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Convert AMSv2 microphone samples from 14 to 16 bit before storing them.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30209 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Michael Giacomelli 2011-07-25 01:00:15 +00:00
parent c27ea297a3
commit 62d666df6f
1 changed files with 22 additions and 0 deletions
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22
firmware/target/arm/as3525/pcm-as3525.c
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@ -337,10 +337,32 @@ static inline void mono2stereo(int16_t *end)
}
#endif /* CONFIG_CPU == AS3525 */
#if CONFIG_CPU == AS3525v2
/* scale microphone audio by 2 bits due to 14 bit ADC */
static inline void scalevolume(int16_t *end, int size)
{
if(audio_channels != 1) /* only for microphone */
return;
/* load pointer in a register and avoid updating it in each loop */
register int16_t *samples = end;
do {
*samples++ <<=2;
} while(samples != end+size);
}
#endif /* CONFIG_CPU == AS3525v2 */
static void rec_dma_callback(void)
{
if(rec_dma_transfer_size)
{
#if CONFIG_CPU == AS3525v2
scalevolume(AS3525_UNCACHED_ADDR((int16_t*)rec_dma_start_addr), rec_dma_transfer_size);
#endif
rec_dma_size -= rec_dma_transfer_size;
rec_dma_start_addr += rec_dma_transfer_size;