/*
* return the highest sample rate supported by audio device |dev|.
*/
static int
find_highest_samplerate(int dev)
{
#if HAVE_SYS_MIXER_H
am_sample_rates_t *sr;
int i, num, max_rate;
for (num = 16; num < 1024; num *= 2) {
sr = malloc(AUDIO_MIXER_SAMP_RATES_STRUCT_SIZE(num));
if (!sr)
return 0;
sr->type = AUDIO_PLAY;
sr->flags = 0;
sr->num_samp_rates = num;
if (ioctl(dev, AUDIO_MIXER_GET_SAMPLE_RATES, sr)) {
free(sr);
return 0;
}
if (sr->num_samp_rates <= num)
break;
free(sr);
}
if (sr->flags & MIXER_SR_LIMITS) {
/*
* HW can playback any rate between
* sr->samp_rates[0] .. sr->samp_rates[1]
*/
max_rate = sr->samp_rates[1];
} else {
/* HW supports fixed sample rates only */
max_rate = 0;
for (i = 0; i < sr->num_samp_rates; i++) {
if (sr->samp_rates[i] > max_rate)
max_rate = sr->samp_rates[i];
}
}
free(sr);
return max_rate;
#else
return 44100; /* should be supported even on old ISA SB cards */
#endif
}
/*
* match the requested sample rate |sample_rate| against the
* sample rates supported by the audio device |dev|. Return
* a supported sample rate, it that sample rate is close to
* (< 1% difference) the requested rate; return 0 otherwise.
*/
static int
find_close_samplerate_match(int dev, int sample_rate)
{
#if HAVE_SYS_MIXER_H
am_sample_rates_t *sr;
int i, num, err, best_err, best_rate;
for (num = 16; num < 1024; num *= 2) {
sr = malloc(AUDIO_MIXER_SAMP_RATES_STRUCT_SIZE(num));
if (!sr)
return 0;
sr->type = AUDIO_PLAY;
sr->flags = 0;
sr->num_samp_rates = num;
if (ioctl(dev, AUDIO_MIXER_GET_SAMPLE_RATES, sr)) {
free(sr);
return 0;
}
if (sr->num_samp_rates <= num)
break;
free(sr);
}
if (sr->flags & MIXER_SR_LIMITS) {
/*
* HW can playback any rate between
* sr->samp_rates[0] .. sr->samp_rates[1]
*/
free(sr);
return 0;
} else {
/* HW supports fixed sample rates only */
best_err = 65535;
best_rate = 0;
for (i = 0; i < sr->num_samp_rates; i++) {
err = abs(sr->samp_rates[i] - sample_rate);
if (err == 0) {
/*
* exact supported sample rate match, no need to
* retry something else
*/
best_rate = 0;
break;
}
if (err < best_err) {
best_err = err;
best_rate = sr->samp_rates[i];
}
}
free(sr);
if (best_rate > 0 && 100*best_err < sample_rate) {
/* found a supported sample rate with <1% error? */
return best_rate;
}
return 0;
}
#else
int i, err;
int audiocs_rates[] = {
5510, 6620, 8000, 9600, 11025, 16000, 18900, 22050,
27420, 32000, 33075, 37800, 44100, 48000, 0
};
for (i = 0; audiocs_rates[i]; i++) {
err = abs(audiocs_rates[i] - sample_rate);
if (err == 0) {
/*
* exact supported sample rate match, no need to
* retry something elise
*/
return 0;
}
if (100*err < audiocs_rates[i]) {
/* <1% error? */
return audiocs_rates[i];
}
}
return 0;
#endif
}
void DAUDIO_GetFormats(INT32 mixerIndex, INT32 deviceID, int isSource, void* creator) {
int fd = -1;
AudioDeviceDescription desc;
am_sample_rates_t *sr;
/* hardcoded bits and channels */
int bits[] = {8, 16};
int bitsCount = 2;
int channels[] = {1, 2};
int channelsCount = 2;
/* for querying sample rates */
int err;
int ch, b, s;
TRACE2("DAUDIO_GetFormats, mixer %d, isSource=%d\n", mixerIndex, isSource);
if (getAudioDeviceDescriptionByIndex(mixerIndex, &desc, FALSE)) {
fd = open(desc.pathctl, O_RDONLY);
}
if (fd < 0) {
ERROR1("Couldn't open audio device ctl for device %d!\n", mixerIndex);
return;
}
/* get sample rates */
sr = (am_sample_rates_t*) malloc(AUDIO_MIXER_SAMP_RATES_STRUCT_SIZE(MAX_SAMPLE_RATES));
if (sr == NULL) {
ERROR1("DAUDIO_GetFormats: out of memory for mixer %d\n", (int) mixerIndex);
close(fd);
return;
}
sr->num_samp_rates = MAX_SAMPLE_RATES;
sr->type = isSource?AUDIO_PLAY:AUDIO_RECORD;
sr->samp_rates[0] = -2;
err = ioctl(fd, AUDIO_MIXER_GET_SAMPLE_RATES, sr);
if (err < 0) {
ERROR1(" DAUDIO_GetFormats: AUDIO_MIXER_GET_SAMPLE_RATES failed for mixer %d!\n",
(int)mixerIndex);
ERROR2(" -> num_sample_rates=%d sample_rates[0] = %d\n",
(int) sr->num_samp_rates,
(int) sr->samp_rates[0]);
/* Some Solaris 8 drivers fail for get sample rates!
* Do as if we support all sample rates
*/
sr->flags = MIXER_SR_LIMITS;
}
if ((sr->flags & MIXER_SR_LIMITS)
|| (sr->num_samp_rates > MAX_SAMPLE_RATES)) {
#ifdef USE_TRACE
if ((sr->flags & MIXER_SR_LIMITS)) {
TRACE1(" DAUDIO_GetFormats: floating sample rate allowed by mixer %d\n",
(int)mixerIndex);
}
if (sr->num_samp_rates > MAX_SAMPLE_RATES) {
TRACE2(" DAUDIO_GetFormats: more than %d formats. Use -1 for sample rates mixer %d\n",
MAX_SAMPLE_RATES, (int)mixerIndex);
}
#endif
/*
* Fake it to have only one sample rate: -1
*/
sr->num_samp_rates = 1;
sr->samp_rates[0] = -1;
}
close(fd);
for (ch = 0; ch < channelsCount; ch++) {
for (b = 0; b < bitsCount; b++) {
for (s = 0; s < sr->num_samp_rates; s++) {
DAUDIO_AddAudioFormat(creator,
bits[b], /* significant bits */
0, /* frameSize: let it be calculated */
channels[ch],
(float) ((int) sr->samp_rates[s]),
DAUDIO_PCM, /* encoding - let's only do PCM */
(bits[b] > 8)?TRUE:TRUE, /* isSigned */
#if (X_WORD_ORDER == TRUE)
FALSE /* little endian */
#else
(bits[b] > 8)?TRUE:FALSE /* big endian */
#endif
);
}
}
}
free(sr);
}
