speex - Add echo-cancelling option to speexdsp plugin

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 10 insertions, 1 deletions

diff --git a/doc/speexdsp.txt b/doc/speexdsp.txt
index 875fc19..5b5e5a0 100644
--- a/doc/speexdsp.txt
+++ b/doc/speexdsp.txt
@@ -12,7 +12,7 @@ using libspeex DSP API.  You can use the plugin with the plugin type
 
 Then record like
 
-	% arecord -fdat -c1 -Dplug:speex foo.wav
+	% arecord -fdat -c1 -Dplug:my_pcm foo.wav
 
 so that you'll get 48kHz mono stream with the denoising effect.
 
@@ -44,6 +44,15 @@ The following parameters can be set optionally:
 
   A boolean value to enable/disable dereverb function.  Default is no.
 
+* echo
+
+  A boolean value to enable/disable echo-cancellation function.
+  Default is no.
+
+* filter_length
+
+  Number of samples of echo to cancel.  As default it's 256.
+
 For example, you can enable agc like
 
 	pcm.my_pcm {