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-rw-r--r--pcsound/pcsound_sdl.c31
-rw-r--r--src/i_sdlsound.c35
2 files changed, 58 insertions, 8 deletions
diff --git a/pcsound/pcsound_sdl.c b/pcsound/pcsound_sdl.c
index 546e6a36..6ba06785 100644
--- a/pcsound/pcsound_sdl.c
+++ b/pcsound/pcsound_sdl.c
@@ -32,7 +32,7 @@
#include "pcsound.h"
#include "pcsound_internal.h"
-#define SOUND_SLICE_TIME 100 /* ms */
+#define MAX_SOUND_SLICE_TIME 70 /* ms */
#define SQUARE_WAVE_AMP 0x2000
// If true, we initialised SDL and have the responsibility to shut it
@@ -164,6 +164,33 @@ static void PCSound_SDL_Shutdown(void)
}
}
+// Calculate slice size, based on MAX_SOUND_SLICE_TIME.
+// The result must be a power of two.
+
+static int GetSliceSize(void)
+{
+ int limit;
+ int n;
+
+ limit = (pcsound_sample_rate * MAX_SOUND_SLICE_TIME) / 1000;
+
+ // Try all powers of two, not exceeding the limit.
+
+ for (n=0;; ++n)
+ {
+ // 2^n <= limit < 2^n+1 ?
+
+ if ((1 << (n + 1)) > limit)
+ {
+ return (1 << n);
+ }
+ }
+
+ // Should never happen?
+
+ return 1024;
+}
+
static int PCSound_SDL_Init(pcsound_callback_func callback_func)
{
int slicesize;
@@ -179,7 +206,7 @@ static int PCSound_SDL_Init(pcsound_callback_func callback_func)
return 0;
}
- slicesize = (SOUND_SLICE_TIME * pcsound_sample_rate) / 1000;
+ slicesize = GetSliceSize();
if (Mix_OpenAudio(pcsound_sample_rate, AUDIO_S16SYS, 2, slicesize) < 0)
{
diff --git a/src/i_sdlsound.c b/src/i_sdlsound.c
index 34adf9de..cdb771e9 100644
--- a/src/i_sdlsound.c
+++ b/src/i_sdlsound.c
@@ -49,7 +49,7 @@
#include "doomdef.h"
#define LOW_PASS_FILTER
-#define SOUND_SLICE_TIME 100 /* ms */
+#define MAX_SOUND_SLICE_TIME 70 /* ms */
#define NUM_CHANNELS 16
static boolean sound_initialised = false;
@@ -65,7 +65,6 @@ int use_libsamplerate = 0;
extern int mb_used;
-
// When a sound stops, check if it is still playing. If it is not,
// we can mark the sound data as CACHE to be freed back for other
// means.
@@ -667,10 +666,36 @@ static void I_SDL_ShutdownSound(void)
sound_initialised = false;
}
+// Calculate slice size, based on MAX_SOUND_SLICE_TIME.
+// The result must be a power of two.
+
+static int GetSliceSize(void)
+{
+ int limit;
+ int n;
+
+ limit = (snd_samplerate * MAX_SOUND_SLICE_TIME) / 1000;
+
+ // Try all powers of two, not exceeding the limit.
+
+ for (n=0;; ++n)
+ {
+ // 2^n <= limit < 2^n+1 ?
+
+ if ((1 << (n + 1)) > limit)
+ {
+ return (1 << n);
+ }
+ }
+
+ // Should never happen?
+
+ return 1024;
+}
+
static boolean I_SDL_InitSound(void)
{
int i;
- int slicesize;
// No sounds yet
@@ -690,9 +715,7 @@ static boolean I_SDL_InitSound(void)
return false;
}
- slicesize = (snd_samplerate * SOUND_SLICE_TIME) / 1000;
-
- if (Mix_OpenAudio(snd_samplerate, AUDIO_S16SYS, 2, slicesize) < 0)
+ if (Mix_OpenAudio(snd_samplerate, AUDIO_S16SYS, 2, GetSliceSize()) < 0)
{
fprintf(stderr, "Error initialising SDL_mixer: %s\n", Mix_GetError());
return false;