diff options
Diffstat (limited to 'ffmpeg/doc/faq.texi')
| -rw-r--r-- | ffmpeg/doc/faq.texi | 48 |
1 files changed, 23 insertions, 25 deletions
diff --git a/ffmpeg/doc/faq.texi b/ffmpeg/doc/faq.texi index ebf21f5..c47d9d9 100644 --- a/ffmpeg/doc/faq.texi +++ b/ffmpeg/doc/faq.texi @@ -105,7 +105,7 @@ For example, img1.jpg, img2.jpg, img3.jpg,... Then you may run: @example - ffmpeg -f image2 -i img%d.jpg /tmp/a.mpg +ffmpeg -f image2 -i img%d.jpg /tmp/a.mpg @end example Notice that @samp{%d} is replaced by the image number. @@ -118,7 +118,7 @@ the sequence. This is useful if your sequence does not start with example will start with @file{img100.jpg}: @example - ffmpeg -f image2 -start_number 100 -i img%d.jpg /tmp/a.mpg +ffmpeg -f image2 -start_number 100 -i img%d.jpg /tmp/a.mpg @end example If you have large number of pictures to rename, you can use the @@ -128,7 +128,7 @@ 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"$counter".jpg; x=$(($x+1)); done +x=1; for i in *jpg; do counter=$(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 @@ -137,7 +137,7 @@ If you want to sequence them by oldest modified first, substitute Then run: @example - ffmpeg -f image2 -i /tmp/img%03d.jpg /tmp/a.mpg +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. @@ -145,7 +145,7 @@ The same logic is used for any image format that ffmpeg reads. You can also use @command{cat} to pipe images to ffmpeg: @example - cat *.jpg | ffmpeg -f image2pipe -c:v mjpeg -i - output.mpg +cat *.jpg | ffmpeg -f image2pipe -c:v mjpeg -i - output.mpg @end example @section How do I encode movie to single pictures? @@ -153,7 +153,7 @@ You can also use @command{cat} to pipe images to ffmpeg: Use: @example - ffmpeg -i movie.mpg movie%d.jpg +ffmpeg -i movie.mpg movie%d.jpg @end example The @file{movie.mpg} used as input will be converted to @@ -169,7 +169,7 @@ to force the encoding. Applying that to the previous example: @example - ffmpeg -i movie.mpg -f image2 -c:v mjpeg menu%d.jpg +ffmpeg -i movie.mpg -f image2 -c:v mjpeg menu%d.jpg @end example Beware that there is no "jpeg" codec. Use "mjpeg" instead. @@ -227,15 +227,15 @@ then you may use any file that DirectShow can read as input. Just create an "input.avs" text file with this single line ... @example - DirectShowSource("C:\path to your file\yourfile.asf") +DirectShowSource("C:\path to your file\yourfile.asf") @end example ... and then feed that text file to ffmpeg: @example - ffmpeg -i input.avs +ffmpeg -i input.avs @end example -For ANY other help on Avisynth, please visit the -@uref{http://www.avisynth.org/, Avisynth homepage}. +For ANY other help on AviSynth, please visit the +@uref{http://www.avisynth.org/, AviSynth homepage}. @section How can I join video files? @@ -393,17 +393,17 @@ Appending @code{:v} to it will do exactly that. Use @option{-dumpgraph -} to find out exactly where the channel layout is lost. -Most likely, it is through @code{auto-inserted aconvert}. Try to understand +Most likely, it is through @code{auto-inserted aresample}. Try to understand why the converting filter was needed at that place. Just before the output is a likely place, as @option{-f lavfi} currently only support packed S16. -Then insert the correct @code{aconvert} explicitly in the filter graph, +Then insert the correct @code{aformat} explicitly in the filtergraph, specifying the exact format. @example -aconvert=s16:stereo:packed +aformat=sample_fmts=s16:channel_layouts=stereo @end example @section Why does FFmpeg not see the subtitles in my VOB file? @@ -475,9 +475,10 @@ read @uref{http://www.tux.org/lkml/#s15, "Programming Religion"}. @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 stripped to create ffmpeg, ffplay, etc. If -you need the debug information, use the *_g versions. +The build process creates @command{ffmpeg_g}, @command{ffplay_g}, etc. which +contain full debug information. Those binaries are stripped to create +@command{ffmpeg}, @command{ffplay}, etc. If you need the debug information, use +the *_g versions. @section I do not like the LGPL, can I contribute code under the GPL instead? @@ -497,7 +498,7 @@ An easy way to get the full list of required libraries in dependency order is to use @code{pkg-config}. @example - c99 -o program program.c $(pkg-config --cflags --libs libavformat libavcodec) +c99 -o program program.c $(pkg-config --cflags --libs libavformat libavcodec) @end example See @file{doc/example/Makefile} and @file{doc/example/pc-uninstalled} for @@ -521,10 +522,6 @@ to use them you have to append -D__STDC_CONSTANT_MACROS to your CXXFLAGS You have to create a custom AVIOContext using @code{avio_alloc_context}, see @file{libavformat/aviobuf.c} in FFmpeg and @file{libmpdemux/demux_lavf.c} in MPlayer or MPlayer2 sources. -@section Where can I find libav* headers for Pascal/Delphi? - -see @url{http://www.iversenit.dk/dev/ffmpeg-headers/} - @section Where is the documentation about ffv1, msmpeg4, asv1, 4xm? see @url{http://www.ffmpeg.org/~michael/} @@ -537,11 +534,12 @@ 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 frame rate. -r_frame_rate is NOT the average frame rate, it is the smallest frame rate +@code{r_frame_rate} is NOT the average frame rate, it is the smallest frame rate 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. +For example, if you have mixed 25 and 30 fps content, then @code{r_frame_rate} +will be 150 (it is the least common multiple). +If you are looking for the average frame rate, see @code{AVStream.avg_frame_rate}. @section Why is @code{make fate} not running all tests? |