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[alsa-utils,2/5] aplay: Handle 16bit sample negative overflow in peak calculations

Message ID 20210824094756.12540-3-tiwai@suse.de (mailing list archive)
State New, archived
Headers show
Series aplay: Fix bugs in peak calculations | expand

Commit Message

Takashi Iwai Aug. 24, 2021, 9:47 a.m. UTC 
The handling of 16bit samples in the peak calculations has a bug when
a sample with 0x8000 is passed.  As abs() treats 32bit int, it returns
0x8000.  And yet the code stores back into 16bit value again.

To fix that overflow, use 32bit value (i.e. val instead of sval) for
the further calculations.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 aplay/aplay.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
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Patch

diff --git a/aplay/aplay.c b/aplay/aplay.c
index 91af244edb60..c884346c9f25 100644
--- a/aplay/aplay.c
+++ b/aplay/aplay.c
@@ -1829,9 +1829,9 @@  static void compute_max_peak(u_char *data, size_t samples)
 			else
 				sval = be16toh(*valp);
 			sval ^= mask;
-			sval = abs(sval);
-			if (max_peak[c] < sval)
-				max_peak[c] = sval;
+			val = abs(sval);
+			if (max_peak[c] < val)
+				max_peak[c] = val;
 			valp++;
 			if (vumeter == VUMETER_STEREO)
 				c = !c;