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output/openal: improve synchronization

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This plugin's use of the "Timer" library was wrong; it added the same
amount of virtual data in every iteration in _play(), but did not
actually play something.  This created an artificial, but useless,
delay.  This patch implements the method _cancel(), and implements
hard-coded sleep values.  This is only slightly better, but does not
attempt to look sane.
This commit is contained in:
Max Kellermann 2011-12-13 21:48:15 +01:00
parent 0a427890fe
commit 78c4351e04
1 changed files with 16 additions and 13 deletions
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29
src/output/openal_output_plugin.c
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@ -20,7 +20,6 @@
#include "config.h"
#include "openal_output_plugin.h"
#include "output_api.h"
#include "timer.h"
#include <glib.h>
@ -44,7 +43,6 @@ struct openal_data {
const char *device_name;
ALCdevice *device;
ALCcontext *context;
struct timer *timer;
ALuint buffers[NUM_BUFFERS];
unsigned filled;
ALuint source;
@ -193,7 +191,6 @@ openal_open(struct audio_output *ao, struct audio_format *audio_format,
}
od->filled = 0;
od->timer = timer_new(audio_format);
od->frequency = audio_format->sample_rate;
return true;
@ -204,7 +201,6 @@ openal_close(struct audio_output *ao)
{
struct openal_data *od = (struct openal_data *)ao;
timer_free(od->timer);
alcMakeContextCurrent(od->context);
alDeleteSources(1, &od->source);
alDeleteBuffers(NUM_BUFFERS, od->buffers);
@ -212,6 +208,19 @@ openal_close(struct audio_output *ao)
alcCloseDevice(od->device);
}
static unsigned
openal_delay(struct audio_output *ao)
{
struct openal_data *od = (struct openal_data *)ao;
return od->filled < NUM_BUFFERS || openal_has_processed(od)
? 0
/* we don't know exactly how long we must wait for the
next buffer to finish, so this is a random
guess: */
: 50;
}
static size_t
openal_play(struct audio_output *ao, const void *chunk, size_t size,
G_GNUC_UNUSED GError **error)
@ -229,15 +238,8 @@ openal_play(struct audio_output *ao, const void *chunk, size_t size,
od->filled++;
} else {
/* wait for processed buffer */
while (!openal_has_processed(od)) {
if (!od->timer->started) {
timer_start(od->timer);
} else {
timer_sync(od->timer);
}
timer_add(od->timer, size);
}
while (!openal_has_processed(od))
g_usleep(10);
alSourceUnqueueBuffers(od->source, 1, &buffer);
}
@ -271,6 +273,7 @@ const struct audio_output_plugin openal_output_plugin = {
.finish = openal_finish,
.open = openal_open,
.close = openal_close,
.delay = openal_delay,
.play = openal_play,
.cancel = openal_cancel,
};