diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/audio.c | 52 |
1 files changed, 44 insertions, 8 deletions
diff --git a/src/audio.c b/src/audio.c index bc2e04d..9caf199 100644 --- a/src/audio.c +++ b/src/audio.c @@ -1,6 +1,7 @@ #include <stdlib.h> #include <string.h> #include <errno.h> +#include <math.h> #include <xas/audio.h> @@ -10,6 +11,17 @@ int xas_audio_format_eq(xas_audio_format a, xas_audio_format b) { && a.sample_rate == b.sample_rate; } +void xas_audio_zero(xas_audio_format format, + void *dest, + size_t index, + size_t count) { + size_t stride = format.channels * format.sample_size; + + memset((uint8_t *)dest + stride * index, + '\0', + stride * count); +} + void xas_audio_copy(xas_audio_format format, void *dest, void *src, @@ -23,15 +35,39 @@ void xas_audio_copy(xas_audio_format format, stride * count); } -void xas_audio_zero(xas_audio_format format, - void *dest, - size_t index, - size_t count) { - size_t stride = format.channels * format.sample_size; +static inline void apply_gain_mono(int16_t *samples, + float gain, + size_t index, + size_t count) { + size_t i; - memset((uint8_t *)dest + stride * index, - '\0', - stride * count); + for (i=index; i<count; i++) { + samples[i] *= (int16_t)roundf(gain * samples[i]); + } +} + +static inline void apply_gain_stereo(int16_t *samples, + float gain, + size_t index, + size_t count) { + size_t i; + + for (i=index; i<count; i++) { + samples[i*2] *= (int16_t)roundf(gain * samples[i*2]); + samples[i*2+1] *= (int16_t)roundf(gain * samples[i*2+1]); + } +} + +void xas_audio_apply_gain(xas_audio_format format, + void *dest, + float gain, + size_t index, + size_t count) { + if (format.channels == XAS_AUDIO_MONO) { + apply_gain_mono(dest, gain, index, count); + } else if (format.channels == XAS_AUDIO_STEREO) { + apply_gain_stereo(dest, gain, index, count); + } } static xas_audio_stream *stream_new(enum xas_audio_stream_type type, |