f2d522f2a8
The option tables of the various fftools (in particular ffprobe) are arrays of OptionDef; said type contains a union of a pointer to void and a function pointer of type int (*)(void *, const char *, const char *) as well as a size_t. Some entries (namely the common entry for writing a report as well as several more of ffprobe's entries) used the pointer to void to store a pointer to functions of type int (*)(const char *) or type int (*)(const char *, const char *); nevertheless, when the functions are actually called in write_option (in cmdutils.c), it is done via a pointer of the first type. There are two things wrong here: 1. Pointer to void can be converted to any pointer to incomplete or object type and back; but they are nevertheless not completely generic pointers: There is no provision in the C standard that guarantees their convertibility with function pointers. C90 lacks a generic function pointer, C99 made every function pointer a generic function pointer and still disallows the convertibility with void *. 2. The signature of the called function differs from the signature of the pointed-to type. This is undefined behaviour in C99 (given that C90 lacks a way to convert function pointers at all, it doesn't say anything about such a situation). It only works because none of the functions this patch is about make any use of their parameters at all. Therefore this commit changes the type of the relevant functions to match the type used for the call and uses the union's function pointer to store it. This is legal even in C90. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com> Reviewed-by: Paul B Mahol <onemda@gmail.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
FFmpeg README
FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
Libraries
libavcodecprovides implementation of a wider range of codecs.libavformatimplements streaming protocols, container formats and basic I/O access.libavutilincludes hashers, decompressors and miscellaneous utility functions.libavfilterprovides a mean to alter decoded Audio and Video through chain of filters.libavdeviceprovides an abstraction to access capture and playback devices.libswresampleimplements audio mixing and resampling routines.libswscaleimplements color conversion and scaling routines.
Tools
- ffmpeg is a command line toolbox to manipulate, convert and stream multimedia content.
- ffplay is a minimalistic multimedia player.
- ffprobe is a simple analysis tool to inspect multimedia content.
- Additional small tools such as
aviocat,ismindexandqt-faststart.
Documentation
The offline documentation is available in the doc/ directory.
The online documentation is available in the main website and in the wiki.
Examples
Coding examples are available in the doc/examples directory.
License
FFmpeg codebase is mainly LGPL-licensed with optional components licensed under GPL. Please refer to the LICENSE file for detailed information.
Contributing
Patches should be submitted to the ffmpeg-devel mailing list using
git format-patch or git send-email. Github pull requests should be
avoided because they are not part of our review process and will be ignored.