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authorMichael Niedermayer <michaelni@gmx.at>2012-06-24 02:09:53 +0200
committerMichael Niedermayer <michaelni@gmx.at>2012-06-24 02:09:53 +0200
commit1c600888857544986d6576bc164e0dc8f0f4b6c7 (patch)
treef4e77c53d1050223a9170f75e4ea719f29cd04eb /doc
parentda728d5d2e7993911c7ed92c212ab900b7be180c (diff)
parentfe07c9c6b5a870b8f2ffcfac649228b4d76e9505 (diff)
Merge remote-tracking branch 'qatar/master'
* qatar/master: x86: Only use optimizations with cmov if the CPU supports the instruction x86: Add CPU flag for the i686 cmov instruction x86: remove unused inline asm macros from dsputil_mmx.h x86: move some inline asm macros to the only places they are used lavfi: Add the af_channelmap audio channel mapping filter. lavfi: add join audio filter. lavfi: allow audio filters to request a given number of samples. lavfi: support automatically inserting the fifo filter when needed. lavfi/audio: eliminate ff_default_filter_samples(). Conflicts: Changelog libavcodec/x86/h264dsp_mmx.c libavfilter/Makefile libavfilter/allfilters.c libavfilter/avfilter.h libavfilter/avfiltergraph.c libavfilter/version.h libavutil/x86/cpu.c Merged-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'doc')
-rw-r--r--doc/APIchanges2
-rw-r--r--doc/filters.texi70
2 files changed, 71 insertions, 1 deletions
diff --git a/doc/APIchanges b/doc/APIchanges
index 0b5ccc9216..2703610639 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -4,7 +4,7 @@ since the last major version increase.
The last version increases were:
libavcodec: 2012-01-27
libavdevice: 2011-04-18
-libavfilter: 2011-04-18
+libavfilter: 2012-06-22
libavformat: 2012-01-27
libavresample: 2012-04-24
libpostproc: 2011-04-18
diff --git a/doc/filters.texi b/doc/filters.texi
index bf7b12b610..0a5bea6299 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -649,6 +649,76 @@ front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
side_right.wav
@end example
+@section channelmap
+Remap input channels to new locations.
+
+This filter accepts the following named parameters:
+@table @option
+@item channel_layout
+Channel layout of the output stream.
+
+@item map
+Map channels from input to output. The argument is a comma-separated list of
+mappings, each in the @code{@var{in_channel}-@var{out_channel}} or
+@var{in_channel} form. @var{in_channel} can be either the name of the input
+channel (e.g. FL for front left) or its index in the input channel layout.
+@var{out_channel} is the name of the output channel or its index in the output
+channel layout. If @var{out_channel} is not given then it is implicitly an
+index, starting with zero and increasing by one for each mapping.
+@end table
+
+If no mapping is present, the filter will implicitly map input channels to
+output channels preserving index.
+
+For example, assuming a 5.1+downmix input MOV file
+@example
+ffmpeg -i in.mov -filter 'channelmap=map=DL-FL\,DR-FR' out.wav
+@end example
+will create an output WAV file tagged as stereo from the downmix channels of
+the input.
+
+To fix a 5.1 WAV improperly encoded in AAC's native channel order
+@example
+ffmpeg -i in.wav -filter 'channelmap=1\,2\,0\,5\,3\,4:channel_layout=5.1' out.wav
+@end example
+
+@section join
+Join multiple input streams into one multi-channel stream.
+
+The filter accepts the following named parameters:
+@table @option
+
+@item inputs
+Number of input streams. Defaults to 2.
+
+@item channel_layout
+Desired output channel layout. Defaults to stereo.
+
+@item map
+Map channels from inputs to output. The argument is a comma-separated list of
+mappings, each in the @code{@var{input_idx}.@var{in_channel}-@var{out_channel}}
+form. @var{input_idx} is the 0-based index of the input stream. @var{in_channel}
+can be either the name of the input channel (e.g. FR for front left) or its
+index in the specified input stream. @var{out_channel} is the name of the output
+channel.
+@end table
+
+The filter will attempt to guess the mappings when those are not specified
+explicitly. It does so by first trying to find an unused matching input channel
+and if that fails it picks the first unused input channel.
+
+E.g. to join 3 inputs (with properly set channel layouts)
+@example
+ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
+@end example
+
+To build a 5.1 output from 6 single-channel streams:
+@example
+ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
+'join=inputs=6:channel_layout=5.1:map=0.0-FL\,1.0-FR\,2.0-FC\,3.0-SL\,4.0-SR\,5.0-LFE'
+out
+@end example
+
@section resample
Convert the audio sample format, sample rate and channel layout. This filter is
not meant to be used directly.