ref: 2c8b29806b96058d756340d9664e14848edbcfb8
dir: /src/framepack.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. - Neither the name of the Xiph.org Foundation nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. 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; }