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 "get_bits.h"
31 #include "dsputil.h"
32 #include "mpegaudiodsp.h"
33 #include "libavutil/audioconvert.h"
34 
35 #include "mpc.h"
36 #include "mpc7data.h"
37 
38 #define BANDS 32
39 #define SAMPLES_PER_BAND 36
40 #define MPC_FRAME_SIZE (BANDS * SAMPLES_PER_BAND)
41 
43 
44 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
45 {
46  0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
47  5636, 6164, 6676, 7224
48 };
49 
50 
52 {
53  int i, j;
54  MPCContext *c = avctx->priv_data;
55  GetBitContext gb;
56  uint8_t buf[16];
57  static int vlc_initialized = 0;
58 
59  static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
60  static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
61  static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
62  static VLC_TYPE quant_tables[7224][2];
63 
64  /* Musepack SV7 is always stereo */
65  if (avctx->channels != 2) {
66  av_log_ask_for_sample(avctx, "Unsupported number of channels: %d\n",
67  avctx->channels);
68  return AVERROR_PATCHWELCOME;
69  }
70 
71  if(avctx->extradata_size < 16){
72  av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
73  return -1;
74  }
75  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
76  av_lfg_init(&c->rnd, 0xDEADBEEF);
77  dsputil_init(&c->dsp, avctx);
79  c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
80  ff_mpc_init();
81  init_get_bits(&gb, buf, 128);
82 
83  c->IS = get_bits1(&gb);
84  c->MSS = get_bits1(&gb);
85  c->maxbands = get_bits(&gb, 6);
86  if(c->maxbands >= BANDS){
87  av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
88  return -1;
89  }
90  skip_bits_long(&gb, 88);
91  c->gapless = get_bits1(&gb);
92  c->lastframelen = get_bits(&gb, 11);
93  av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
94  c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
95  c->frames_to_skip = 0;
96 
99 
100  if(vlc_initialized) return 0;
101  av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
102  scfi_vlc.table = scfi_table;
103  scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
104  if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
105  &mpc7_scfi[1], 2, 1,
106  &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
107  av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
108  return -1;
109  }
110  dscf_vlc.table = dscf_table;
111  dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
112  if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
113  &mpc7_dscf[1], 2, 1,
114  &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
115  av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
116  return -1;
117  }
118  hdr_vlc.table = hdr_table;
119  hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
120  if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
121  &mpc7_hdr[1], 2, 1,
122  &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
123  av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
124  return -1;
125  }
126  for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
127  for(j = 0; j < 2; j++){
128  quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
129  quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
130  if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
131  &mpc7_quant_vlc[i][j][1], 4, 2,
132  &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
133  av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
134  return -1;
135  }
136  }
137  }
138  vlc_initialized = 1;
139 
141  avctx->coded_frame = &c->frame;
142 
143  return 0;
144 }
145 
149 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
150 {
151  int i, i1, t;
152  switch(idx){
153  case -1:
154  for(i = 0; i < SAMPLES_PER_BAND; i++){
155  *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
156  }
157  break;
158  case 1:
159  i1 = get_bits1(gb);
160  for(i = 0; i < SAMPLES_PER_BAND/3; i++){
161  t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
162  *dst++ = mpc7_idx30[t];
163  *dst++ = mpc7_idx31[t];
164  *dst++ = mpc7_idx32[t];
165  }
166  break;
167  case 2:
168  i1 = get_bits1(gb);
169  for(i = 0; i < SAMPLES_PER_BAND/2; i++){
170  t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
171  *dst++ = mpc7_idx50[t];
172  *dst++ = mpc7_idx51[t];
173  }
174  break;
175  case 3: case 4: case 5: case 6: case 7:
176  i1 = get_bits1(gb);
177  for(i = 0; i < SAMPLES_PER_BAND; i++)
178  *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
179  break;
180  case 8: case 9: case 10: case 11: case 12:
181  case 13: case 14: case 15: case 16: case 17:
182  t = (1 << (idx - 2)) - 1;
183  for(i = 0; i < SAMPLES_PER_BAND; i++)
184  *dst++ = get_bits(gb, idx - 1) - t;
185  break;
186  default: // case 0 and -2..-17
187  return;
188  }
189 }
190 
191 static int get_scale_idx(GetBitContext *gb, int ref)
192 {
193  int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
194  if (t == 8)
195  return get_bits(gb, 6);
196  return av_clip_uintp2(ref + t, 7);
197 }
198 
199 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
200  int *got_frame_ptr, AVPacket *avpkt)
201 {
202  const uint8_t *buf = avpkt->data;
203  int buf_size = avpkt->size;
204  MPCContext *c = avctx->priv_data;
205  GetBitContext gb;
206  uint8_t *bits;
207  int i, ch;
208  int mb = -1;
209  Band *bands = c->bands;
210  int off, ret;
211  int bits_used, bits_avail;
212 
213  memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
214  if(buf_size <= 4){
215  av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);
216  return AVERROR(EINVAL);
217  }
218 
219  /* get output buffer */
220  c->frame.nb_samples = buf[1] ? c->lastframelen : MPC_FRAME_SIZE;
221  if ((ret = avctx->get_buffer(avctx, &c->frame)) < 0) {
222  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
223  return ret;
224  }
225 
226  bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);
227  c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);
228  init_get_bits(&gb, bits, (buf_size - 4)* 8);
229  skip_bits_long(&gb, buf[0]);
230 
231  /* read subband indexes */
232  for(i = 0; i <= c->maxbands; i++){
233  for(ch = 0; ch < 2; ch++){
234  int t = 4;
235  if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
236  if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
237  else bands[i].res[ch] = av_clip(bands[i-1].res[ch] + t, 0, 17);
238  }
239 
240  if(bands[i].res[0] || bands[i].res[1]){
241  mb = i;
242  if(c->MSS) bands[i].msf = get_bits1(&gb);
243  }
244  }
245  /* get scale indexes coding method */
246  for(i = 0; i <= mb; i++)
247  for(ch = 0; ch < 2; ch++)
248  if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
249  /* get scale indexes */
250  for(i = 0; i <= mb; i++){
251  for(ch = 0; ch < 2; ch++){
252  if(bands[i].res[ch]){
253  bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
254  bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
255  switch(bands[i].scfi[ch]){
256  case 0:
257  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
258  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
259  break;
260  case 1:
261  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
262  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
263  break;
264  case 2:
265  bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
266  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
267  break;
268  case 3:
269  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
270  break;
271  }
272  c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
273  }
274  }
275  }
276  /* get quantizers */
277  memset(c->Q, 0, sizeof(c->Q));
278  off = 0;
279  for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
280  for(ch = 0; ch < 2; ch++)
281  idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
282 
283  ff_mpc_dequantize_and_synth(c, mb, c->frame.data[0], 2);
284 
285  av_free(bits);
286 
287  bits_used = get_bits_count(&gb);
288  bits_avail = (buf_size - 4) * 8;
289  if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){
290  av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
291  return -1;
292  }
293  if(c->frames_to_skip){
294  c->frames_to_skip--;
295  *got_frame_ptr = 0;
296  return buf_size;
297  }
298 
299  *got_frame_ptr = 1;
300  *(AVFrame *)data = c->frame;
301 
302  return buf_size;
303 }
304 
306 {
307  MPCContext *c = avctx->priv_data;
308 
309  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
310  c->frames_to_skip = 32;
311 }
312 
314  .name = "mpc7",
315  .type = AVMEDIA_TYPE_AUDIO,
316  .id = CODEC_ID_MUSEPACK7,
317  .priv_data_size = sizeof(MPCContext),
321  .capabilities = CODEC_CAP_DR1,
322  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
323 };