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-rw-r--r--src/pcm_utils.c106
1 files changed, 58 insertions, 48 deletions
diff --git a/src/pcm_utils.c b/src/pcm_utils.c
index 90856fa1d..a798223c7 100644
--- a/src/pcm_utils.c
+++ b/src/pcm_utils.c
@@ -24,12 +24,32 @@
#include "conf.h"
#include "os_compat.h"
+static inline int
+pcm_dither(void)
+{
+ return (rand() & 511) - (rand() & 511);
+}
+
+/**
+ * Check if the value is within the range of the provided bit size,
+ * and caps it if necessary.
+ */
+static int32_t
+pcm_range(int32_t sample, unsigned bits)
+{
+ if (mpd_unlikely(sample < (-1 << (bits - 1))))
+ return -1 << (bits - 1);
+ if (mpd_unlikely(sample >= (1 << (bits - 1))))
+ return (1 << (bits - 1)) - 1;
+ return sample;
+}
+
void pcm_volumeChange(char *buffer, int bufferSize, const AudioFormat * format,
int volume)
{
- mpd_sint32 temp32;
- mpd_sint8 *buffer8 = (mpd_sint8 *) buffer;
- mpd_sint16 *buffer16 = (mpd_sint16 *) buffer;
+ int32_t temp32;
+ int8_t *buffer8 = (int8_t *) buffer;
+ int16_t *buffer16 = (int16_t *) buffer;
if (volume >= 1000)
return;
@@ -44,12 +64,10 @@ void pcm_volumeChange(char *buffer, int bufferSize, const AudioFormat * format,
while (bufferSize > 0) {
temp32 = *buffer16;
temp32 *= volume;
- temp32 += rand() & 511;
- temp32 -= rand() & 511;
+ temp32 += pcm_dither();
temp32 += 500;
temp32 /= 1000;
- *buffer16 = temp32 > 32767 ? 32767 :
- (temp32 < -32768 ? -32768 : temp32);
+ *buffer16 = pcm_range(temp32, 16);
buffer16++;
bufferSize -= 2;
}
@@ -58,12 +76,10 @@ void pcm_volumeChange(char *buffer, int bufferSize, const AudioFormat * format,
while (bufferSize > 0) {
temp32 = *buffer8;
temp32 *= volume;
- temp32 += rand() & 511;
- temp32 -= rand() & 511;
+ temp32 += pcm_dither();
temp32 += 500;
temp32 /= 1000;
- *buffer8 = temp32 > 127 ? 127 :
- (temp32 < -128 ? -128 : temp32);
+ *buffer8 = pcm_range(temp32, 8);
buffer8++;
bufferSize--;
}
@@ -78,11 +94,11 @@ static void pcm_add(char *buffer1, const char *buffer2, size_t bufferSize1,
size_t bufferSize2, int vol1, int vol2,
const AudioFormat * format)
{
- mpd_sint32 temp32;
- mpd_sint8 *buffer8_1 = (mpd_sint8 *) buffer1;
- const mpd_sint8 *buffer8_2 = (const mpd_sint8 *) buffer2;
- mpd_sint16 *buffer16_1 = (mpd_sint16 *) buffer1;
- const mpd_sint16 *buffer16_2 = (const mpd_sint16 *) buffer2;
+ int32_t temp32;
+ int8_t *buffer8_1 = (int8_t *) buffer1;
+ const int8_t *buffer8_2 = (const int8_t *) buffer2;
+ int16_t *buffer16_1 = (int16_t *) buffer1;
+ const int16_t *buffer16_2 = (const int16_t *) buffer2;
switch (format->bits) {
case 16:
@@ -90,13 +106,10 @@ 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 =
- temp32 > 32767 ? 32767 : (temp32 <
- -32768 ? -32768 : temp32);
+ *buffer16_1 = pcm_range(temp32, 16);
buffer16_1++;
buffer16_2++;
bufferSize1 -= 2;
@@ -109,13 +122,10 @@ 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 =
- temp32 > 127 ? 127 : (temp32 <
- -128 ? -128 : temp32);
+ *buffer8_1 = pcm_range(temp32, 8);
buffer8_1++;
buffer8_2++;
bufferSize1--;
@@ -182,9 +192,9 @@ out:
#endif
#ifdef HAVE_LIBSAMPLERATE
-static size_t pcm_convertSampleRate(mpd_sint8 channels, mpd_uint32 inSampleRate,
+static size_t pcm_convertSampleRate(int8_t channels, uint32_t inSampleRate,
const char *inBuffer, size_t inSize,
- mpd_uint32 outSampleRate, char *outBuffer,
+ uint32_t outSampleRate, char *outBuffer,
size_t outSize, ConvState *convState)
{
static int convalgo = -1;
@@ -258,19 +268,19 @@ static size_t pcm_convertSampleRate(mpd_sint8 channels, mpd_uint32 inSampleRate,
}
#else /* !HAVE_LIBSAMPLERATE */
/* resampling code blatantly ripped from ESD */
-static size_t pcm_convertSampleRate(mpd_sint8 channels, mpd_uint32 inSampleRate,
+static size_t pcm_convertSampleRate(int8_t channels, uint32_t inSampleRate,
const char *inBuffer,
mpd_unused size_t inSize,
- mpd_uint32 outSampleRate, char *outBuffer,
+ uint32_t outSampleRate, char *outBuffer,
size_t outSize,
mpd_unused ConvState *convState)
{
- mpd_uint32 rd_dat = 0;
- mpd_uint32 wr_dat = 0;
- mpd_sint16 *in = (mpd_sint16 *)inBuffer;
- mpd_sint16 *out = (mpd_sint16 *)outBuffer;
- mpd_uint32 nlen = outSize / 2;
- mpd_sint16 lsample, rsample;
+ uint32_t rd_dat = 0;
+ uint32_t wr_dat = 0;
+ int16_t *in = (int16_t *)inBuffer;
+ int16_t *out = (int16_t *)outBuffer;
+ uint32_t nlen = outSize / 2;
+ int16_t lsample, rsample;
switch (channels) {
case 1:
@@ -300,14 +310,14 @@ static size_t pcm_convertSampleRate(mpd_sint8 channels, mpd_uint32 inSampleRate,
}
#endif /* !HAVE_LIBSAMPLERATE */
-static char *pcm_convertChannels(mpd_sint8 channels, const char *inBuffer,
+static char *pcm_convertChannels(int8_t channels, const char *inBuffer,
size_t inSize, size_t *outSize)
{
static char *buf;
static size_t len;
char *outBuffer = NULL;
- const mpd_sint16 *in;
- mpd_sint16 *out;
+ const int16_t *in;
+ int16_t *out;
int inSamples, i;
switch (channels) {
@@ -321,8 +331,8 @@ static char *pcm_convertChannels(mpd_sint8 channels, const char *inBuffer,
outBuffer = buf;
inSamples = inSize >> 1;
- in = (const mpd_sint16 *)inBuffer;
- out = (mpd_sint16 *)outBuffer;
+ in = (const int16_t *)inBuffer;
+ out = (int16_t *)outBuffer;
for (i = 0; i < inSamples; i++) {
*out++ = *in;
*out++ = *in++;
@@ -339,8 +349,8 @@ static char *pcm_convertChannels(mpd_sint8 channels, const char *inBuffer,
outBuffer = buf;
inSamples = inSize >> 2;
- in = (const mpd_sint16 *)inBuffer;
- out = (mpd_sint16 *)outBuffer;
+ in = (const int16_t *)inBuffer;
+ out = (int16_t *)outBuffer;
for (i = 0; i < inSamples; i++) {
*out = (*in++) / 2;
*out++ += (*in++) / 2;
@@ -354,14 +364,14 @@ static char *pcm_convertChannels(mpd_sint8 channels, const char *inBuffer,
return outBuffer;
}
-static const char *pcm_convertTo16bit(mpd_sint8 bits, const char *inBuffer,
+static const char *pcm_convertTo16bit(int8_t bits, const char *inBuffer,
size_t inSize, size_t *outSize)
{
static char *buf;
static size_t len;
char *outBuffer = NULL;
- const mpd_sint8 *in;
- mpd_sint16 *out;
+ const int8_t *in;
+ int16_t *out;
size_t i;
switch (bits) {
@@ -373,8 +383,8 @@ static const char *pcm_convertTo16bit(mpd_sint8 bits, const char *inBuffer,
}
outBuffer = buf;
- in = (const mpd_sint8 *)inBuffer;
- out = (mpd_sint16 *)outBuffer;
+ in = (const int8_t *)inBuffer;
+ out = (int16_t *)outBuffer;
for (i = 0; i < inSize; i++)
*out++ = (*in++) << 8;
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-21 11:44:08 +0000