Option to fix bug #851

For some people setting the period size works better (and is what SDL 1.2.13 did), but for most people it's the same or worse.  You can use an environment variable to pick which one you want.

--HG--
branch : SDL-1.2
This commit is contained in:
Sam Lantinga
2009-10-17 06:55:17 +00:00
parent 54db02f8b2
commit b634b7d198

View File

@@ -43,8 +43,6 @@
/* The tag name used by ALSA audio */
#define DRIVER_NAME "alsa"
/* Whether we should set the buffer size or the period size */
/*#define SET_PERIOD_SIZE*/
/*#define DEBUG_PERIOD_SIZE*/
/* Audio driver functions */
@@ -377,9 +375,7 @@ static int ALSA_OpenAudio(_THIS, SDL_AudioSpec *spec)
snd_pcm_format_t format;
snd_pcm_uframes_t frames;
unsigned int rate;
#ifdef SET_PERIOD_SIZE
unsigned int periods;
#endif
unsigned int channels;
Uint16 test_format;
@@ -475,28 +471,33 @@ static int ALSA_OpenAudio(_THIS, SDL_AudioSpec *spec)
spec->freq = rate;
/* Set the buffer size, in samples */
#ifdef SET_PERIOD_SIZE
frames = spec->samples;
status = SDL_NAME(snd_pcm_hw_params_set_period_size_near)(pcm_handle, hwparams, &frames, NULL);
if ( status < 0 ) {
SDL_SetError("Couldn't set period size: %s", SDL_NAME(snd_strerror)(status));
ALSA_CloseAudio(this);
return(-1);
}
if (getenv("SDL_AUDIO_ALSA_SET_PERIOD_SIZE")) {
frames = spec->samples;
status = SDL_NAME(snd_pcm_hw_params_set_period_size_near)(pcm_handle, hwparams, &frames, NULL);
if ( status < 0 ) {
SDL_SetError("Couldn't set period size: %s", SDL_NAME(snd_strerror)(status));
ALSA_CloseAudio(this);
return(-1);
}
spec->samples = frames;
spec->samples = frames;
periods = 2;
status = SDL_NAME(snd_pcm_hw_params_set_periods_near)(pcm_handle, hwparams, &periods, NULL);
if ( status < 0 ) {
SDL_SetError("Couldn't set period count: %s", SDL_NAME(snd_strerror)(status));
ALSA_CloseAudio(this);
return(-1);
periods = 2;
status = SDL_NAME(snd_pcm_hw_params_set_periods_near)(pcm_handle, hwparams, &periods, NULL);
if ( status < 0 ) {
SDL_SetError("Couldn't set period count: %s", SDL_NAME(snd_strerror)(status));
ALSA_CloseAudio(this);
return(-1);
}
} else {
frames = spec->samples * 2;
status = SDL_NAME(snd_pcm_hw_params_set_buffer_size_near)(pcm_handle, hwparams, &frames);
if ( status < 0 ) {
SDL_SetError("Couldn't set buffer size: %s", SDL_NAME(snd_strerror)(status));
ALSA_CloseAudio(this);
return(-1);
}
}
#else
frames = spec->samples * 2;
status = SDL_NAME(snd_pcm_hw_params_set_buffer_size_near)(pcm_handle, hwparams, &frames);
#endif
/* "set" the hardware with the desired parameters */
status = SDL_NAME(snd_pcm_hw_params)(pcm_handle, hwparams);