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sound: sandbox: Use the correct frequency

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At present we request a particular frequency but we may not get the exact
same frequency in response. So use the actual frequency for generation of
the square wave. This ensures that the pitch remains accurate on all host
machines.

Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass 2018-11-15 19:56:14 -07:00
parent 7d92b06090
commit 856b8f5629
1 changed files with 9 additions and 2 deletions
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11
arch/sandbox/cpu/sdl.c
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@ -9,6 +9,10 @@
#include <sound.h>
#include <asm/state.h>
enum {
SAMPLE_RATE = 22050,
};
static struct sdl_info {
SDL_Surface *screen;
int width;
@ -18,6 +22,7 @@ static struct sdl_info {
uint frequency;
uint audio_pos;
uint audio_size;
uint sample_rate;
uint8_t *audio_data;
bool audio_active;
bool inited;
@ -283,7 +288,7 @@ int sandbox_sdl_sound_init(void)
return 0;
/* Set the audio format */
wanted.freq = 22050;
wanted.freq = SAMPLE_RATE;
wanted.format = AUDIO_S16;
wanted.channels = 1; /* 1 = mono, 2 = stereo */
wanted.samples = 1024; /* Good low-latency value for callback */
@ -309,6 +314,7 @@ int sandbox_sdl_sound_init(void)
goto err;
}
sdl.audio_active = true;
sdl.sample_rate = wanted.freq;
return 0;
@ -322,7 +328,8 @@ int sandbox_sdl_sound_start(uint frequency)
if (!sdl.audio_active)
return -1;
sdl.frequency = frequency;
sound_create_square_wave(22050, (unsigned short *)sdl.audio_data,
sound_create_square_wave(sdl.sample_rate,
(unsigned short *)sdl.audio_data,
sdl.audio_size, frequency);
sdl.audio_pos = 0;
SDL_PauseAudio(0);