ardour/livetrax
13
0
Fork 0
Code

Fix ALSA available buffersize detection:

Browse Source 
buffer-size = periods * period-size

Previously, buffersize was used for period-size.

This fixes an issue with a dedicated .asoundrc configuring a specific
period-size or buffer-size that has to be exact.
Ardour's device configuration failed in this case.

This has not been an issues since most hardware devices offer a wide
range: 8 < period-size < 262144 ; 16 < buffer-size < 524288.
Only a subset of which (32 .8192) is allowed by Ardour.
This commit is contained in:
Robin Gareus 2019-07-24 16:29:59 +02:00
parent 31ec8ce7d1
commit 0fe3cba8b1
Signed by: rgareus
GPG Key ID: A090BCE02CF57F04
1 changed files with 56 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
libs/ardouralsautil/deviceparams.cc
View File

@ -33,6 +33,10 @@ ARDOUR::get_alsa_device_parameters (const char* device_name, const bool play, AL
nfo->valid = false;
unsigned long min_psiz, max_psiz;
unsigned long min_bufz, max_bufz;
unsigned int min_nper, max_nper;
err = snd_pcm_open (&pcm, device_name,
play ? SND_PCM_STREAM_PLAYBACK : SND_PCM_STREAM_CAPTURE,
SND_PCM_NONBLOCK);
@ -66,17 +70,67 @@ ARDOUR::get_alsa_device_parameters (const char* device_name, const bool play, AL
goto error_out;
}
err = snd_pcm_hw_params_get_buffer_size_min (hw_params, &nfo->min_size);
err = snd_pcm_hw_params_get_period_size_min (hw_params, &min_psiz, 0);
if (err < 0) {
errmsg = "Cannot get minimum period size";
goto error_out;
}
err = snd_pcm_hw_params_get_period_size_max (hw_params, &max_psiz, 0);
if (err < 0) {
errmsg = "Cannot get maximum period size";
goto error_out;
}
err = snd_pcm_hw_params_get_buffer_size_min (hw_params, &min_bufz);
if (err < 0) {
errmsg = "Cannot get minimum buffer size";
goto error_out;
}
err = snd_pcm_hw_params_get_buffer_size_max (hw_params, &nfo->max_size);
err = snd_pcm_hw_params_get_buffer_size_max (hw_params, &max_bufz);
if (err < 0) {
errmsg = "Cannot get maximum buffer size";
goto error_out;
}
err = snd_pcm_hw_params_get_periods_min (hw_params, &min_nper, 0);
if (err < 0) {
errmsg = "Cannot get minimum period count";
goto error_out;
}
err = snd_pcm_hw_params_get_periods_max (hw_params, &max_nper, 0);
if (err < 0) {
errmsg = "Cannot get maximum period count";
goto error_out;
}
snd_pcm_close (pcm);
/* see also libs/backends/alsa/zita-alsa-pcmi.cc
* If any debug parameter is set, print device info.
*/
if (getenv ("ZITA_ALSA_PCMI_DEBUG")) {
fprintf (stdout, "ALSA: *%s* device-info\n", play ? "playback" : "capture");
fprintf (stdout, " dev_name : %s\n", device_name);
fprintf (stdout, " channels : %u\n", nfo->max_channels);
fprintf (stdout, " min_rate : %u\n", nfo->min_rate);
fprintf (stdout, " max_rate : %u\n", nfo->max_rate);
fprintf (stdout, " min_psiz : %lu\n", nfo->min_size);
fprintf (stdout, " max_psiz : %lu\n", nfo->max_size);
fprintf (stdout, " min_bufz : %lu\n", min_bufz);
fprintf (stdout, " max_bufz : %lu\n", max_bufz);
fprintf (stdout, " min_nper : %d\n", min_nper);
fprintf (stdout, " max_nper : %d\n", max_nper);
fprintf (stdout, " possible : %lu .. %lu\n", nfo->min_size, nfo->max_size);
}
/* AlsaAudioBackend supports n-periods 2, 3 */
if (min_nper > 2 || max_nper < 3) {
errmsg = "Unsupported period count";
return 1;
}
nfo->min_size = std::max (min_psiz, min_bufz / 3);
nfo->max_size = std::min (max_psiz, max_bufz / 2);
nfo->valid = true;
return 0;