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Diffstat (limited to 'gr-vocoder/lib/g7xx/g721.c')
| -rw-r--r-- | gr-vocoder/lib/g7xx/g721.c | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/gr-vocoder/lib/g7xx/g721.c b/gr-vocoder/lib/g7xx/g721.c deleted file mode 100644 index 445f177e8..000000000 --- a/gr-vocoder/lib/g7xx/g721.c +++ /dev/null @@ -1,173 +0,0 @@ -/* - * This source code is a product of Sun Microsystems, Inc. and is provided - * for unrestricted use. Users may copy or modify this source code without - * charge. - * - * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING - * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR - * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. - * - * Sun source code is provided with no support and without any obligation on - * the part of Sun Microsystems, Inc. to assist in its use, correction, - * modification or enhancement. - * - * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE - * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE - * OR ANY PART THEREOF. - * - * In no event will Sun Microsystems, Inc. be liable for any lost revenue - * or profits or other special, indirect and consequential damages, even if - * Sun has been advised of the possibility of such damages. - * - * Sun Microsystems, Inc. - * 2550 Garcia Avenue - * Mountain View, California 94043 - */ - -/* - * g721.c - * - * Description: - * - * g721_encoder(), g721_decoder() - * - * These routines comprise an implementation of the CCITT G.721 ADPCM - * coding algorithm. Essentially, this implementation is identical to - * the bit level description except for a few deviations which - * take advantage of work station attributes, such as hardware 2's - * complement arithmetic and large memory. Specifically, certain time - * consuming operations such as multiplications are replaced - * with lookup tables and software 2's complement operations are - * replaced with hardware 2's complement. - * - * The deviation from the bit level specification (lookup tables) - * preserves the bit level performance specifications. - * - * As outlined in the G.721 Recommendation, the algorithm is broken - * down into modules. Each section of code below is preceded by - * the name of the module which it is implementing. - * - */ -#include "g72x.h" - -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}; - -/* - * g721_encoder() - * - * 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. - */ -int -g721_encoder( - int sl, - int in_coding, - struct g72x_state *state_ptr) -{ - short sezi, se, sez; /* ACCUM */ - short d; /* SUBTA */ - short sr; /* ADDB */ - short y; /* MIX */ - short dqsez; /* ADDC */ - short dq, i; - - switch (in_coding) { /* linearize input sample to 14-bit PCM */ - case AUDIO_ENCODING_ALAW: - sl = alaw2linear(sl) >> 2; - break; - case AUDIO_ENCODING_ULAW: - sl = ulaw2linear(sl) >> 2; - break; - case AUDIO_ENCODING_LINEAR: - sl >>= 2; /* 14-bit dynamic range */ - break; - default: - return (-1); - } - - 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 = ADPCM 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); -} - -/* - * g721_decoder() - * - * Description: - * - * Decodes a 4-bit code of G.721 encoded data of i and - * returns the resulting linear PCM, A-law or u-law value. - * return -1 for unknown out_coding value. - */ -int -g721_decoder( - int i, - int out_coding, - struct g72x_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); - - switch (out_coding) { - case AUDIO_ENCODING_ALAW: - return (tandem_adjust_alaw(sr, se, y, i, 8, qtab_721)); - case AUDIO_ENCODING_ULAW: - return (tandem_adjust_ulaw(sr, se, y, i, 8, qtab_721)); - case AUDIO_ENCODING_LINEAR: - return (sr << 2); /* sr was 14-bit dynamic range */ - default: - return (-1); - } -} |