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ALSA: line6: Do clipping in volume / monitor manipulations 

Tested-by: Chris Rorvick <chris@rorvick.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
hifive-unleashed-5.1
Takashi Iwai 2015-01-23 16:54:36 +01:00
parent e90576c595
commit c8491535d7
1 changed files with 7 additions and 3 deletions
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10
sound/usb/line6/playback.c
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@ -37,7 +37,8 @@ static void change_volume(struct urb *urb_out, int volume[],
buf_end = p + urb_out->transfer_buffer_length / sizeof(*p);
for (; p < buf_end; ++p) {
*p = (*p * volume[chn & 1]) >> 8;
int val = (*p * volume[chn & 1]) >> 8;
*p = clamp(val, 0x7fff, -0x8000);
++chn;
}
} else if (bytes_per_frame == 6) {
@ -51,6 +52,7 @@ static void change_volume(struct urb *urb_out, int volume[],
val = p[0] + (p[1] << 8) + ((signed char)p[2] << 16);
val = (val * volume[chn & 1]) >> 8;
val = clamp(val, 0x7fffff, -0x800000);
p[0] = val;
p[1] = val >> 8;
p[2] = val >> 16;
@ -118,8 +120,10 @@ static void add_monitor_signal(struct urb *urb_out, unsigned char *signal,
po = (short *)urb_out->transfer_buffer;
buf_end = po + urb_out->transfer_buffer_length / sizeof(*po);
for (; po < buf_end; ++pi, ++po)
*po += (*pi * volume) >> 8;
for (; po < buf_end; ++pi, ++po) {
int val = *po + ((*pi * volume) >> 8);
*po = clamp(val, 0x7fff, -0x8000);
}
}
/*