ref: 265b40c258001c69ae1f652484a54c87a52b128a
parent: 57de8a3660dcdb347bbfb387703df4269c8f0ee5
author: Jean-Marc Valin <[email protected]>
date: Wed Sep 8 13:47:26 EDT 2010
Initial code for parsing/packing/unpacking packets Warning: untested, may not even compile
--- /dev/null
+++ b/src/framepack.c
@@ -1,0 +1,108 @@
+/* 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)
+ {+ /* Many packets, different sizes */
+ int count = 0;
+ int pos = 1;
+ int bytes = 1;
+ while (bytes < len)
+ {+ int tmp=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;
+ } else {+
+ }
+}
+
+#define MAX_FRAMES 256
+int hybrid_merge_packets(unsigned char **packets, int *len, unsigned *output, int maxlen)
+{+ unsigned char cfg[MAX_FRAMES];
+ unsigned char len[MAX_FRAMES];
+ int nb_frames=0;
+
+}