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This file contains the actual mixing and resampling engine for output. The actual algorithms are implemented in outexport.inc and playmix.inc.
This file is part of Open Sound System.
Copyright (C) 4Front Technologies 1996-2008.
This this source file is released under GPL v2 license (no other versions). See the COPYING file included in the main directory of this source distribution for the license terms and conditions.
#define SWAP_SUPPORT
#include <oss_config.h>
#include "vmix.h"
#if 0
/* Debugging macros*/
extern unsigned char tmp_status;
# define UP_STATUS(v) OUTB(NULL, (tmp_status=tmp_status|(v)), 0x378)
# define DOWN_STATUS(v) OUTB(NULL, (tmp_status=tmp_status&~(v)), 0x378)
#else
# define UP_STATUS(v)
# define DOWN_STATUS(v)
#endif
#undef SINE_DEBUG
#ifndef CONFIG_OSS_VMIX_FLOAT
#undef SINE_DEBUG
#endif
#ifdef SINE_DEBUG
#define SINE_SIZE 48
static const float sine_table[SINE_SIZE] = {
0.000000, 0.130526, 0.258819, 0.382683,
0.500000, 0.608761, 0.707107, 0.793353,
0.866025, 0.923880, 0.965926, 0.991445,
1.000000, 0.991445, 0.965926, 0.923880,
0.866025, 0.793353, 0.707107, 0.608761,
0.500000, 0.382683, 0.258819, 0.130526,
0.000000, -0.130526, -0.258819, -0.382683,
-0.500000, -0.608761, -0.707107, -0.793353,
-0.866025, -0.923880, -0.965926, -0.991445,
-1.000000, -0.991445, -0.965926, -0.923880,
-0.866025, -0.793353, -0.707107, -0.608761,
-0.500000, -0.382683, -0.258819, -0.130526
};
static int sine_phase[MAX_PLAY_CHANNELS] = { 0 };
#endif
#ifndef CONFIG_OSS_VMIX_FLOAT
Simple limiter to prevent overflows when using fixed point computations
void
process_limiter (unsigned int *statevar, int *chbufs[], int nchannels,
int nsamples)
{
#define Abs(x) ((x) < 0 ? -(x) : (x))
int k, t;
unsigned int q, amp, amp2;
for (t = 0; t < nsamples; t++)
{
amp = (unsigned) Abs (chbufs[0][t]);
for (k = 1; k < nchannels; k++)
{
amp2 = (unsigned) Abs (chbufs[k][t]);
if (amp2 > amp)
amp = amp2;
}
amp >>= 8;
q = 0x10000;
if (amp > 0x7FFF)
q = 0x7FFF0000 / amp;
if (*statevar > q)
*statevar = q;
else
{
q = *statevar;
Simplier (linear) tracking algo (gives less distortion, but more pumping)
*statevar += 2; if (*statevar > 0x10000) *statevar = 0x10000;
Classic tracking algo gives more distortion with no-lookahead statevar=0x10000-((0x10000-*statevar)*0xFFF4>>16);
}
for (k = 0; k < nchannels; k++)
{
int in = chbufs[k][t];
int out = 0;
unsigned int p;
if (in >= 0)
{
p = in;
p = ((p & 0xFFFF) * (q >> 4) >> 12) + (p >> 16) * q;
out = p;
}
else
{
p = -in;
p = ((p & 0xFFFF) * (q >> 4) >> 12) + (p >> 16) * q;
out = -p;
}
/* safety code */
/* if output after limiter is clamped, then it can be dropped */
if (out > 0x7FFFFF)
out = 0x7FFFFF;
else if (out < -0x7FFFFF)
out = -0x7FFFFF;
chbufs[k][t] = out;
}
}
}
#endif
Output export functions
#undef INT_EXPORT
#define INT_EXPORT(x) (x / 256)
static void
export16ne (vmix_engine_t * eng, void *outbuf, vmix_sample_t * chbufs[],
int channels, int samples)
{
short *op;
#define SAMPLE_TYPE short
#define SAMPLE_RANGE 32768.0
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#include "outexport.inc"
}
static void
export16oe (vmix_engine_t * eng, void *outbuf, vmix_sample_t * chbufs[],
int channels, int samples)
{
short *op;
#undef SAMPLE_TYPE
#undef SAMPLE_RANGE
#define SAMPLE_TYPE short
#define SAMPLE_RANGE 32768.0
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) bswap16(x)
#include "outexport.inc"
}
#undef INT_EXPORT
#define INT_EXPORT(x) (x * 256)
static void
export32ne (vmix_engine_t * eng, void *outbuf, vmix_sample_t * chbufs[],
int channels, int samples)
{
int *op;
#undef SAMPLE_TYPE
#undef SAMPLE_RANGE
#define SAMPLE_TYPE int
#define SAMPLE_RANGE 2147483648.0
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#include "outexport.inc"
}
static void
export32oe (vmix_engine_t * eng, void *outbuf, vmix_sample_t * chbufs[],
int channels, int samples)
{
int *op;
#define SAMPLE_TYPE int
#define SAMPLE_RANGE 2147483648.0
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) bswap32(x)
#include "outexport.inc"
}
Mixing functions
#undef BUFFER_TYPE
#define BUFFER_TYPE short *
#undef INT_OUTMIX
#define INT_OUTMIX(x) (x * 256)
void
vmix_outmix_16ne (vmix_portc_t * portc, int nsamples)
{
short *inp;
#ifdef CONFIG_OSS_VMIX_FLOAT
double range = 3.0517578125e-5; /* 1.0 / 32768.0 */
#endif
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#include "playmix.inc"
}
void
vmix_outmix_16oe (vmix_portc_t * portc, int nsamples)
{
short *inp;
#ifdef CONFIG_OSS_VMIX_FLOAT
double range = 3.0517578125e-5; /* 1.0 / 32768.0 */
#endif
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) bswap16(x)
#include "playmix.inc"
}
#undef BUFFER_TYPE
#define BUFFER_TYPE int *
#undef INT_OUTMIX
#define INT_OUTMIX(x) (x / 256)
void
vmix_outmix_32ne (vmix_portc_t * portc, int nsamples)
{
int *inp;
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#ifdef CONFIG_OSS_VMIX_FLOAT
double range = 4.65661287308e-10; /* 1.0 / 2147483648.0 */
#endif
#include "playmix.inc"
}
void
vmix_outmix_32oe (vmix_portc_t * portc, int nsamples)
{
int *inp;
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) bswap32(x)
#ifdef CONFIG_OSS_VMIX_FLOAT
double range = 4.65661287308e-10; /* 1.0 / 2147483648.0 */
#endif
#include "playmix.inc"
}
#ifdef CONFIG_OSS_VMIX_FLOAT
void
vmix_outmix_float (vmix_portc_t * portc, int nsamples)
{
float *inp;
double range = 1.0;
#undef BUFFER_TYPE
#define BUFFER_TYPE float *
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#include "playmix.inc"
}
#endif
#ifdef CONFIG_OSS_VMIX_FLOAT
Mixing functions (with sample rate conversions)
#undef BUFFER_TYPE
#define BUFFER_TYPE short *
#undef INT_OUTMIX
#define INT_OUTMIX(x) (x * 256)
void
vmix_outmix_16ne_src (vmix_portc_t * portc, int nsamples)
{
short *inp;
double range = 3.0517578125e-5; /* 1.0 / 32768.0 */
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#include "playmix_src.inc"
}
void
vmix_outmix_16oe_src (vmix_portc_t * portc, int nsamples)
{
short *inp;
double range = 3.0517578125e-5; /* 1.0 / 32768.0 */
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) bswap16(x)
#include "playmix_src.inc"
}
#undef BUFFER_TYPE
#define BUFFER_TYPE int *
#undef INT_OUTMIX
#define INT_OUTMIX(x) (x / 256)
void
vmix_outmix_32ne_src (vmix_portc_t * portc, int nsamples)
{
int *inp;
double range = 4.65661287308e-10; /* 1.0 / 2147483648.0 */
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#include "playmix_src.inc"
}
void
vmix_outmix_32oe_src (vmix_portc_t * portc, int nsamples)
{
int *inp;
double range = 4.65661287308e-10; /* 1.0 / 2147483648.0 */
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) bswap32(x)
#include "playmix_src.inc"
}
void
vmix_outmix_float_src (vmix_portc_t * portc, int nsamples)
{
float *inp;
double range = 1.0;
#undef BUFFER_TYPE
#define BUFFER_TYPE float *
#undef VMIX_BYTESWAP
#define VMIX_BYTESWAP(x) x
#include "playmix_src.inc"
}
#endif
static void
vmix_play_callback (int dev, int parm)
{
int n;
adev_t *adev = audio_engines[dev];
dmap_t *dmap = adev->dmap_out;
oss_native_word flags;
int i;
vmix_mixer_t *mixer = adev->vmix_mixer;
vmix_engine_t *eng = &mixer->play_engine;
#ifdef CONFIG_OSS_VMIX_FLOAT
fp_env_t fp_buf;
short *fp_env = fp_buf;
fp_flags_t fp_flags;
#endif
UP_STATUS (0x04);
if (dmap == NULL || dmap->dmabuf == NULL)
return;
if (dmap->bytes_in_use == 0)
{
cmn_err (CE_WARN, "Bytes in use=0, eng=%d\n", adev->engine_num);
return;
}
MUTEX_ENTER_IRQDISABLE (mixer->mutex, flags);
if (dmap->dmabuf == NULL)
{
MUTEX_EXIT_IRQRESTORE (mixer->mutex, flags);
return;
}
#ifdef CONFIG_OSS_VMIX_FLOAT
{
Align the FP save buffer to 16 byte boundary
oss_native_word p;
p = (oss_native_word) fp_buf;
p = ((p + 15ULL) / 16) * 16;
fp_env = (short *) p;
}
FP_SAVE (fp_env, fp_flags);
#endif
n = 0;
while (n++ < eng->max_playahead
&& dmap_get_qlen (dmap) < eng->max_playahead)
{
int p;
unsigned char *outbuf;
int nstreams = 0;
for (i = 0; i < eng->channels; i++)
memset (eng->chbufs[i], 0, CHBUF_SAMPLES * sizeof (vmix_sample_t));
for (i = 0; i < mixer->num_clientdevs; i++)
if (mixer->client_portc[i]->trigger_bits & PCM_ENABLE_OUTPUT)
{
vmix_portc_t *portc = mixer->client_portc[i];
if (portc->play_mixing_func == NULL)
continue;
if (portc->play_choffs + portc->channels >
mixer->play_engine.channels)
portc->play_choffs = 0;
portc->play_mixing_func (portc,
mixer->play_engine.samples_per_frag);
nstreams++; /* Count the number of active output streams */
}
eng->num_active_outputs = (nstreams > 0) ? nstreams : 1;
/* Export the output mix to the device */
p = (int) (dmap->user_counter % dmap->bytes_in_use);
outbuf = dmap->dmabuf + p;
if (dmap->dmabuf != NULL)
{
#ifndef CONFIG_OSS_VMIX_FLOAT
process_limiter (&eng->limiter_statevar, eng->chbufs, eng->channels,
eng->samples_per_frag);
#endif
eng->converter (eng, outbuf, eng->chbufs, eng->channels,
eng->samples_per_frag);
}
dmap->user_counter += dmap->fragment_size;
}
#ifdef CONFIG_OSS_VMIX_FLOAT
FP_RESTORE (fp_env, fp_flags);
#endif
MUTEX_EXIT_IRQRESTORE (mixer->mutex, flags);
Call oss_audio_outputintr outside FP mode because it may cause a task switch (under Solaris). Task switch may turn on CR0.TS under x86 which in turn will cause #nm exception.
for (i = 0; i < mixer->num_clientdevs; i++)
if (mixer->client_portc[i]->trigger_bits & PCM_ENABLE_OUTPUT)
{
vmix_portc_t *portc = mixer->client_portc[i];
oss_audio_outputintr (portc->audio_dev, 1);
}
for (i = 0; i < mixer->num_loopdevs; i++)
{
if (mixer->loop_portc[i]->trigger_bits & PCM_ENABLE_INPUT)
{
oss_audio_inputintr (mixer->loop_portc[i]->audio_dev, 0);
}
}
DOWN_STATUS (0x04);
}
void
vmix_setup_play_engine (vmix_mixer_t * mixer, adev_t * adev, dmap_t * dmap)
{
int fmt;
int frags = 0x7fff0007; /* fragment size of 128 bytes */
int i;
int old_min;
Sample format (and endianess) setup
/* First make sure a sane format is selected before starting to probe */
fmt = adev->d->adrv_set_format (mixer->masterdev, AFMT_S16_LE);
fmt = adev->d->adrv_set_format (mixer->masterdev, AFMT_S16_NE);
/* Find out the "best" sample format supported by the device */
if (adev->oformat_mask & AFMT_S16_OE)
fmt = AFMT_S16_OE;
if (adev->oformat_mask & AFMT_S16_NE)
fmt = AFMT_S16_NE;
if (mixer->multich_enable) /* Better quality enabled */
{
if (adev->oformat_mask & AFMT_S32_OE)
fmt = AFMT_S32_OE;
if (adev->oformat_mask & AFMT_S32_NE)
fmt = AFMT_S32_NE;
}
fmt = adev->d->adrv_set_format (mixer->masterdev, fmt);
mixer->play_engine.fmt = fmt;
switch (fmt)
{
case AFMT_S16_NE:
mixer->play_engine.bits = 16;
mixer->play_engine.converter = export16ne;
break;
case AFMT_S16_OE:
mixer->play_engine.bits = 16;
mixer->play_engine.converter = export16oe;
break;
case AFMT_S32_NE:
mixer->play_engine.bits = 32;
mixer->play_engine.converter = export32ne;
break;
case AFMT_S32_OE:
mixer->play_engine.bits = 32;
mixer->play_engine.converter = export32oe;
break;
default:
cmn_err (CE_CONT, "Unrecognized sample format %x\n", fmt);
return;
}
Number of channels
mixer->play_engine.channels = mixer->max_channels;
if (mixer->play_engine.channels > MAX_PLAY_CHANNELS)
mixer->play_engine.channels = MAX_PLAY_CHANNELS;
if (!mixer->multich_enable)
mixer->play_engine.channels = 2;
/* Force the device to stereo before trying with (possibly) imultiple channels */
adev->d->adrv_set_channels (mixer->masterdev, 2);
mixer->play_engine.channels =
adev->d->adrv_set_channels (mixer->masterdev,
mixer->play_engine.channels);
if (mixer->play_engine.channels > MAX_PLAY_CHANNELS)
{
cmn_err (CE_WARN,
"Number of channels (%d) is larger than maximum (%d)\n",
mixer->play_engine.channels, MAX_PLAY_CHANNELS);
return;
}
mixer->play_engine.rate =
oss_audio_set_rate (mixer->masterdev, mixer->rate);
mixer->rate = mixer->play_engine.rate;
if (mixer->play_engine.rate <= 22050)
frags = 0x7fff0004; /* Use smaller fragments */
audio_engines[mixer->masterdev]->hw_parms.channels =
mixer->play_engine.channels;
audio_engines[mixer->masterdev]->hw_parms.rate = mixer->play_engine.rate;
audio_engines[mixer->masterdev]->dmap_out->data_rate =
mixer->play_engine.rate * mixer->play_engine.channels *
mixer->play_engine.bits / 8;
audio_engines[mixer->masterdev]->dmap_out->frame_size =
mixer->play_engine.channels * mixer->play_engine.bits / 8;
old_min = adev->min_fragments;
#if 0
if ((adev->max_fragments == 0 || adev->max_fragments >= 4)
&& adev->min_block == 0)
adev->min_fragments = 4;
#endif
oss_audio_ioctl (mixer->masterdev, NULL, SNDCTL_DSP_SETFRAGMENT,
(ioctl_arg) & frags);
oss_audio_ioctl (mixer->masterdev, NULL, SNDCTL_DSP_GETBLKSIZE,
(ioctl_arg) & mixer->play_engine.fragsize);
dmap->bytes_in_use = dmap->fragment_size * dmap->nfrags;
oss_audio_ioctl (mixer->masterdev, NULL, SNDCTL_DSP_GETBLKSIZE,
(ioctl_arg) & mixer->play_engine.fragsize);
adev->min_fragments = old_min;
mixer->play_engine.fragsize = dmap->fragment_size;
if (mixer->play_engine.channels > 2)
{
DDB (cmn_err
(CE_CONT, "Enabling multi channel play mode, %d hw channels\n",
mixer->play_engine.channels));
}
else if (mixer->play_engine.channels != 2)
{
cmn_err (CE_WARN,
"Master device doesn't support suitable channel configuration\n");
return;
}
Determine how many fragments we need to keep filled.
if (adev->vmix_flags & VMIX_MULTIFRAG)
mixer->play_engine.max_playahead = 32;
else
mixer->play_engine.max_playahead = 4;
if (mixer->play_engine.max_playahead >
audio_engines[mixer->masterdev]->dmap_out->nfrags)
mixer->play_engine.max_playahead =
audio_engines[mixer->masterdev]->dmap_out->nfrags;
Try to keep one empty fragment after the one currently being played by the device. Writing too close to the playback point may cause massive clicking with some devices.
if (dmap->nfrags > 2 && mixer->play_engine.max_playahead == dmap->nfrags)
mixer->play_engine.max_playahead--;
mixer->play_engine.samples_per_frag =
mixer->play_engine.fragsize / mixer->play_engine.channels /
(mixer->play_engine.bits / 8);
if (mixer->play_engine.samples_per_frag > CHBUF_SAMPLES)
{
cmn_err (CE_WARN, "Too many samples per fragment (%d,%d)\n",
mixer->play_engine.samples_per_frag, CHBUF_SAMPLES);
return;
}
for (i = 0; i < mixer->play_engine.channels; i++)
if (mixer->play_engine.chbufs[i] == NULL) /* Not allocated yet */
{
mixer->play_engine.chbufs[i] =
PMALLOC (mixer->master_portc,
CHBUF_SAMPLES * sizeof (vmix_sample_t));
if (mixer->play_engine.chbufs[i] == NULL)
{
cmn_err (CE_WARN, "Out of memory\n");
return;
}
}
dmap->audio_callback = vmix_play_callback; /* Enable conversions */
dmap->callback_parm = mixer->instance_num;
dmap->dma_mode = PCM_ENABLE_OUTPUT;
if (mixer->inputdev == mixer->masterdev)
{
mixer->record_engine.rate = mixer->play_engine.rate;
mixer->record_engine.bits = mixer->play_engine.bits;
mixer->record_engine.fragsize = mixer->play_engine.fragsize;
mixer->record_engine.channels = mixer->play_engine.channels;
mixer->record_engine.samples_per_frag =
mixer->play_engine.samples_per_frag;
}
if (mixer->num_clientdevs > 1)
{
adev->redirect_out = mixer->client_portc[0]->audio_dev;
}
Fill in the initial playback data (silence) to avoid underruns
vmix_play_callback (mixer->masterdev, mixer->instance_num);
if (mixer->masterdev == mixer->inputdev)
finalize_record_engine (mixer, fmt, audio_engines[mixer->inputdev],
audio_engines[mixer->inputdev]->dmap_in);
}