115 lines
3.3 KiB
C
115 lines
3.3 KiB
C
/* Copyright (c) 2010 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 FOUNDATION 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.
|
|
*/
|
|
|
|
static int decode_length(unsigned char *c, int len)
|
|
{
|
|
int tmp;
|
|
tmp = c[0];
|
|
if (len < 1)
|
|
return -1;
|
|
if (tmp >= 252)
|
|
{
|
|
if (len >= 2)
|
|
return 4*c[1] + (tmp&0x3) + 252;
|
|
else
|
|
return -1;
|
|
} else {
|
|
return tmp;
|
|
}
|
|
}
|
|
|
|
int count_frames(unsigned char *packet, int len)
|
|
{
|
|
int sz = packet[0]&0x7;
|
|
|
|
if (sz == 0)
|
|
return 1;
|
|
else if (sz == 1 || sz == 4)
|
|
return 2;
|
|
else if (sz == 2 || sz == 5)
|
|
return 3;
|
|
else if (sz == 3)
|
|
{
|
|
/* Many packets, same size */
|
|
int count, payload;
|
|
int flen = decode_length(packet+1, len-1);
|
|
if (flen<=0)
|
|
return -1;
|
|
payload = len - 2;
|
|
if (flen>=252)
|
|
payload--;
|
|
count = payload/flen;
|
|
if (count*flen==payload)
|
|
return count;
|
|
else
|
|
return -1;
|
|
} else /* if (sz == 6 || sz == 7) */
|
|
{
|
|
/* Many packets, different sizes */
|
|
int count = 0;
|
|
int pos = 1;
|
|
int bytes = 1;
|
|
int extra = 0;
|
|
if (sz==7)
|
|
extra = 1;
|
|
while (bytes < len)
|
|
{
|
|
int tmp=extra+1;
|
|
int flen = decode_length(packet+pos, len-bytes);
|
|
if (flen==-1)
|
|
return -1;
|
|
if (flen >= 252)
|
|
tmp = 2;
|
|
pos += tmp;
|
|
bytes += tmp+flen;
|
|
count++;
|
|
}
|
|
if (bytes != len)
|
|
return -1;
|
|
else
|
|
return count;
|
|
}
|
|
}
|
|
|
|
#define MAX_FRAMES 256
|
|
int opus_merge_packets(unsigned char **packets, int *plen, int nb_packets,
|
|
unsigned *output, int maxlen)
|
|
{
|
|
int i;
|
|
unsigned char cfg[MAX_FRAMES];
|
|
unsigned char flen[MAX_FRAMES];
|
|
int nb_frames=0;
|
|
|
|
for (i=0;i<nb_packets;i++)
|
|
{
|
|
int tmp = count_frames(packets[i], plen[i]);
|
|
if (tmp<=0)
|
|
return -1;
|
|
nb_frames += tmp;
|
|
}
|
|
return nb_frames;
|
|
}
|