pcm_dither: added pcm_dither_32_to_16()

For 32 bit dithering, reuse the 24 bit dithering code, but apply a 8
bit right shift first.
This commit is contained in:
Max Kellermann 2009-03-02 16:37:11 +01:00
parent 78e08f655a
commit d24f2ba5ee
2 changed files with 20 additions and 0 deletions

View File

@ -76,3 +76,18 @@ pcm_dither_24_to_16(struct pcm_dither *dither,
while (num_samples-- > 0)
*dest++ = pcm_dither_sample_24_to_16(*src++, dither);
}
static int16_t
pcm_dither_sample_32_to_16(int32_t sample, struct pcm_dither *dither)
{
return pcm_dither_sample_24_to_16(sample >> 8, dither);
}
void
pcm_dither_32_to_16(struct pcm_dither *dither,
int16_t *dest, const int32_t *src,
unsigned num_samples)
{
while (num_samples-- > 0)
*dest++ = pcm_dither_sample_32_to_16(*src++, dither);
}

View File

@ -38,4 +38,9 @@ pcm_dither_24_to_16(struct pcm_dither *dither,
int16_t *dest, const int32_t *src,
unsigned num_samples);
void
pcm_dither_32_to_16(struct pcm_dither *dither,
int16_t *dest, const int32_t *src,
unsigned num_samples);
#endif