diff options
author | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 2004-02-25 04:10:32 +0000 |
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committer | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 2004-02-25 04:10:32 +0000 |
commit | 91a49dbd77ef94e316d10913c950fbd3753581d2 (patch) | |
tree | 340405f4743954fc4f2662d43f2c3e532e541e8d /codecs/codec_g726.c | |
parent | b343a418182009f512a145765c0ddde458e81cc0 (diff) |
Add G.726-32kbps Codec Transcoder (Tested with Cisco ATA-186)
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@2239 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'codecs/codec_g726.c')
-rwxr-xr-x | codecs/codec_g726.c | 927 |
1 files changed, 927 insertions, 0 deletions
diff --git a/codecs/codec_g726.c b/codecs/codec_g726.c new file mode 100755 index 000000000..ac32678ca --- /dev/null +++ b/codecs/codec_g726.c @@ -0,0 +1,927 @@ +/* codec_g726.c - translate between signed linear and ITU G.726-32kbps + * + * Asterisk -- A telephony toolkit for Linux. + * + * Based on frompcm.c and topcm.c from the Emiliano MIPL browser/ + * interpreter. See http://www.bsdtelephony.com.mx + * + * Copyright (c) 2004, Digium + * + * Mark Spencer <markster@digium.com> + * + * This program is free software, distributed under the terms of + * the GNU General Public License + */ + +#include <asterisk/lock.h> +#include <asterisk/logger.h> +#include <asterisk/module.h> +#include <asterisk/translate.h> +#include <asterisk/channel.h> +#include <fcntl.h> +#include <netinet/in.h> +#include <pthread.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#define BUFFER_SIZE 8096 /* size for the translation buffers */ +#define BUF_SHIFT 5 + +static ast_mutex_t localuser_lock = AST_MUTEX_INITIALIZER; +static int localusecnt = 0; + +static char *tdesc = "ITU G.726-32kbps G726 Transcoder"; + +/* Sample frame data */ + +#include "slin_g726_ex.h" +#include "g726_slin_ex.h" + +/* + * The following is the definition of the state structure + * used by the G.721/G.723 encoder and decoder to preserve their internal + * state between successive calls. The meanings of the majority + * of the state structure fields are explained in detail in the + * CCITT Recommendation G.721. The field names are essentially indentical + * to variable names in the bit level description of the coding algorithm + * included in this Recommendation. + */ +struct g726_state { + long yl; /* Locked or steady state step size multiplier. */ + short yu; /* Unlocked or non-steady state step size multiplier. */ + short dms; /* Short term energy estimate. */ + short dml; /* Long term energy estimate. */ + short ap; /* Linear weighting coefficient of 'yl' and 'yu'. */ + + short a[2]; /* Coefficients of pole portion of prediction filter. */ + short b[6]; /* Coefficients of zero portion of prediction filter. */ + short pk[2]; /* + * Signs of previous two samples of a partially + * reconstructed signal. + */ + short dq[6]; /* + * Previous 6 samples of the quantized difference + * signal represented in an internal floating point + * format. + */ + short sr[2]; /* + * Previous 2 samples of the quantized difference + * signal represented in an internal floating point + * format. + */ + char td; /* delayed tone detect, new in 1988 version */ +}; + + + +static short qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400}; +/* + * Maps G.721 code word to reconstructed scale factor normalized log + * magnitude values. + */ +static short _dqlntab[16] = {-2048, 4, 135, 213, 273, 323, 373, 425, + 425, 373, 323, 273, 213, 135, 4, -2048}; + +/* Maps G.721 code word to log of scale factor multiplier. */ +static short _witab[16] = {-12, 18, 41, 64, 112, 198, 355, 1122, + 1122, 355, 198, 112, 64, 41, 18, -12}; +/* + * Maps G.721 code words to a set of values whose long and short + * term averages are computed and then compared to give an indication + * how stationary (steady state) the signal is. + */ +static short _fitab[16] = {0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00, + 0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0}; + +static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80, + 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000}; + +/* + * quan() + * + * quantizes the input val against the table of size short integers. + * It returns i if table[i - 1] <= val < table[i]. + * + * Using linear search for simple coding. + */ +static int quan(int val, short *table, int size) +{ + int i; + + for (i = 0; i < size; i++) + if (val < *table++) + break; + return (i); +} + +/* + * fmult() + * + * returns the integer product of the 14-bit integer "an" and + * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn". + */ +static int fmult(int an, int srn) +{ + short anmag, anexp, anmant; + short wanexp, wanmant; + short retval; + + anmag = (an > 0) ? an : ((-an) & 0x1FFF); + anexp = quan(anmag, power2, 15) - 6; + anmant = (anmag == 0) ? 32 : + (anexp >= 0) ? anmag >> anexp : anmag << -anexp; + wanexp = anexp + ((srn >> 6) & 0xF) - 13; + + wanmant = (anmant * (srn & 077) + 0x30) >> 4; + retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) : + (wanmant >> -wanexp); + + return (((an ^ srn) < 0) ? -retval : retval); +} + +/* + * g72x_init_state() + * + * This routine initializes and/or resets the g726_state structure + * pointed to by 'state_ptr'. + * All the initial state values are specified in the CCITT G.721 document. + */ +static void g726_init_state(struct g726_state *state_ptr) +{ + int cnta; + + state_ptr->yl = 34816; + state_ptr->yu = 544; + state_ptr->dms = 0; + state_ptr->dml = 0; + state_ptr->ap = 0; + for (cnta = 0; cnta < 2; cnta++) { + state_ptr->a[cnta] = 0; + state_ptr->pk[cnta] = 0; + state_ptr->sr[cnta] = 32; + } + for (cnta = 0; cnta < 6; cnta++) { + state_ptr->b[cnta] = 0; + state_ptr->dq[cnta] = 32; + } + state_ptr->td = 0; +} + +/* + * predictor_zero() + * + * computes the estimated signal from 6-zero predictor. + * + */ +static int predictor_zero(struct g726_state *state_ptr) +{ + int i; + int sezi; + + sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]); + for (i = 1; i < 6; i++) /* ACCUM */ + sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]); + return (sezi); +} +/* + * predictor_pole() + * + * computes the estimated signal from 2-pole predictor. + * + */ +static int predictor_pole(struct g726_state *state_ptr) +{ + return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) + + fmult(state_ptr->a[0] >> 2, state_ptr->sr[0])); +} + +/* + * step_size() + * + * computes the quantization step size of the adaptive quantizer. + * + */ +static int step_size(struct g726_state *state_ptr) +{ + int y; + int dif; + int al; + + if (state_ptr->ap >= 256) + return (state_ptr->yu); + else { + y = state_ptr->yl >> 6; + dif = state_ptr->yu - y; + al = state_ptr->ap >> 2; + if (dif > 0) + y += (dif * al) >> 6; + else if (dif < 0) + y += (dif * al + 0x3F) >> 6; + return (y); + } +} + +/* + * quantize() + * + * Given a raw sample, 'd', of the difference signal and a + * quantization step size scale factor, 'y', this routine returns the + * ADPCM codeword to which that sample gets quantized. The step + * size scale factor division operation is done in the log base 2 domain + * as a subtraction. + */ +static int quantize( + int d, /* Raw difference signal sample */ + int y, /* Step size multiplier */ + short *table, /* quantization table */ + int size) /* table size of short integers */ +{ + short dqm; /* Magnitude of 'd' */ + short exp; /* Integer part of base 2 log of 'd' */ + short mant; /* Fractional part of base 2 log */ + short dl; /* Log of magnitude of 'd' */ + short dln; /* Step size scale factor normalized log */ + int i; + + /* + * LOG + * + * Compute base 2 log of 'd', and store in 'dl'. + */ + dqm = abs(d); + exp = quan(dqm >> 1, power2, 15); + mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */ + dl = (exp << 7) + mant; + + /* + * SUBTB + * + * "Divide" by step size multiplier. + */ + dln = dl - (y >> 2); + + /* + * QUAN + * + * Obtain codword i for 'd'. + */ + i = quan(dln, table, size); + if (d < 0) /* take 1's complement of i */ + return ((size << 1) + 1 - i); + else if (i == 0) /* take 1's complement of 0 */ + return ((size << 1) + 1); /* new in 1988 */ + else + return (i); +} + +/* + * reconstruct() + * + * Returns reconstructed difference signal 'dq' obtained from + * codeword 'i' and quantization step size scale factor 'y'. + * Multiplication is performed in log base 2 domain as addition. + */ +static int reconstruct( + int sign, /* 0 for non-negative value */ + int dqln, /* G.72x codeword */ + int y) /* Step size multiplier */ +{ + short dql; /* Log of 'dq' magnitude */ + short dex; /* Integer part of log */ + short dqt; + short dq; /* Reconstructed difference signal sample */ + + dql = dqln + (y >> 2); /* ADDA */ + + if (dql < 0) { + return ((sign) ? -0x8000 : 0); + } else { /* ANTILOG */ + dex = (dql >> 7) & 15; + dqt = 128 + (dql & 127); + dq = (dqt << 7) >> (14 - dex); + return ((sign) ? (dq - 0x8000) : dq); + } +} + +/* + * update() + * + * updates the state variables for each output code + */ +static void update( + int code_size, /* distinguish 723_40 with others */ + int y, /* quantizer step size */ + int wi, /* scale factor multiplier */ + int fi, /* for long/short term energies */ + int dq, /* quantized prediction difference */ + int sr, /* reconstructed signal */ + int dqsez, /* difference from 2-pole predictor */ + struct g726_state *state_ptr) /* coder state pointer */ +{ + int cnt; + short mag, exp; /* Adaptive predictor, FLOAT A */ + short a2p=0; /* LIMC */ + short a1ul; /* UPA1 */ + short pks1; /* UPA2 */ + short fa1; + char tr; /* tone/transition detector */ + short ylint, thr2, dqthr; + short ylfrac, thr1; + short pk0; + + pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */ + + mag = dq & 0x7FFF; /* prediction difference magnitude */ + /* TRANS */ + ylint = state_ptr->yl >> 15; /* exponent part of yl */ + ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */ + thr1 = (32 + ylfrac) << ylint; /* threshold */ + thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */ + dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */ + if (state_ptr->td == 0) /* signal supposed voice */ + tr = 0; + else if (mag <= dqthr) /* supposed data, but small mag */ + tr = 0; /* treated as voice */ + else /* signal is data (modem) */ + tr = 1; + + /* + * Quantizer scale factor adaptation. + */ + + /* FUNCTW & FILTD & DELAY */ + /* update non-steady state step size multiplier */ + state_ptr->yu = y + ((wi - y) >> 5); + + /* LIMB */ + if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */ + state_ptr->yu = 544; + else if (state_ptr->yu > 5120) + state_ptr->yu = 5120; + + /* FILTE & DELAY */ + /* update steady state step size multiplier */ + state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6); + + /* + * Adaptive predictor coefficients. + */ + if (tr == 1) { /* reset a's and b's for modem signal */ + state_ptr->a[0] = 0; + state_ptr->a[1] = 0; + state_ptr->b[0] = 0; + state_ptr->b[1] = 0; + state_ptr->b[2] = 0; + state_ptr->b[3] = 0; + state_ptr->b[4] = 0; + state_ptr->b[5] = 0; + } else { /* update a's and b's */ + pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */ + + /* update predictor pole a[1] */ + a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7); + if (dqsez != 0) { + fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0]; + if (fa1 < -8191) /* a2p = function of fa1 */ + a2p -= 0x100; + else if (fa1 > 8191) + a2p += 0xFF; + else + a2p += fa1 >> 5; + + if (pk0 ^ state_ptr->pk[1]) + /* LIMC */ + if (a2p <= -12160) + a2p = -12288; + else if (a2p >= 12416) + a2p = 12288; + else + a2p -= 0x80; + else if (a2p <= -12416) + a2p = -12288; + else if (a2p >= 12160) + a2p = 12288; + else + a2p += 0x80; + } + + /* TRIGB & DELAY */ + state_ptr->a[1] = a2p; + + /* UPA1 */ + /* update predictor pole a[0] */ + state_ptr->a[0] -= state_ptr->a[0] >> 8; + if (dqsez != 0) { + if (pks1 == 0) + state_ptr->a[0] += 192; + else + state_ptr->a[0] -= 192; + } + /* LIMD */ + a1ul = 15360 - a2p; + if (state_ptr->a[0] < -a1ul) + state_ptr->a[0] = -a1ul; + else if (state_ptr->a[0] > a1ul) + state_ptr->a[0] = a1ul; + + /* UPB : update predictor zeros b[6] */ + for (cnt = 0; cnt < 6; cnt++) { + if (code_size == 5) /* for 40Kbps G.723 */ + state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9; + else /* for G.721 and 24Kbps G.723 */ + state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8; + if (dq & 0x7FFF) { /* XOR */ + if ((dq ^ state_ptr->dq[cnt]) >= 0) + state_ptr->b[cnt] += 128; + else + state_ptr->b[cnt] -= 128; + } + } + } + + for (cnt = 5; cnt > 0; cnt--) + state_ptr->dq[cnt] = state_ptr->dq[cnt-1]; + /* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */ + if (mag == 0) { + state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20; + } else { + exp = quan(mag, power2, 15); + state_ptr->dq[0] = (dq >= 0) ? + (exp << 6) + ((mag << 6) >> exp) : + (exp << 6) + ((mag << 6) >> exp) - 0x400; + } + + state_ptr->sr[1] = state_ptr->sr[0]; + /* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */ + if (sr == 0) { + state_ptr->sr[0] = 0x20; + } else if (sr > 0) { + exp = quan(sr, power2, 15); + state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp); + } else if (sr > -32768) { + mag = -sr; + exp = quan(mag, power2, 15); + state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400; + } else + state_ptr->sr[0] = 0xFC20; + + /* DELAY A */ + state_ptr->pk[1] = state_ptr->pk[0]; + state_ptr->pk[0] = pk0; + + /* TONE */ + if (tr == 1) /* this sample has been treated as data */ + state_ptr->td = 0; /* next one will be treated as voice */ + else if (a2p < -11776) /* small sample-to-sample correlation */ + state_ptr->td = 1; /* signal may be data */ + else /* signal is voice */ + state_ptr->td = 0; + + /* + * Adaptation speed control. + */ + state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */ + state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */ + + if (tr == 1) + state_ptr->ap = 256; + else if (y < 1536) /* SUBTC */ + state_ptr->ap += (0x200 - state_ptr->ap) >> 4; + else if (state_ptr->td == 1) + state_ptr->ap += (0x200 - state_ptr->ap) >> 4; + else if (abs((state_ptr->dms << 2) - state_ptr->dml) >= + (state_ptr->dml >> 3)) + state_ptr->ap += (0x200 - state_ptr->ap) >> 4; + else + state_ptr->ap += (-state_ptr->ap) >> 4; +} + +/* + * g726_decode() + * + * Description: + * + * Decodes a 4-bit code of G.726-32 encoded data of i and + * returns the resulting linear PCM, A-law or u-law value. + * return -1 for unknown out_coding value. + */ +static int g726_decode(int i, struct g726_state *state_ptr) +{ + short sezi, sei, sez, se; /* ACCUM */ + short y; /* MIX */ + short sr; /* ADDB */ + short dq; + short dqsez; + + i &= 0x0f; /* mask to get proper bits */ + sezi = predictor_zero(state_ptr); + sez = sezi >> 1; + sei = sezi + predictor_pole(state_ptr); + se = sei >> 1; /* se = estimated signal */ + + y = step_size(state_ptr); /* dynamic quantizer step size */ + + dq = reconstruct(i & 0x08, _dqlntab[i], y); /* quantized diff. */ + + sr = (dq < 0) ? (se - (dq & 0x3FFF)) : se + dq; /* reconst. signal */ + + dqsez = sr - se + sez; /* pole prediction diff. */ + + update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); + + return (sr << 2); /* sr was 14-bit dynamic range */ +} +/* + * g726_encode() + * + * Encodes the input vale of linear PCM, A-law or u-law data sl and returns + * the resulting code. -1 is returned for unknown input coding value. + */ +static int g726_encode(int sl, struct g726_state *state_ptr) +{ + short sezi, se, sez; /* ACCUM */ + short d; /* SUBTA */ + short sr; /* ADDB */ + short y; /* MIX */ + short dqsez; /* ADDC */ + short dq, i; + + sl >>= 2; /* 14-bit dynamic range */ + + sezi = predictor_zero(state_ptr); + sez = sezi >> 1; + se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */ + + d = sl - se; /* estimation difference */ + + /* quantize the prediction difference */ + y = step_size(state_ptr); /* quantizer step size */ + i = quantize(d, y, qtab_721, 7); /* i = G726 code */ + + dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */ + + sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */ + + dqsez = sr + sez - se; /* pole prediction diff. */ + + update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr); + + return (i); +} + +/* + * Private workspace for translating signed linear signals to G726. + */ + +struct g726_encoder_pvt +{ + struct ast_frame f; + char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */ + unsigned char outbuf[BUFFER_SIZE]; /* Encoded G726, two nibbles to a word */ + unsigned char next_flag; + struct g726_state g726; + int tail; +}; + +/* + * Private workspace for translating G726 signals to signed linear. + */ + +struct g726_decoder_pvt +{ + struct ast_frame f; + char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */ + short outbuf[BUFFER_SIZE]; /* Decoded signed linear values */ + struct g726_state g726; + int tail; +}; + +/* + * G726ToLin_New + * Create a new instance of g726_decoder_pvt. + * + * Results: + * Returns a pointer to the new instance. + * + * Side effects: + * None. + */ + +static struct ast_translator_pvt * +g726tolin_new (void) +{ + struct g726_decoder_pvt *tmp; + tmp = malloc (sizeof (struct g726_decoder_pvt)); + if (tmp) + { + memset(tmp, 0, sizeof(*tmp)); + tmp->tail = 0; + localusecnt++; + g726_init_state(&tmp->g726); + ast_update_use_count (); + } + return (struct ast_translator_pvt *) tmp; +} + +/* + * LinToG726_New + * Create a new instance of g726_encoder_pvt. + * + * Results: + * Returns a pointer to the new instance. + * + * Side effects: + * None. + */ + +static struct ast_translator_pvt * +lintog726_new (void) +{ + struct g726_encoder_pvt *tmp; + tmp = malloc (sizeof (struct g726_encoder_pvt)); + if (tmp) + { + memset(tmp, 0, sizeof(*tmp)); + localusecnt++; + tmp->tail = 0; + g726_init_state(&tmp->g726); + ast_update_use_count (); + } + return (struct ast_translator_pvt *) tmp; +} + +/* + * G726ToLin_FrameIn + * Fill an input buffer with packed 4-bit G726 values if there is room + * left. + * + * Results: + * Foo + * + * Side effects: + * tmp->tail is the number of packed values in the buffer. + */ + +static int +g726tolin_framein (struct ast_translator_pvt *pvt, struct ast_frame *f) +{ + struct g726_decoder_pvt *tmp = (struct g726_decoder_pvt *) pvt; + unsigned char *b; + int x; + + b = f->data; + for (x=0;x<f->datalen;x++) { + if (tmp->tail >= BUFFER_SIZE) { + ast_log(LOG_WARNING, "Out of buffer space!\n"); + return -1; + } + tmp->outbuf[tmp->tail++] = g726_decode((b[x] >> 4) & 0xf, &tmp->g726); + if (tmp->tail >= BUFFER_SIZE) { + ast_log(LOG_WARNING, "Out of buffer space!\n"); + return -1; + } + tmp->outbuf[tmp->tail++] = g726_decode(b[x] & 0x0f, &tmp->g726); + } + + return 0; +} + +/* + * G726ToLin_FrameOut + * Convert 4-bit G726 encoded signals to 16-bit signed linear. + * + * Results: + * Converted signals are placed in tmp->f.data, tmp->f.datalen + * and tmp->f.samples are calculated. + * + * Side effects: + * None. + */ + +static struct ast_frame * +g726tolin_frameout (struct ast_translator_pvt *pvt) +{ + struct g726_decoder_pvt *tmp = (struct g726_decoder_pvt *) pvt; + + if (!tmp->tail) + return NULL; + + tmp->f.frametype = AST_FRAME_VOICE; + tmp->f.subclass = AST_FORMAT_SLINEAR; + tmp->f.datalen = tmp->tail * 2; + tmp->f.samples = tmp->tail; + tmp->f.mallocd = 0; + tmp->f.offset = AST_FRIENDLY_OFFSET; + tmp->f.src = __PRETTY_FUNCTION__; + tmp->f.data = tmp->outbuf; + tmp->tail = 0; + return &tmp->f; +} + +/* + * LinToG726_FrameIn + * Fill an input buffer with 16-bit signed linear PCM values. + * + * Results: + * None. + * + * Side effects: + * tmp->tail is number of signal values in the input buffer. + */ + +static int +lintog726_framein (struct ast_translator_pvt *pvt, struct ast_frame *f) +{ + struct g726_encoder_pvt *tmp = (struct g726_encoder_pvt *) pvt; + short *s = f->data; + int samples = f->datalen / 2; + int x; + for (x=0;x<samples;x++) { + if (tmp->next_flag & 0x80) { + if (tmp->tail >= BUFFER_SIZE) { + ast_log(LOG_WARNING, "Out of buffer space\n"); + return -1; + } + tmp->outbuf[tmp->tail++] = ((tmp->next_flag & 0xf)<< 4) | g726_encode(s[x], &tmp->g726); + tmp->next_flag = 0; + } else { + tmp->next_flag = 0x80 | g726_encode(s[x], &tmp->g726); + } + } + return 0; +} + +/* + * LinToG726_FrameOut + * Convert a buffer of raw 16-bit signed linear PCM to a buffer + * of 4-bit G726 packed two to a byte (Big Endian). + * + * Results: + * Foo + * + * Side effects: + * Leftover inbuf data gets packed, tail gets updated. + */ + +static struct ast_frame * +lintog726_frameout (struct ast_translator_pvt *pvt) +{ + struct g726_encoder_pvt *tmp = (struct g726_encoder_pvt *) pvt; + + if (!tmp->tail) + return NULL; + tmp->f.frametype = AST_FRAME_VOICE; + tmp->f.subclass = AST_FORMAT_G726; + tmp->f.samples = tmp->tail * 2; + tmp->f.mallocd = 0; + tmp->f.offset = AST_FRIENDLY_OFFSET; + tmp->f.src = __PRETTY_FUNCTION__; + tmp->f.data = tmp->outbuf; + tmp->f.datalen = tmp->tail; + + tmp->tail = 0; + return &tmp->f; +} + + +/* + * G726ToLin_Sample + */ + +static struct ast_frame * +g726tolin_sample (void) +{ + static struct ast_frame f; + f.frametype = AST_FRAME_VOICE; + f.subclass = AST_FORMAT_G726; + f.datalen = sizeof (g726_slin_ex); + f.samples = sizeof(g726_slin_ex) * 2; + f.mallocd = 0; + f.offset = 0; + f.src = __PRETTY_FUNCTION__; + f.data = g726_slin_ex; + return &f; +} + +/* + * LinToG726_Sample + */ + +static struct ast_frame * +lintog726_sample (void) +{ + static struct ast_frame f; + f.frametype = AST_FRAME_VOICE; + f.subclass = AST_FORMAT_SLINEAR; + f.datalen = sizeof (slin_g726_ex); + /* Assume 8000 Hz */ + f.samples = sizeof (slin_g726_ex) / 2; + f.mallocd = 0; + f.offset = 0; + f.src = __PRETTY_FUNCTION__; + f.data = slin_g726_ex; + return &f; +} + +/* + * G726_Destroy + * Destroys a private workspace. + * + * Results: + * It's gone! + * + * Side effects: + * None. + */ + +static void +g726_destroy (struct ast_translator_pvt *pvt) +{ + free (pvt); + localusecnt--; + ast_update_use_count (); +} + +/* + * The complete translator for G726ToLin. + */ + +static struct ast_translator g726tolin = { + "g726tolin", + AST_FORMAT_G726, + AST_FORMAT_SLINEAR, + g726tolin_new, + g726tolin_framein, + g726tolin_frameout, + g726_destroy, + /* NULL */ + g726tolin_sample +}; + +/* + * The complete translator for LinToG726. + */ + +static struct ast_translator lintog726 = { + "lintog726", + AST_FORMAT_SLINEAR, + AST_FORMAT_G726, + lintog726_new, + lintog726_framein, + lintog726_frameout, + g726_destroy, + /* NULL */ + lintog726_sample +}; + +int +unload_module (void) +{ + int res; + ast_mutex_lock (&localuser_lock); + res = ast_unregister_translator (&lintog726); + if (!res) + res = ast_unregister_translator (&g726tolin); + if (localusecnt) + res = -1; + ast_mutex_unlock (&localuser_lock); + return res; +} + +int +load_module (void) +{ + int res; + res = ast_register_translator (&g726tolin); + if (!res) + res = ast_register_translator (&lintog726); + else + ast_unregister_translator (&g726tolin); + 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; +} |