mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-10-29 05:40:25 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

added support for more sample widths

Browse source 
- patch taken from ALSA bug #1140
This commit is contained in:
Jaroslav Kysela 2005-05-30 10:22:18 +00:00
parent 3a763ae3c5
commit 3d1fa92490
1 changed files with 26 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

36
test/pcm.c
View file

@ -34,10 +34,12 @@ static void generate_sine(const snd_pcm_channel_area_t *areas,
double phase = *_phase;
double step = max_phase*freq/(double)rate;
double res;
signed short *samples[channels];
unsigned char *samples[channels], *tmp;
int steps[channels];
unsigned int chn;
unsigned int chn, byte;
int ires;
unsigned int maxval = (1 << (snd_pcm_format_width(format) - 1)) - 1;
int bps = snd_pcm_format_width(format) / 8; /* bytes per sample */
/* verify and prepare the contents of areas */
for (chn = 0; chn < channels; chn++) {
@ -45,20 +47,22 @@ static void generate_sine(const snd_pcm_channel_area_t *areas,
printf("areas[%i].first == %i, aborting...\n", chn, areas[chn].first);
exit(EXIT_FAILURE);
}
samples[chn] = (signed short *)(((unsigned char *)areas[chn].addr) + (areas[chn].first / 8));
samples[chn] = /*(signed short *)*/(((unsigned char *)areas[chn].addr) + (areas[chn].first / 8));
if ((areas[chn].step % 16) != 0) {
printf("areas[%i].step == %i, aborting...\n", chn, areas[chn].step);
exit(EXIT_FAILURE);
}
steps[chn] = areas[chn].step / 16;
steps[chn] = areas[chn].step / 8;
samples[chn] += offset * steps[chn];
}
/* fill the channel areas */
while (count-- > 0) {
res = sin(phase) * 32767;
res = sin(phase) * maxval;
ires = res;
tmp = (unsigned char *)(&ires);
for (chn = 0; chn < channels; chn++) {
*samples[chn] = ires;
for (byte = 0; byte < bps; byte++)
*(samples[chn] + byte) = tmp[byte];
samples[chn] += steps[chn];
}
phase += step;
@ -708,6 +712,7 @@ static void help(void)
"-b,--buffer ring buffer size in us\n"
"-p,--period period size in us\n"
"-m,--method transfer method\n"
"-o,--format sample format\n"
"-v,--verbose show the PCM setup parameters\n"
"\n");
printf("Recognized sample formats are:");
@ -735,6 +740,7 @@ int main(int argc, char *argv[])
{"buffer", 1, NULL, 'b'},
{"period", 1, NULL, 'p'},
{"method", 1, NULL, 'm'},
{"format", 1, NULL, 'o'},
{"verbose", 1, NULL, 'v'},
{"noresample", 1, NULL, 'n'},
{NULL, 0, NULL, 0},
@ -754,7 +760,7 @@ int main(int argc, char *argv[])
morehelp = 0;
while (1) {
int c;
if ((c = getopt_long(argc, argv, "hD:r:c:f:b:p:m:vn", long_option, NULL)) < 0)
if ((c = getopt_long(argc, argv, "hD:r:c:f:b:p:m:o:vn", long_option, NULL)) < 0)
break;
switch (c) {
case 'h':
@ -790,11 +796,21 @@ int main(int argc, char *argv[])
break;
case 'm':
for (method = 0; transfer_methods[method].name; method++)
if (!strcasecmp(transfer_methods[method].name, optarg))
if (!strcasecmp(transfer_methods[method].name, optarg))
break;
if (transfer_methods[method].name == NULL)
method = 0;
break;
case 'o':
for (format = 0; format < SND_PCM_FORMAT_LAST; format++) {
const char *format_name = snd_pcm_format_name(format);
if (format_name)
if (!strcasecmp(format_name, optarg))
break;
}
if (format == SND_PCM_FORMAT_LAST)
format = SND_PCM_FORMAT_S16;
break;
case 'v':
verbose = 1;
break;
@ -850,8 +866,8 @@ int main(int argc, char *argv[])
}
for (chn = 0; chn < channels; chn++) {
areas[chn].addr = samples;
areas[chn].first = chn * 16;
areas[chn].step = channels * 16;
areas[chn].first = chn * snd_pcm_format_width(format);
areas[chn].step = channels * snd_pcm_format_width(format);
}
err = transfer_methods[method].transfer_loop(handle, samples, areas);