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Wed, 1 Dec 1999 19:46:33 +0100 (CET)

Browse source 
Uros Bizjak <uros@kss-loka.si>
  Included in this message, you will find a diff to alsa-lib, which
implements g721 adpcm codec. It works well (only consumes a lot of CPU),
and it plays back the same data as is recorded.

  Also added is CSP patch, which adds noise suppression when CSP is
started or stopped (A few TODOs less :) Also changed is copyright for
mulaw, alaw and adpcm codecs (Based on sun implementation ... + I added
myself - if you don't mind. Please check this copyright, if it is OK)
This commit is contained in:
Jaroslav Kysela 1999-12-01 19:44:14 +00:00
parent 34018cf902
commit 12e03f1928
4 changed files with 23 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

1
include/pcm.h
View file

@ -126,6 +126,7 @@ int snd_pcm_plugin_build_interleave(int src_interleave, int dst_interleave, int
int snd_pcm_plugin_build_linear(int src_format, int dst_format, snd_pcm_plugin_t **r_plugin);
int snd_pcm_plugin_build_mulaw(int src_format, int dst_format, snd_pcm_plugin_t **r_plugin);
int snd_pcm_plugin_build_alaw(int src_format, int dst_format, snd_pcm_plugin_t **r_plugin);
int snd_pcm_plugin_build_adpcm(int src_format, int dst_format, snd_pcm_plugin_t **r_plugin);
int snd_pcm_plugin_build_rate(int src_format, int src_rate, int src_voices,
int dst_format, int dst_rate, int dst_voices,
snd_pcm_plugin_t **r_plugin);

20
src/pcm/pcm_plugin.c
View file

@ -248,7 +248,7 @@ double snd_pcm_plugin_hardware_ratio(snd_pcm_t *pcm, int channel)
static unsigned int snd_pcm_plugin_formats(snd_pcm_t *pcm, unsigned int formats)
{
formats |= SND_PCM_FMT_MU_LAW | SND_PCM_FMT_A_LAW;
formats |= SND_PCM_FMT_MU_LAW | SND_PCM_FMT_A_LAW | SND_PCM_FMT_IMA_ADPCM;
if (formats & (SND_PCM_FMT_U8|SND_PCM_FMT_S8|
SND_PCM_FMT_U16_LE|SND_PCM_FMT_S16_LE))
formats |= SND_PCM_FMT_U8|SND_PCM_FMT_S8|
@ -393,6 +393,18 @@ int snd_pcm_plugin_params(snd_pcm_t *pcm, snd_pcm_channel_params_t *params)
} else {
return -EINVAL;
}
case SND_PCM_SFMT_IMA_ADPCM:
if (sinfo.formats & SND_PCM_FMT_S16_LE) {
sparams.format.format = SND_PCM_SFMT_S16_LE;
} else if (sinfo.formats & SND_PCM_FMT_U16_LE) {
sparams.format.format = SND_PCM_SFMT_U16_LE;
} else if (sinfo.formats & SND_PCM_FMT_S8) {
sparams.format.format = SND_PCM_SFMT_S8;
} else if (sinfo.formats & SND_PCM_FMT_U8) {
sparams.format.format = SND_PCM_SFMT_U8;
} else {
return -EINVAL;
}
break;
default:
return -EINVAL;
@ -449,6 +461,12 @@ int snd_pcm_plugin_params(snd_pcm_t *pcm, snd_pcm_channel_params_t *params)
swap_formats(params->channel, &srcfmt, &dstfmt);
err = snd_pcm_plugin_build_alaw(srcfmt, dstfmt, &plugin);
break;
case SND_PCM_SFMT_IMA_ADPCM:
srcfmt = SND_PCM_SFMT_IMA_ADPCM;
dstfmt = sparams.format.format;
swap_formats(params->channel, &srcfmt, &dstfmt);
err = snd_pcm_plugin_build_adpcm(srcfmt, dstfmt, &plugin);
break;
default:
srcfmt = params->format.format;
dstfmt = sparams.format.format;

2
src/pcm/plugin/Makefile.am
View file

@ -1,7 +1,7 @@
EXTRA_LTLIBRARIES = libpcmplugin.la
libpcmplugin_la_SOURCES = block.c mmap.c stream.c linear.c interleave.c \
mulaw.c alaw.c rate.c voices.c
mulaw.c alaw.c adpcm.c rate.c voices.c
all: libpcmplugin.la

3
src/pcm/plugin/alaw.c
View file

@ -1,8 +1,9 @@
/*
* A-Law conversion Plug-In Interface
* Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>
* Portions (c) by Sun Microsystems, Inc.
* Uros Bizjak <uros@kss-loka.si>
*
* Based on reference implementation by Sun Microsystems, Inc.
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as