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| author | Max Kellermann <max@duempel.org> | 2008-09-28 18:35:42 +0200 |
|---|---|---|
| committer | Max Kellermann <max@duempel.org> | 2008-09-28 18:35:42 +0200 |
| commit | 5b5e46f5ef34bdc6c1745c4e778b116e856393c9 (patch) | |
| tree | f859a0cf09c17128af370e8a6c4b981a1d620b98 | |
| parent | 75cba9343ec4bf93d9677792c1fbf9e9f5837a72 (diff) | |
| download | mpd-5b5e46f5ef34bdc6c1745c4e778b116e856393c9.tar.gz mpd-5b5e46f5ef34bdc6c1745c4e778b116e856393c9.tar.xz mpd-5b5e46f5ef34bdc6c1745c4e778b116e856393c9.zip | |
pcm_utils: added inline function pcm_dither()
Merge some code into an inline function, so we can optimize it later
only once.
| -rw-r--r-- | src/pcm_utils.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/src/pcm_utils.c b/src/pcm_utils.c index a9706e019..bd7192acf 100644 --- a/src/pcm_utils.c +++ b/src/pcm_utils.c @@ -25,6 +25,12 @@ #include "audio_format.h" #include "os_compat.h" +static inline int +pcm_dither(void) +{ + return (rand() & 511) - (rand() & 511); +} + void pcm_volumeChange(char *buffer, int bufferSize, const struct audio_format *format, int volume) @@ -46,8 +52,7 @@ void pcm_volumeChange(char *buffer, int bufferSize, while (bufferSize > 0) { temp32 = *buffer16; temp32 *= volume; - temp32 += rand() & 511; - temp32 -= rand() & 511; + temp32 += pcm_dither(); temp32 += 500; temp32 /= 1000; *buffer16 = temp32 > 32767 ? 32767 : @@ -60,8 +65,7 @@ void pcm_volumeChange(char *buffer, int bufferSize, while (bufferSize > 0) { temp32 = *buffer8; temp32 *= volume; - temp32 += rand() & 511; - temp32 -= rand() & 511; + temp32 += pcm_dither(); temp32 += 500; temp32 /= 1000; *buffer8 = temp32 > 127 ? 127 : @@ -92,8 +96,7 @@ static void pcm_add(char *buffer1, const char *buffer2, size_t bufferSize1, temp32 = (vol1 * (*buffer16_1) + vol2 * (*buffer16_2)); - temp32 += rand() & 511; - temp32 -= rand() & 511; + temp32 += pcm_dither(); temp32 += 500; temp32 /= 1000; *buffer16_1 = @@ -111,8 +114,7 @@ static void pcm_add(char *buffer1, const char *buffer2, size_t bufferSize1, while (bufferSize1 > 0 && bufferSize2 > 0) { temp32 = (vol1 * (*buffer8_1) + vol2 * (*buffer8_2)); - temp32 += rand() & 511; - temp32 -= rand() & 511; + temp32 += pcm_dither(); temp32 += 500; temp32 /= 1000; *buffer8_1 = |