- Prepare the release tarballs in @code{bz2} and @code{gz} formats, and
- supplementing files that contain @code{gpg} signatures
-Prepare the release tarballs in @code{xz} and @code{gz} formats, and
-supplementing files that contain @code{md5} and @code{sha1}
-checksums.
++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.
-Publish the tarballs at @url{http://libav.org/releases}. Create and
-push an annotated tag in the form @code{vX}, with @code{X}
++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.
-Build the tarballs with the Windows binaries, and publish them at
-@url{http://win32.libav.org/releases}.
-
-@item
-Propose and send a patch to the @strong{libav-devel} mailing list
++Propose and send a patch to the @strong{ffmpeg-devel} mailing list
+ with a news entry for the website.
+
@item
- Publish the news entry.
+ Publish the news entry.
+
@item
- Send announcement to the mailing list.
+ Send announcement to the mailing list.
@end enumerate
@bye
@chapter Introduction
-FATE provides a regression testsuite embedded within the Libav build system.
-It can be run locally and optionally configured to send reports to a web
-aggregator and viewer @url{http://fate.libav.org}.
+ FATE is an extended regression suite on the client-side and a means
+for results aggregation and presentation on the server-side.
-It is advised to run FATE before submitting patches to the current codebase
-and provide new tests when submitting patches to add additional features.
+ The first part of this document explains how you can use FATE from
+your FFmpeg source directory to test your ffmpeg binary. The second
+part describes how you can run FATE to submit the results to FFmpeg's
+FATE server.
-@chapter Running FATE
+ In any way you can have a look at the publicly viewable FATE results
+by visiting this website:
-@section Samples and References
-In order to run, FATE needs a large amount of data (samples and references)
-that is provided separately from the actual source distribution.
+ @url{http://fate.ffmpeg.org/}
-To inform the build system about the testsuite location, pass
-@option{--samples=<path to the samples>} to @command{configure} or set the
-@var{SAMPLES} Make variable or the @var{LIBAV_SAMPLES} environment variable
-to a suitable value.
+ This is especially recommended for all people contributing source
+code to FFmpeg, as it can be seen if some test on some platform broke
+with their recent contribution. This usually happens on the platforms
+the developers could not test on.
+
+ The second part of this document describes how you can run FATE to
+submit your results to FFmpeg's FATE server. If you want to submit your
+results be sure to check that your combination of CPU, OS and compiler
+is not already listed on the above mentioned website.
+
+ In the third part you can find a comprehensive listing of FATE makefile
+targets and variables.
-To use a custom wrapper to run the test, pass @option{--target-exec} to
-@command{configure} or set the @var{TARGET_EXEC} Make variable.
-The dataset is available through @command{rsync}, is possible to fetch
-the current sample using the straight rsync command or through a specific
-@ref{Makefile target}.
+@chapter Using FATE from your FFmpeg source directory
+
+ If you want to run FATE on your machine you need to have the samples
+in place. You can get the samples via the build target fate-rsync.
+Use this command from the top-level source directory:
@example
-# rsync -aL rsync://fate-suite.libav.org/fate-suite/ fate-suite
+make fate-rsync SAMPLES=fate-suite/
+make fate SAMPLES=fate-suite/
@end example
+ The above commands set the samples location by passing a makefile
+variable via command line. It is also possible to set the samples
+location at source configuration time by invoking configure with
+`--samples=<path to the samples directory>'. Afterwards you can
+invoke the makefile targets without setting the SAMPLES makefile
+variable. This is illustrated by the following commands:
+
@example
-# make fate-rsync SAMPLES=fate-suite
+./configure --samples=fate-suite/
+make fate-rsync
+make fate
@end example
+ Yet another way to tell FATE about the location of the sample
+directory is by making sure the environment variable FATE_SAMPLES
+contains the path to your samples directory. This can be achieved
+by e.g. putting that variable in your shell profile or by setting
+it in your interactive session.
+
+@example
+FATE_SAMPLES=fate-suite/ make fate
+@end example
+
+@float NOTE
+Do not put a '~' character in the samples path to indicate a home
+directory. Because of shell nuances, this will cause FATE to fail.
+@end float
+
+To use a custom wrapper to run the test, pass @option{--target-exec} to
+@command{configure} or set the @var{TARGET_EXEC} Make variable.
-@chapter Manual Run
-FATE regression test can be run through @command{make}.
-Specific Makefile targets and Makefile variables are available:
-@anchor{Makefile target}
-@section FATE Makefile targets
+@chapter Submitting the results to the FFmpeg result aggregation server
+
+ To submit your results to the server you should run fate through the
+shell script @file{tests/fate.sh} from the FFmpeg sources. This script needs
+to be invoked with a configuration file as its first argument.
+
+@example
+tests/fate.sh /path/to/fate_config
+@end example
+
+ A configuration file template with comments describing the individual
+configuration variables can be found at @file{doc/fate_config.sh.template}.
+
+@ifhtml
+ The mentioned configuration template is also available here:
+@verbatiminclude fate_config.sh.template
+@end ifhtml
+
+ Create a configuration that suits your needs, based on the configuration
+template. The `slot' configuration variable can be any string that is not
+yet used, but it is suggested that you name it adhering to the following
+pattern <arch>-<os>-<compiler>-<compiler version>. The configuration file
+itself will be sourced in a shell script, therefore all shell features may
+be used. This enables you to setup the environment as you need it for your
+build.
+
+ For your first test runs the `fate_recv' variable should be empty or
+commented out. This will run everything as normal except that it will omit
+the submission of the results to the server. The following files should be
+present in $workdir as specified in the configuration file:
+
+@itemize
+ @item configure.log
+ @item compile.log
+ @item test.log
+ @item report
+ @item version
+@end itemize
+
+ When you have everything working properly you can create an SSH key pair
+and send the public key to the FATE server administrator who can be contacted
+at the email address @email{fate-admin@@ffmpeg.org}.
+
+ Configure your SSH client to use public key authentication with that key
+when connecting to the FATE server. Also do not forget to check the identity
+of the server and to accept its host key. This can usually be achieved by
+running your SSH client manually and killing it after you accepted the key.
+The FATE server's fingerprint is:
@table @option
-@item fate-list
-List all fate/regression test targets.
+@item RSA
+ d3:f1:83:97:a4:75:2b:a6:fb:d6:e8:aa:81:93:97:51
+@item ECDSA
+ 76:9f:68:32:04:1e:d5:d4:ec:47:3f:dc:fc:18:17:86
+@end table
+
+ If you have problems connecting to the FATE server, it may help to try out
+the @command{ssh} command with one or more @option{-v} options. You should
+get detailed output concerning your SSH configuration and the authentication
+process.
+
+ The only thing left is to automate the execution of the fate.sh script and
+the synchronisation of the samples directory.
+
+
+@chapter FATE makefile targets and variables
+
+@section Makefile targets
+@table @option
@item fate-rsync
- Download/synchronize sample files to the configured samples directory.
-Shortcut to download the fate test samples to the specified testsuite location.
++Download/synchronize sample files to the configured samples directory.
+
+@item fate-list
- Will list all fate/regression test targets.
++Will list all fate/regression test targets.
@item fate
- Run the FATE test suite (requires the fate-suite dataset).
+ Run the FATE test suite (requires the fate-suite dataset).
@end table
-@section FATE Makefile variables
+@section Makefile variables
+
@table @option
@item V
- Verbosity level, can be set to 0, 1 or 2.
+ Verbosity level, can be set to 0, 1 or 2.
-
-@table @option
-@item 0
-show just the test arguments
-
-@item 1
-show just the command used in the test
-
-@item 2
-show everything
-@end table
+ @itemize
+ @item 0: show just the test arguments
+ @item 1: show just the command used in the test
+ @item 2: show everything
+ @end itemize
@item SAMPLES
- Specify or override the path to the FATE samples at make time, it has a
- meaning only while running the regression tests.
+ Specify or override the path to the FATE samples at make time, it has a
+ meaning only while running the regression tests.
@item THREADS
- Specify how many threads to use while running regression tests, it is
- quite useful to detect thread-related regressions.
+ Specify how many threads to use while running regression tests, it is
+ quite useful to detect thread-related regressions.
+
@item THREAD_TYPE
- Specify which threading strategy test, either @var{slice} or @var{frame},
- by default @var{slice+frame}
+ Specify which threading strategy test, either @var{slice} or @var{frame},
+ by default @var{slice+frame}
+
@item CPUFLAGS
- Specify CPU flags.
-Specify a mask to be applied to autodetected CPU flags.
++Specify CPU flags.
+
@item TARGET_EXEC
- Specify or override the wrapper used to run the tests.
- The @var{TARGET_EXEC} option provides a way to run FATE wrapped in
- @command{valgrind}, @command{qemu-user} or @command{wine} or on remote targets
- through @command{ssh}.
+ Specify or override the wrapper used to run the tests.
++The @var{TARGET_EXEC} option provides a way to run FATE wrapped in
++@command{valgrind}, @command{qemu-user} or @command{wine} or on remote targets
++through @command{ssh}.
+
@item GEN
Set to @var{1} to generate the missing or mismatched references.
@end table
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