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2ba45a60 DM |
1 | /* |
2 | * Copyright (c) CMU 1993 Computer Science, Speech Group | |
3 | * Chengxiang Lu and Alex Hauptmann | |
4 | * Copyright (c) 2005 Steve Underwood <steveu at coppice.org> | |
5 | * Copyright (c) 2009 Kenan Gillet | |
6 | * Copyright (c) 2010 Martin Storsjo | |
7 | * | |
8 | * This file is part of FFmpeg. | |
9 | * | |
10 | * FFmpeg is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU Lesser General Public | |
12 | * License as published by the Free Software Foundation; either | |
13 | * version 2.1 of the License, or (at your option) any later version. | |
14 | * | |
15 | * FFmpeg is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * Lesser General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU Lesser General Public | |
21 | * License along with FFmpeg; if not, write to the Free Software | |
22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
23 | */ | |
24 | ||
25 | /** | |
26 | * @file | |
27 | * G.722 ADPCM audio encoder | |
28 | */ | |
29 | ||
30 | #include "libavutil/avassert.h" | |
31 | #include "avcodec.h" | |
32 | #include "internal.h" | |
33 | #include "g722.h" | |
34 | #include "libavutil/common.h" | |
35 | ||
36 | #define FREEZE_INTERVAL 128 | |
37 | ||
38 | /* This is an arbitrary value. Allowing insanely large values leads to strange | |
39 | problems, so we limit it to a reasonable value */ | |
40 | #define MAX_FRAME_SIZE 32768 | |
41 | ||
42 | /* We clip the value of avctx->trellis to prevent data type overflows and | |
43 | undefined behavior. Using larger values is insanely slow anyway. */ | |
44 | #define MIN_TRELLIS 0 | |
45 | #define MAX_TRELLIS 16 | |
46 | ||
47 | static av_cold int g722_encode_close(AVCodecContext *avctx) | |
48 | { | |
49 | G722Context *c = avctx->priv_data; | |
50 | int i; | |
51 | for (i = 0; i < 2; i++) { | |
52 | av_freep(&c->paths[i]); | |
53 | av_freep(&c->node_buf[i]); | |
54 | av_freep(&c->nodep_buf[i]); | |
55 | } | |
56 | return 0; | |
57 | } | |
58 | ||
59 | static av_cold int g722_encode_init(AVCodecContext * avctx) | |
60 | { | |
61 | G722Context *c = avctx->priv_data; | |
62 | int ret; | |
63 | ||
64 | if (avctx->channels != 1) { | |
65 | av_log(avctx, AV_LOG_ERROR, "Only mono tracks are allowed.\n"); | |
66 | return AVERROR_INVALIDDATA; | |
67 | } | |
68 | ||
69 | c->band[0].scale_factor = 8; | |
70 | c->band[1].scale_factor = 2; | |
71 | c->prev_samples_pos = 22; | |
72 | ||
73 | if (avctx->trellis) { | |
74 | int frontier = 1 << avctx->trellis; | |
75 | int max_paths = frontier * FREEZE_INTERVAL; | |
76 | int i; | |
77 | for (i = 0; i < 2; i++) { | |
78 | c->paths[i] = av_mallocz(max_paths * sizeof(**c->paths)); | |
79 | c->node_buf[i] = av_mallocz(2 * frontier * sizeof(**c->node_buf)); | |
80 | c->nodep_buf[i] = av_mallocz(2 * frontier * sizeof(**c->nodep_buf)); | |
81 | if (!c->paths[i] || !c->node_buf[i] || !c->nodep_buf[i]) { | |
82 | ret = AVERROR(ENOMEM); | |
83 | goto error; | |
84 | } | |
85 | } | |
86 | } | |
87 | ||
88 | if (avctx->frame_size) { | |
89 | /* validate frame size */ | |
90 | if (avctx->frame_size & 1 || avctx->frame_size > MAX_FRAME_SIZE) { | |
91 | int new_frame_size; | |
92 | ||
93 | if (avctx->frame_size == 1) | |
94 | new_frame_size = 2; | |
95 | else if (avctx->frame_size > MAX_FRAME_SIZE) | |
96 | new_frame_size = MAX_FRAME_SIZE; | |
97 | else | |
98 | new_frame_size = avctx->frame_size - 1; | |
99 | ||
100 | av_log(avctx, AV_LOG_WARNING, "Requested frame size is not " | |
101 | "allowed. Using %d instead of %d\n", new_frame_size, | |
102 | avctx->frame_size); | |
103 | avctx->frame_size = new_frame_size; | |
104 | } | |
105 | } else { | |
106 | /* This is arbitrary. We use 320 because it's 20ms @ 16kHz, which is | |
107 | a common packet size for VoIP applications */ | |
108 | avctx->frame_size = 320; | |
109 | } | |
f6fa7814 | 110 | avctx->initial_padding = 22; |
2ba45a60 DM |
111 | |
112 | if (avctx->trellis) { | |
113 | /* validate trellis */ | |
114 | if (avctx->trellis < MIN_TRELLIS || avctx->trellis > MAX_TRELLIS) { | |
115 | int new_trellis = av_clip(avctx->trellis, MIN_TRELLIS, MAX_TRELLIS); | |
116 | av_log(avctx, AV_LOG_WARNING, "Requested trellis value is not " | |
117 | "allowed. Using %d instead of %d\n", new_trellis, | |
118 | avctx->trellis); | |
119 | avctx->trellis = new_trellis; | |
120 | } | |
121 | } | |
122 | ||
123 | return 0; | |
124 | error: | |
125 | g722_encode_close(avctx); | |
126 | return ret; | |
127 | } | |
128 | ||
129 | static const int16_t low_quant[33] = { | |
130 | 35, 72, 110, 150, 190, 233, 276, 323, | |
131 | 370, 422, 473, 530, 587, 650, 714, 786, | |
132 | 858, 940, 1023, 1121, 1219, 1339, 1458, 1612, | |
133 | 1765, 1980, 2195, 2557, 2919 | |
134 | }; | |
135 | ||
136 | static inline void filter_samples(G722Context *c, const int16_t *samples, | |
137 | int *xlow, int *xhigh) | |
138 | { | |
139 | int xout1, xout2; | |
140 | c->prev_samples[c->prev_samples_pos++] = samples[0]; | |
141 | c->prev_samples[c->prev_samples_pos++] = samples[1]; | |
142 | ff_g722_apply_qmf(c->prev_samples + c->prev_samples_pos - 24, &xout1, &xout2); | |
143 | *xlow = xout1 + xout2 >> 14; | |
144 | *xhigh = xout1 - xout2 >> 14; | |
145 | if (c->prev_samples_pos >= PREV_SAMPLES_BUF_SIZE) { | |
146 | memmove(c->prev_samples, | |
147 | c->prev_samples + c->prev_samples_pos - 22, | |
148 | 22 * sizeof(c->prev_samples[0])); | |
149 | c->prev_samples_pos = 22; | |
150 | } | |
151 | } | |
152 | ||
153 | static inline int encode_high(const struct G722Band *state, int xhigh) | |
154 | { | |
155 | int diff = av_clip_int16(xhigh - state->s_predictor); | |
156 | int pred = 141 * state->scale_factor >> 8; | |
157 | /* = diff >= 0 ? (diff < pred) + 2 : diff >= -pred */ | |
158 | return ((diff ^ (diff >> (sizeof(diff)*8-1))) < pred) + 2*(diff >= 0); | |
159 | } | |
160 | ||
161 | static inline int encode_low(const struct G722Band* state, int xlow) | |
162 | { | |
163 | int diff = av_clip_int16(xlow - state->s_predictor); | |
164 | /* = diff >= 0 ? diff : -(diff + 1) */ | |
165 | int limit = diff ^ (diff >> (sizeof(diff)*8-1)); | |
166 | int i = 0; | |
167 | limit = limit + 1 << 10; | |
168 | if (limit > low_quant[8] * state->scale_factor) | |
169 | i = 9; | |
170 | while (i < 29 && limit > low_quant[i] * state->scale_factor) | |
171 | i++; | |
172 | return (diff < 0 ? (i < 2 ? 63 : 33) : 61) - i; | |
173 | } | |
174 | ||
175 | static void g722_encode_trellis(G722Context *c, int trellis, | |
176 | uint8_t *dst, int nb_samples, | |
177 | const int16_t *samples) | |
178 | { | |
179 | int i, j, k; | |
180 | int frontier = 1 << trellis; | |
181 | struct TrellisNode **nodes[2]; | |
182 | struct TrellisNode **nodes_next[2]; | |
183 | int pathn[2] = {0, 0}, froze = -1; | |
184 | struct TrellisPath *p[2]; | |
185 | ||
186 | for (i = 0; i < 2; i++) { | |
187 | nodes[i] = c->nodep_buf[i]; | |
188 | nodes_next[i] = c->nodep_buf[i] + frontier; | |
189 | memset(c->nodep_buf[i], 0, 2 * frontier * sizeof(*c->nodep_buf[i])); | |
190 | nodes[i][0] = c->node_buf[i] + frontier; | |
191 | nodes[i][0]->ssd = 0; | |
192 | nodes[i][0]->path = 0; | |
193 | nodes[i][0]->state = c->band[i]; | |
194 | } | |
195 | ||
196 | for (i = 0; i < nb_samples >> 1; i++) { | |
197 | int xlow, xhigh; | |
198 | struct TrellisNode *next[2]; | |
199 | int heap_pos[2] = {0, 0}; | |
200 | ||
201 | for (j = 0; j < 2; j++) { | |
202 | next[j] = c->node_buf[j] + frontier*(i & 1); | |
203 | memset(nodes_next[j], 0, frontier * sizeof(**nodes_next)); | |
204 | } | |
205 | ||
206 | filter_samples(c, &samples[2*i], &xlow, &xhigh); | |
207 | ||
208 | for (j = 0; j < frontier && nodes[0][j]; j++) { | |
209 | /* Only k >> 2 affects the future adaptive state, therefore testing | |
210 | * small steps that don't change k >> 2 is useless, the original | |
211 | * value from encode_low is better than them. Since we step k | |
212 | * in steps of 4, make sure range is a multiple of 4, so that | |
213 | * we don't miss the original value from encode_low. */ | |
214 | int range = j < frontier/2 ? 4 : 0; | |
215 | struct TrellisNode *cur_node = nodes[0][j]; | |
216 | ||
217 | int ilow = encode_low(&cur_node->state, xlow); | |
218 | ||
219 | for (k = ilow - range; k <= ilow + range && k <= 63; k += 4) { | |
220 | int decoded, dec_diff, pos; | |
221 | uint32_t ssd; | |
222 | struct TrellisNode* node; | |
223 | ||
224 | if (k < 0) | |
225 | continue; | |
226 | ||
227 | decoded = av_clip((cur_node->state.scale_factor * | |
228 | ff_g722_low_inv_quant6[k] >> 10) | |
229 | + cur_node->state.s_predictor, -16384, 16383); | |
230 | dec_diff = xlow - decoded; | |
231 | ||
232 | #define STORE_NODE(index, UPDATE, VALUE)\ | |
233 | ssd = cur_node->ssd + dec_diff*dec_diff;\ | |
234 | /* Check for wraparound. Using 64 bit ssd counters would \ | |
235 | * be simpler, but is slower on x86 32 bit. */\ | |
236 | if (ssd < cur_node->ssd)\ | |
237 | continue;\ | |
238 | if (heap_pos[index] < frontier) {\ | |
239 | pos = heap_pos[index]++;\ | |
240 | av_assert2(pathn[index] < FREEZE_INTERVAL * frontier);\ | |
241 | node = nodes_next[index][pos] = next[index]++;\ | |
242 | node->path = pathn[index]++;\ | |
243 | } else {\ | |
244 | /* Try to replace one of the leaf nodes with the new \ | |
245 | * one, but not always testing the same leaf position */\ | |
246 | pos = (frontier>>1) + (heap_pos[index] & ((frontier>>1) - 1));\ | |
247 | if (ssd >= nodes_next[index][pos]->ssd)\ | |
248 | continue;\ | |
249 | heap_pos[index]++;\ | |
250 | node = nodes_next[index][pos];\ | |
251 | }\ | |
252 | node->ssd = ssd;\ | |
253 | node->state = cur_node->state;\ | |
254 | UPDATE;\ | |
255 | c->paths[index][node->path].value = VALUE;\ | |
256 | c->paths[index][node->path].prev = cur_node->path;\ | |
257 | /* Sift the newly inserted node up in the heap to restore \ | |
258 | * the heap property */\ | |
259 | while (pos > 0) {\ | |
260 | int parent = (pos - 1) >> 1;\ | |
261 | if (nodes_next[index][parent]->ssd <= ssd)\ | |
262 | break;\ | |
263 | FFSWAP(struct TrellisNode*, nodes_next[index][parent],\ | |
264 | nodes_next[index][pos]);\ | |
265 | pos = parent;\ | |
266 | } | |
267 | STORE_NODE(0, ff_g722_update_low_predictor(&node->state, k >> 2), k); | |
268 | } | |
269 | } | |
270 | ||
271 | for (j = 0; j < frontier && nodes[1][j]; j++) { | |
272 | int ihigh; | |
273 | struct TrellisNode *cur_node = nodes[1][j]; | |
274 | ||
275 | /* We don't try to get any initial guess for ihigh via | |
276 | * encode_high - since there's only 4 possible values, test | |
277 | * them all. Testing all of these gives a much, much larger | |
278 | * gain than testing a larger range around ilow. */ | |
279 | for (ihigh = 0; ihigh < 4; ihigh++) { | |
280 | int dhigh, decoded, dec_diff, pos; | |
281 | uint32_t ssd; | |
282 | struct TrellisNode* node; | |
283 | ||
284 | dhigh = cur_node->state.scale_factor * | |
285 | ff_g722_high_inv_quant[ihigh] >> 10; | |
286 | decoded = av_clip(dhigh + cur_node->state.s_predictor, | |
287 | -16384, 16383); | |
288 | dec_diff = xhigh - decoded; | |
289 | ||
290 | STORE_NODE(1, ff_g722_update_high_predictor(&node->state, dhigh, ihigh), ihigh); | |
291 | } | |
292 | } | |
293 | ||
294 | for (j = 0; j < 2; j++) { | |
295 | FFSWAP(struct TrellisNode**, nodes[j], nodes_next[j]); | |
296 | ||
297 | if (nodes[j][0]->ssd > (1 << 16)) { | |
298 | for (k = 1; k < frontier && nodes[j][k]; k++) | |
299 | nodes[j][k]->ssd -= nodes[j][0]->ssd; | |
300 | nodes[j][0]->ssd = 0; | |
301 | } | |
302 | } | |
303 | ||
304 | if (i == froze + FREEZE_INTERVAL) { | |
305 | p[0] = &c->paths[0][nodes[0][0]->path]; | |
306 | p[1] = &c->paths[1][nodes[1][0]->path]; | |
307 | for (j = i; j > froze; j--) { | |
308 | dst[j] = p[1]->value << 6 | p[0]->value; | |
309 | p[0] = &c->paths[0][p[0]->prev]; | |
310 | p[1] = &c->paths[1][p[1]->prev]; | |
311 | } | |
312 | froze = i; | |
313 | pathn[0] = pathn[1] = 0; | |
314 | memset(nodes[0] + 1, 0, (frontier - 1)*sizeof(**nodes)); | |
315 | memset(nodes[1] + 1, 0, (frontier - 1)*sizeof(**nodes)); | |
316 | } | |
317 | } | |
318 | ||
319 | p[0] = &c->paths[0][nodes[0][0]->path]; | |
320 | p[1] = &c->paths[1][nodes[1][0]->path]; | |
321 | for (j = i; j > froze; j--) { | |
322 | dst[j] = p[1]->value << 6 | p[0]->value; | |
323 | p[0] = &c->paths[0][p[0]->prev]; | |
324 | p[1] = &c->paths[1][p[1]->prev]; | |
325 | } | |
326 | c->band[0] = nodes[0][0]->state; | |
327 | c->band[1] = nodes[1][0]->state; | |
328 | } | |
329 | ||
330 | static av_always_inline void encode_byte(G722Context *c, uint8_t *dst, | |
331 | const int16_t *samples) | |
332 | { | |
333 | int xlow, xhigh, ilow, ihigh; | |
334 | filter_samples(c, samples, &xlow, &xhigh); | |
335 | ihigh = encode_high(&c->band[1], xhigh); | |
336 | ilow = encode_low (&c->band[0], xlow); | |
337 | ff_g722_update_high_predictor(&c->band[1], c->band[1].scale_factor * | |
338 | ff_g722_high_inv_quant[ihigh] >> 10, ihigh); | |
339 | ff_g722_update_low_predictor(&c->band[0], ilow >> 2); | |
340 | *dst = ihigh << 6 | ilow; | |
341 | } | |
342 | ||
343 | static void g722_encode_no_trellis(G722Context *c, | |
344 | uint8_t *dst, int nb_samples, | |
345 | const int16_t *samples) | |
346 | { | |
347 | int i; | |
348 | for (i = 0; i < nb_samples; i += 2) | |
349 | encode_byte(c, dst++, &samples[i]); | |
350 | } | |
351 | ||
352 | static int g722_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, | |
353 | const AVFrame *frame, int *got_packet_ptr) | |
354 | { | |
355 | G722Context *c = avctx->priv_data; | |
356 | const int16_t *samples = (const int16_t *)frame->data[0]; | |
357 | int nb_samples, out_size, ret; | |
358 | ||
359 | out_size = (frame->nb_samples + 1) / 2; | |
360 | if ((ret = ff_alloc_packet2(avctx, avpkt, out_size)) < 0) | |
361 | return ret; | |
362 | ||
363 | nb_samples = frame->nb_samples - (frame->nb_samples & 1); | |
364 | ||
365 | if (avctx->trellis) | |
366 | g722_encode_trellis(c, avctx->trellis, avpkt->data, nb_samples, samples); | |
367 | else | |
368 | g722_encode_no_trellis(c, avpkt->data, nb_samples, samples); | |
369 | ||
370 | /* handle last frame with odd frame_size */ | |
371 | if (nb_samples < frame->nb_samples) { | |
372 | int16_t last_samples[2] = { samples[nb_samples], samples[nb_samples] }; | |
373 | encode_byte(c, &avpkt->data[nb_samples >> 1], last_samples); | |
374 | } | |
375 | ||
376 | if (frame->pts != AV_NOPTS_VALUE) | |
f6fa7814 | 377 | avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding); |
2ba45a60 DM |
378 | *got_packet_ptr = 1; |
379 | return 0; | |
380 | } | |
381 | ||
382 | AVCodec ff_adpcm_g722_encoder = { | |
383 | .name = "g722", | |
384 | .long_name = NULL_IF_CONFIG_SMALL("G.722 ADPCM"), | |
385 | .type = AVMEDIA_TYPE_AUDIO, | |
386 | .id = AV_CODEC_ID_ADPCM_G722, | |
387 | .priv_data_size = sizeof(G722Context), | |
388 | .init = g722_encode_init, | |
389 | .close = g722_encode_close, | |
390 | .encode2 = g722_encode_frame, | |
391 | .capabilities = CODEC_CAP_SMALL_LAST_FRAME, | |
392 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, | |
393 | AV_SAMPLE_FMT_NONE }, | |
394 | }; |