3
* Copyright (c) 2008 Vladimir Voroshilov
5
* This file is part of Libav.
7
* Libav is free software; you can redistribute it and/or
8
* modify it under the terms of the GNU Lesser General Public
9
* License as published by the Free Software Foundation; either
10
* version 2.1 of the License, or (at your option) any later version.
12
* Libav is distributed in the hope that it will be useful,
13
* but WITHOUT ANY WARRANTY; without even the implied warranty of
14
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15
* Lesser General Public License for more details.
17
* You should have received a copy of the GNU Lesser General Public
18
* License along with Libav; if not, write to the Free Software
19
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30
#include "libavutil/avutil.h"
34
#include "celp_math.h"
35
#include "acelp_filters.h"
36
#include "acelp_pitch_delay.h"
37
#include "acelp_vectors.h"
41
* minimum quantized LSF value (3.2.4)
47
* maximum quantized LSF value (3.2.4)
50
#define LSFQ_MAX 25681
53
* minimum LSF distance (3.2.4)
56
#define LSFQ_DIFF_MIN 321
59
* minimum gain pitch value (3.8, Equation 47)
62
#define SHARP_MIN 3277
65
* maximum gain pitch value (3.8, Equation 47)
66
* (EE) This does not comply with the specification.
67
* Specification says about 0.8, which should be
68
* 13107 in (1.14), but reference C code uses
69
* 13017 (equals to 0.7945) instead of it.
71
#define SHARP_MAX 13017
76
#define SUBFRAME_SIZE 40
80
uint8_t ac_index_bits[2]; ///< adaptive codebook index for second subframe (size in bits)
81
uint8_t parity_bit; ///< parity bit for pitch delay
82
uint8_t gc_1st_index_bits; ///< gain codebook (first stage) index (size in bits)
83
uint8_t gc_2nd_index_bits; ///< gain codebook (second stage) index (size in bits)
84
uint8_t fc_signs_bits; ///< number of pulses in fixed-codebook vector
85
uint8_t fc_indexes_bits; ///< size (in bits) of fixed-codebook index entry
86
} G729FormatDescription;
89
int pitch_delay_int_prev; ///< integer part of previous subframe's pitch delay (4.1.3)
91
/// (2.13) LSP quantizer outputs
92
int16_t past_quantizer_output_buf[MA_NP + 1][10];
93
int16_t* past_quantizer_outputs[MA_NP + 1];
95
int16_t lsfq[10]; ///< (2.13) quantized LSF coefficients from previous frame
96
int16_t lsp_buf[2][10]; ///< (0.15) LSP coefficients (previous and current frames) (3.2.5)
97
int16_t *lsp[2]; ///< pointers to lsp_buf
100
static const G729FormatDescription format_g729_8k = {
101
.ac_index_bits = {8,5},
103
.gc_1st_index_bits = GC_1ST_IDX_BITS_8K,
104
.gc_2nd_index_bits = GC_2ND_IDX_BITS_8K,
106
.fc_indexes_bits = 13,
109
static const G729FormatDescription format_g729d_6k4 = {
110
.ac_index_bits = {8,4},
112
.gc_1st_index_bits = GC_1ST_IDX_BITS_6K4,
113
.gc_2nd_index_bits = GC_2ND_IDX_BITS_6K4,
115
.fc_indexes_bits = 9,
119
* \brief pseudo random number generator
121
static inline uint16_t g729_prng(uint16_t value)
123
return 31821 * value + 13849;
127
* Get parity bit of bit 2..7
129
static inline int get_parity(uint8_t value)
131
return (0x6996966996696996ULL >> (value >> 2)) & 1;
134
static void lsf_decode(int16_t* lsfq, int16_t* past_quantizer_outputs[MA_NP + 1],
135
int16_t ma_predictor,
136
int16_t vq_1st, int16_t vq_2nd_low, int16_t vq_2nd_high)
139
static const uint8_t min_distance[2]={10, 5}; //(2.13)
140
int16_t* quantizer_output = past_quantizer_outputs[MA_NP];
142
for (i = 0; i < 5; i++) {
143
quantizer_output[i] = cb_lsp_1st[vq_1st][i ] + cb_lsp_2nd[vq_2nd_low ][i ];
144
quantizer_output[i + 5] = cb_lsp_1st[vq_1st][i + 5] + cb_lsp_2nd[vq_2nd_high][i + 5];
147
for (j = 0; j < 2; j++) {
148
for (i = 1; i < 10; i++) {
149
int diff = (quantizer_output[i - 1] - quantizer_output[i] + min_distance[j]) >> 1;
151
quantizer_output[i - 1] -= diff;
152
quantizer_output[i ] += diff;
157
for (i = 0; i < 10; i++) {
158
int sum = quantizer_output[i] * cb_ma_predictor_sum[ma_predictor][i];
159
for (j = 0; j < MA_NP; j++)
160
sum += past_quantizer_outputs[j][i] * cb_ma_predictor[ma_predictor][j][i];
165
/* Rotate past_quantizer_outputs. */
166
memmove(past_quantizer_outputs + 1, past_quantizer_outputs, MA_NP * sizeof(int16_t*));
167
past_quantizer_outputs[0] = quantizer_output;
169
ff_acelp_reorder_lsf(lsfq, LSFQ_DIFF_MIN, LSFQ_MIN, LSFQ_MAX, 10);
172
static av_cold int decoder_init(AVCodecContext * avctx)
174
G729Context* ctx = avctx->priv_data;
177
if (avctx->channels != 1) {
178
av_log(avctx, AV_LOG_ERROR, "Only mono sound is supported (requested channels: %d).\n", avctx->channels);
179
return AVERROR(EINVAL);
182
/* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */
183
avctx->frame_size = SUBFRAME_SIZE << 1;
185
for (k = 0; k < MA_NP + 1; k++) {
186
ctx->past_quantizer_outputs[k] = ctx->past_quantizer_output_buf[k];
187
for (i = 1; i < 11; i++)
188
ctx->past_quantizer_outputs[k][i - 1] = (18717 * i) >> 3;
191
ctx->lsp[0] = ctx->lsp_buf[0];
192
ctx->lsp[1] = ctx->lsp_buf[1];
193
memcpy(ctx->lsp[0], lsp_init, 10 * sizeof(int16_t));
198
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
201
const uint8_t *buf = avpkt->data;
202
int buf_size = avpkt->size;
203
int16_t *out_frame = data;
205
G729FormatDescription format;
206
int frame_erasure = 0; ///< frame erasure detected during decoding
207
int bad_pitch = 0; ///< parity check failed
209
G729Context *ctx = avctx->priv_data;
210
int16_t lp[2][11]; // (3.12)
211
uint8_t ma_predictor; ///< switched MA predictor of LSP quantizer
212
uint8_t quantizer_1st; ///< first stage vector of quantizer
213
uint8_t quantizer_2nd_lo; ///< second stage lower vector of quantizer (size in bits)
214
uint8_t quantizer_2nd_hi; ///< second stage higher vector of quantizer (size in bits)
216
int pitch_delay_int; // pitch delay, integer part
217
int pitch_delay_3x; // pitch delay, multiplied by 3
219
if (*data_size < SUBFRAME_SIZE << 2) {
220
av_log(avctx, AV_LOG_ERROR, "Error processing packet: output buffer too small\n");
224
if (buf_size == 10) {
225
format = format_g729_8k;
226
av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729 @ 8kbit/s");
227
} else if (buf_size == 8) {
228
format = format_g729d_6k4;
229
av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729D @ 6.4kbit/s");
231
av_log(avctx, AV_LOG_ERROR, "Packet size %d is unknown.\n", buf_size);
232
return AVERROR_INVALIDDATA;
235
for (i=0; i < buf_size; i++)
236
frame_erasure |= buf[i];
237
frame_erasure = !frame_erasure;
239
init_get_bits(&gb, buf, buf_size);
241
ma_predictor = get_bits(&gb, 1);
242
quantizer_1st = get_bits(&gb, VQ_1ST_BITS);
243
quantizer_2nd_lo = get_bits(&gb, VQ_2ND_BITS);
244
quantizer_2nd_hi = get_bits(&gb, VQ_2ND_BITS);
246
lsf_decode(ctx->lsfq, ctx->past_quantizer_outputs,
248
quantizer_1st, quantizer_2nd_lo, quantizer_2nd_hi);
250
ff_acelp_lsf2lsp(ctx->lsp[1], ctx->lsfq, 10);
252
ff_acelp_lp_decode(&lp[0][0], &lp[1][0], ctx->lsp[1], ctx->lsp[0], 10);
254
FFSWAP(int16_t*, ctx->lsp[1], ctx->lsp[0]);
256
for (i = 0; i < 2; i++) {
257
uint8_t ac_index; ///< adaptive codebook index
258
uint8_t pulses_signs; ///< fixed-codebook vector pulse signs
259
int fc_indexes; ///< fixed-codebook indexes
260
uint8_t gc_1st_index; ///< gain codebook (first stage) index
261
uint8_t gc_2nd_index; ///< gain codebook (second stage) index
263
ac_index = get_bits(&gb, format.ac_index_bits[i]);
264
if(!i && format.parity_bit)
265
bad_pitch = get_parity(ac_index) == get_bits1(&gb);
266
fc_indexes = get_bits(&gb, format.fc_indexes_bits);
267
pulses_signs = get_bits(&gb, format.fc_signs_bits);
268
gc_1st_index = get_bits(&gb, format.gc_1st_index_bits);
269
gc_2nd_index = get_bits(&gb, format.gc_2nd_index_bits);
273
pitch_delay_3x = 3 * ctx->pitch_delay_int_prev;
275
pitch_delay_3x = ff_acelp_decode_8bit_to_1st_delay3(ac_index);
277
int pitch_delay_min = av_clip(ctx->pitch_delay_int_prev - 5,
278
PITCH_DELAY_MIN, PITCH_DELAY_MAX - 9);
280
if(packet_type == FORMAT_G729D_6K4)
281
pitch_delay_3x = ff_acelp_decode_4bit_to_2nd_delay3(ac_index, pitch_delay_min);
283
pitch_delay_3x = ff_acelp_decode_5_6_bit_to_2nd_delay3(ac_index, pitch_delay_min);
286
/* Round pitch delay to nearest (used everywhere except ff_acelp_interpolate). */
287
pitch_delay_int = (pitch_delay_3x + 1) / 3;
289
ff_acelp_weighted_vector_sum(fc + pitch_delay_int,
290
fc + pitch_delay_int,
292
av_clip(ctx->gain_pitch, SHARP_MIN, SHARP_MAX),
294
SUBFRAME_SIZE - pitch_delay_int);
297
ctx->gain_pitch = (29491 * ctx->gain_pitch) >> 15; // 0.90 (0.15)
298
ctx->gain_code = ( 2007 * ctx->gain_code ) >> 11; // 0.98 (0.11)
300
gain_corr_factor = 0;
302
ctx->gain_pitch = cb_gain_1st_8k[gc_1st_index][0] +
303
cb_gain_2nd_8k[gc_2nd_index][0];
304
gain_corr_factor = cb_gain_1st_8k[gc_1st_index][1] +
305
cb_gain_2nd_8k[gc_2nd_index][1];
307
ff_acelp_weighted_vector_sum(ctx->exc + i * SUBFRAME_SIZE,
308
ctx->exc + i * SUBFRAME_SIZE, fc,
309
(!voicing && frame_erasure) ? 0 : ctx->gain_pitch,
310
( voicing && frame_erasure) ? 0 : ctx->gain_code,
311
1 << 13, 14, SUBFRAME_SIZE);
313
ctx->pitch_delay_int_prev = pitch_delay_int;
316
*data_size = SUBFRAME_SIZE << 2;
320
AVCodec ff_g729_decoder =
330
.long_name = NULL_IF_CONFIG_SMALL("G.729"),
added
removed
ffmpeg/libavcodec/g729dec.c
