Libav
mpc7.c
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1 /*
2  * Musepack SV7 decoder
3  * Copyright (c) 2006 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
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.
11  *
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.
16  *
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
20  */
21 
29 #include "libavutil/internal.h"
30 #include "libavutil/lfg.h"
31 #include "avcodec.h"
32 #include "get_bits.h"
33 #include "dsputil.h"
34 #include "internal.h"
35 #include "mpegaudiodsp.h"
36 
37 #include "mpc.h"
38 #include "mpc7data.h"
39 
40 #define BANDS 32
41 #define SAMPLES_PER_BAND 36
42 #define MPC_FRAME_SIZE (BANDS * SAMPLES_PER_BAND)
43 
45 
46 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
47 {
48  0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
49  5636, 6164, 6676, 7224
50 };
51 
52 
54 {
55  int i, j;
56  MPCContext *c = avctx->priv_data;
57  GetBitContext gb;
58  LOCAL_ALIGNED_16(uint8_t, buf, [16]);
59  static int vlc_initialized = 0;
60 
61  static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
62  static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
63  static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
64  static VLC_TYPE quant_tables[7224][2];
65 
66  /* Musepack SV7 is always stereo */
67  if (avctx->channels != 2) {
68  avpriv_request_sample(avctx, "%d channels", avctx->channels);
69  return AVERROR_PATCHWELCOME;
70  }
71 
72  if(avctx->extradata_size < 16){
73  av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
74  return -1;
75  }
76  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
77  av_lfg_init(&c->rnd, 0xDEADBEEF);
78  ff_dsputil_init(&c->dsp, avctx);
80  c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
81  ff_mpc_init();
82  init_get_bits(&gb, buf, 128);
83 
84  c->IS = get_bits1(&gb);
85  c->MSS = get_bits1(&gb);
86  c->maxbands = get_bits(&gb, 6);
87  if(c->maxbands >= BANDS){
88  av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
89  return -1;
90  }
91  skip_bits_long(&gb, 88);
92  c->gapless = get_bits1(&gb);
93  c->lastframelen = get_bits(&gb, 11);
94  av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
95  c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
96  c->frames_to_skip = 0;
97 
100 
101  if(vlc_initialized) return 0;
102  av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
103  scfi_vlc.table = scfi_table;
104  scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
105  if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
106  &mpc7_scfi[1], 2, 1,
107  &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
108  av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
109  return -1;
110  }
111  dscf_vlc.table = dscf_table;
112  dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
113  if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
114  &mpc7_dscf[1], 2, 1,
115  &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
116  av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
117  return -1;
118  }
119  hdr_vlc.table = hdr_table;
120  hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
121  if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
122  &mpc7_hdr[1], 2, 1,
123  &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
124  av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
125  return -1;
126  }
127  for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
128  for(j = 0; j < 2; j++){
129  quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
130  quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
131  if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
132  &mpc7_quant_vlc[i][j][1], 4, 2,
133  &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
134  av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
135  return -1;
136  }
137  }
138  }
139  vlc_initialized = 1;
140 
141  return 0;
142 }
143 
147 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
148 {
149  int i, i1, t;
150  switch(idx){
151  case -1:
152  for(i = 0; i < SAMPLES_PER_BAND; i++){
153  *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
154  }
155  break;
156  case 1:
157  i1 = get_bits1(gb);
158  for(i = 0; i < SAMPLES_PER_BAND/3; i++){
159  t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
160  *dst++ = mpc7_idx30[t];
161  *dst++ = mpc7_idx31[t];
162  *dst++ = mpc7_idx32[t];
163  }
164  break;
165  case 2:
166  i1 = get_bits1(gb);
167  for(i = 0; i < SAMPLES_PER_BAND/2; i++){
168  t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
169  *dst++ = mpc7_idx50[t];
170  *dst++ = mpc7_idx51[t];
171  }
172  break;
173  case 3: case 4: case 5: case 6: case 7:
174  i1 = get_bits1(gb);
175  for(i = 0; i < SAMPLES_PER_BAND; i++)
176  *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
177  break;
178  case 8: case 9: case 10: case 11: case 12:
179  case 13: case 14: case 15: case 16: case 17:
180  t = (1 << (idx - 2)) - 1;
181  for(i = 0; i < SAMPLES_PER_BAND; i++)
182  *dst++ = get_bits(gb, idx - 1) - t;
183  break;
184  default: // case 0 and -2..-17
185  return;
186  }
187 }
188 
189 static int get_scale_idx(GetBitContext *gb, int ref)
190 {
191  int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
192  if (t == 8)
193  return get_bits(gb, 6);
194  return av_clip_uintp2(ref + t, 7);
195 }
196 
197 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
198  int *got_frame_ptr, AVPacket *avpkt)
199 {
200  AVFrame *frame = data;
201  const uint8_t *buf = avpkt->data;
202  int buf_size;
203  MPCContext *c = avctx->priv_data;
204  GetBitContext gb;
205  int i, ch;
206  int mb = -1;
207  Band *bands = c->bands;
208  int off, ret, last_frame, skip;
209  int bits_used, bits_avail;
210 
211  memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
212 
213  buf_size = avpkt->size & ~3;
214  if (buf_size <= 0) {
215  av_log(avctx, AV_LOG_ERROR, "packet size is too small (%i bytes)\n",
216  avpkt->size);
217  return AVERROR_INVALIDDATA;
218  }
219  if (buf_size != avpkt->size) {
220  av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
221  "extra bytes at the end will be skipped.\n");
222  }
223 
224  skip = buf[0];
225  last_frame = buf[1];
226  buf += 4;
227  buf_size -= 4;
228 
229  /* get output buffer */
230  frame->nb_samples = last_frame ? c->lastframelen : MPC_FRAME_SIZE;
231  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
232  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
233  return ret;
234  }
235 
236  av_fast_padded_malloc(&c->bits, &c->buf_size, buf_size);
237  if (!c->bits)
238  return AVERROR(ENOMEM);
239  c->dsp.bswap_buf((uint32_t *)c->bits, (const uint32_t *)buf, buf_size >> 2);
240  init_get_bits(&gb, c->bits, buf_size * 8);
241  skip_bits_long(&gb, skip);
242 
243  /* read subband indexes */
244  for(i = 0; i <= c->maxbands; i++){
245  for(ch = 0; ch < 2; ch++){
246  int t = 4;
247  if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
248  if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
249  else bands[i].res[ch] = av_clip(bands[i-1].res[ch] + t, 0, 17);
250  }
251 
252  if(bands[i].res[0] || bands[i].res[1]){
253  mb = i;
254  if(c->MSS) bands[i].msf = get_bits1(&gb);
255  }
256  }
257  /* get scale indexes coding method */
258  for(i = 0; i <= mb; i++)
259  for(ch = 0; ch < 2; ch++)
260  if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
261  /* get scale indexes */
262  for(i = 0; i <= mb; i++){
263  for(ch = 0; ch < 2; ch++){
264  if(bands[i].res[ch]){
265  bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
266  bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
267  switch(bands[i].scfi[ch]){
268  case 0:
269  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
270  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
271  break;
272  case 1:
273  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
274  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
275  break;
276  case 2:
277  bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
278  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
279  break;
280  case 3:
281  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
282  break;
283  }
284  c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
285  }
286  }
287  }
288  /* get quantizers */
289  memset(c->Q, 0, sizeof(c->Q));
290  off = 0;
291  for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
292  for(ch = 0; ch < 2; ch++)
293  idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
294 
295  ff_mpc_dequantize_and_synth(c, mb, (int16_t **)frame->extended_data, 2);
296 
297  bits_used = get_bits_count(&gb);
298  bits_avail = buf_size * 8;
299  if (!last_frame && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))) {
300  av_log(avctx, AV_LOG_ERROR, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
301  return -1;
302  }
303  if(c->frames_to_skip){
304  c->frames_to_skip--;
305  *got_frame_ptr = 0;
306  return avpkt->size;
307  }
308 
309  *got_frame_ptr = 1;
310 
311  return avpkt->size;
312 }
313 
315 {
316  MPCContext *c = avctx->priv_data;
317 
318  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
319  c->frames_to_skip = 32;
320 }
321 
323 {
324  MPCContext *c = avctx->priv_data;
325  av_freep(&c->bits);
326  c->buf_size = 0;
327  return 0;
328 }
329 
331  .name = "mpc7",
332  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
333  .type = AVMEDIA_TYPE_AUDIO,
334  .id = AV_CODEC_ID_MUSEPACK7,
335  .priv_data_size = sizeof(MPCContext),
340  .capabilities = CODEC_CAP_DR1,
341  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
343 };