1 /*
2 * Musepack SV8 decoder
3 * Copyright (c) 2007 Konstantin Shishkov
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
22 /**
23 * @file
24 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
25 * divided into 32 subbands.
26 */
27
28 #include "libavutil/channel_layout.h"
29 #include "libavutil/lfg.h"
30 #include "libavutil/thread.h"
31 #include "avcodec.h"
32 #include "get_bits.h"
33 #include "internal.h"
34 #include "mpegaudiodsp.h"
35
36 #include "mpc.h"
37 #include "mpc8data.h"
38 #include "mpc8huff.h"
39
40 static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
41 static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
42
mpc8_dec_base(GetBitContext * gb,int k,int n)43 static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
44 {
45 int len = mpc8_cnk_len[k-1][n-1] - 1;
46 int code = len ? get_bits_long(gb, len) : 0;
47
48 if (code >= mpc8_cnk_lost[k-1][n-1])
49 code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
50
51 return code;
52 }
53
mpc8_dec_enum(GetBitContext * gb,int k,int n)54 static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
55 {
56 int bits = 0;
57 const uint32_t * C = mpc8_cnk[k-1];
58 int code = mpc8_dec_base(gb, k, n);
59
60 do {
61 n--;
62 if (code >= C[n]) {
63 bits |= 1U << n;
64 code -= C[n];
65 C -= 32;
66 k--;
67 }
68 } while(k > 0);
69
70 return bits;
71 }
72
mpc8_get_mod_golomb(GetBitContext * gb,int m)73 static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
74 {
75 if(mpc8_cnk_len[0][m] < 1) return 0;
76 return mpc8_dec_base(gb, 1, m+1);
77 }
78
mpc8_get_mask(GetBitContext * gb,int size,int t)79 static int mpc8_get_mask(GetBitContext *gb, int size, int t)
80 {
81 int mask = 0;
82
83 if(t && t != size)
84 mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
85 if((t << 1) > size) mask = ~mask;
86
87 return mask;
88 }
89
build_vlc(VLC * vlc,unsigned * buf_offset,const uint8_t codes_counts[16],const uint8_t ** syms,int offset)90 static av_cold void build_vlc(VLC *vlc, unsigned *buf_offset,
91 const uint8_t codes_counts[16],
92 const uint8_t **syms, int offset)
93 {
94 static VLC_TYPE vlc_buf[9296][2];
95 uint8_t len[MPC8_MAX_VLC_SIZE];
96 unsigned num = 0;
97
98 vlc->table = &vlc_buf[*buf_offset];
99 vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *buf_offset;
100
101 for (int i = 16; i > 0; i--)
102 for (unsigned tmp = num + codes_counts[i - 1]; num < tmp; num++)
103 len[num] = i;
104
105 ff_init_vlc_from_lengths(vlc, FFMIN(len[0], 9), num, len, 1,
106 *syms, 1, 1, offset, INIT_VLC_STATIC_OVERLONG, NULL);
107 *buf_offset += vlc->table_size;
108 *syms += num;
109 }
110
mpc8_init_static(void)111 static av_cold void mpc8_init_static(void)
112 {
113 const uint8_t *q_syms = mpc8_q_syms, *bands_syms = mpc8_bands_syms;
114 const uint8_t *res_syms = mpc8_res_syms, *scfi_syms = mpc8_scfi_syms;
115 const uint8_t *dscf_syms = mpc8_dscf_syms;
116 unsigned offset = 0;
117
118 build_vlc(&band_vlc, &offset, mpc8_bands_len_counts, &bands_syms, 0);
119
120 build_vlc(&q1_vlc, &offset, mpc8_q1_len_counts, &q_syms, 0);
121 build_vlc(&q9up_vlc, &offset, mpc8_q9up_len_counts, &q_syms, 0);
122
123 for (int i = 0; i < 2; i++){
124 build_vlc(&scfi_vlc[i], &offset, mpc8_scfi_len_counts[i], &scfi_syms, 0);
125
126 build_vlc(&dscf_vlc[i], &offset, mpc8_dscf_len_counts[i], &dscf_syms, 0);
127
128 build_vlc(&res_vlc[i], &offset, mpc8_res_len_counts[i], &res_syms, 0);
129
130 build_vlc(&q2_vlc[i], &offset, mpc8_q2_len_counts[i], &q_syms, 0);
131 build_vlc(&q3_vlc[i], &offset, mpc8_q34_len_counts[i],
132 &q_syms, -48 - 16 * i);
133 for (int j = 0; j < 4; j++)
134 build_vlc(&quant_vlc[j][i], &offset, mpc8_q5_8_len_counts[i][j],
135 &q_syms, -((8 << j) - 1));
136 }
137 ff_mpa_synth_init_fixed();
138 }
139
mpc8_decode_init(AVCodecContext * avctx)140 static av_cold int mpc8_decode_init(AVCodecContext * avctx)
141 {
142 static AVOnce init_static_once = AV_ONCE_INIT;
143 MPCContext *c = avctx->priv_data;
144 GetBitContext gb;
145 int channels;
146
147 if(avctx->extradata_size < 2){
148 av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
149 return -1;
150 }
151 memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
152 av_lfg_init(&c->rnd, 0xDEADBEEF);
153 ff_mpadsp_init(&c->mpadsp);
154
155 init_get_bits(&gb, avctx->extradata, 16);
156
157 skip_bits(&gb, 3);//sample rate
158 c->maxbands = get_bits(&gb, 5) + 1;
159 if (c->maxbands >= BANDS) {
160 av_log(avctx,AV_LOG_ERROR, "maxbands %d too high\n", c->maxbands);
161 return AVERROR_INVALIDDATA;
162 }
163 channels = get_bits(&gb, 4) + 1;
164 if (channels > 2) {
165 avpriv_request_sample(avctx, "Multichannel MPC SV8");
166 return AVERROR_PATCHWELCOME;
167 }
168 c->MSS = get_bits1(&gb);
169 c->frames = 1 << (get_bits(&gb, 3) * 2);
170
171 avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
172 avctx->channel_layout = (channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
173 avctx->channels = channels;
174
175 ff_thread_once(&init_static_once, mpc8_init_static);
176
177 return 0;
178 }
179
mpc8_decode_frame(AVCodecContext * avctx,void * data,int * got_frame_ptr,AVPacket * avpkt)180 static int mpc8_decode_frame(AVCodecContext * avctx, void *data,
181 int *got_frame_ptr, AVPacket *avpkt)
182 {
183 AVFrame *frame = data;
184 const uint8_t *buf = avpkt->data;
185 int buf_size = avpkt->size;
186 MPCContext *c = avctx->priv_data;
187 GetBitContext gb2, *gb = &gb2;
188 int i, j, k, ch, cnt, res, t;
189 Band *bands = c->bands;
190 int off;
191 int maxband, keyframe;
192 int last[2];
193
194 keyframe = c->cur_frame == 0;
195
196 if(keyframe){
197 memset(c->Q, 0, sizeof(c->Q));
198 c->last_bits_used = 0;
199 }
200 if ((res = init_get_bits8(gb, buf, buf_size)) < 0)
201 return res;
202
203 skip_bits(gb, c->last_bits_used & 7);
204
205 if(keyframe)
206 maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
207 else{
208 maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
209 if(maxband > 32) maxband -= 33;
210 }
211
212 if (get_bits_left(gb) < 0) {
213 *got_frame_ptr = 0;
214 return buf_size;
215 }
216
217 if(maxband > c->maxbands + 1) {
218 av_log(avctx, AV_LOG_ERROR, "maxband %d too large\n",maxband);
219 return AVERROR_INVALIDDATA;
220 }
221 c->last_max_band = maxband;
222
223 /* read subband indexes */
224 if(maxband){
225 last[0] = last[1] = 0;
226 for(i = maxband - 1; i >= 0; i--){
227 for(ch = 0; ch < 2; ch++){
228 last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
229 if(last[ch] > 15) last[ch] -= 17;
230 bands[i].res[ch] = last[ch];
231 }
232 }
233 if(c->MSS){
234 int mask;
235
236 cnt = 0;
237 for(i = 0; i < maxband; i++)
238 if(bands[i].res[0] || bands[i].res[1])
239 cnt++;
240 t = mpc8_get_mod_golomb(gb, cnt);
241 mask = mpc8_get_mask(gb, cnt, t);
242 for(i = maxband - 1; i >= 0; i--)
243 if(bands[i].res[0] || bands[i].res[1]){
244 bands[i].msf = mask & 1;
245 mask >>= 1;
246 }
247 }
248 }
249 for(i = maxband; i < c->maxbands; i++)
250 bands[i].res[0] = bands[i].res[1] = 0;
251
252 if(keyframe){
253 for(i = 0; i < 32; i++)
254 c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
255 }
256
257 for(i = 0; i < maxband; i++){
258 if(bands[i].res[0] || bands[i].res[1]){
259 cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
260 if(cnt >= 0){
261 t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
262 if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
263 if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
264 }
265 }
266 }
267
268 for(i = 0; i < maxband; i++){
269 for(ch = 0; ch < 2; ch++){
270 if(!bands[i].res[ch]) continue;
271
272 if(c->oldDSCF[ch][i]){
273 bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
274 c->oldDSCF[ch][i] = 0;
275 }else{
276 t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
277 if(t == 64)
278 t += get_bits(gb, 6);
279 bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
280 }
281 for(j = 0; j < 2; j++){
282 if((bands[i].scfi[ch] << j) & 2)
283 bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
284 else{
285 t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
286 if(t == 31)
287 t = 64 + get_bits(gb, 6);
288 bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
289 }
290 }
291 }
292 }
293
294 for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
295 for(ch = 0; ch < 2; ch++){
296 res = bands[i].res[ch];
297 switch(res){
298 case -1:
299 for(j = 0; j < SAMPLES_PER_BAND; j++)
300 c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
301 break;
302 case 0:
303 break;
304 case 1:
305 for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
306 cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
307 t = mpc8_get_mask(gb, 18, cnt);
308 for(k = 0; k < SAMPLES_PER_BAND / 2; k++)
309 c->Q[ch][off + j + k] = t & (1 << (SAMPLES_PER_BAND / 2 - k - 1))
310 ? (get_bits1(gb) << 1) - 1 : 0;
311 }
312 break;
313 case 2:
314 cnt = 6;//2*mpc8_thres[res]
315 for(j = 0; j < SAMPLES_PER_BAND; j += 3){
316 t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
317 c->Q[ch][off + j + 0] = mpc8_idx50[t];
318 c->Q[ch][off + j + 1] = mpc8_idx51[t];
319 c->Q[ch][off + j + 2] = mpc8_idx52[t];
320 cnt = (cnt >> 1) + mpc8_huffq2[t];
321 }
322 break;
323 case 3:
324 case 4:
325 for(j = 0; j < SAMPLES_PER_BAND; j += 2){
326 t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2);
327 c->Q[ch][off + j + 1] = t >> 4;
328 c->Q[ch][off + j + 0] = sign_extend(t, 4);
329 }
330 break;
331 case 5:
332 case 6:
333 case 7:
334 case 8:
335 cnt = 2 * mpc8_thres[res];
336 for(j = 0; j < SAMPLES_PER_BAND; j++){
337 const VLC *vlc = &quant_vlc[res - 5][cnt > mpc8_thres[res]];
338 c->Q[ch][off + j] = get_vlc2(gb, vlc->table, vlc->bits, 2);
339 cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
340 }
341 break;
342 default:
343 for(j = 0; j < SAMPLES_PER_BAND; j++){
344 c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
345 if(res != 9){
346 c->Q[ch][off + j] <<= res - 9;
347 c->Q[ch][off + j] |= get_bits(gb, res - 9);
348 }
349 c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
350 }
351 }
352 }
353 }
354
355 frame->nb_samples = MPC_FRAME_SIZE;
356 if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
357 return res;
358
359 ff_mpc_dequantize_and_synth(c, maxband - 1,
360 (int16_t **)frame->extended_data,
361 avctx->channels);
362
363 c->cur_frame++;
364
365 c->last_bits_used = get_bits_count(gb);
366 if(c->cur_frame >= c->frames)
367 c->cur_frame = 0;
368 if (get_bits_left(gb) < 0) {
369 av_log(avctx, AV_LOG_ERROR, "Overread %d\n", -get_bits_left(gb));
370 c->last_bits_used = buf_size << 3;
371 } else if (c->cur_frame == 0 && get_bits_left(gb) < 8) {// we have only padding left
372 c->last_bits_used = buf_size << 3;
373 }
374
375 *got_frame_ptr = 1;
376
377 return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
378 }
379
mpc8_decode_flush(AVCodecContext * avctx)380 static av_cold void mpc8_decode_flush(AVCodecContext *avctx)
381 {
382 MPCContext *c = avctx->priv_data;
383 c->cur_frame = 0;
384 }
385
386 AVCodec ff_mpc8_decoder = {
387 .name = "mpc8",
388 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
389 .type = AVMEDIA_TYPE_AUDIO,
390 .id = AV_CODEC_ID_MUSEPACK8,
391 .priv_data_size = sizeof(MPCContext),
392 .init = mpc8_decode_init,
393 .decode = mpc8_decode_frame,
394 .flush = mpc8_decode_flush,
395 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
396 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
397 AV_SAMPLE_FMT_NONE },
398 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
399 };
400