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7082d0584e
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5192 65c4cc65-6c06-0410-ace0-fbb531ad65f3
637 lines
12 KiB
C
Executable File
637 lines
12 KiB
C
Executable File
/* codec_adpcm.c - translate between signed linear and Dialogic ADPCM
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*
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* Asterisk -- A telephony toolkit for Linux.
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*
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* Based on frompcm.c and topcm.c from the Emiliano MIPL browser/
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* interpreter. See http://www.bsdtelephony.com.mx
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*
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* Copyright (c) 2001 - 2005 Digium, Inc.
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* All rights reserved.
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*
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* Karl Sackett <krs@linux-support.net>, 2001-03-21
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License
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*/
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#include <asterisk/lock.h>
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#include <asterisk/logger.h>
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#include <asterisk/module.h>
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#include <asterisk/config.h>
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#include <asterisk/options.h>
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#include <asterisk/translate.h>
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#include <asterisk/channel.h>
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#include <fcntl.h>
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#include <netinet/in.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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/* define NOT_BLI to use a faster but not bit-level identical version */
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/* #define NOT_BLI */
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#define BUFFER_SIZE 8096 /* size for the translation buffers */
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AST_MUTEX_DEFINE_STATIC(localuser_lock);
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static int localusecnt = 0;
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static char *tdesc = "Adaptive Differential PCM Coder/Decoder";
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static int useplc = 0;
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/* Sample frame data */
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#include "slin_adpcm_ex.h"
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#include "adpcm_slin_ex.h"
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/*
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* Step size index shift table
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*/
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static int indsft[8] = { -1, -1, -1, -1, 2, 4, 6, 8 };
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/*
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* Step size table, where stpsz[i]=floor[16*(11/10)^i]
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*/
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static int stpsz[49] = {
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16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73,
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80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279,
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307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963,
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1060, 1166, 1282, 1411, 1552
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};
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/*
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* Decoder/Encoder state
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* States for both encoder and decoder are synchronized
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*/
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struct adpcm_state {
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int ssindex;
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int signal;
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int zero_count;
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int next_flag;
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};
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/*
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* Decode(encoded)
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* Decodes the encoded nibble from the adpcm file.
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*
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* Results:
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* Returns the encoded difference.
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*
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* Side effects:
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* Sets the index to the step size table for the next encode.
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*/
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static inline short
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decode(int encoded, struct adpcm_state* state)
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{
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int diff;
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int step;
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int sign;
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step = stpsz[state->ssindex];
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sign = encoded & 0x08;
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encoded &= 0x07;
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#ifdef NOT_BLI
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diff = (((encoded << 1) + 1) * step) >> 3;
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#else /* BLI code */
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diff = step >> 3;
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if (encoded & 4) diff += step;
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if (encoded & 2) diff += step >> 1;
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if (encoded & 1) diff += step >> 2;
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if ((encoded >> 1) & step & 0x1)
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diff++;
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#endif
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if (sign)
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diff = -diff;
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if (state->next_flag & 0x1)
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state->signal -= 8;
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else if (state->next_flag & 0x2)
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state->signal += 8;
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state->signal += diff;
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if (state->signal > 2047)
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state->signal = 2047;
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else if (state->signal < -2047)
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state->signal = -2047;
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state->next_flag = 0;
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#ifdef AUTO_RETURN
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if (encoded)
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state->zero_count = 0;
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else if (++(state->zero_count) == 24)
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{
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state->zero_count = 0;
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if (state->signal > 0)
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state->next_flag = 0x1;
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else if (state->signal < 0)
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state->next_flag = 0x2;
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}
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#endif
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state->ssindex += indsft[encoded];
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if (state->ssindex < 0)
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state->ssindex = 0;
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else if (state->ssindex > 48)
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state->ssindex = 48;
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return state->signal << 4;
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}
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/*
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* Adpcm
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* Takes a signed linear signal and encodes it as ADPCM
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* For more information see http://support.dialogic.com/appnotes/adpcm.pdf
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*
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* Results:
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* Foo.
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*
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* Side effects:
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* signal gets updated with each pass.
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*/
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static inline int
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adpcm(short csig, struct adpcm_state* state)
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{
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int diff;
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int step;
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int encoded;
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/*
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* Clip csig if too large or too small
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*/
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csig >>= 4;
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step = stpsz[state->ssindex];
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diff = csig - state->signal;
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#ifdef NOT_BLI
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if (diff < 0)
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{
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encoded = (-diff << 2) / step;
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if (encoded > 7)
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encoded = 7;
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encoded |= 0x08;
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}
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else
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{
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encoded = (diff << 2) / step;
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if (encoded > 7)
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encoded = 7;
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}
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#else /* BLI code */
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if (diff < 0)
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{
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encoded = 8;
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diff = -diff;
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}
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else
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encoded = 0;
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if (diff >= step)
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{
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encoded |= 4;
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diff -= step;
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}
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step >>= 1;
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if (diff >= step)
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{
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encoded |= 2;
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diff -= step;
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}
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step >>= 1;
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if (diff >= step)
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encoded |= 1;
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#endif /* NOT_BLI */
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/* feedback to state */
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decode(encoded, state);
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return encoded;
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}
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/*
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* Private workspace for translating signed linear signals to ADPCM.
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*/
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struct adpcm_encoder_pvt
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{
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struct ast_frame f;
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char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */
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short inbuf[BUFFER_SIZE]; /* Unencoded signed linear values */
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unsigned char outbuf[BUFFER_SIZE]; /* Encoded ADPCM, two nibbles to a word */
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struct adpcm_state state;
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int tail;
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};
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/*
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* Private workspace for translating ADPCM signals to signed linear.
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*/
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struct adpcm_decoder_pvt
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{
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struct ast_frame f;
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char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */
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short outbuf[BUFFER_SIZE]; /* Decoded signed linear values */
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struct adpcm_state state;
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int tail;
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plc_state_t plc;
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};
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/*
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* AdpcmToLin_New
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* Create a new instance of adpcm_decoder_pvt.
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*
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* Results:
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* Returns a pointer to the new instance.
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*
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* Side effects:
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* None.
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*/
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static struct ast_translator_pvt *
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adpcmtolin_new (void)
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{
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struct adpcm_decoder_pvt *tmp;
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tmp = malloc (sizeof (struct adpcm_decoder_pvt));
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if (tmp)
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{
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memset(tmp, 0, sizeof(*tmp));
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tmp->tail = 0;
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plc_init(&tmp->plc);
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localusecnt++;
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ast_update_use_count ();
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}
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return (struct ast_translator_pvt *) tmp;
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}
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/*
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* LinToAdpcm_New
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* Create a new instance of adpcm_encoder_pvt.
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*
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* Results:
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* Returns a pointer to the new instance.
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*
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* Side effects:
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* None.
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*/
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static struct ast_translator_pvt *
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lintoadpcm_new (void)
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{
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struct adpcm_encoder_pvt *tmp;
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tmp = malloc (sizeof (struct adpcm_encoder_pvt));
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if (tmp)
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{
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memset(tmp, 0, sizeof(*tmp));
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localusecnt++;
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ast_update_use_count ();
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tmp->tail = 0;
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}
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return (struct ast_translator_pvt *) tmp;
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}
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/*
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* AdpcmToLin_FrameIn
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* Take an input buffer with packed 4-bit ADPCM values and put decoded PCM in outbuf,
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* if there is room left.
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*
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* Results:
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* Foo
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*
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* Side effects:
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* tmp->tail is the number of packed values in the buffer.
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*/
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static int
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adpcmtolin_framein (struct ast_translator_pvt *pvt, struct ast_frame *f)
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{
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struct adpcm_decoder_pvt *tmp = (struct adpcm_decoder_pvt *) pvt;
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int x;
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unsigned char *b;
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if(f->datalen == 0) { /* perform PLC with nominal framesize of 20ms/160 samples */
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if((tmp->tail + 160) > sizeof(tmp->outbuf) / 2) {
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ast_log(LOG_WARNING, "Out of buffer space\n");
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return -1;
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}
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if(useplc) {
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plc_fillin(&tmp->plc, tmp->outbuf+tmp->tail, 160);
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tmp->tail += 160;
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}
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return 0;
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}
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if (f->datalen * 4 + tmp->tail * 2 > sizeof(tmp->outbuf)) {
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ast_log(LOG_WARNING, "Out of buffer space\n");
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return -1;
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}
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b = f->data;
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for (x=0;x<f->datalen;x++) {
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tmp->outbuf[tmp->tail++] = decode((b[x] >> 4) & 0xf, &tmp->state);
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tmp->outbuf[tmp->tail++] = decode(b[x] & 0x0f, &tmp->state);
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}
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if(useplc) plc_rx(&tmp->plc, tmp->outbuf+tmp->tail-f->datalen*2, f->datalen*2);
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return 0;
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}
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/*
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* AdpcmToLin_FrameOut
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* Convert 4-bit ADPCM encoded signals to 16-bit signed linear.
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*
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* Results:
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* Converted signals are placed in tmp->f.data, tmp->f.datalen
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* and tmp->f.samples are calculated.
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*
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* Side effects:
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* None.
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*/
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static struct ast_frame *
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adpcmtolin_frameout (struct ast_translator_pvt *pvt)
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{
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struct adpcm_decoder_pvt *tmp = (struct adpcm_decoder_pvt *) pvt;
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if (!tmp->tail)
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return NULL;
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tmp->f.frametype = AST_FRAME_VOICE;
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tmp->f.subclass = AST_FORMAT_SLINEAR;
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tmp->f.datalen = tmp->tail *2;
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tmp->f.samples = tmp->tail;
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tmp->f.mallocd = 0;
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tmp->f.offset = AST_FRIENDLY_OFFSET;
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tmp->f.src = __PRETTY_FUNCTION__;
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tmp->f.data = tmp->outbuf;
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tmp->tail = 0;
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return &tmp->f;
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}
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/*
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* LinToAdpcm_FrameIn
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* Fill an input buffer with 16-bit signed linear PCM values.
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*
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* Results:
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* None.
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*
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* Side effects:
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* tmp->tail is number of signal values in the input buffer.
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*/
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static int
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lintoadpcm_framein (struct ast_translator_pvt *pvt, struct ast_frame *f)
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{
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struct adpcm_encoder_pvt *tmp = (struct adpcm_encoder_pvt *) pvt;
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if ((tmp->tail + f->datalen / 2) < (sizeof (tmp->inbuf) / 2))
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{
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memcpy (&tmp->inbuf[tmp->tail], f->data, f->datalen);
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tmp->tail += f->datalen / 2;
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}
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else
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{
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ast_log (LOG_WARNING, "Out of buffer space\n");
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return -1;
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}
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return 0;
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}
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/*
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* LinToAdpcm_FrameOut
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* Convert a buffer of raw 16-bit signed linear PCM to a buffer
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* of 4-bit ADPCM packed two to a byte (Big Endian).
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*
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* Results:
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* Foo
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*
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* Side effects:
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* Leftover inbuf data gets packed, tail gets updated.
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*/
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static struct ast_frame *
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lintoadpcm_frameout (struct ast_translator_pvt *pvt)
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{
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struct adpcm_encoder_pvt *tmp = (struct adpcm_encoder_pvt *) pvt;
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int i_max, i;
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if (tmp->tail < 2) return NULL;
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i_max = tmp->tail & ~1; /* atomic size is 2 samples */
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/* What is this, state debugging? should be #ifdef'd then
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tmp->outbuf[0] = tmp->ssindex & 0xff;
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tmp->outbuf[1] = (tmp->signal >> 8) & 0xff;
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tmp->outbuf[2] = (tmp->signal & 0xff);
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tmp->outbuf[3] = tmp->zero_count;
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tmp->outbuf[4] = tmp->next_flag;
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*/
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for (i = 0; i < i_max; i+=2)
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{
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tmp->outbuf[i/2] =
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(adpcm(tmp->inbuf[i ], &tmp->state) << 4) |
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(adpcm(tmp->inbuf[i+1], &tmp->state) );
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};
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tmp->f.frametype = AST_FRAME_VOICE;
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tmp->f.subclass = AST_FORMAT_ADPCM;
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tmp->f.samples = i_max;
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tmp->f.mallocd = 0;
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tmp->f.offset = AST_FRIENDLY_OFFSET;
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tmp->f.src = __PRETTY_FUNCTION__;
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tmp->f.data = tmp->outbuf;
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tmp->f.datalen = i_max / 2;
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/*
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* If there is a signal left over (there should be no more than
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* one) move it to the beginning of the input buffer.
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*/
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if (tmp->tail == i_max)
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tmp->tail = 0;
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else
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{
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tmp->inbuf[0] = tmp->inbuf[tmp->tail];
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tmp->tail = 1;
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}
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return &tmp->f;
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}
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/*
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* AdpcmToLin_Sample
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*/
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static struct ast_frame *
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adpcmtolin_sample (void)
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{
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static struct ast_frame f;
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f.frametype = AST_FRAME_VOICE;
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f.subclass = AST_FORMAT_ADPCM;
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f.datalen = sizeof (adpcm_slin_ex);
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f.samples = sizeof(adpcm_slin_ex) * 2;
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f.mallocd = 0;
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f.offset = 0;
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f.src = __PRETTY_FUNCTION__;
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f.data = adpcm_slin_ex;
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return &f;
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}
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/*
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* LinToAdpcm_Sample
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*/
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static struct ast_frame *
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lintoadpcm_sample (void)
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{
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static struct ast_frame f;
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f.frametype = AST_FRAME_VOICE;
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f.subclass = AST_FORMAT_SLINEAR;
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f.datalen = sizeof (slin_adpcm_ex);
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/* Assume 8000 Hz */
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f.samples = sizeof (slin_adpcm_ex) / 2;
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f.mallocd = 0;
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f.offset = 0;
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f.src = __PRETTY_FUNCTION__;
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f.data = slin_adpcm_ex;
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return &f;
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}
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/*
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* Adpcm_Destroy
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* Destroys a private workspace.
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*
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* Results:
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* It's gone!
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*
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* Side effects:
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* None.
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*/
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static void
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adpcm_destroy (struct ast_translator_pvt *pvt)
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{
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free (pvt);
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localusecnt--;
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ast_update_use_count ();
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}
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/*
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* The complete translator for ADPCMToLin.
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*/
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static struct ast_translator adpcmtolin = {
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"adpcmtolin",
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AST_FORMAT_ADPCM,
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AST_FORMAT_SLINEAR,
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adpcmtolin_new,
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adpcmtolin_framein,
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adpcmtolin_frameout,
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adpcm_destroy,
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/* NULL */
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adpcmtolin_sample
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};
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/*
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* The complete translator for LinToADPCM.
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*/
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static struct ast_translator lintoadpcm = {
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"lintoadpcm",
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AST_FORMAT_SLINEAR,
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AST_FORMAT_ADPCM,
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lintoadpcm_new,
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lintoadpcm_framein,
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lintoadpcm_frameout,
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adpcm_destroy,
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/* NULL */
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lintoadpcm_sample
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};
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static void
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parse_config(void)
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{
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struct ast_config *cfg;
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struct ast_variable *var;
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if ((cfg = ast_config_load("codecs.conf"))) {
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if ((var = ast_variable_browse(cfg, "plc"))) {
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while (var) {
|
|
if (!strcasecmp(var->name, "genericplc")) {
|
|
useplc = ast_true(var->value) ? 1 : 0;
|
|
if (option_verbose > 2)
|
|
ast_verbose(VERBOSE_PREFIX_3 "CODEC ULAW: %susing generic PLC\n", useplc ? "" : "not ");
|
|
}
|
|
var = var->next;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
int
|
|
reload(void)
|
|
{
|
|
parse_config();
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
unload_module (void)
|
|
{
|
|
int res;
|
|
ast_mutex_lock (&localuser_lock);
|
|
res = ast_unregister_translator (&lintoadpcm);
|
|
if (!res)
|
|
res = ast_unregister_translator (&adpcmtolin);
|
|
if (localusecnt)
|
|
res = -1;
|
|
ast_mutex_unlock (&localuser_lock);
|
|
return res;
|
|
}
|
|
|
|
int
|
|
load_module (void)
|
|
{
|
|
int res;
|
|
parse_config();
|
|
res = ast_register_translator (&adpcmtolin);
|
|
if (!res)
|
|
res = ast_register_translator (&lintoadpcm);
|
|
else
|
|
ast_unregister_translator (&adpcmtolin);
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Return a description of this module.
|
|
*/
|
|
|
|
char *
|
|
description (void)
|
|
{
|
|
return tdesc;
|
|
}
|
|
|
|
int
|
|
usecount (void)
|
|
{
|
|
int res;
|
|
STANDARD_USECOUNT (res);
|
|
return res;
|
|
}
|
|
|
|
char *
|
|
key ()
|
|
{
|
|
return ASTERISK_GPL_KEY;
|
|
}
|