ALSA: pcm: Add snd_pcm_rate_bit_to_rate()

This is essentially the reverse of snd_pcm_rate_to_rate_bit().

This is generally useful as the Compress API uses the rate bit
directly and it helps to be able to map back to the actual sample
rate.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Dimitris Papastamos 2012-06-15 16:35:28 +01:00 committed by Takashi Iwai
parent 989b01385f
commit 4be77a530b
2 changed files with 19 additions and 0 deletions

View File

@ -893,6 +893,7 @@ extern const struct snd_pcm_hw_constraint_list snd_pcm_known_rates;
int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime);
unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate);
unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit);
static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substream,
struct snd_dma_buffer *bufp)

View File

@ -488,3 +488,21 @@ unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
return SNDRV_PCM_RATE_KNOT;
}
EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
/**
* snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
* @rate_bit: the rate bit to convert
*
* Returns the sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
* or 0 for an unknown rate bit
*/
unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
{
unsigned int i;
for (i = 0; i < snd_pcm_known_rates.count; i++)
if ((1u << i) == rate_bit)
return snd_pcm_known_rates.list[i];
return 0;
}
EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);