5370d96f85
Incorrect variable was used to get the next sample which caused S2 to be stuck with the same value resulting in loud background noise. Signed-off-by: Steve Chen <schen at mvista.com> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
349 lines
9.7 KiB
C
349 lines
9.7 KiB
C
/*
|
|
* Rate conversion Plug-In
|
|
* Copyright (c) 1999 by Jaroslav Kysela <perex@perex.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
#include <linux/time.h>
|
|
#include <sound/core.h>
|
|
#include <sound/pcm.h>
|
|
#include "pcm_plugin.h"
|
|
|
|
#define SHIFT 11
|
|
#define BITS (1<<SHIFT)
|
|
#define R_MASK (BITS-1)
|
|
|
|
/*
|
|
* Basic rate conversion plugin
|
|
*/
|
|
|
|
struct rate_channel {
|
|
signed short last_S1;
|
|
signed short last_S2;
|
|
};
|
|
|
|
typedef void (*rate_f)(struct snd_pcm_plugin *plugin,
|
|
const struct snd_pcm_plugin_channel *src_channels,
|
|
struct snd_pcm_plugin_channel *dst_channels,
|
|
int src_frames, int dst_frames);
|
|
|
|
struct rate_priv {
|
|
unsigned int pitch;
|
|
unsigned int pos;
|
|
rate_f func;
|
|
snd_pcm_sframes_t old_src_frames, old_dst_frames;
|
|
struct rate_channel channels[0];
|
|
};
|
|
|
|
static void rate_init(struct snd_pcm_plugin *plugin)
|
|
{
|
|
unsigned int channel;
|
|
struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
|
|
data->pos = 0;
|
|
for (channel = 0; channel < plugin->src_format.channels; channel++) {
|
|
data->channels[channel].last_S1 = 0;
|
|
data->channels[channel].last_S2 = 0;
|
|
}
|
|
}
|
|
|
|
static void resample_expand(struct snd_pcm_plugin *plugin,
|
|
const struct snd_pcm_plugin_channel *src_channels,
|
|
struct snd_pcm_plugin_channel *dst_channels,
|
|
int src_frames, int dst_frames)
|
|
{
|
|
unsigned int pos = 0;
|
|
signed int val;
|
|
signed short S1, S2;
|
|
signed short *src, *dst;
|
|
unsigned int channel;
|
|
int src_step, dst_step;
|
|
int src_frames1, dst_frames1;
|
|
struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
|
|
struct rate_channel *rchannels = data->channels;
|
|
|
|
for (channel = 0; channel < plugin->src_format.channels; channel++) {
|
|
pos = data->pos;
|
|
S1 = rchannels->last_S1;
|
|
S2 = rchannels->last_S2;
|
|
if (!src_channels[channel].enabled) {
|
|
if (dst_channels[channel].wanted)
|
|
snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
|
|
dst_channels[channel].enabled = 0;
|
|
continue;
|
|
}
|
|
dst_channels[channel].enabled = 1;
|
|
src = (signed short *)src_channels[channel].area.addr +
|
|
src_channels[channel].area.first / 8 / 2;
|
|
dst = (signed short *)dst_channels[channel].area.addr +
|
|
dst_channels[channel].area.first / 8 / 2;
|
|
src_step = src_channels[channel].area.step / 8 / 2;
|
|
dst_step = dst_channels[channel].area.step / 8 / 2;
|
|
src_frames1 = src_frames;
|
|
dst_frames1 = dst_frames;
|
|
while (dst_frames1-- > 0) {
|
|
if (pos & ~R_MASK) {
|
|
pos &= R_MASK;
|
|
S1 = S2;
|
|
if (src_frames1-- > 0) {
|
|
S2 = *src;
|
|
src += src_step;
|
|
}
|
|
}
|
|
val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
|
|
if (val < -32768)
|
|
val = -32768;
|
|
else if (val > 32767)
|
|
val = 32767;
|
|
*dst = val;
|
|
dst += dst_step;
|
|
pos += data->pitch;
|
|
}
|
|
rchannels->last_S1 = S1;
|
|
rchannels->last_S2 = S2;
|
|
rchannels++;
|
|
}
|
|
data->pos = pos;
|
|
}
|
|
|
|
static void resample_shrink(struct snd_pcm_plugin *plugin,
|
|
const struct snd_pcm_plugin_channel *src_channels,
|
|
struct snd_pcm_plugin_channel *dst_channels,
|
|
int src_frames, int dst_frames)
|
|
{
|
|
unsigned int pos = 0;
|
|
signed int val;
|
|
signed short S1, S2;
|
|
signed short *src, *dst;
|
|
unsigned int channel;
|
|
int src_step, dst_step;
|
|
int src_frames1, dst_frames1;
|
|
struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
|
|
struct rate_channel *rchannels = data->channels;
|
|
|
|
for (channel = 0; channel < plugin->src_format.channels; ++channel) {
|
|
pos = data->pos;
|
|
S1 = rchannels->last_S1;
|
|
S2 = rchannels->last_S2;
|
|
if (!src_channels[channel].enabled) {
|
|
if (dst_channels[channel].wanted)
|
|
snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
|
|
dst_channels[channel].enabled = 0;
|
|
continue;
|
|
}
|
|
dst_channels[channel].enabled = 1;
|
|
src = (signed short *)src_channels[channel].area.addr +
|
|
src_channels[channel].area.first / 8 / 2;
|
|
dst = (signed short *)dst_channels[channel].area.addr +
|
|
dst_channels[channel].area.first / 8 / 2;
|
|
src_step = src_channels[channel].area.step / 8 / 2;
|
|
dst_step = dst_channels[channel].area.step / 8 / 2;
|
|
src_frames1 = src_frames;
|
|
dst_frames1 = dst_frames;
|
|
while (dst_frames1 > 0) {
|
|
S1 = S2;
|
|
if (src_frames1-- > 0) {
|
|
S2 = *src;
|
|
src += src_step;
|
|
}
|
|
if (pos & ~R_MASK) {
|
|
pos &= R_MASK;
|
|
val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
|
|
if (val < -32768)
|
|
val = -32768;
|
|
else if (val > 32767)
|
|
val = 32767;
|
|
*dst = val;
|
|
dst += dst_step;
|
|
dst_frames1--;
|
|
}
|
|
pos += data->pitch;
|
|
}
|
|
rchannels->last_S1 = S1;
|
|
rchannels->last_S2 = S2;
|
|
rchannels++;
|
|
}
|
|
data->pos = pos;
|
|
}
|
|
|
|
static snd_pcm_sframes_t rate_src_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
|
|
{
|
|
struct rate_priv *data;
|
|
snd_pcm_sframes_t res;
|
|
|
|
if (snd_BUG_ON(!plugin))
|
|
return -ENXIO;
|
|
if (frames == 0)
|
|
return 0;
|
|
data = (struct rate_priv *)plugin->extra_data;
|
|
if (plugin->src_format.rate < plugin->dst_format.rate) {
|
|
res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
|
|
} else {
|
|
res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);
|
|
}
|
|
if (data->old_src_frames > 0) {
|
|
snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames;
|
|
while (data->old_src_frames < frames1) {
|
|
frames1 >>= 1;
|
|
res1 <<= 1;
|
|
}
|
|
while (data->old_src_frames > frames1) {
|
|
frames1 <<= 1;
|
|
res1 >>= 1;
|
|
}
|
|
if (data->old_src_frames == frames1)
|
|
return res1;
|
|
}
|
|
data->old_src_frames = frames;
|
|
data->old_dst_frames = res;
|
|
return res;
|
|
}
|
|
|
|
static snd_pcm_sframes_t rate_dst_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
|
|
{
|
|
struct rate_priv *data;
|
|
snd_pcm_sframes_t res;
|
|
|
|
if (snd_BUG_ON(!plugin))
|
|
return -ENXIO;
|
|
if (frames == 0)
|
|
return 0;
|
|
data = (struct rate_priv *)plugin->extra_data;
|
|
if (plugin->src_format.rate < plugin->dst_format.rate) {
|
|
res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);
|
|
} else {
|
|
res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
|
|
}
|
|
if (data->old_dst_frames > 0) {
|
|
snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames;
|
|
while (data->old_dst_frames < frames1) {
|
|
frames1 >>= 1;
|
|
res1 <<= 1;
|
|
}
|
|
while (data->old_dst_frames > frames1) {
|
|
frames1 <<= 1;
|
|
res1 >>= 1;
|
|
}
|
|
if (data->old_dst_frames == frames1)
|
|
return res1;
|
|
}
|
|
data->old_dst_frames = frames;
|
|
data->old_src_frames = res;
|
|
return res;
|
|
}
|
|
|
|
static snd_pcm_sframes_t rate_transfer(struct snd_pcm_plugin *plugin,
|
|
const struct snd_pcm_plugin_channel *src_channels,
|
|
struct snd_pcm_plugin_channel *dst_channels,
|
|
snd_pcm_uframes_t frames)
|
|
{
|
|
snd_pcm_uframes_t dst_frames;
|
|
struct rate_priv *data;
|
|
|
|
if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
|
|
return -ENXIO;
|
|
if (frames == 0)
|
|
return 0;
|
|
#ifdef CONFIG_SND_DEBUG
|
|
{
|
|
unsigned int channel;
|
|
for (channel = 0; channel < plugin->src_format.channels; channel++) {
|
|
if (snd_BUG_ON(src_channels[channel].area.first % 8 ||
|
|
src_channels[channel].area.step % 8))
|
|
return -ENXIO;
|
|
if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||
|
|
dst_channels[channel].area.step % 8))
|
|
return -ENXIO;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
dst_frames = rate_dst_frames(plugin, frames);
|
|
if (dst_frames > dst_channels[0].frames)
|
|
dst_frames = dst_channels[0].frames;
|
|
data = (struct rate_priv *)plugin->extra_data;
|
|
data->func(plugin, src_channels, dst_channels, frames, dst_frames);
|
|
return dst_frames;
|
|
}
|
|
|
|
static int rate_action(struct snd_pcm_plugin *plugin,
|
|
enum snd_pcm_plugin_action action,
|
|
unsigned long udata)
|
|
{
|
|
if (snd_BUG_ON(!plugin))
|
|
return -ENXIO;
|
|
switch (action) {
|
|
case INIT:
|
|
case PREPARE:
|
|
rate_init(plugin);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return 0; /* silenty ignore other actions */
|
|
}
|
|
|
|
int snd_pcm_plugin_build_rate(struct snd_pcm_substream *plug,
|
|
struct snd_pcm_plugin_format *src_format,
|
|
struct snd_pcm_plugin_format *dst_format,
|
|
struct snd_pcm_plugin **r_plugin)
|
|
{
|
|
int err;
|
|
struct rate_priv *data;
|
|
struct snd_pcm_plugin *plugin;
|
|
|
|
if (snd_BUG_ON(!r_plugin))
|
|
return -ENXIO;
|
|
*r_plugin = NULL;
|
|
|
|
if (snd_BUG_ON(src_format->channels != dst_format->channels))
|
|
return -ENXIO;
|
|
if (snd_BUG_ON(src_format->channels <= 0))
|
|
return -ENXIO;
|
|
if (snd_BUG_ON(src_format->format != SNDRV_PCM_FORMAT_S16))
|
|
return -ENXIO;
|
|
if (snd_BUG_ON(dst_format->format != SNDRV_PCM_FORMAT_S16))
|
|
return -ENXIO;
|
|
if (snd_BUG_ON(src_format->rate == dst_format->rate))
|
|
return -ENXIO;
|
|
|
|
err = snd_pcm_plugin_build(plug, "rate conversion",
|
|
src_format, dst_format,
|
|
sizeof(struct rate_priv) +
|
|
src_format->channels * sizeof(struct rate_channel),
|
|
&plugin);
|
|
if (err < 0)
|
|
return err;
|
|
data = (struct rate_priv *)plugin->extra_data;
|
|
if (src_format->rate < dst_format->rate) {
|
|
data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate;
|
|
data->func = resample_expand;
|
|
} else {
|
|
data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate;
|
|
data->func = resample_shrink;
|
|
}
|
|
data->pos = 0;
|
|
rate_init(plugin);
|
|
data->old_src_frames = data->old_dst_frames = 0;
|
|
plugin->transfer = rate_transfer;
|
|
plugin->src_frames = rate_src_frames;
|
|
plugin->dst_frames = rate_dst_frames;
|
|
plugin->action = rate_action;
|
|
*r_plugin = plugin;
|
|
return 0;
|
|
}
|