Make g729dec.c:decoder_init() return AVERROR(EINVAL) rather than
[libav.git] / libavcodec / g729dec.c
1 /*
2 * G.729 decoder
3 * Copyright (c) 2008 Vladimir Voroshilov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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.
11 *
12 * FFmpeg 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.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21 #include <stdlib.h>
22 #include <inttypes.h>
23 #include <limits.h>
24 #include <stdio.h>
25 #include <string.h>
26 #include <math.h>
27 #include <assert.h>
28
29 #include "avcodec.h"
30 #include "libavutil/avutil.h"
31 #include "get_bits.h"
32
33 #include "g729.h"
34 #include "lsp.h"
35 #include "celp_math.h"
36 #include "acelp_filters.h"
37 #include "acelp_pitch_delay.h"
38 #include "acelp_vectors.h"
39 #include "g729data.h"
40
41 /**
42 * minimum quantized LSF value (3.2.4)
43 * 0.005 in Q13
44 */
45 #define LSFQ_MIN 40
46
47 /**
48 * maximum quantized LSF value (3.2.4)
49 * 3.135 in Q13
50 */
51 #define LSFQ_MAX 25681
52
53 /**
54 * minimum LSF distance (3.2.4)
55 * 0.0391 in Q13
56 */
57 #define LSFQ_DIFF_MIN 321
58
59 /**
60 * minimum gain pitch value (3.8, Equation 47)
61 * 0.2 in (1.14)
62 */
63 #define SHARP_MIN 3277
64
65 /**
66 * maximum gain pitch value (3.8, Equation 47)
67 * (EE) This does not comply with the specification.
68 * Specification says about 0.8, which should be
69 * 13107 in (1.14), but reference C code uses
70 * 13017 (equals to 0.7945) instead of it.
71 */
72 #define SHARP_MAX 13017
73
74 typedef struct {
75 uint8_t ac_index_bits[2]; ///< adaptive codebook index for second subframe (size in bits)
76 uint8_t parity_bit; ///< parity bit for pitch delay
77 uint8_t gc_1st_index_bits; ///< gain codebook (first stage) index (size in bits)
78 uint8_t gc_2nd_index_bits; ///< gain codebook (second stage) index (size in bits)
79 uint8_t fc_signs_bits; ///< number of pulses in fixed-codebook vector
80 uint8_t fc_indexes_bits; ///< size (in bits) of fixed-codebook index entry
81 } G729FormatDescription;
82
83 typedef struct {
84 int pitch_delay_int_prev; ///< integer part of previous subframe's pitch delay (4.1.3)
85
86 /// (2.13) LSP quantizer outputs
87 int16_t past_quantizer_output_buf[MA_NP + 1][10];
88 int16_t* past_quantizer_outputs[MA_NP + 1];
89
90 int16_t lsfq[10]; ///< (2.13) quantized LSF coefficients from previous frame
91 int16_t lsp_buf[2][10]; ///< (0.15) LSP coefficients (previous and current frames) (3.2.5)
92 int16_t *lsp[2]; ///< pointers to lsp_buf
93 } G729Context;
94
95 static const G729FormatDescription format_g729_8k = {
96 .ac_index_bits = {8,5},
97 .parity_bit = 1,
98 .gc_1st_index_bits = GC_1ST_IDX_BITS_8K,
99 .gc_2nd_index_bits = GC_2ND_IDX_BITS_8K,
100 .fc_signs_bits = 4,
101 .fc_indexes_bits = 13,
102 };
103
104 static const G729FormatDescription format_g729d_6k4 = {
105 .ac_index_bits = {8,4},
106 .parity_bit = 0,
107 .gc_1st_index_bits = GC_1ST_IDX_BITS_6K4,
108 .gc_2nd_index_bits = GC_2ND_IDX_BITS_6K4,
109 .fc_signs_bits = 2,
110 .fc_indexes_bits = 9,
111 };
112
113 /**
114 * \brief pseudo random number generator
115 */
116 static inline uint16_t g729_prng(uint16_t value)
117 {
118 return 31821 * value + 13849;
119 }
120
121 /**
122 * Get parity bit of bit 2..7
123 */
124 static inline int get_parity(uint8_t value)
125 {
126 return (0x6996966996696996ULL >> (value >> 2)) & 1;
127 }
128
129 static void lsf_decode(int16_t* lsfq, int16_t* past_quantizer_outputs[MA_NP + 1],
130 int16_t ma_predictor,
131 int16_t vq_1st, int16_t vq_2nd_low, int16_t vq_2nd_high)
132 {
133 int i,j;
134 static const uint8_t min_distance[2]={10, 5}; //(2.13)
135 int16_t* quantizer_output = past_quantizer_outputs[MA_NP];
136
137 for (i = 0; i < 5; i++) {
138 quantizer_output[i] = cb_lsp_1st[vq_1st][i ] + cb_lsp_2nd[vq_2nd_low ][i ];
139 quantizer_output[i + 5] = cb_lsp_1st[vq_1st][i + 5] + cb_lsp_2nd[vq_2nd_high][i + 5];
140 }
141
142 for (j = 0; j < 2; j++) {
143 for (i = 1; i < 10; i++) {
144 int diff = (quantizer_output[i - 1] - quantizer_output[i] + min_distance[j]) >> 1;
145 if (diff > 0) {
146 quantizer_output[i - 1] -= diff;
147 quantizer_output[i ] += diff;
148 }
149 }
150 }
151
152 for (i = 0; i < 10; i++) {
153 int sum = quantizer_output[i] * cb_ma_predictor_sum[ma_predictor][i];
154 for (j = 0; j < MA_NP; j++)
155 sum += past_quantizer_outputs[j][i] * cb_ma_predictor[ma_predictor][j][i];
156
157 lsfq[i] = sum >> 15;
158 }
159
160 /* Rotate past_quantizer_outputs. */
161 memmove(past_quantizer_outputs + 1, past_quantizer_outputs, MA_NP * sizeof(int16_t*));
162 past_quantizer_outputs[0] = quantizer_output;
163
164 ff_acelp_reorder_lsf(lsfq, LSFQ_DIFF_MIN, LSFQ_MIN, LSFQ_MAX, 10);
165 }
166
167 static av_cold int decoder_init(AVCodecContext * avctx)
168 {
169 G729Context* ctx = avctx->priv_data;
170 int i,k;
171
172 if (avctx->channels != 1) {
173 av_log(avctx, AV_LOG_ERROR, "Only mono sound is supported (requested channels: %d).\n", avctx->channels);
174 return AVERROR(EINVAL);
175 }
176
177 /* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */
178 avctx->frame_size = SUBFRAME_SIZE << 1;
179
180 for (k = 0; k < MA_NP + 1; k++) {
181 ctx->past_quantizer_outputs[k] = ctx->past_quantizer_output_buf[k];
182 for (i = 1; i < 11; i++)
183 ctx->past_quantizer_outputs[k][i - 1] = (18717 * i) >> 3;
184 }
185
186 ctx->lsp[0] = ctx->lsp_buf[0];
187 ctx->lsp[1] = ctx->lsp_buf[1];
188 memcpy(ctx->lsp[0], lsp_init, 10 * sizeof(int16_t));
189
190 return 0;
191 }
192
193 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
194 AVPacket *avpkt)
195 {
196 const uint8_t *buf = avpkt->data;
197 int buf_size = avpkt->size;
198 int16_t *out_frame = data;
199 GetBitContext gb;
200 G729FormatDescription format;
201 int frame_erasure = 0; ///< frame erasure detected during decoding
202 int bad_pitch = 0; ///< parity check failed
203 int i;
204 G729Context *ctx = avctx->priv_data;
205 int16_t lp[2][11]; // (3.12)
206 uint8_t ma_predictor; ///< switched MA predictor of LSP quantizer
207 uint8_t quantizer_1st; ///< first stage vector of quantizer
208 uint8_t quantizer_2nd_lo; ///< second stage lower vector of quantizer (size in bits)
209 uint8_t quantizer_2nd_hi; ///< second stage higher vector of quantizer (size in bits)
210
211 int pitch_delay_int; // pitch delay, integer part
212 int pitch_delay_3x; // pitch delay, multiplied by 3
213
214 if (*data_size < SUBFRAME_SIZE << 2) {
215 av_log(avctx, AV_LOG_ERROR, "Error processing packet: output buffer too small\n");
216 return AVERROR(EIO);
217 }
218
219 if (buf_size == 10) {
220 format = format_g729_8k;
221 av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729 @ 8kbit/s");
222 } else if (buf_size == 8) {
223 format = format_g729d_6k4;
224 av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729D @ 6.4kbit/s");
225 } else {
226 av_log(avctx, AV_LOG_ERROR, "Packet size %d is unknown.\n", buf_size);
227 return (AVERROR_NOFMT);
228 }
229
230 for (i=0; i < buf_size; i++)
231 frame_erasure |= buf[i];
232 frame_erasure = !frame_erasure;
233
234 init_get_bits(&gb, buf, buf_size);
235
236 ma_predictor = get_bits(&gb, 1);
237 quantizer_1st = get_bits(&gb, VQ_1ST_BITS);
238 quantizer_2nd_lo = get_bits(&gb, VQ_2ND_BITS);
239 quantizer_2nd_hi = get_bits(&gb, VQ_2ND_BITS);
240
241 lsf_decode(ctx->lsfq, ctx->past_quantizer_outputs,
242 ma_predictor,
243 quantizer_1st, quantizer_2nd_lo, quantizer_2nd_hi);
244
245 ff_acelp_lsf2lsp(ctx->lsp[1], ctx->lsfq, 10);
246
247 ff_acelp_lp_decode(&lp[0][0], &lp[1][0], ctx->lsp[1], ctx->lsp[0], 10);
248
249 FFSWAP(int16_t*, ctx->lsp[1], ctx->lsp[0]);
250
251 for (i = 0; i < 2; i++) {
252 uint8_t ac_index; ///< adaptive codebook index
253 uint8_t pulses_signs; ///< fixed-codebook vector pulse signs
254 int fc_indexes; ///< fixed-codebook indexes
255 uint8_t gc_1st_index; ///< gain codebook (first stage) index
256 uint8_t gc_2nd_index; ///< gain codebook (second stage) index
257
258 ac_index = get_bits(&gb, format.ac_index_bits[i]);
259 if(!i && format.parity_bit)
260 bad_pitch = get_parity(ac_index) == get_bits1(&gb);
261 fc_indexes = get_bits(&gb, format.fc_indexes_bits);
262 pulses_signs = get_bits(&gb, format.fc_signs_bits);
263 gc_1st_index = get_bits(&gb, format.gc_1st_index_bits);
264 gc_2nd_index = get_bits(&gb, format.gc_2nd_index_bits);
265
266 if(!i) {
267 if (bad_pitch)
268 pitch_delay_3x = 3 * ctx->pitch_delay_int_prev;
269 else
270 pitch_delay_3x = ff_acelp_decode_8bit_to_1st_delay3(ac_index);
271 } else {
272 int pitch_delay_min = av_clip(ctx->pitch_delay_int_prev - 5,
273 PITCH_DELAY_MIN, PITCH_DELAY_MAX - 9);
274
275 if(packet_type == FORMAT_G729D_6K4)
276 pitch_delay_3x = ff_acelp_decode_4bit_to_2nd_delay3(ac_index, pitch_delay_min);
277 else
278 pitch_delay_3x = ff_acelp_decode_5_6_bit_to_2nd_delay3(ac_index, pitch_delay_min);
279 }
280
281 /* Round pitch delay to nearest (used everywhere except ff_acelp_interpolate). */
282 pitch_delay_int = (pitch_delay_3x + 1) / 3;
283
284 ff_acelp_weighted_vector_sum(fc + pitch_delay_int,
285 fc + pitch_delay_int,
286 fc, 1 << 14,
287 av_clip(ctx->gain_pitch, SHARP_MIN, SHARP_MAX),
288 0, 14,
289 SUBFRAME_SIZE - pitch_delay_int);
290
291 if (frame_erasure) {
292 ctx->gain_pitch = (29491 * ctx->gain_pitch) >> 15; // 0.90 (0.15)
293 ctx->gain_code = ( 2007 * ctx->gain_code ) >> 11; // 0.98 (0.11)
294
295 gain_corr_factor = 0;
296 } else {
297 ctx->gain_pitch = cb_gain_1st_8k[gc_1st_index][0] +
298 cb_gain_2nd_8k[gc_2nd_index][0];
299 gain_corr_factor = cb_gain_1st_8k[gc_1st_index][1] +
300 cb_gain_2nd_8k[gc_2nd_index][1];
301
302 ff_acelp_weighted_vector_sum(ctx->exc + i * SUBFRAME_SIZE,
303 ctx->exc + i * SUBFRAME_SIZE, fc,
304 (!voicing && frame_erasure) ? 0 : ctx->gain_pitch,
305 ( voicing && frame_erasure) ? 0 : ctx->gain_code,
306 1 << 13, 14, SUBFRAME_SIZE);
307
308 ctx->pitch_delay_int_prev = pitch_delay_int;
309 }
310
311 *data_size = SUBFRAME_SIZE << 2;
312 return buf_size;
313 }
314
315 AVCodec g729_decoder =
316 {
317 "g729",
318 CODEC_TYPE_AUDIO,
319 CODEC_ID_G729,
320 sizeof(G729Context),
321 decoder_init,
322 NULL,
323 NULL,
324 decode_frame,
325 .long_name = NULL_IF_CONFIG_SMALL("G.729"),
326 };