Added new PCM functions (pcm_misc.c).

New plugins: rate, voices.
This commit is contained in:
Jaroslav Kysela 1999-11-24 17:00:16 +00:00
parent a743444ef3
commit 4a01380a7b
7 changed files with 655 additions and 33 deletions

View file

@ -2,7 +2,7 @@ SUBDIRS = plugin
EXTRA_LTLIBRARIES = libpcm.la
libpcm_la_SOURCES = pcm.c pcm_plugin.c pcm_loopback.c
libpcm_la_SOURCES = pcm.c pcm_plugin.c pcm_misc.c pcm_loopback.c
libpcm_la_LIBADD = plugin/libpcmplugin.la
all: libpcm.la

185
src/pcm/pcm_misc.c Normal file
View file

@ -0,0 +1,185 @@
/*
* PCM Interface - misc routines
* Copyright (c) 1998 by Jaroslav Kysela <perex@suse.cz>
*
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include "pcm_local.h"
int snd_pcm_format_signed(int format)
{
switch (format) {
case SND_PCM_SFMT_S8:
case SND_PCM_SFMT_S16_LE:
case SND_PCM_SFMT_S16_BE:
case SND_PCM_SFMT_S24_LE:
case SND_PCM_SFMT_S24_BE:
case SND_PCM_SFMT_S32_LE:
case SND_PCM_SFMT_S32_BE:
return 1;
case SND_PCM_SFMT_U8:
case SND_PCM_SFMT_U16_LE:
case SND_PCM_SFMT_U16_BE:
case SND_PCM_SFMT_U24_LE:
case SND_PCM_SFMT_U24_BE:
case SND_PCM_SFMT_U32_LE:
case SND_PCM_SFMT_U32_BE:
return 0;
default:
return -EINVAL;
}
}
int snd_pcm_format_unsigned(int format)
{
int val;
val = snd_pcm_format_signed(format);
if (val >= 0)
val ^= 1;
return val;
}
int snd_pcm_format_little_endian(int format)
{
switch (format) {
case SND_PCM_SFMT_S16_LE:
case SND_PCM_SFMT_U16_LE:
case SND_PCM_SFMT_S24_LE:
case SND_PCM_SFMT_U24_LE:
case SND_PCM_SFMT_S32_LE:
case SND_PCM_SFMT_U32_LE:
case SND_PCM_SFMT_FLOAT_LE:
case SND_PCM_SFMT_FLOAT64_LE:
case SND_PCM_SFMT_IEC958_SUBFRAME_LE:
return 1;
case SND_PCM_SFMT_S16_BE:
case SND_PCM_SFMT_U16_BE:
case SND_PCM_SFMT_S24_BE:
case SND_PCM_SFMT_U24_BE:
case SND_PCM_SFMT_S32_BE:
case SND_PCM_SFMT_U32_BE:
case SND_PCM_SFMT_FLOAT_BE:
case SND_PCM_SFMT_FLOAT64_BE:
case SND_PCM_SFMT_IEC958_SUBFRAME_BE:
return 0;
default:
return -EINVAL;
}
}
int snd_pcm_format_big_endian(int format)
{
int val;
val = snd_pcm_format_little_endian(format);
if (val >= 0)
val ^= 1;
return val;
}
int snd_pcm_format_width(int format)
{
switch (format) {
case SND_PCM_SFMT_S8:
case SND_PCM_SFMT_U8:
return 8;
case SND_PCM_SFMT_S16_LE:
case SND_PCM_SFMT_S16_BE:
case SND_PCM_SFMT_U16_LE:
case SND_PCM_SFMT_U16_BE:
return 16;
case SND_PCM_SFMT_S24_LE:
case SND_PCM_SFMT_S24_BE:
case SND_PCM_SFMT_U24_LE:
case SND_PCM_SFMT_U24_BE:
return 24;
case SND_PCM_SFMT_S32_LE:
case SND_PCM_SFMT_S32_BE:
case SND_PCM_SFMT_U32_LE:
case SND_PCM_SFMT_U32_BE:
case SND_PCM_SFMT_FLOAT_LE:
case SND_PCM_SFMT_FLOAT_BE:
return 32;
case SND_PCM_SFMT_FLOAT64_LE:
case SND_PCM_SFMT_FLOAT64_BE:
return 64;
case SND_PCM_SFMT_IEC958_SUBFRAME_LE:
case SND_PCM_SFMT_IEC958_SUBFRAME_BE:
return 24;
case SND_PCM_SFMT_MU_LAW:
case SND_PCM_SFMT_A_LAW:
return 8;
case SND_PCM_SFMT_IMA_ADPCM:
return 4;
default:
return -EINVAL;
}
}
ssize_t snd_pcm_format_size(int format, size_t samples)
{
if (samples < 0)
return -EINVAL;
if (samples == 0)
return samples;
switch (format) {
case SND_PCM_SFMT_S8:
case SND_PCM_SFMT_U8:
return samples;
case SND_PCM_SFMT_S16_LE:
case SND_PCM_SFMT_S16_BE:
case SND_PCM_SFMT_U16_LE:
case SND_PCM_SFMT_U16_BE:
return samples * 2;
case SND_PCM_SFMT_S24_LE:
case SND_PCM_SFMT_S24_BE:
case SND_PCM_SFMT_U24_LE:
case SND_PCM_SFMT_U24_BE:
case SND_PCM_SFMT_S32_LE:
case SND_PCM_SFMT_S32_BE:
case SND_PCM_SFMT_U32_LE:
case SND_PCM_SFMT_U32_BE:
case SND_PCM_SFMT_FLOAT_LE:
case SND_PCM_SFMT_FLOAT_BE:
return samples * 4;
case SND_PCM_SFMT_FLOAT64_LE:
case SND_PCM_SFMT_FLOAT64_BE:
return samples * 8;
case SND_PCM_SFMT_IEC958_SUBFRAME_LE:
case SND_PCM_SFMT_IEC958_SUBFRAME_BE:
return samples * 4;
case SND_PCM_SFMT_MU_LAW:
case SND_PCM_SFMT_A_LAW:
return samples;
case SND_PCM_SFMT_IMA_ADPCM:
if (samples & 1)
return -EINVAL;
return samples / 2;
default:
return -EINVAL;
}
}

View file

@ -97,6 +97,22 @@ int snd_pcm_plugin_insert(snd_pcm_t *pcm, int channel, snd_pcm_plugin_t *plugin)
return 0;
}
int snd_pcm_plugin_append(snd_pcm_t *pcm, int channel, snd_pcm_plugin_t *plugin)
{
if (!pcm || channel < 0 || channel > 1 || !plugin)
return -EINVAL;
plugin->next = NULL;
plugin->prev = pcm->plugin_last[channel];
if (pcm->plugin_last[channel]) {
pcm->plugin_last[channel]->next = plugin;
pcm->plugin_last[channel] = plugin;
} else {
pcm->plugin_last[channel] =
pcm->plugin_first[channel] = plugin;
}
return 0;
}
int snd_pcm_plugin_remove_to(snd_pcm_t *pcm, int channel, snd_pcm_plugin_t *plugin)
{
snd_pcm_plugin_t *plugin1, *plugin1_prev;
@ -247,6 +263,9 @@ int snd_pcm_plugin_info(snd_pcm_t *pcm, snd_pcm_channel_info_t *info)
if ((err = snd_pcm_channel_info(pcm, info)) < 0)
return err;
info->formats = snd_pcm_plugin_formats(pcm, info->formats);
info->min_rate = 4000;
info->max_rate = 192000;
info->rates = SND_PCM_RATE_8000_48000;
return 0;
}
@ -372,25 +391,90 @@ int snd_pcm_plugin_params(snd_pcm_t *pcm, snd_pcm_channel_params_t *params)
*/
snd_pcm_plugin_clear(pcm, params->channel);
if (sinfo.mode == SND_PCM_MODE_STREAM) {
err = snd_pcm_plugin_build_stream(pcm, params->channel, &plugin);
} else if (sinfo.mode == SND_PCM_MODE_BLOCK) {
if (sinfo.flags & SND_PCM_CHNINFO_MMAP) {
err = snd_pcm_plugin_build_mmap(pcm, params->channel, &plugin);
} else {
err = snd_pcm_plugin_build_block(pcm, params->channel, &plugin);
if (sparams.format.voices < sinfo.min_voices ||
sparams.format.voices > sinfo.max_voices) {
int src_voices = sparams.format.voices;
int dst_voices = sparams.format.voices < sinfo.min_voices ?
sinfo.min_voices : sinfo.max_voices;
if (sparams.format.rate < sinfo.min_rate ||
sparams.format.rate > sinfo.max_rate)
dst_voices = 2;
sparams.format.voices = dst_voices;
swap_formats(params->channel, &src_voices, &dst_voices);
err = snd_pcm_plugin_build_voices(params->format.format, src_voices,
params->format.format, dst_voices,
&plugin);
if (err < 0) {
snd_pcm_plugin_free(plugin);
return err;
}
err = snd_pcm_plugin_append(pcm, params->channel, plugin);
if (err < 0) {
snd_pcm_plugin_free(plugin);
return err;
}
} else {
return -EINVAL;
}
/*
* formats
*/
if (params->format.format == sparams.format.format)
goto __format_skip;
/* build additional plugins for conversion */
switch (params->format.format) {
case SND_PCM_SFMT_MU_LAW:
srcfmt = SND_PCM_SFMT_MU_LAW;
dstfmt = sparams.format.format;
swap_formats(params->channel, &srcfmt, &dstfmt);
err = snd_pcm_plugin_build_mulaw(srcfmt, dstfmt, &plugin);
break;
default:
srcfmt = params->format.format;
dstfmt = sparams.format.format;
swap_formats(params->channel, &srcfmt, &dstfmt);
err = snd_pcm_plugin_build_linear(srcfmt, dstfmt, &plugin);
}
if (err < 0)
return err;
err = snd_pcm_plugin_insert(pcm, params->channel, plugin);
err = snd_pcm_plugin_append(pcm, params->channel, plugin);
if (err < 0) {
snd_pcm_plugin_free(plugin);
return err;
}
__format_skip:
/*
* rate
*/
if (sparams.format.rate < sinfo.min_rate ||
sparams.format.rate > sinfo.max_rate) {
int src_rate = sparams.format.rate;
int dst_rate = sparams.format.rate < sinfo.min_rate ?
sinfo.min_rate : sinfo.max_rate;
sparams.format.rate = dst_rate;
swap_formats(params->channel, &src_rate, &dst_rate);
err = snd_pcm_plugin_build_rate(sparams.format.format, src_rate, sparams.format.voices,
sparams.format.format, dst_rate, sparams.format.voices,
&plugin);
if (err < 0) {
snd_pcm_plugin_free(plugin);
return err;
}
err = snd_pcm_plugin_append(pcm, params->channel, plugin);
if (err < 0) {
snd_pcm_plugin_free(plugin);
return err;
}
}
/*
* interleave
*/
if (params->format.voices > 1 && sinfo.mode == SND_PCM_MODE_BLOCK) {
int src_interleave, dst_interleave;
@ -409,7 +493,7 @@ int snd_pcm_plugin_params(snd_pcm_t *pcm, snd_pcm_channel_params_t *params)
err = snd_pcm_plugin_build_interleave(src_interleave, dst_interleave, sparams.format.format, &plugin);
if (err < 0)
return err;
err = snd_pcm_plugin_insert(pcm, params->channel, plugin);
err = snd_pcm_plugin_append(pcm, params->channel, plugin);
if (err < 0) {
snd_pcm_plugin_free(plugin);
return err;
@ -417,31 +501,33 @@ int snd_pcm_plugin_params(snd_pcm_t *pcm, snd_pcm_channel_params_t *params)
}
}
if (params->format.format == sparams.format.format)
goto __skip;
/* build additional plugins for conversion */
switch (params->format.format) {
case SND_PCM_SFMT_MU_LAW:
srcfmt = SND_PCM_SFMT_MU_LAW;
dstfmt = sparams.format.format;
swap_formats(params->channel, &srcfmt, &dstfmt);
err = snd_pcm_plugin_build_mulaw(srcfmt, dstfmt, &plugin);
break;
default:
srcfmt = params->format.format;
dstfmt = sparams.format.format;
swap_formats(params->channel, &srcfmt, &dstfmt);
err = snd_pcm_plugin_build_linear(srcfmt, dstfmt, &plugin);
/*
* I/O plugins
*/
if (sinfo.mode == SND_PCM_MODE_STREAM) {
err = snd_pcm_plugin_build_stream(pcm, params->channel, &plugin);
} else if (sinfo.mode == SND_PCM_MODE_BLOCK) {
if (sinfo.flags & SND_PCM_CHNINFO_MMAP) {
err = snd_pcm_plugin_build_mmap(pcm, params->channel, &plugin);
} else {
err = snd_pcm_plugin_build_block(pcm, params->channel, &plugin);
}
} else {
return -EINVAL;
}
if (err < 0)
return err;
err = snd_pcm_plugin_insert(pcm, params->channel, plugin);
err = snd_pcm_plugin_append(pcm, params->channel, plugin);
if (err < 0) {
snd_pcm_plugin_free(plugin);
return err;
}
__skip:
/*
* ratio
*/
ratio = snd_pcm_plugin_hardware_ratio(pcm, params->channel);
if (ratio <= 0)
return -EINVAL;

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
mulaw.c rate.c voices.c
all: libpcmplugin.la

View file

@ -330,10 +330,10 @@ int snd_pcm_plugin_build_linear(int src_format, int dst_format, snd_pcm_plugin_t
return -EINVAL;
#if __BYTE_ORDER == __LITTLE_ENDIAN
endian1 = endian1 == __BIG_ENDIAN ? 1 : 0;
endian1 = endian2 == __BIG_ENDIAN ? 1 : 0;
endian2 = endian2 == __BIG_ENDIAN ? 1 : 0;
#elif __BYTE_ORDER == __BIG_ENDIAN
endian1 = endian1 == __LITTLE_ENDIAN ? 1 : 0;
endian1 = endian2 == __LITTLE_ENDIAN ? 1 : 0;
endian2 = endian2 == __LITTLE_ENDIAN ? 1 : 0;
#else
#error "Unsupported endian..."
#endif
@ -380,7 +380,7 @@ int snd_pcm_plugin_build_linear(int src_format, int dst_format, snd_pcm_plugin_t
return -ENOMEM;
data = (struct linear_private_data *)snd_pcm_plugin_extra_data(plugin);
data->cmd = cmd;
if (!endian1 && !endian2) {
if (endian1 == endian2) {
data->endian = NONE;
} else if (endian1 && !endian2) {
data->endian = SOURCE;

144
src/pcm/plugin/rate.c Normal file
View file

@ -0,0 +1,144 @@
/*
* Rate conversion Plug-In
* Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>
*
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <endian.h>
#include <byteswap.h>
#include "../pcm_local.h"
/*
* Basic rate conversion plugin
*/
struct rate_private_data {
unsigned int src_rate;
unsigned int dst_rate;
unsigned int pitch;
unsigned int pos;
signed short last_L_S1, last_R_S1;
};
static void mix(struct rate_private_data *data,
signed short *src_ptr, int src_size,
signed short *dst_ptr, int dst_size)
{
unsigned int pos;
signed int val;
signed short L_S1, R_S1, L_S2, R_S2;
pos = data->pos;
L_S1 = L_S2 = data->last_L_S1;
R_S1 = R_S2 = data->last_R_S1;
while (dst_size-- > 0) {
pos += data->pitch;
src_ptr += (pos >> 10) * 2; pos &= 0x3ff;
L_S2 = *src_ptr;
val = L_S1 + ((L_S2 + L_S1) * (signed int)pos) / 1024;
if (val < -32768)
val = -32768;
else if (val > 32767)
val = 32767;
*dst_ptr++ = val;
R_S2 = *(src_ptr + 1);
val = R_S1 + ((R_S2 + R_S1) * (signed int)pos) / 1024;
if (val < -32768)
val = -32768;
else if (val > 32767)
val = 32767;
*dst_ptr++ = val;
}
data->last_L_S1 = L_S2;
data->last_R_S1 = R_S2;
data->pos = pos & 0x3ff;
}
static ssize_t rate_transfer(snd_pcm_plugin_t *plugin,
char *src_ptr, size_t src_size,
char *dst_ptr, size_t dst_size)
{
struct rate_private_data *data;
if (plugin == NULL || src_ptr == NULL || src_size < 0 ||
dst_ptr == NULL || dst_size < 0)
return -EINVAL;
if (src_size == 0)
return 0;
data = (struct rate_private_data *)snd_pcm_plugin_extra_data(plugin);
if (data == NULL)
return -EINVAL;
mix(data, (signed short *)src_ptr, src_size / 4,
(signed short *)dst_ptr, dst_size / 4);
return (dst_size / 4) * 4;
}
static ssize_t rate_src_size(snd_pcm_plugin_t *plugin, size_t size)
{
struct rate_private_data *data;
if (!plugin || size <= 0)
return -EINVAL;
data = (struct rate_private_data *)snd_pcm_plugin_extra_data(plugin);
return (((size * data->pitch) + 0x1ff) >> 10) & ~3;
}
static ssize_t rate_dst_size(snd_pcm_plugin_t *plugin, size_t size)
{
struct rate_private_data *data;
if (!plugin || size <= 0)
return -EINVAL;
data = (struct rate_private_data *)snd_pcm_plugin_extra_data(plugin);
return (((size << 10) + (data->pitch / 2)) / data->pitch) & ~3;
}
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)
{
struct rate_private_data *data;
snd_pcm_plugin_t *plugin;
if (!r_plugin)
return -EINVAL;
*r_plugin = NULL;
if (src_voices != 2 || dst_voices != 2)
return -EINVAL;
if (src_format != SND_PCM_SFMT_S16_LE ||
dst_format != SND_PCM_SFMT_S16_LE)
return -EINVAL;
if (src_rate == dst_rate)
return -EINVAL;
plugin = snd_pcm_plugin_build("rate format conversion",
sizeof(struct rate_private_data));
if (plugin == NULL)
return -ENOMEM;
data = (struct rate_private_data *)snd_pcm_plugin_extra_data(plugin);
data->pitch = ((src_rate << 10) + (dst_rate >> 1)) / dst_rate;
plugin->transfer = rate_transfer;
plugin->src_size = rate_src_size;
plugin->dst_size = rate_dst_size;
*r_plugin = plugin;
return 0;
}

207
src/pcm/plugin/voices.c Normal file
View file

@ -0,0 +1,207 @@
/*
* Voices conversion Plug-In
* Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>
*
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <endian.h>
#include <byteswap.h>
#include "../pcm_local.h"
/*
* Basic voices conversion plugin
*/
struct voices_private_data {
int src_voices;
int dst_voices;
int width; /* in bites */
int flg_merge: 1,
flg_signed: 1;
};
static void divide_8bit(char *src_ptr, char *dst_ptr, int size)
{
while (size-- > 0) {
*dst_ptr++ = *src_ptr;
*dst_ptr++ = *src_ptr++;
}
}
static void divide_16bit(short *src_ptr, short *dst_ptr, int size)
{
while (size-- > 0) {
*dst_ptr++ = *src_ptr;
*dst_ptr++ = *src_ptr++;
}
}
static void merge_8bit_unsigned(unsigned char *src_ptr,
unsigned char *dst_ptr,
int size)
{
while (size-- > 0) {
*dst_ptr++ = (*src_ptr + *(src_ptr + 1)) / 2;
src_ptr += 2;
}
}
static void merge_8bit_signed(signed char *src_ptr,
signed char *dst_ptr,
int size)
{
while (size-- > 0) {
*dst_ptr++ = (*src_ptr + *(src_ptr + 1)) / 2;
src_ptr += 2;
}
}
static void merge_16bit_unsigned(unsigned short *src_ptr,
unsigned short *dst_ptr,
int size)
{
while (size-- > 0) {
*dst_ptr++ = (*src_ptr + *(src_ptr + 1)) / 2;
src_ptr += 2;
}
}
static void merge_16bit_signed(signed short *src_ptr,
signed short *dst_ptr,
int size)
{
while (size-- > 0) {
*dst_ptr++ = (*src_ptr + *(src_ptr + 1)) / 2;
src_ptr += 2;
}
}
static ssize_t voices_transfer(snd_pcm_plugin_t *plugin,
char *src_ptr, size_t src_size,
char *dst_ptr, size_t dst_size)
{
struct voices_private_data *data;
if (plugin == NULL || src_ptr == NULL || src_size < 0 ||
dst_ptr == NULL || dst_size < 0)
return -EINVAL;
if (src_size == 0)
return 0;
data = (struct voices_private_data *)snd_pcm_plugin_extra_data(plugin);
if (data == NULL)
return -EINVAL;
switch (data->width) {
case 8:
if (data->src_voices > data->dst_voices) {
if (data->flg_signed) {
merge_8bit_signed(src_ptr, dst_ptr, src_size / 2);
} else {
merge_8bit_unsigned(src_ptr, dst_ptr, src_size / 2);
}
return (src_size * data->src_voices) / data->dst_voices;
} else {
divide_8bit(src_ptr, dst_ptr, src_size);
return (src_size * data->dst_voices) / data->src_voices;
}
break;
case 16:
if (data->src_voices > data->dst_voices) {
if (data->flg_signed) {
merge_16bit_signed((short *)src_ptr, (short *)dst_ptr, src_size / 4);
} else {
merge_16bit_unsigned((short *)src_ptr, (short *)dst_ptr, src_size / 4);
}
return (src_size * data->src_voices) / data->dst_voices;
} else {
divide_16bit((short *)src_ptr, (short *)dst_ptr, src_size / 2);
return (src_size * data->dst_voices) / data->src_voices;
}
break;
default:
return -EINVAL;
}
}
static ssize_t voices_src_size(snd_pcm_plugin_t *plugin, size_t size)
{
struct voices_private_data *data;
if (!plugin || size <= 0)
return -EINVAL;
data = (struct voices_private_data *)snd_pcm_plugin_extra_data(plugin);
if (data->src_voices < data->dst_voices)
return (size * data->src_voices) / data->dst_voices;
else
return (size * data->dst_voices) / data->src_voices;
}
static ssize_t voices_dst_size(snd_pcm_plugin_t *plugin, size_t size)
{
struct voices_private_data *data;
if (!plugin || size <= 0)
return -EINVAL;
data = (struct voices_private_data *)snd_pcm_plugin_extra_data(plugin);
if (data->src_voices > data->dst_voices)
return (size * data->src_voices) / data->dst_voices;
else
return (size * data->dst_voices) / data->src_voices;
}
int snd_pcm_plugin_build_voices(int src_format, int src_voices,
int dst_format, int dst_voices,
snd_pcm_plugin_t **r_plugin)
{
struct voices_private_data *data;
snd_pcm_plugin_t *plugin;
if (!r_plugin)
return -EINVAL;
*r_plugin = NULL;
if (src_voices == dst_voices)
return -EINVAL;
if (src_voices < 1 || src_voices > 2 ||
dst_voices < 1 || dst_voices > 2)
return -EINVAL;
if (src_format != dst_format)
return -EINVAL;
if (src_format < SND_PCM_SFMT_S8 || src_format > SND_PCM_SFMT_U16_BE) {
if (src_format != SND_PCM_SFMT_MU_LAW && src_format != SND_PCM_SFMT_A_LAW)
return -EINVAL;
}
plugin = snd_pcm_plugin_build("voices conversion",
sizeof(struct voices_private_data));
if (plugin == NULL)
return -ENOMEM;
data = (struct voices_private_data *)snd_pcm_plugin_extra_data(plugin);
data->src_voices = src_voices;
data->dst_voices = dst_voices;
data->width = snd_pcm_format_width(src_format);
data->flg_merge = src_voices > dst_voices;
data->flg_signed = snd_pcm_format_signed(src_format);
plugin->transfer = voices_transfer;
plugin->src_size = voices_src_size;
plugin->dst_size = voices_dst_size;
*r_plugin = plugin;
return 0;
}