330 lines
8.9 KiB
C
330 lines
8.9 KiB
C
/* Copyright (c) 2011 Xiph.Org Foundation, Skype Limited
|
|
Written by Jean-Marc Valin and Koen Vos */
|
|
/*
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
|
|
- Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
- Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
|
|
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifdef OPUS_HAVE_CONFIG_H
|
|
#include "opus_config.h"
|
|
#endif
|
|
|
|
#include "opus.h"
|
|
#include "opus_private.h"
|
|
|
|
#ifndef DISABLE_FLOAT_API
|
|
OPUS_EXPORT void opus_pcm_soft_clip(float *_x, int N, int C, float *declip_mem)
|
|
{
|
|
int c;
|
|
int i;
|
|
float *x;
|
|
|
|
if (C<1 || N<1 || !_x || !declip_mem) return;
|
|
|
|
/* First thing: saturate everything to +/- 2 which is the highest level our
|
|
non-linearity can handle. At the point where the signal reaches +/-2,
|
|
the derivative will be zero anyway, so this doesn't introduce any
|
|
discontinuity in the derivative. */
|
|
for (i=0;i<N*C;i++)
|
|
_x[i] = MAX16(-2.f, MIN16(2.f, _x[i]));
|
|
for (c=0;c<C;c++)
|
|
{
|
|
float a;
|
|
float x0;
|
|
int curr;
|
|
|
|
x = _x+c;
|
|
a = declip_mem[c];
|
|
/* Continue applying the non-linearity from the previous frame to avoid
|
|
any discontinuity. */
|
|
for (i=0;i<N;i++)
|
|
{
|
|
if (x[i*C]*a>=0)
|
|
break;
|
|
x[i*C] = x[i*C]+a*x[i*C]*x[i*C];
|
|
}
|
|
|
|
curr=0;
|
|
x0 = x[0];
|
|
while(1)
|
|
{
|
|
int start, end;
|
|
float maxval;
|
|
int special=0;
|
|
int peak_pos;
|
|
for (i=curr;i<N;i++)
|
|
{
|
|
if (x[i*C]>1 || x[i*C]<-1)
|
|
break;
|
|
}
|
|
if (i==N)
|
|
{
|
|
a=0;
|
|
break;
|
|
}
|
|
peak_pos = i;
|
|
start=end=i;
|
|
maxval=ABS16(x[i*C]);
|
|
/* Look for first zero crossing before clipping */
|
|
while (start>0 && x[i*C]*x[(start-1)*C]>=0)
|
|
start--;
|
|
/* Look for first zero crossing after clipping */
|
|
while (end<N && x[i*C]*x[end*C]>=0)
|
|
{
|
|
/* Look for other peaks until the next zero-crossing. */
|
|
if (ABS16(x[end*C])>maxval)
|
|
{
|
|
maxval = ABS16(x[end*C]);
|
|
peak_pos = end;
|
|
}
|
|
end++;
|
|
}
|
|
/* Detect the special case where we clip before the first zero crossing */
|
|
special = (start==0 && x[i*C]*x[0]>=0);
|
|
|
|
/* Compute a such that maxval + a*maxval^2 = 1 */
|
|
a=(maxval-1)/(maxval*maxval);
|
|
if (x[i*C]>0)
|
|
a = -a;
|
|
/* Apply soft clipping */
|
|
for (i=start;i<end;i++)
|
|
x[i*C] = x[i*C]+a*x[i*C]*x[i*C];
|
|
|
|
if (special && peak_pos>=2)
|
|
{
|
|
/* Add a linear ramp from the first sample to the signal peak.
|
|
This avoids a discontinuity at the beginning of the frame. */
|
|
float delta;
|
|
float offset = x0-x[0];
|
|
delta = offset / peak_pos;
|
|
for (i=curr;i<peak_pos;i++)
|
|
{
|
|
offset -= delta;
|
|
x[i*C] += offset;
|
|
x[i*C] = MAX16(-1.f, MIN16(1.f, x[i*C]));
|
|
}
|
|
}
|
|
curr = end;
|
|
if (curr==N)
|
|
break;
|
|
}
|
|
declip_mem[c] = a;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
int encode_size(int size, unsigned char *data)
|
|
{
|
|
if (size < 252)
|
|
{
|
|
data[0] = size;
|
|
return 1;
|
|
} else {
|
|
data[0] = 252+(size&0x3);
|
|
data[1] = (size-(int)data[0])>>2;
|
|
return 2;
|
|
}
|
|
}
|
|
|
|
static int parse_size(const unsigned char *data, opus_int32 len, opus_int16 *size)
|
|
{
|
|
if (len<1)
|
|
{
|
|
*size = -1;
|
|
return -1;
|
|
} else if (data[0]<252)
|
|
{
|
|
*size = data[0];
|
|
return 1;
|
|
} else if (len<2)
|
|
{
|
|
*size = -1;
|
|
return -1;
|
|
} else {
|
|
*size = 4*data[1] + data[0];
|
|
return 2;
|
|
}
|
|
}
|
|
|
|
int opus_packet_parse_impl(const unsigned char *data, opus_int32 len,
|
|
int self_delimited, unsigned char *out_toc,
|
|
const unsigned char *frames[48], opus_int16 size[48],
|
|
int *payload_offset, opus_int32 *packet_offset)
|
|
{
|
|
int i, bytes;
|
|
int count;
|
|
int cbr;
|
|
unsigned char ch, toc;
|
|
int framesize;
|
|
opus_int32 last_size;
|
|
opus_int32 pad = 0;
|
|
const unsigned char *data0 = data;
|
|
|
|
if (size==NULL)
|
|
return OPUS_BAD_ARG;
|
|
|
|
framesize = opus_packet_get_samples_per_frame(data, 48000);
|
|
|
|
cbr = 0;
|
|
toc = *data++;
|
|
len--;
|
|
last_size = len;
|
|
switch (toc&0x3)
|
|
{
|
|
/* One frame */
|
|
case 0:
|
|
count=1;
|
|
break;
|
|
/* Two CBR frames */
|
|
case 1:
|
|
count=2;
|
|
cbr = 1;
|
|
if (!self_delimited)
|
|
{
|
|
if (len&0x1)
|
|
return OPUS_INVALID_PACKET;
|
|
last_size = len/2;
|
|
/* If last_size doesn't fit in size[0], we'll catch it later */
|
|
size[0] = (opus_int16)last_size;
|
|
}
|
|
break;
|
|
/* Two VBR frames */
|
|
case 2:
|
|
count = 2;
|
|
bytes = parse_size(data, len, size);
|
|
len -= bytes;
|
|
if (size[0]<0 || size[0] > len)
|
|
return OPUS_INVALID_PACKET;
|
|
data += bytes;
|
|
last_size = len-size[0];
|
|
break;
|
|
/* Multiple CBR/VBR frames (from 0 to 120 ms) */
|
|
default: /*case 3:*/
|
|
if (len<1)
|
|
return OPUS_INVALID_PACKET;
|
|
/* Number of frames encoded in bits 0 to 5 */
|
|
ch = *data++;
|
|
count = ch&0x3F;
|
|
if (count <= 0 || framesize*count > 5760)
|
|
return OPUS_INVALID_PACKET;
|
|
len--;
|
|
/* Padding flag is bit 6 */
|
|
if (ch&0x40)
|
|
{
|
|
int p;
|
|
do {
|
|
int tmp;
|
|
if (len<=0)
|
|
return OPUS_INVALID_PACKET;
|
|
p = *data++;
|
|
len--;
|
|
tmp = p==255 ? 254: p;
|
|
len -= tmp;
|
|
pad += tmp;
|
|
} while (p==255);
|
|
}
|
|
if (len<0)
|
|
return OPUS_INVALID_PACKET;
|
|
/* VBR flag is bit 7 */
|
|
cbr = !(ch&0x80);
|
|
if (!cbr)
|
|
{
|
|
/* VBR case */
|
|
last_size = len;
|
|
for (i=0;i<count-1;i++)
|
|
{
|
|
bytes = parse_size(data, len, size+i);
|
|
len -= bytes;
|
|
if (size[i]<0 || size[i] > len)
|
|
return OPUS_INVALID_PACKET;
|
|
data += bytes;
|
|
last_size -= bytes+size[i];
|
|
}
|
|
if (last_size<0)
|
|
return OPUS_INVALID_PACKET;
|
|
} else if (!self_delimited)
|
|
{
|
|
/* CBR case */
|
|
last_size = len/count;
|
|
if (last_size*count!=len)
|
|
return OPUS_INVALID_PACKET;
|
|
for (i=0;i<count-1;i++)
|
|
size[i] = (opus_int16)last_size;
|
|
}
|
|
break;
|
|
}
|
|
/* Self-delimited framing has an extra size for the last frame. */
|
|
if (self_delimited)
|
|
{
|
|
bytes = parse_size(data, len, size+count-1);
|
|
len -= bytes;
|
|
if (size[count-1]<0 || size[count-1] > len)
|
|
return OPUS_INVALID_PACKET;
|
|
data += bytes;
|
|
/* For CBR packets, apply the size to all the frames. */
|
|
if (cbr)
|
|
{
|
|
if (size[count-1]*count > len)
|
|
return OPUS_INVALID_PACKET;
|
|
for (i=0;i<count-1;i++)
|
|
size[i] = size[count-1];
|
|
} else if (bytes+size[count-1] > last_size)
|
|
return OPUS_INVALID_PACKET;
|
|
} else
|
|
{
|
|
/* Because it's not encoded explicitly, it's possible the size of the
|
|
last packet (or all the packets, for the CBR case) is larger than
|
|
1275. Reject them here.*/
|
|
if (last_size > 1275)
|
|
return OPUS_INVALID_PACKET;
|
|
size[count-1] = (opus_int16)last_size;
|
|
}
|
|
|
|
if (payload_offset)
|
|
*payload_offset = (int)(data-data0);
|
|
|
|
for (i=0;i<count;i++)
|
|
{
|
|
if (frames)
|
|
frames[i] = data;
|
|
data += size[i];
|
|
}
|
|
|
|
if (packet_offset)
|
|
*packet_offset = pad+(opus_int32)(data-data0);
|
|
|
|
if (out_toc)
|
|
*out_toc = toc;
|
|
|
|
return count;
|
|
}
|
|
|
|
int opus_packet_parse(const unsigned char *data, opus_int32 len,
|
|
unsigned char *out_toc, const unsigned char *frames[48],
|
|
opus_int16 size[48], int *payload_offset)
|
|
{
|
|
return opus_packet_parse_impl(data, len, 0, out_toc,
|
|
frames, size, payload_offset, NULL);
|
|
}
|
|
|