1 /*
2 * encoder-lpc.cc --
3 *
4 * LPC Audio encoder
5 *
6 * Copyright (c) 1995-2002 The Regents of the University of California.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 *
12 * A. Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 * B. Redistributions in binary form must reproduce the above copyright notice,
15 * this list of conditions and the following disclaimer in the documentation
16 * and/or other materials provided with the distribution.
17 * C. Neither the names of the copyright holders nor the names of its
18 * contributors may be used to endorse or promote products derived from this
19 * software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
22 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #ifndef lint
35 static char rcsid[] =
36 "@(#) $Header: /usr/mash/src/repository/mash/mash-1/codec/audio/encoder-lpc.cc,v 1.7 2002/02/03 03:11:42 lim Exp $";
37 #endif
38
39 #include "tclcl.h"
40 #include "config.h"
41 #include "encoder.h"
42 #include "rtp.h"
43 #include "transmitter.h"
44 extern "C" {
45 #include "lpc.h"
46 }
47
48 class LPCEncoder : public EncoderModule {
49 public:
50 LPCEncoder();
51 protected:
52 void encode(u_int32_t ts, const u_int8_t* samples, int cc);
53 u_int32_t last_ts_;
54 };
55
56 static class LPCEncoderClass : public TclClass {
57 public:
58 LPCEncoderClass() : Matcher("Module/Encoder/LPC") {}
59 TclObject* create(int, const char*const*) {
60 return (new LPCEncoder);
61 }
62 } lpc_encoder_class;
63
64 LPCEncoder::LPCEncoder()
65 {
66 lpcstate_t dummy;
67 lpc_init(&dummy);
68 }
69
70 void LPCEncoder::encode(u_int32_t ts, const u_int8_t* frame, int len)
71 {
72 register int marker = (ts != last_ts_) ? htons(RTP_M) : 0;
73 last_ts_ = ts + len;
74
75 pktbuf* pb = pool_->alloc(ts, RTP_PT_LPC);
76 rtphdr* rh = (rtphdr*)pb->hdr;
77 rh->rh_flags |= marker;
78 pb->iov[0].iov_len = sizeof(rtphdr);
79 u_int8_t* o = (u_int8_t*)pb->iov[1].iov_base;
80 int outlen = 0;
81 while (len > 0) {
82 lpcparams_t* p = (lpcparams_t*)o;
83 lpc_analyze(frame, p);
84 HTONS(p->period);
85 o += LPCRECSIZE;
86 outlen += LPCRECSIZE;
87 len -= FRAMESIZE;
88 frame += FRAMESIZE;
89 }
90 pb->iov[1].iov_len = outlen;
91 target_->recv(pb);
92 return (outlen + sizeof(rtphdr));
93 }
94
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