Volume: Bug fix for vol_mult_s24_to_s16() function

singalsu · singalsu · commit f4049bb7d6df · 2018-11-08T18:36:06.000+02:00
The previous commit introduced a bug in this volume function. The input
parameter for s24 PCM samples must be int32_t. The bug causes for s24 to
s16 converted audio very low signal level and noise due to overflows.

Signed-off-by: Seppo Ingalsuo &lt;seppo.ingalsuo@linux.intel.com&gt;
diff --git a/src/audio/volume_generic.c b/src/audio/volume_generic.c
@@ -50,7 +50,7 @@
  *
  * Volume multiply for 24 bit input and 16 bit bit output.
  */
-static inline int16_t vol_mult_s24_to_s16(int16_t x, int32_t vol)
+static inline int16_t vol_mult_s24_to_s16(int32_t x, int32_t vol)
 {
 	return (int16_t)q_multsr_sat_32x32_16(sign_extend_s24(x), vol,
 					      Q_SHIFT_BITS_64(23, 16, 15));

Original file line number	Diff line number	Diff line change
`@@ -50,7 +50,7 @@`
`50`	`50`	`*`
`51`	`51`	`* Volume multiply for 24 bit input and 16 bit bit output.`
`52`	`52`	`*/`
`53`		`-static inline int16_t vol_mult_s24_to_s16(int16_t x, int32_t vol)`
	`53`	`+static inline int16_t vol_mult_s24_to_s16(int32_t x, int32_t vol)`
`54`	`54`	`{`
`55`	`55`	`return (int16_t)q_multsr_sat_32x32_16(sign_extend_s24(x), vol,`
`56`	`56`	`Q_SHIFT_BITS_64(23, 16, 15));`