diff options
Diffstat (limited to 'doc')
-rw-r--r-- | doc/Makefile.am | 3 | ||||
-rw-r--r-- | doc/upmix.txt | 34 | ||||
-rw-r--r-- | doc/vdownmix.txt | 23 |
3 files changed, 59 insertions, 1 deletions
diff --git a/doc/Makefile.am b/doc/Makefile.am index 70bcc3e..dfb40b3 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -1 +1,2 @@ -EXTRA_DIST = README-pcm-oss README-jack README-polyp +EXTRA_DIST = README-pcm-oss README-jack README-polyp \ + upmix.txt vdownmix.txt diff --git a/doc/upmix.txt b/doc/upmix.txt new file mode 100644 index 0000000..b8a6da4 --- /dev/null +++ b/doc/upmix.txt @@ -0,0 +1,34 @@ +UPMIX PLUGIN +============ + +The upmix plugin is an easy-to-use plugin for upmixing from 1 or 2 +channel stream to 4 or 6-channel stream. The number of channels to be +expanded is determined by the slave PCM. For example, the following +PCM defines upmixing to 5.1 from 2-6 channels input: + + pcm.upmix51 { + type upmix + slave.pcm "surround51" + } + +You can use this PCM as a default one by defining below: + + pcm.!default "plug:upmix51" + +The upmix plugin copies left and right channels to rear left and right +with a certain delay. The delay size can be specified by "delay" PCM +option in msec. For example, to set 10ms delay in the above case: + + pcm.upmix51 { + type upmix + slave.pcm "surround51" + channels 6 + delay 10 + } + +As default, 15ms delay is used. + +The center and LFE channels are the average of sum of left and right +signals. + +The accepted format is currently only S16. diff --git a/doc/vdownmix.txt b/doc/vdownmix.txt new file mode 100644 index 0000000..0e1403f --- /dev/null +++ b/doc/vdownmix.txt @@ -0,0 +1,23 @@ +VDOWNMIX PLUGIN +=============== + +The vdownmix plugin is a downmixer from 4-6 channels to 2-channel +stereo headphone output. This plugin processes the input signals with +a simple spacialization, so the output sounds like a kind of "virtual +surround". + +For example, define the below: + + pcm.!surround51 { + type vdownmix + slave.pcm "default" + } + pcm.!surround40 { + type vdownmix + slave.pcm "default" + } + +and the outputs from video player to these PCMs are converted to the +default 2.0 output with a proper downmix. + +The accepted format is currently only S16. |