1 /*
2 * decoder-lpc.cc --
3 *
4 * FIXME: This file needs a description here.
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 static const char rcsid[] =
35 "@(#) $Header: /usr/mash/src/repository/mash/mash-1/audio/decoder-lpc.cc,v 1.8 2003/11/19 19:20:14 aswan Exp $";
36
37 #include "audio/decoder.h"
38 #include "audio/controller.h"
39 extern "C" {
40 #include "audio/lpc.h"
41 }
42 #include "net/pktbuf.h"
43
44 class LPCDecoder : public PCM_Decoder {
45 public:
46 LPCDecoder();
47 virtual void recv(pktbuf*);
48 private:
49 lpcstate_t rstate_;
50 };
51
52 static class LPCDecoderClass : public TclClass {
53 public:
54 LPCDecoderClass() : TclClass("Module/AudioDecoder/LPC") {}
55 TclObject* create(int /* argc */, const char*const* /* argv */) {
56 return (new LPCDecoder);
57 };
58 } lpc_decoder_class;
59
60 LPCDecoder::LPCDecoder()
61 {
62 memset(&rstate_, 0, sizeof(rstate_));
63 }
64
65 void LPCDecoder::recv(pktbuf* pb)
66 {
67 const struct rtphdr* rh = (rtphdr*)pb->dp;
68 const u_int8_t* frame = (u_int8_t*)(rh + 1);
69 int len = pb->len - sizeof(*rh);
70 if (active()) {
71 if (len >= LPCRECSIZE && len <= int(8*LPCRECSIZE)) {
72 u_char wrkbuf[AUDIO_FRAMESIZE*8];
73 u_char* wp = wrkbuf;
74 int outlen = 0;
75 for (const u_char* ep = frame + len; frame < ep;
76 wp += framesize_, frame += LPCRECSIZE) {
77 NTOHS(((lpcparams_t *)frame)->period);
78 lpc_synthesize(wp, (lpcparams_t*)frame, &rstate_);
79 outlen += framesize_;
80 }
81 consume_samples(rh, wrkbuf, outlen);
82 }
83 }
84 pb->release();
85 }
86
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