diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/APIchanges | 13 | ||||
| -rw-r--r-- | doc/developer.texi | 100 | ||||
| -rw-r--r-- | doc/general.texi | 13 |
3 files changed, 92 insertions, 34 deletions
diff --git a/doc/APIchanges b/doc/APIchanges index 97a5c0068d..23e568922c 100644 --- a/doc/APIchanges +++ b/doc/APIchanges @@ -22,6 +22,19 @@ API changes, most recent first: 2011-10-20 - b35e9e1 - lavu 51.22.0 Add av_strtok() to avstring.h. +2011-xx-xx - xxxxxxx - lavc 53.25.0 + Add nb_samples and extended_data fields to AVFrame. + Deprecate AVCODEC_MAX_AUDIO_FRAME_SIZE. + Deprecate avcodec_decode_audio3() in favor of avcodec_decode_audio4(). + avcodec_decode_audio4() writes output samples to an AVFrame, which allows + audio decoders to use get_buffer(). + +2011-xx-xx - xxxxxxx - lavc 53.24.0 + Change AVFrame.data[4]/base[4]/linesize[4]/error[4] to [8] at next major bump. + Change AVPicture.data[4]/linesize[4] to [8] at next major bump. + Change AVCodecContext.error[4] to [8] at next major bump. + Add AV_NUM_DATA_POINTERS to simplify the bump transition. + 2011-11-23 - bbb46f3 - lavu 51.18.0 Add av_samples_get_buffer_size(), av_samples_fill_arrays(), and av_samples_alloc(), to samplefmt.h. diff --git a/doc/developer.texi b/doc/developer.texi index 2052854a40..800ca7d045 100644 --- a/doc/developer.texi +++ b/doc/developer.texi @@ -53,48 +53,26 @@ and should try to fix issues their commit causes. @anchor{Coding Rules} @section Coding Rules -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. +@subsection Code formatting conventions -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: +There are the following guidelines regarding the indentation in files: @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 - Indent size is 4. -The presentation is one inspired by 'indent -i4 -kr -nut'. +@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. -Comments: Use the JavaDoc/Doxygen -format (see examples below) so that code documentation +@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. @@ -128,11 +106,69 @@ 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 are using underscores (_), not CamelCase. For example, @samp{avfilter_get_video_buffer} is +a valid function name and @samp{AVFilterGetVideo} is not. The only exception from this are structure names; +they should always be in the CamelCase + +There are following conventions for naming variables and functions: +@itemize @bullet +@item +For local variables no prefix is required. +@item +For variables and functions declared as @code{static} no prefixes are required. +@item +For variables and functions used internally by the library, @code{ff_} prefix should be used. +For example, @samp{ff_w64_demuxer}. +@item +For variables and functions used internally across multiple libraries, use @code{avpriv_}. For example, +@samp{avpriv_aac_parse_header}. +@item +For exported names, each library has its own prefixes. Just check the existing code and name accordingly. +@end itemize + +@subsection Miscellanous 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 @section Development Policy diff --git a/doc/general.texi b/doc/general.texi index 120b7160c2..04ca71db91 100644 --- a/doc/general.texi +++ b/doc/general.texi @@ -840,13 +840,22 @@ bash directly to work around this: bash ./configure @end example -@subsection Darwin (MacOS X, iPhone) +@anchor{Darwin} +@subsection Darwin (OSX, iPhone) -MacOS X on PowerPC or ARM (iPhone) requires a preprocessor from +The toolchain provided with Xcode is sufficient to build the basic +unacelerated code. + +OSX on PowerPC or ARM (iPhone) requires a preprocessor from @url{http://github.com/yuvi/gas-preprocessor} to build the optimized assembler functions. Just download the Perl script and put it somewhere in your PATH, FFmpeg's configure will pick it up automatically. +OSX on amd64 and x86 requires @command{yasm} to build most of the +optimized assembler functions @url{http://mxcl.github.com/homebrew/, Homebrew}, +@url{http://www.gentoo.org/proj/en/gentoo-alt/prefix/bootstrap-macos.xml, Gentoo Prefix} +or @url{http://www.macports.org, MacPorts} can easily provide it. + @section Windows To get help and instructions for building FFmpeg under Windows, check out |