From 715e5051c3026655154003799069ae55dc81cf5a Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 21 Jan 2009 18:11:43 +0100 Subject: Add Speex pre-processing plugin Added Speex pre-processing filter plugin for denoise, AGC, etc. Signed-off-by: Takashi Iwai --- doc/Makefile.am | 3 ++- doc/speexdsp.txt | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+), 1 deletion(-) create mode 100644 doc/speexdsp.txt (limited to 'doc') diff --git a/doc/Makefile.am b/doc/Makefile.am index 41a7ebe..3e89be8 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -1,3 +1,4 @@ EXTRA_DIST = README-pcm-oss README-jack README-pulse README-maemo \ upmix.txt vdownmix.txt samplerate.txt a52.txt lavcrate.txt \ - speexrate.txt + speexrate.txt speexdsp.txt + diff --git a/doc/speexdsp.txt b/doc/speexdsp.txt new file mode 100644 index 0000000..875fc19 --- /dev/null +++ b/doc/speexdsp.txt @@ -0,0 +1,54 @@ +Speex Preprocessing Plugin +========================== + +This plugin provides a pre-processing of a mono stream like denoise +using libspeex DSP API. You can use the plugin with the plugin type +"speex" like below: + + pcm.my_pcm { + type speex + slave.pcm "default" + } + +Then record like + + % arecord -fdat -c1 -Dplug:speex foo.wav + +so that you'll get 48kHz mono stream with the denoising effect. + +Right now, the plugin supports only a mono stream. +The accepted format is only S16. + +The following parameters can be set optionally: + +* frames + + This controls the frames of the intermediate buffer. This + corresponds to the latency of the filter. As default it's 64. + +* denoise + + A boolean value to enable/disable the denoise function. Default is + yes. + +* agc + + A boolean value to enable/disable the auto-gain control function. + Default is no. + +* agc_level + + A float value for the automatic gain-control level. Default is 8000. + +* dereverb + + A boolean value to enable/disable dereverb function. Default is no. + +For example, you can enable agc like + + pcm.my_pcm { + type speex + slave.pcm "default" + agc 1 + agc_level 8000 + } -- cgit