mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-11-02 09:01:48 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

dmix - Allow more flexible buffer sizes

Browse source 
With the patch, dmix allows apps to use more flexible buffer sizes.
The max buffer size is unlimited, and the minimal buffer size is
(period size * 2).  The buffer size is aligned to period size.

The period size is still bound to the period size of slave PCM.

To back to the old behavior (the fixed buffer size), you can set

   defaults.pcm.dmix_variable_buffer false

in your configuration.
This commit is contained in:
Takashi Iwai 2006-03-21 10:27:35 +00:00
parent 8ef339762a
commit 7e6c920836
7 changed files with 83 additions and 57 deletions
Download patch file Download diff file Expand all files Collapse all files

60
src/pcm/pcm_direct.c
View file

@ -632,6 +632,19 @@ static int hw_param_interval_refine_one(snd_pcm_hw_params_t *params,
return 0;
}
static int hw_param_interval_refine_minmax(snd_pcm_hw_params_t *params,
snd_pcm_hw_param_t var,
unsigned int imin,
unsigned int imax)
{
snd_interval_t t;
memset(&t, 0, sizeof(t));
snd_interval_set_minmax(&t, imin, imax);
t.integer = 1;
return hw_param_interval_refine_one(params, var, &t);
}
#undef REFINE_DEBUG
int snd_pcm_direct_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
@ -682,14 +695,6 @@ int snd_pcm_direct_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
&dshare->shmptr->hw.rate);
if (err < 0)
return err;
err = hw_param_interval_refine_one(params, SND_PCM_HW_PARAM_BUFFER_SIZE,
&dshare->shmptr->hw.buffer_size);
if (err < 0)
return err;
err = hw_param_interval_refine_one(params, SND_PCM_HW_PARAM_BUFFER_TIME,
&dshare->shmptr->hw.buffer_time);
if (err < 0)
return err;
err = hw_param_interval_refine_one(params, SND_PCM_HW_PARAM_PERIOD_SIZE,
&dshare->shmptr->hw.period_size);
if (err < 0)
@ -698,10 +703,33 @@ int snd_pcm_direct_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
&dshare->shmptr->hw.period_time);
if (err < 0)
return err;
err = hw_param_interval_refine_one(params, SND_PCM_HW_PARAM_PERIODS,
&dshare->shmptr->hw.periods);
if (err < 0)
return err;
if (! dshare->variable_buffer_size) {
err = hw_param_interval_refine_one(params, SND_PCM_HW_PARAM_BUFFER_SIZE,
&dshare->shmptr->hw.buffer_size);
if (err < 0)
return err;
err = hw_param_interval_refine_one(params, SND_PCM_HW_PARAM_BUFFER_TIME,
&dshare->shmptr->hw.buffer_time);
if (err < 0)
return err;
} else if (params->rmask & ((1<<SND_PCM_HW_PARAM_PERIODS)|
(1<<SND_PCM_HW_PARAM_BUFFER_BYTES)|
(1<<SND_PCM_HW_PARAM_BUFFER_SIZE)|
(1<<SND_PCM_HW_PARAM_BUFFER_TIME))) {
int changed;
do {
changed = 0;
err = hw_param_interval_refine_minmax(params, SND_PCM_HW_PARAM_PERIODS,
2, INT_MAX);
if (err < 0)
return err;
changed |= err;
err = snd_pcm_hw_refine_soft(pcm, params);
if (err < 0)
return err;
changed |= err;
} while (changed);
}
params->info = dshare->shmptr->s.info;
#ifdef REFINE_DEBUG
snd_output_puts(log, "DMIX REFINE (end):\n");
@ -1376,6 +1404,7 @@ int snd_pcm_direct_parse_open_conf(snd_config_t *conf, struct snd_pcm_direct_ope
rec->ipc_perm = 0600;
rec->ipc_gid = -1;
rec->slowptr = 0;
rec->variable_buffer_size = 0;
snd_config_for_each(i, next, conf) {
snd_config_t *n = snd_config_iterator_entry(i);
@ -1462,6 +1491,13 @@ int snd_pcm_direct_parse_open_conf(snd_config_t *conf, struct snd_pcm_direct_ope
rec->slowptr = err;
continue;
}
if (strcmp(id, "variable_buffer_size") == 0) {
err = snd_config_get_bool(n);
if (err < 0)
return err;
rec->variable_buffer_size = err;
continue;
}
SNDERR("Unknown field %s", id);
return -EINVAL;
}