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Clamp audio data after applying volume

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Make sure audio multiplication is clamped, and also make sure that
larger volume values can be safely used.
This commit is contained in:
jp9000 2014-02-21 20:31:18 -07:00
parent be81276f03
commit 4f4652040c
1 changed files with 14 additions and 9 deletions
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23
libobs/media-io/audio-io.c
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@ -686,21 +686,24 @@ size_t audio_output_channels(audio_t audio)
static inline void mul_vol_u8bit(void *array, float volume, size_t total_num)
{
uint8_t *vals = array;
int16_t vol = (int16_t)(volume * 127.0f);
int32_t vol = (int32_t)(volume * 127.0f);
for (size_t i = 0; i < total_num; i++) {
int16_t val = (int16_t)(vals[i] ^ 0x80) << 8;
vals[i] = (uint8_t)((val * vol / 127) + 128);
int32_t val = (int32_t)(vals[i] ^ 0x80) << 8;
int32_t output = val * vol / 127;
vals[i] = (uint8_t)(CLAMP(output, MIN_S8, MAX_S8) + 128);
}
}
static inline void mul_vol_16bit(void *array, float volume, size_t total_num)
{
uint16_t *vals = array;
int32_t vol = (int32_t)(volume * 32767.0f);
int64_t vol = (int64_t)(volume * 32767.0f);
for (size_t i = 0; i < total_num; i++)
vals[i] = (int32_t)((int32_t)vals[i] * vol / 32767);
for (size_t i = 0; i < total_num; i++) {
int64_t output = (int64_t)vals[i] * vol / 32767;
vals[i] = (int32_t)CLAMP(output, MIN_S16, MAX_S16);
}
}
static inline float conv_24bit_to_float(uint8_t *vals)
@ -729,7 +732,7 @@ static inline void mul_vol_24bit(void *array, float volume, size_t total_num)
for (size_t i = 0; i < total_num; i++) {
float val = conv_24bit_to_float(vals) * volume;
conv_float_to_24bit(val, vals);
conv_float_to_24bit(CLAMP(val, -1.0f, 1.0f), vals);
vals += 3;
}
}
@ -737,10 +740,12 @@ static inline void mul_vol_24bit(void *array, float volume, size_t total_num)
static inline void mul_vol_32bit(void *array, float volume, size_t total_num)
{
int32_t *vals = array;
double dvol = (double)volume;
for (size_t i = 0; i < total_num; i++) {
float val = (float)vals[i] / 2147483647.0f;
vals[i] = (int32_t)(val * volume / 2147483647.0f);
double val = (double)vals[i] / 2147483647.0;
double output = val * volume;
vals[i] = (int32_t)(CLAMP(output, -1.0, 1.0) * 2147483647.0);
}
}