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Fix buffer size handling of direct plugins

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Introduce "max_periods" option to specify the max number of periods
per buffer to each plugin.

- When max_periods = -1, the fixed buffer size as the slave size is
  used (old behavior).
- When max_periods = 0 (or 1), the number of periods is variable
  between 2 and the slave buffer size.
- When max_periods greater than 2 is given, it specifies the max
  periods of that pcm explicitly.

When no option is given in the PCM defintion, the value
"defaults.pcm.dmix_max_periods" is referred as default.
The default value is 0, as defined in alsa.conf.
You can override this in ~/.asoundrc or /etc/asound.conf as you like.
This commit is contained in:
Takashi Iwai 2006-04-06 18:49:11 +02:00
parent 33d69ef33b
commit 1128efc7d4
7 changed files with 41 additions and 56 deletions
Download patch file Download diff file Expand all files Collapse all files

44
src/pcm/pcm_direct.c
View file

@ -697,7 +697,7 @@ 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;
if (! dshare->variable_buffer_size) {
if (dshare->max_periods < 0) {
err = hw_param_interval_refine_one(params, SND_PCM_HW_PARAM_BUFFER_SIZE,
&dshare->shmptr->hw.buffer_size);
if (err < 0)
@ -711,13 +711,13 @@ int snd_pcm_direct_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
(1<<SND_PCM_HW_PARAM_BUFFER_SIZE)|
(1<<SND_PCM_HW_PARAM_BUFFER_TIME))) {
int changed;
unsigned int max_periods = dshare->max_periods;
if (max_periods < 2)
max_periods = dshare->slave_buffer_size / dshare->slave_period_size;
do {
changed = 0;
/* Set min/max size to [2:1024] since INT_MAX as the
* upper-limit results in a too big buffer on some apps.
*/
err = hw_param_interval_refine_minmax(params, SND_PCM_HW_PARAM_PERIODS,
2, 1024);
2, max_periods);
if (err < 0)
return err;
changed |= err;
@ -1382,17 +1382,19 @@ static int _snd_pcm_direct_get_slave_ipc_offset(snd_config_t *root,
return (direction << 1) + (device << 2) + (subdevice << 8) + (card << 12);
}
int snd_pcm_direct_get_slave_ipc_offset(snd_config_t *root,
static int snd_pcm_direct_get_slave_ipc_offset(snd_config_t *root,
snd_config_t *sconf,
int direction)
{
return _snd_pcm_direct_get_slave_ipc_offset(root, sconf, direction, 0);
}
int snd_pcm_direct_parse_open_conf(snd_config_t *conf, struct snd_pcm_direct_open_conf *rec)
int snd_pcm_direct_parse_open_conf(snd_config_t *root, snd_config_t *conf,
int stream, struct snd_pcm_direct_open_conf *rec)
{
snd_config_iterator_t i, next;
int ipc_key_add_uid = 0;
snd_config_t *n;
int err;
rec->slave = NULL;
@ -1401,10 +1403,18 @@ 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;
rec->max_periods = 0;
/* read defaults */
if (snd_config_search(root, "defaults.pcm.dmix_max_periods", &n) >= 0) {
long val;
err = snd_config_get_integer(n, &val);
if (err >= 0)
rec->max_periods = val;
}
snd_config_for_each(i, next, conf) {
snd_config_t *n = snd_config_iterator_entry(i);
n = snd_config_iterator_entry(i);
const char *id;
if (snd_config_get_id(n, &id) < 0)
continue;
@ -1488,11 +1498,12 @@ 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 (strcmp(id, "max_periods") == 0) {
long val;
err = snd_config_get_integer(n, &val);
if (err < 0)
return err;
rec->variable_buffer_size = err;
rec->max_periods = val;
continue;
}
SNDERR("Unknown field %s", id);
@ -1502,11 +1513,16 @@ int snd_pcm_direct_parse_open_conf(snd_config_t *conf, struct snd_pcm_direct_ope
SNDERR("slave is not defined");
return -EINVAL;
}
if (ipc_key_add_uid)
rec->ipc_key += getuid();
if (!rec->ipc_key) {
SNDERR("Unique IPC key is not defined");
return -EINVAL;
}
if (ipc_key_add_uid)
rec->ipc_key += getuid();
err = snd_pcm_direct_get_slave_ipc_offset(root, rec->slave, stream);
if (err < 0)
return err;
rec->ipc_key += err;
return 0;
}