FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/bonk.c
Date: 2023-12-04 05:51:44
Exec Total Coverage
Lines: 0 229 0.0%
Functions: 0 9 0.0%
Branches: 0 154 0.0%

Line Branch Exec Source
1 /*
2 * Bonk audio decoder
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "libavutil/internal.h"
22 #include "libavutil/intreadwrite.h"
23 #include "avcodec.h"
24 #include "codec_internal.h"
25 #include "decode.h"
26 #define BITSTREAM_READER_LE
27 #include "get_bits.h"
28 #include "bytestream.h"
29
30 typedef struct BitCount {
31 uint8_t bit;
32 unsigned count;
33 } BitCount;
34
35 typedef struct BonkContext {
36 GetBitContext gb;
37 int skip;
38
39 uint8_t *bitstream;
40 int64_t max_framesize;
41 int bitstream_size;
42 int bitstream_index;
43
44 uint64_t nb_samples;
45 int lossless;
46 int mid_side;
47 int n_taps;
48 int down_sampling;
49 int samples_per_packet;
50
51 int state[2][2048], k[2048];
52 int *samples[2];
53 int *input_samples;
54 uint8_t quant[2048];
55 BitCount *bits;
56 } BonkContext;
57
58 static av_cold int bonk_close(AVCodecContext *avctx)
59 {
60 BonkContext *s = avctx->priv_data;
61
62 av_freep(&s->bitstream);
63 av_freep(&s->input_samples);
64 av_freep(&s->samples[0]);
65 av_freep(&s->samples[1]);
66 av_freep(&s->bits);
67 s->bitstream_size = 0;
68
69 return 0;
70 }
71
72 static av_cold int bonk_init(AVCodecContext *avctx)
73 {
74 BonkContext *s = avctx->priv_data;
75
76 avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
77 if (avctx->extradata_size < 17)
78 return AVERROR(EINVAL);
79
80 if (avctx->extradata[0]) {
81 av_log(avctx, AV_LOG_ERROR, "Unsupported version.\n");
82 return AVERROR_INVALIDDATA;
83 }
84
85 if (avctx->ch_layout.nb_channels < 1 || avctx->ch_layout.nb_channels > 2)
86 return AVERROR_INVALIDDATA;
87
88 s->nb_samples = AV_RL32(avctx->extradata + 1) / avctx->ch_layout.nb_channels;
89 if (!s->nb_samples)
90 s->nb_samples = UINT64_MAX;
91 s->lossless = avctx->extradata[10] != 0;
92 s->mid_side = avctx->extradata[11] != 0;
93 s->n_taps = AV_RL16(avctx->extradata + 12);
94 if (!s->n_taps || s->n_taps > 2048)
95 return AVERROR(EINVAL);
96
97 s->down_sampling = avctx->extradata[14];
98 if (!s->down_sampling)
99 return AVERROR(EINVAL);
100
101 s->samples_per_packet = AV_RL16(avctx->extradata + 15);
102 if (!s->samples_per_packet)
103 return AVERROR(EINVAL);
104
105 if (s->down_sampling * s->samples_per_packet < s->n_taps)
106 return AVERROR_INVALIDDATA;
107
108 s->max_framesize = s->samples_per_packet * avctx->ch_layout.nb_channels * s->down_sampling * 16LL;
109 if (s->max_framesize > (INT32_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 8)
110 return AVERROR_INVALIDDATA;
111
112 s->bitstream = av_calloc(s->max_framesize + AV_INPUT_BUFFER_PADDING_SIZE, sizeof(*s->bitstream));
113 if (!s->bitstream)
114 return AVERROR(ENOMEM);
115
116 s->input_samples = av_calloc(s->samples_per_packet, sizeof(*s->input_samples));
117 if (!s->input_samples)
118 return AVERROR(ENOMEM);
119
120 s->samples[0] = av_calloc(s->samples_per_packet * s->down_sampling, sizeof(*s->samples[0]));
121 s->samples[1] = av_calloc(s->samples_per_packet * s->down_sampling, sizeof(*s->samples[0]));
122 if (!s->samples[0] || !s->samples[1])
123 return AVERROR(ENOMEM);
124
125 s->bits = av_calloc(s->max_framesize * 8, sizeof(*s->bits));
126 if (!s->bits)
127 return AVERROR(ENOMEM);
128
129 for (int i = 0; i < 512; i++) {
130 s->quant[i] = sqrt(i + 1);
131 }
132
133 return 0;
134 }
135
136 static unsigned read_uint_max(BonkContext *s, uint32_t max)
137 {
138 unsigned value = 0;
139
140 if (max == 0)
141 return 0;
142
143 av_assert0(max >> 31 == 0);
144
145 for (unsigned i = 1; i <= max - value; i+=i)
146 if (get_bits1(&s->gb))
147 value += i;
148
149 return value;
150 }
151
152 static int intlist_read(BonkContext *s, int *buf, int entries, int base_2_part)
153 {
154 int i, low_bits = 0, x = 0, max_x;
155 int n_zeros = 0, step = 256, dominant = 0;
156 int pos = 0, level = 0;
157 BitCount *bits = s->bits;
158 int passes = 1;
159
160 memset(buf, 0, entries * sizeof(*buf));
161 if (base_2_part) {
162 low_bits = get_bits(&s->gb, 4);
163
164 if (low_bits)
165 for (i = 0; i < entries; i++)
166 buf[i] = get_bits(&s->gb, low_bits);
167 }
168
169 while (n_zeros < entries) {
170 int steplet = step >> 8;
171
172 if (get_bits_left(&s->gb) <= 0)
173 return AVERROR_INVALIDDATA;
174
175 if (!get_bits1(&s->gb)) {
176 av_assert0(steplet >= 0);
177
178 if (steplet > 0) {
179 bits[x ].bit = dominant;
180 bits[x++].count = steplet;
181 }
182
183 if (!dominant)
184 n_zeros += steplet;
185
186 if (step > INT32_MAX*8LL/9 + 1)
187 return AVERROR_INVALIDDATA;
188 step += step / 8;
189 } else if (steplet > 0) {
190 int actual_run = read_uint_max(s, steplet - 1);
191
192 av_assert0(actual_run >= 0);
193
194 if (actual_run > 0) {
195 bits[x ].bit = dominant;
196 bits[x++].count = actual_run;
197 }
198
199 bits[x ].bit = !dominant;
200 bits[x++].count = 1;
201
202 if (!dominant)
203 n_zeros += actual_run;
204 else
205 n_zeros++;
206
207 step -= step / 8;
208 }
209
210 if (step < 256) {
211 step = 65536 / step;
212 dominant = !dominant;
213 }
214 }
215
216 max_x = x;
217 x = 0;
218 n_zeros = 0;
219 for (i = 0; n_zeros < entries; i++) {
220 if (x >= max_x)
221 return AVERROR_INVALIDDATA;
222
223 if (pos >= entries) {
224 pos = 0;
225 level += passes << low_bits;
226 passes = 1;
227 if (bits[x].bit && bits[x].count > entries - n_zeros)
228 passes = bits[x].count / (entries - n_zeros);
229 }
230
231 if (level > 1 << 16)
232 return AVERROR_INVALIDDATA;
233
234 if (buf[pos] >= level) {
235 if (bits[x].bit)
236 buf[pos] += passes << low_bits;
237 else
238 n_zeros++;
239
240 av_assert1(bits[x].count >= passes);
241 bits[x].count -= passes;
242 x += bits[x].count == 0;
243 }
244
245 pos++;
246 }
247
248 for (i = 0; i < entries; i++) {
249 if (buf[i] && get_bits1(&s->gb)) {
250 buf[i] = -buf[i];
251 }
252 }
253
254 return 0;
255 }
256
257 static inline int shift_down(int a, int b)
258 {
259 return (a >> b) + (a < 0);
260 }
261
262 static inline int shift(int a, int b)
263 {
264 return a + (1 << b - 1) >> b;
265 }
266
267 #define LATTICE_SHIFT 10
268 #define SAMPLE_SHIFT 4
269 #define SAMPLE_FACTOR (1 << SAMPLE_SHIFT)
270
271 static int predictor_calc_error(int *k, int *state, int order, int error)
272 {
273 int i, x = error - (unsigned)shift_down(k[order-1] * (unsigned)state[order-1], LATTICE_SHIFT);
274 int *k_ptr = &(k[order-2]),
275 *state_ptr = &(state[order-2]);
276
277 for (i = order-2; i >= 0; i--, k_ptr--, state_ptr--) {
278 unsigned k_value = *k_ptr, state_value = *state_ptr;
279
280 x -= (unsigned) shift_down(k_value * (unsigned)state_value, LATTICE_SHIFT);
281 state_ptr[1] = state_value + shift_down(k_value * x, LATTICE_SHIFT);
282 }
283
284 // don't drift too far, to avoid overflows
285 x = av_clip(x, -(SAMPLE_FACTOR << 16), SAMPLE_FACTOR << 16);
286
287 state[0] = x;
288
289 return x;
290 }
291
292 static void predictor_init_state(int *k, unsigned *state, int order)
293 {
294 for (int i = order - 2; i >= 0; i--) {
295 unsigned x = state[i];
296
297 for (int j = 0, p = i + 1; p < order; j++, p++) {
298 int tmp = x + shift_down(k[j] * state[p], LATTICE_SHIFT);
299
300 state[p] += shift_down(k[j] * x, LATTICE_SHIFT);
301 x = tmp;
302 }
303 }
304 }
305
306 static int bonk_decode(AVCodecContext *avctx, AVFrame *frame,
307 int *got_frame_ptr, AVPacket *pkt)
308 {
309 BonkContext *s = avctx->priv_data;
310 GetBitContext *gb = &s->gb;
311 const uint8_t *buf;
312 int quant, n, buf_size, input_buf_size;
313 int ret = AVERROR_INVALIDDATA;
314
315 if ((!pkt->size && !s->bitstream_size) || s->nb_samples == 0) {
316 *got_frame_ptr = 0;
317 return pkt->size;
318 }
319
320 buf_size = FFMIN(pkt->size, s->max_framesize - s->bitstream_size);
321 input_buf_size = buf_size;
322 if (s->bitstream_index + s->bitstream_size + buf_size + AV_INPUT_BUFFER_PADDING_SIZE > s->max_framesize) {
323 memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
324 s->bitstream_index = 0;
325 }
326 if (pkt->data)
327 memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], pkt->data, buf_size);
328 buf = &s->bitstream[s->bitstream_index];
329 buf_size += s->bitstream_size;
330 s->bitstream_size = buf_size;
331 if (buf_size < s->max_framesize && pkt->data) {
332 *got_frame_ptr = 0;
333 return input_buf_size;
334 }
335
336 frame->nb_samples = FFMIN(s->samples_per_packet * s->down_sampling, s->nb_samples);
337 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
338 goto fail;
339
340 if ((ret = init_get_bits8(gb, buf, buf_size)) < 0)
341 goto fail;
342
343 skip_bits(gb, s->skip);
344 if ((ret = intlist_read(s, s->k, s->n_taps, 0)) < 0)
345 goto fail;
346
347 for (int i = 0; i < s->n_taps; i++)
348 s->k[i] *= s->quant[i];
349 quant = s->lossless ? 1 : get_bits(&s->gb, 16) * SAMPLE_FACTOR;
350
351 for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) {
352 const int samples_per_packet = s->samples_per_packet;
353 const int down_sampling = s->down_sampling;
354 const int offset = samples_per_packet * down_sampling - 1;
355 int *state = s->state[ch];
356 int *sample = s->samples[ch];
357
358 predictor_init_state(s->k, state, s->n_taps);
359 if ((ret = intlist_read(s, s->input_samples, samples_per_packet, 1)) < 0)
360 goto fail;
361
362 for (int i = 0; i < samples_per_packet; i++) {
363 for (int j = 0; j < s->down_sampling - 1; j++) {
364 sample[0] = predictor_calc_error(s->k, state, s->n_taps, 0);
365 sample++;
366 }
367
368 sample[0] = predictor_calc_error(s->k, state, s->n_taps, s->input_samples[i] * (unsigned)quant);
369 sample++;
370 }
371
372 sample = s->samples[ch];
373 for (int i = 0; i < s->n_taps; i++)
374 state[i] = sample[offset - i];
375 }
376
377 if (s->mid_side && avctx->ch_layout.nb_channels == 2) {
378 for (int i = 0; i < frame->nb_samples; i++) {
379 s->samples[1][i] += shift(s->samples[0][i], 1);
380 s->samples[0][i] -= s->samples[1][i];
381 }
382 }
383
384 if (!s->lossless) {
385 for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) {
386 int *samples = s->samples[ch];
387 for (int i = 0; i < frame->nb_samples; i++)
388 samples[i] = shift(samples[i], 4);
389 }
390 }
391
392 for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) {
393 int16_t *osamples = (int16_t *)frame->extended_data[ch];
394 int *samples = s->samples[ch];
395 for (int i = 0; i < frame->nb_samples; i++)
396 osamples[i] = av_clip_int16(samples[i]);
397 }
398
399 s->nb_samples -= frame->nb_samples;
400
401 s->skip = get_bits_count(gb) - 8 * (get_bits_count(gb) / 8);
402 n = get_bits_count(gb) / 8;
403
404 if (n > buf_size) {
405 fail:
406 s->bitstream_size = 0;
407 s->bitstream_index = 0;
408 return AVERROR_INVALIDDATA;
409 }
410
411 *got_frame_ptr = 1;
412
413 if (s->bitstream_size) {
414 s->bitstream_index += n;
415 s->bitstream_size -= n;
416 return input_buf_size;
417 }
418 return n;
419 }
420
421 const FFCodec ff_bonk_decoder = {
422 .p.name = "bonk",
423 CODEC_LONG_NAME("Bonk audio"),
424 .p.type = AVMEDIA_TYPE_AUDIO,
425 .p.id = AV_CODEC_ID_BONK,
426 .priv_data_size = sizeof(BonkContext),
427 .init = bonk_init,
428 FF_CODEC_DECODE_CB(bonk_decode),
429 .close = bonk_close,
430 .p.capabilities = AV_CODEC_CAP_DELAY |
431 #if FF_API_SUBFRAMES
432 AV_CODEC_CAP_SUBFRAMES |
433 #endif
434 AV_CODEC_CAP_DR1,
435 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
436 .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
437 AV_SAMPLE_FMT_NONE },
438 };
439