\input texinfo @c -*- texinfo -*-
-@settitle FFmpeg FAQ
+@settitle Libav FAQ
@titlepage
-@sp 7
-@center @titlefont{FFmpeg FAQ}
-@sp 3
+@center @titlefont{Libav FAQ}
@end titlepage
+@top
-@chapter General Problems
+@contents
+
+@chapter General Questions
+
+@section When will the next Libav version be released? / Why are Libav releases so few and far between?
+
+Like most open source projects Libav suffers from a certain lack of
+manpower. For this reason the developers have to prioritize the work
+they do and putting out releases is not at the top of the list, fixing
+bugs and reviewing patches takes precedence. Please don't complain or
+request more timely and/or frequent releases unless you are willing to
+help out creating them.
+
+@section I have a problem with an old version of Libav; where should I report it?
+Nowhere. We do not support old Libav versions in any way, we simply lack
+the time, motivation and manpower to do so. If you have a problem with an
+old version of Libav, upgrade to the latest git snapshot. If you
+still experience the problem, then you can report it according to our
+@uref{http://libav.org/bugreports.html, bug reporting guidelines}.
+
+@section Why doesn't Libav support feature [xyz]?
+
+Because no one has taken on that task yet. Libav development is
+driven by the tasks that are important to the individual developers.
+If there is a feature that is important to you, the best way to get
+it implemented is to undertake the task yourself or sponsor a developer.
+
+@section Libav does not support codec XXX. Can you include a Windows DLL loader to support it?
+
+No. Windows DLLs are not portable, bloated and often slow.
+Moreover Libav strives to support all codecs natively.
+A DLL loader is not conducive to that goal.
+
+@section My bug report/mail to libav-devel/user has not received any replies.
+
+Likely reasons
+@itemize
+@item We are busy and haven't had time yet to read your report or
+investigate the issue.
+@item You did not follow our
+ @uref{http://libav.org/bugreports.html, bug reporting guidelines}.
+@item You didn't use git master.
+@item You reported a segmentation fault without gdb output.
+@item You describe a problem but not how to reproduce it.
+@item It's unclear if you use ffmpeg as command line tool or use
+libav* from another application.
+@item You speak about a video having problems on playback but
+not what you use to play it.
+@item We have no faint clue what you are talking about besides
+that it is related to Libav.
+@end itemize
+
+@section Is there a forum for Libav? I do not like mailing lists.
+
+You may view our mailing lists with a more forum-alike look here:
+@url{http://dir.gmane.org/gmane.comp.video.ffmpeg.user},
+but, if you post, please remember that our mailing list rules still apply there.
@section I cannot read this file although this format seems to be supported by ffmpeg.
-Even if ffmpeg can read the file format, it may not support all its
+Even if ffmpeg can read the container format, it may not support all its
codecs. Please consult the supported codec list in the ffmpeg
documentation.
-@section How do I encode single pictures to movies?
+@section Which codecs are supported by Windows?
+
+Windows does not support standard formats like MPEG very well, unless you
+install some additional codecs.
+
+The following list of video codecs should work on most Windows systems:
+@table @option
+@item msmpeg4v2
+.avi/.asf
+@item msmpeg4
+.asf only
+@item wmv1
+.asf only
+@item wmv2
+.asf only
+@item mpeg4
+Only if you have some MPEG-4 codec like ffdshow or Xvid installed.
+@item mpeg1video
+.mpg only
+@end table
+Note, ASF files often have .wmv or .wma extensions in Windows. It should also
+be mentioned that Microsoft claims a patent on the ASF format, and may sue
+or threaten users who create ASF files with non-Microsoft software. It is
+strongly advised to avoid ASF where possible.
+
+The following list of audio codecs should work on most Windows systems:
+@table @option
+@item adpcm_ima_wav
+@item adpcm_ms
+@item pcm_s16le
+always
+@item libmp3lame
+If some MP3 codec like LAME is installed.
+@end table
+
+
+@chapter Compilation
+
+@section @code{error: can't find a register in class 'GENERAL_REGS' while reloading 'asm'}
+
+This is a bug in gcc. Do not report it to us. Instead, please report it to
+the gcc developers. Note that we will not add workarounds for gcc bugs.
+
+Also note that (some of) the gcc developers believe this is not a bug or
+not a bug they should fix:
+@url{http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11203}.
+Then again, some of them do not know the difference between an undecidable
+problem and an NP-hard problem...
+
+@chapter Usage
+
+@section ffmpeg does not work; what is wrong?
+
+Try a @code{make distclean} in the ffmpeg source directory before the build.
+If this does not help see our
+@uref{http://libav.org/bugreports.html, bug reporting guidelines}.
+
+@section How do I encode single pictures into movies?
First, rename your pictures to follow a numerical sequence.
For example, img1.jpg, img2.jpg, img3.jpg,...
@file{img%03d.jpg} means the sequence @file{img001.jpg}, @file{img002.jpg}, etc...
+If you have large number of pictures to rename, you can use the
+following command to ease the burden. The command, using the bourne
+shell syntax, symbolically links all files in the current directory
+that match @code{*jpg} to the @file{/tmp} directory in the sequence of
+@file{img001.jpg}, @file{img002.jpg} and so on.
+
+@example
+ x=1; for i in *jpg; do counter=$(printf %03d $x); ln -s "$i" /tmp/img"$counter".jpg; x=$(($x+1)); done
+@end example
+
+If you want to sequence them by oldest modified first, substitute
+@code{$(ls -r -t *jpg)} in place of @code{*jpg}.
+
+Then run:
+
+@example
+ ffmpeg -f image2 -i /tmp/img%03d.jpg /tmp/a.mpg
+@end example
+
The same logic is used for any image format that ffmpeg reads.
@section How do I encode movie to single pictures?
Beware that there is no "jpeg" codec. Use "mjpeg" instead.
-@section FFmpeg does not support codec XXX. Can you include a Windows DLL loader to support it?
-
-No. FFmpeg only supports open source codecs. Windows DLLs are not
-portable, bloated and often slow.
-
-@section I get "Unsupported codec (id=86043) for input stream #0.1". What is the problem?
-
-This is the Qcelp codec, FFmpeg has no support for that codec currently. Try mencoder/mplayer it might work.
-
@section Why do I see a slight quality degradation with multithreaded MPEG* encoding?
For multithreaded MPEG* encoding, the encoded slices must be independent,
@section How can I read from the standard input or write to the standard output?
-Use @file{-} as filename.
-
-@section Why does ffmpeg not decode audio in VOB files?
-
-The audio is AC3 (a.k.a. A/52). AC3 decoding is an optional component in ffmpeg
-as the component that handles AC3 decoding (liba52) is currently released under
-the GPL. If you have liba52 installed on your system, enable AC3 decoding
-with @code{./configure --enable-liba52 --enable-gpl}. Take care: by
-enabling AC3, you automatically change the license of libavcodec from
-LGPL to GPL.
-
-@section Which codecs are supported by Windows?
-
-Windows does not support standard formats like MPEG very well, unless you
-install some additional codecs
-
-The following list of video codecs should work on most Windows systems:
-@table @option
-@item msmpeg4v2
-.avi/.asf
-@item msmpeg4
-.asf only
-@item wmv1
-.asf only
-@item wmv2
-.asf only
-@item mpeg4
-only if you have some MPEG-4 codec installed like ffdshow or XviD
-@item mpeg1
-.mpg only
-@end table
-Note, ASF files often have .wmv or .wma extensions in Windows. It should also
-be mentioned that Microsoft claims a patent on the ASF format, and may sue
-or threaten users who create ASF files with non-Microsoft software. It is
-strongly advised to avoid ASF where possible.
-
-The following list of audio codecs should work on most Windows systems:
-@table @option
-@item adpcm_ima_wav
-@item adpcm_ms
-@item pcm
-@item mp3
-if some MP3 codec like LAME is installed
-@end table
-
-@section Why does the chrominance data seem to be sampled at a different time from the luminance data on bt8x8 captures on Linux?
-
-This is a well-known bug in the bt8x8 driver. For 2.4.26 there is a patch at
-(@url{http://svn.mplayerhq.hu/michael/trunk/patches/bttv-420-2.4.26.patch?view=co}). This may also
-apply cleanly to other 2.4-series kernels.
-
-@section How do I avoid the ugly aliasing artifacts in bt8x8 captures on Linux?
-
-Pass 'combfilter=1 lumafilter=1' to the bttv driver. Note though that 'combfilter=1'
-will cause somewhat too strong filtering. A fix is to apply (@url{http://svn.mplayerhq.hu/michael/trunk/patches/bttv-comb-2.4.26.patch?view=co})
-or (@url{http://svn.mplayerhq.hu/michael/trunk/patches/bttv-comb-2.6.6.patch?view=co})
-and pass 'combfilter=2'.
-
-@section I have a problem with an old version of ffmpeg; where should I report it?
-Nowhere. Upgrade to the latest release or if there is no recent release upgrade
-to Subversion HEAD. You could also try to report it. Maybe you will get lucky and
-become the first person in history to get an answer different from "upgrade
-to Subversion HEAD".
+Use @file{-} as file name.
@section -f jpeg doesn't work.
Some codecs, like MPEG-1/2, only allow a small number of fixed framerates.
Choose a different codec with the -vcodec command line option.
-@section ffmpeg does not work; What is wrong?
+@section How do I encode Xvid or DivX video with ffmpeg?
-Try a 'make distclean' in the ffmpeg source directory before the build. If this does not help see
-(@url{http://ffmpeg.org/bugreports.php}).
-
-@section How do I encode XviD or DivX video with ffmpeg?
-
-Both XviD and DivX (version 4+) are implementations of the ISO MPEG-4
+Both Xvid and DivX (version 4+) are implementations of the ISO MPEG-4
standard (note that there are many other coding formats that use this
-same standard). Thus, use '-vcodec mpeg4' to encode these formats. The
+same standard). Thus, use '-vcodec mpeg4' to encode in these formats. The
default fourcc stored in an MPEG-4-coded file will be 'FMP4'. If you want
a different fourcc, use the '-vtag' option. E.g., '-vtag xvid' will
force the fourcc 'xvid' to be stored as the video fourcc rather than the
@item needed stuff
-acodec libfaac -vcodec mpeg4 width<=320 height<=240
@item working stuff
-4mv, title
+mv4, title
@item non-working stuff
B-frames
@item example command line
-ffmpeg -i input -acodec libfaac -ab 128kb -vcodec mpeg4 -b 1200kb -mbd 2 -flags +4mv+trell -aic 2 -cmp 2 -subcmp 2 -s 320x180 -title X output.mp4
+ffmpeg -i input -acodec libfaac -ab 128k -vcodec mpeg4 -b 1200k -mbd 2 -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -s 320x180 -metadata title=X output.mp4
@end table
@section How do I encode videos which play on the PSP?
@item needed stuff
-acodec libfaac -vcodec mpeg4 width*height<=76800 width%16=0 height%16=0 -ar 24000 -r 30000/1001 or 15000/1001 -f psp
@item working stuff
-4mv, title
+mv4, title
@item non-working stuff
B-frames
@item example command line
-ffmpeg -i input -acodec libfaac -ab 128kb -vcodec mpeg4 -b 1200kb -ar 24000 -mbd 2 -flags +4mv+trell -aic 2 -cmp 2 -subcmp 2 -s 368x192 -r 30000/1001 -title X -f psp output.mp4
+ffmpeg -i input -acodec libfaac -ab 128k -vcodec mpeg4 -b 1200k -ar 24000 -mbd 2 -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -s 368x192 -r 30000/1001 -metadata title=X -f psp output.mp4
@item needed stuff for H.264
--acodec libfaac -vcodec h264 width*height<=76800 width%16=0? height%16=0? -ar 48000 -coder 1 -r 30000/1001 or 15000/1001 -f psp
+-acodec libfaac -vcodec libx264 width*height<=76800 width%16=0? height%16=0? -ar 48000 -coder 1 -r 30000/1001 or 15000/1001 -f psp
@item working stuff for H.264
title, loop filter
@item non-working stuff for H.264
CAVLC
@item example command line
-ffmpeg -i input -acodec libfaac -ab 128kb -vcodec h264 -b 1200kb -ar 48000 -mbd 2 -coder 1 -cmp 2 -subcmp 2 -s 368x192 -r 30000/1001 -title X -f psp -flags loop -trellis 2 -partitions parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 output.mp4
+ffmpeg -i input -acodec libfaac -ab 128k -vcodec libx264 -b 1200k -ar 48000 -mbd 2 -coder 1 -cmp 2 -subcmp 2 -s 368x192 -r 30000/1001 -metadata title=X -f psp -flags loop -trellis 2 -partitions parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 output.mp4
+@item higher resolution for newer PSP firmwares, width<=480, height<=272
+-vcodec libx264 -level 21 -coder 1 -f psp
+@item example command line
+ffmpeg -i input -acodec libfaac -ab 128k -ac 2 -ar 48000 -vcodec libx264 -level 21 -b 640k -coder 1 -f psp -flags +loop -trellis 2 -partitions +parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 -g 250 -s 480x272 output.mp4
@end table
@section Which are good parameters for encoding high quality MPEG-4?
-'-mbd rd -flags +4mv+trell+aic -cmp 2 -subcmp 2 -g 300 -pass 1/2',
+'-mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -g 300 -pass 1/2',
things to try: '-bf 2', '-flags qprd', '-flags mv0', '-flags skiprd'.
@section Which are good parameters for encoding high quality MPEG-1/MPEG-2?
-'-mbd rd -flags +trell -cmp 2 -subcmp 2 -g 100 -pass 1/2'
+'-mbd rd -trellis 2 -cmp 2 -subcmp 2 -g 100 -pass 1/2'
but beware the '-g 100' might cause problems with some decoders.
Things to try: '-bf 2', '-flags qprd', '-flags mv0', '-flags skiprd.
-@section Interlaced video looks very bad when encoded with ffmpeg, whats wrong?
+@section Interlaced video looks very bad when encoded with ffmpeg, what is wrong?
You should use '-flags +ilme+ildct' and maybe '-flags +alt' for interlaced
material, and try '-top 0/1' if the result looks really messed-up.
@section How can I read DirectShow files?
-If you have built FFmpeg with @code{./configure --enable-avisynth}
+If you have built Libav with @code{./configure --enable-avisynth}
(only possible on MinGW/Cygwin platforms),
then you may use any file that DirectShow can read as input.
-(Be aware that this feature has been recently added,
-so you will need to help yourself in case of problems.)
Just create an "input.avs" text file with this single line ...
@example
DirectShowSource("C:\path to your file\yourfile.asf")
@end example
-... and then feed that text file to FFmpeg:
+... and then feed that text file to ffmpeg:
@example
ffmpeg -i input.avs
@end example
-For ANY other help on Avisynth, please visit @url{http://www.avisynth.org/}.
-
-@section My bugreport/mail to ffmpeg-devel/user has not received any replies.
-
-Likely reasons
-@itemize
-@item We are busy and haven't had time yet to read your report or
-investigate the issue.
-@item You didn't follow bugreports.html.
-@item You didn't use Subversion HEAD.
-@item You reported a segmentation fault without gdb output.
-@item You describe a problem but not how to reproduce it.
-@item It's unclear if you use ffmpeg as command line tool or use
-libav* from another application.
-@item You speak about a video having problems on playback but
-not what you use to play it.
-@item We have no faint clue what you are talking about besides
-that it is related to FFmpeg.
-@end itemize
+For ANY other help on Avisynth, please visit the
+@uref{http://www.avisynth.org/, Avisynth homepage}.
@section How can I join video files?
Similarly, the yuv4mpegpipe format, and the raw video, raw audio codecs also
allow concatenation, and the transcoding step is almost lossless.
+When using multiple yuv4mpegpipe(s), the first line needs to be discarded
+from all but the first stream. This can be accomplished by piping through
+@code{tail} as seen below. Note that when piping through @code{tail} you
+must use command grouping, @code{@{ ;@}}, to background properly.
For example, let's say we want to join two FLV files into an output.flv file:
ffmpeg -i input1.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp1.a < /dev/null &
ffmpeg -i input2.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp2.a < /dev/null &
ffmpeg -i input1.flv -an -f yuv4mpegpipe - > temp1.v < /dev/null &
-ffmpeg -i input2.flv -an -f yuv4mpegpipe - > temp2.v < /dev/null &
+@{ ffmpeg -i input2.flv -an -f yuv4mpegpipe - < /dev/null | tail -n +2 > temp2.v ; @} &
cat temp1.a temp2.a > all.a &
cat temp1.v temp2.v > all.v &
ffmpeg -f u16le -acodec pcm_s16le -ac 2 -ar 44100 -i all.a \
rm temp[12].[av] all.[av]
@end example
-@chapter Development
+@section The ffmpeg program does not respect the -maxrate setting, some frames are bigger than maxrate/fps.
-@section When will the next FFmpeg version be released? / Why are FFmpeg releases so few and far between?
+Read the MPEG spec about video buffer verifier.
-Like most open source projects FFmpeg suffers from a certain lack of
-manpower. For this reason the developers have to prioritize the work
-they do and putting out releases is not at the top of the list, fixing
-bugs and reviewing patches takes precedence. Please don't complain or
-request more timely and/or frequent releases unless you are willing to
-help out creating them.
+@section I want CBR, but no matter what I do frame sizes differ.
-@section Why doesn't FFmpeg support feature [xyz]?
+You do not understand what CBR is, please read the MPEG spec.
+Read about video buffer verifier and constant bitrate.
+The one sentence summary is that there is a buffer and the input rate is
+constant, the output can vary as needed.
-Because no one has taken on that task yet. FFmpeg development is
-driven by the tasks that are important to the individual developers.
-If there is a feature that is important to you, the best way to get
-it implemented is to undertake the task yourself.
+@section How do I check if a stream is CBR?
+
+To quote the MPEG-2 spec:
+"There is no way to tell that a bitstream is constant bitrate without
+examining all of the vbv_delay values and making complicated computations."
-@section Are there examples illustrating how to use the FFmpeg libraries, particularly libavcodec and libavformat?
+@chapter Development
-Yes. Read the Developers Guide of the FFmpeg documentation. Alternatively,
+@section Are there examples illustrating how to use the Libav libraries, particularly libavcodec and libavformat?
+
+Yes. Read the Developers Guide of the Libav documentation. Alternatively,
examine the source code for one of the many open source projects that
-already incorporate ffmpeg at (@url{projects.php}).
+already incorporate Libav at (@url{projects.html}).
@section Can you support my C compiler XXX?
it are likely to be welcome if they do not pollute the source code
with @code{#ifdef}s related to the compiler.
-@section Visual C++ produces many errors.
+@section Is Microsoft Visual C++ supported?
-Visual C++ is not compliant to the C standard and does not support
-the inline assembly used in FFmpeg.
-If you wish - for whatever weird reason - to use Visual C++ for your
-project then you can link the Visual C++ code with libav* as long as
+No. Microsoft Visual C++ is not compliant to the C99 standard and does
+not - among other things - support the inline assembly used in Libav.
+If you wish to use MSVC++ for your
+project then you can link the MSVC++ code with libav* as long as
you compile the latter with a working C compiler. For more information, see
-the @emph{Visual C++ compatibility} section in the FFmpeg documentation.
+the @emph{Microsoft Visual C++ compatibility} section in the Libav
+documentation.
-There have been efforts to make FFmpeg compatible with Visual C++ in the
+There have been efforts to make Libav compatible with MSVC++ in the
past. However, they have all been rejected as too intrusive, especially
-since MinGW does the job perfectly adequately. None of the core developers
-work with Visual C++ and thus this item is low priority. Should you find
+since MinGW does the job adequately. None of the core developers
+work with MSVC++ and thus this item is low priority. Should you find
the silver bullet that solves this problem, feel free to shoot it at us.
-@section Can I use FFmpeg or libavcodec under Windows?
+We strongly recommend you to move over from MSVC++ to MinGW tools.
-Yes, but the MinGW tools @emph{must} be used to compile FFmpeg. You
-can link the resulting DLLs with any other Windows program. Read the
-@emph{Native Windows Compilation} and @emph{Visual C++ compatibility}
-sections in the FFmpeg documentation to find more information.
+@section Can I use Libav or libavcodec under Windows?
-To get help and instructions for using FFmpeg under Windows, check out
-the FFmpeg Windows Help Forum at
-@url{http://arrozcru.no-ip.org/ffmpeg/}.
+Yes, but the Cygwin or MinGW tools @emph{must} be used to compile Libav.
+Read the @emph{Windows} section in the Libav documentation to find more
+information.
@section Can you add automake, libtool or autoconf support?
@section Why not rewrite ffmpeg in object-oriented C++?
-ffmpeg is already organized in a highly modular manner and does not need to
+Libav is already organized in a highly modular manner and does not need to
be rewritten in a formal object language. Further, many of the developers
favor straight C; it works for them. For more arguments on this matter,
-read "Programming Religion" at (@url{http://www.tux.org/lkml/#s15}).
-
-@section Why are the ffmpeg programs devoid of debugging symbols?
-
-The build process creates ffmpeg_g, ffplay_g, etc. which contain full debug
-information. Those binaries are strip'd to create ffmpeg, ffplay, etc. If
-you need the debug information, used the *_g versions.
+read @uref{http://www.tux.org/lkml/#s15, "Programming Religion"}.
@section I do not like the LGPL, can I contribute code under the GPL instead?
Yes, as long as the code is optional and can easily and cleanly be placed
-under #ifdef CONFIG_GPL without breaking anything. So for example a new codec
-or filter would be OK under GPL while a bugfix to LGPL code would not.
+under #if CONFIG_GPL without breaking anything. So for example a new codec
+or filter would be OK under GPL while a bug fix to LGPL code would not.
@section I want to compile xyz.c alone but my compiler produced many errors.
You can also try to hack it and remove more, but if you had problems fixing
the compilation failure then you are probably not qualified for this.
-@section I have a file in memory / a API different from *open/*read/ libc how do i use it with libavformat?
+@section I'm using libavcodec from within my C++ application but the linker complains about missing symbols which seem to be available.
+
+Libav is a pure C project, so to use the libraries within your C++ application
+you need to explicitly state that you are using a C library. You can do this by
+encompassing your Libav includes using @code{extern "C"}.
+
+See @url{http://www.parashift.com/c++-faq-lite/mixing-c-and-cpp.html#faq-32.3}
+
+@section I'm using libavutil from within my C++ application but the compiler complains about 'UINT64_C' was not declared in this scope
-You have to implement a URLProtocol, see libavformat/file.c in FFmpeg
-and libmpdemux/demux_lavf.c in MPlayer sources.
+Libav is a pure C project using C99 math features, in order to enable C++
+to use them you have to append -D__STDC_CONSTANT_MACROS to your CXXFLAGS
+
+@section I have a file in memory / a API different from *open/*read/ libc how do I use it with libavformat?
+
+You have to implement a URLProtocol, see @file{libavformat/file.c} in
+Libav and @file{libmpdemux/demux_lavf.c} in MPlayer sources.
@section I get "No compatible shell script interpreter found." in MSys.
The standard MSys bash (2.04) is broken. You need to install 2.05 or later.
-@section I tried to pass RTP packets into a decoder, but it doesn't work.
+@section I get "./configure: line <xxx>: pr: command not found" in MSys.
-RTP is a container format like any other, you must first depacketize the
-codec frames/samples stored in RTP and then feed to the decoder.
+The standard MSys install doesn't come with pr. You need to get it from the coreutils package.
@section Where can I find libav* headers for Pascal/Delphi?
@section Where is the documentation about ffv1, msmpeg4, asv1, 4xm?
-see @url{http://svn.mplayerhq.hu/michael/trunk/docs/}
+see @url{http://www.ffmpeg.org/~michael/}
-@section how do I feed H.263-RTP (and other codecs in rtp) to libavcodec?
+@section How do I feed H.263-RTP (and other codecs in RTP) to libavcodec?
Even if peculiar since it is network oriented, RTP is a container like any
-other. You have to DEMUX RTP before feeding the payload to libavcodec.
-In this specific case please look at rfc 4629 to see how it should be done.
+other. You have to @emph{demux} RTP before feeding the payload to libavcodec.
+In this specific case please look at RFC 4629 to see how it should be done.
+
+@section AVStream.r_frame_rate is wrong, it is much larger than the framerate.
+
+r_frame_rate is NOT the average framerate, it is the smallest framerate
+that can accurately represent all timestamps. So no, it is not
+wrong if it is larger than the average!
+For example, if you have mixed 25 and 30 fps content, then r_frame_rate
+will be 150.
@bye
OSDN Git Service
