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 
28 #include "libavutil/lfg.h"
29 #include "avcodec.h"
30 #include "internal.h"
31 #include "get_bits.h"
32 #include "dsputil.h"
33 #include "mpegaudiodsp.h"
34 #include "libavutil/audioconvert.h"
35 
36 #include "mpc.h"
37 #include "mpc7data.h"
38 
39 #define BANDS 32
40 #define SAMPLES_PER_BAND 36
41 #define MPC_FRAME_SIZE (BANDS * SAMPLES_PER_BAND)
42 
44 
45 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
46 {
47  0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
48  5636, 6164, 6676, 7224
49 };
50 
51 
53 {
54  int i, j;
55  MPCContext *c = avctx->priv_data;
56  GetBitContext gb;
57  uint8_t buf[16];
58  static int vlc_initialized = 0;
59 
60  static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
61  static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
62  static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
63  static VLC_TYPE quant_tables[7224][2];
64 
65  /* Musepack SV7 is always stereo */
66  if (avctx->channels != 2) {
67  av_log_ask_for_sample(avctx, "Unsupported number of channels: %d\n",
68  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  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 
142  avctx->coded_frame = &c->frame;
143 
144  return 0;
145 }
146 
150 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
151 {
152  int i, i1, t;
153  switch(idx){
154  case -1:
155  for(i = 0; i < SAMPLES_PER_BAND; i++){
156  *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
157  }
158  break;
159  case 1:
160  i1 = get_bits1(gb);
161  for(i = 0; i < SAMPLES_PER_BAND/3; i++){
162  t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
163  *dst++ = mpc7_idx30[t];
164  *dst++ = mpc7_idx31[t];
165  *dst++ = mpc7_idx32[t];
166  }
167  break;
168  case 2:
169  i1 = get_bits1(gb);
170  for(i = 0; i < SAMPLES_PER_BAND/2; i++){
171  t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
172  *dst++ = mpc7_idx50[t];
173  *dst++ = mpc7_idx51[t];
174  }
175  break;
176  case 3: case 4: case 5: case 6: case 7:
177  i1 = get_bits1(gb);
178  for(i = 0; i < SAMPLES_PER_BAND; i++)
179  *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
180  break;
181  case 8: case 9: case 10: case 11: case 12:
182  case 13: case 14: case 15: case 16: case 17:
183  t = (1 << (idx - 2)) - 1;
184  for(i = 0; i < SAMPLES_PER_BAND; i++)
185  *dst++ = get_bits(gb, idx - 1) - t;
186  break;
187  default: // case 0 and -2..-17
188  return;
189  }
190 }
191 
192 static int get_scale_idx(GetBitContext *gb, int ref)
193 {
194  int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
195  if (t == 8)
196  return get_bits(gb, 6);
197  return av_clip_uintp2(ref + t, 7);
198 }
199 
200 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
201  int *got_frame_ptr, AVPacket *avpkt)
202 {
203  const uint8_t *buf = avpkt->data;
204  int buf_size = avpkt->size;
205  MPCContext *c = avctx->priv_data;
206  GetBitContext gb;
207  uint8_t *bits;
208  int i, ch;
209  int mb = -1;
210  Band *bands = c->bands;
211  int off, ret;
212  int bits_used, bits_avail;
213 
214  memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
215  if(buf_size <= 4){
216  av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);
217  return AVERROR(EINVAL);
218  }
219 
220  /* get output buffer */
221  c->frame.nb_samples = buf[1] ? c->lastframelen : MPC_FRAME_SIZE;
222  if ((ret = ff_get_buffer(avctx, &c->frame)) < 0) {
223  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
224  return ret;
225  }
226 
227  bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);
228  c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);
229  init_get_bits(&gb, bits, (buf_size - 4)* 8);
230  skip_bits_long(&gb, buf[0]);
231 
232  /* read subband indexes */
233  for(i = 0; i <= c->maxbands; i++){
234  for(ch = 0; ch < 2; ch++){
235  int t = 4;
236  if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
237  if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
238  else bands[i].res[ch] = av_clip(bands[i-1].res[ch] + t, 0, 17);
239  }
240 
241  if(bands[i].res[0] || bands[i].res[1]){
242  mb = i;
243  if(c->MSS) bands[i].msf = get_bits1(&gb);
244  }
245  }
246  /* get scale indexes coding method */
247  for(i = 0; i <= mb; i++)
248  for(ch = 0; ch < 2; ch++)
249  if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
250  /* get scale indexes */
251  for(i = 0; i <= mb; i++){
252  for(ch = 0; ch < 2; ch++){
253  if(bands[i].res[ch]){
254  bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
255  bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
256  switch(bands[i].scfi[ch]){
257  case 0:
258  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
259  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
260  break;
261  case 1:
262  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
263  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
264  break;
265  case 2:
266  bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
267  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
268  break;
269  case 3:
270  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
271  break;
272  }
273  c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
274  }
275  }
276  }
277  /* get quantizers */
278  memset(c->Q, 0, sizeof(c->Q));
279  off = 0;
280  for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
281  for(ch = 0; ch < 2; ch++)
282  idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
283 
284  ff_mpc_dequantize_and_synth(c, mb, c->frame.data[0], 2);
285 
286  av_free(bits);
287 
288  bits_used = get_bits_count(&gb);
289  bits_avail = (buf_size - 4) * 8;
290  if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){
291  av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
292  return -1;
293  }
294  if(c->frames_to_skip){
295  c->frames_to_skip--;
296  *got_frame_ptr = 0;
297  return buf_size;
298  }
299 
300  *got_frame_ptr = 1;
301  *(AVFrame *)data = c->frame;
302 
303  return buf_size;
304 }
305 
307 {
308  MPCContext *c = avctx->priv_data;
309 
310  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
311  c->frames_to_skip = 32;
312 }
313 
315  .name = "mpc7",
316  .type = AVMEDIA_TYPE_AUDIO,
317  .id = CODEC_ID_MUSEPACK7,
318  .priv_data_size = sizeof(MPCContext),
322  .capabilities = CODEC_CAP_DR1,
323  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
324 };