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mpc7.c
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1 /*
2  * Musepack SV7 decoder
3  * Copyright (c) 2006 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 "avcodec.h"
31 #include "get_bits.h"
32 #include "dsputil.h"
33 #include "internal.h"
34 #include "mpegaudiodsp.h"
35 
36 #include "mpc.h"
37 #include "mpc7data.h"
38 
39 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
40 
41 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
42 {
43  0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
44  5636, 6164, 6676, 7224
45 };
46 
47 
48 static av_cold int mpc7_decode_init(AVCodecContext * avctx)
49 {
50  int i, j;
51  MPCContext *c = avctx->priv_data;
52  GetBitContext gb;
53  LOCAL_ALIGNED_16(uint8_t, buf, [16]);
54  static int vlc_initialized = 0;
55 
56  static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
57  static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
58  static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
59  static VLC_TYPE quant_tables[7224][2];
60 
61  /* Musepack SV7 is always stereo */
62  if (avctx->channels != 2) {
63  av_log_ask_for_sample(avctx, "Unsupported number of channels: %d\n",
64  avctx->channels);
65  return AVERROR_PATCHWELCOME;
66  }
67 
68  if(avctx->extradata_size < 16){
69  av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
70  return -1;
71  }
72  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
73  av_lfg_init(&c->rnd, 0xDEADBEEF);
74  ff_dsputil_init(&c->dsp, avctx);
75  ff_mpadsp_init(&c->mpadsp);
76  c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
77  ff_mpc_init();
78  init_get_bits(&gb, buf, 128);
79 
80  c->IS = get_bits1(&gb);
81  c->MSS = get_bits1(&gb);
82  c->maxbands = get_bits(&gb, 6);
83  if(c->maxbands >= BANDS){
84  av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
85  return -1;
86  }
87  skip_bits_long(&gb, 88);
88  c->gapless = get_bits1(&gb);
89  c->lastframelen = get_bits(&gb, 11);
90  av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
91  c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
92  c->frames_to_skip = 0;
93 
94  avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
95  avctx->channel_layout = AV_CH_LAYOUT_STEREO;
96 
97  avcodec_get_frame_defaults(&c->frame);
98  avctx->coded_frame = &c->frame;
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 
140  return 0;
141 }
142 
143 /**
144  * Fill samples for given subband
145  */
146 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
147 {
148  int i, i1, t;
149  switch(idx){
150  case -1:
151  for(i = 0; i < SAMPLES_PER_BAND; i++){
152  *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
153  }
154  break;
155  case 1:
156  i1 = get_bits1(gb);
157  for(i = 0; i < SAMPLES_PER_BAND/3; i++){
158  t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
159  *dst++ = mpc7_idx30[t];
160  *dst++ = mpc7_idx31[t];
161  *dst++ = mpc7_idx32[t];
162  }
163  break;
164  case 2:
165  i1 = get_bits1(gb);
166  for(i = 0; i < SAMPLES_PER_BAND/2; i++){
167  t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
168  *dst++ = mpc7_idx50[t];
169  *dst++ = mpc7_idx51[t];
170  }
171  break;
172  case 3: case 4: case 5: case 6: case 7:
173  i1 = get_bits1(gb);
174  for(i = 0; i < SAMPLES_PER_BAND; i++)
175  *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
176  break;
177  case 8: case 9: case 10: case 11: case 12:
178  case 13: case 14: case 15: case 16: case 17:
179  t = (1 << (idx - 2)) - 1;
180  for(i = 0; i < SAMPLES_PER_BAND; i++)
181  *dst++ = get_bits(gb, idx - 1) - t;
182  break;
183  default: // case 0 and -2..-17
184  return;
185  }
186 }
187 
188 static int get_scale_idx(GetBitContext *gb, int ref)
189 {
190  int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
191  if (t == 8)
192  return get_bits(gb, 6);
193  return ref + t;
194 }
195 
196 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
197  int *got_frame_ptr, AVPacket *avpkt)
198 {
199  const uint8_t *buf = avpkt->data;
200  int buf_size;
201  MPCContext *c = avctx->priv_data;
202  GetBitContext gb;
203  int i, ch;
204  int mb = -1;
205  Band *bands = c->bands;
206  int off, ret, last_frame, skip;
207  int bits_used, bits_avail;
208 
209  memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
210 
211  buf_size = avpkt->size & ~3;
212  if (buf_size <= 0) {
213  av_log(avctx, AV_LOG_ERROR, "packet size is too small (%i bytes)\n",
214  avpkt->size);
215  return AVERROR_INVALIDDATA;
216  }
217  if (buf_size != avpkt->size) {
218  av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
219  "extra bytes at the end will be skipped.\n");
220  }
221 
222  skip = buf[0];
223  last_frame = buf[1];
224  buf += 4;
225  buf_size -= 4;
226 
227  /* get output buffer */
228  c->frame.nb_samples = MPC_FRAME_SIZE;
229  if ((ret = ff_get_buffer(avctx, &c->frame)) < 0) {
230  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
231  return ret;
232  }
233 
234  av_fast_padded_malloc(&c->bits, &c->buf_size, buf_size);
235  if (!c->bits)
236  return AVERROR(ENOMEM);
237  c->dsp.bswap_buf((uint32_t *)c->bits, (const uint32_t *)buf, buf_size >> 2);
238  init_get_bits(&gb, c->bits, buf_size * 8);
239  skip_bits_long(&gb, skip);
240 
241  /* read subband indexes */
242  for(i = 0; i <= c->maxbands; i++){
243  for(ch = 0; ch < 2; ch++){
244  int t = 4;
245  if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
246  if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
247  else bands[i].res[ch] = bands[i-1].res[ch] + t;
248  if (bands[i].res[ch] < -1 || bands[i].res[ch] > 17) {
249  av_log(avctx, AV_LOG_ERROR, "subband index invalid\n");
250  return AVERROR_INVALIDDATA;
251  }
252  }
253 
254  if(bands[i].res[0] || bands[i].res[1]){
255  mb = i;
256  if(c->MSS) bands[i].msf = get_bits1(&gb);
257  }
258  }
259  /* get scale indexes coding method */
260  for(i = 0; i <= mb; i++)
261  for(ch = 0; ch < 2; ch++)
262  if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
263  /* get scale indexes */
264  for(i = 0; i <= mb; i++){
265  for(ch = 0; ch < 2; ch++){
266  if(bands[i].res[ch]){
267  bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
268  bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
269  switch(bands[i].scfi[ch]){
270  case 0:
271  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
272  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
273  break;
274  case 1:
275  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
276  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
277  break;
278  case 2:
279  bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
280  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
281  break;
282  case 3:
283  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
284  break;
285  }
286  c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
287  }
288  }
289  }
290  /* get quantizers */
291  memset(c->Q, 0, sizeof(c->Q));
292  off = 0;
293  for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
294  for(ch = 0; ch < 2; ch++)
295  idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
296 
297  ff_mpc_dequantize_and_synth(c, mb, (int16_t **)c->frame.extended_data, 2);
298  if(last_frame)
299  c->frame.nb_samples = c->lastframelen;
300 
301  bits_used = get_bits_count(&gb);
302  bits_avail = buf_size * 8;
303  if (!last_frame && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))) {
304  av_log(avctx, AV_LOG_ERROR, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
305  return -1;
306  }
307  if(c->frames_to_skip){
308  c->frames_to_skip--;
309  *got_frame_ptr = 0;
310  return avpkt->size;
311  }
312 
313  *got_frame_ptr = 1;
314  *(AVFrame *)data = c->frame;
315 
316  return avpkt->size;
317 }
318 
319 static void mpc7_decode_flush(AVCodecContext *avctx)
320 {
321  MPCContext *c = avctx->priv_data;
322 
323  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
324  c->frames_to_skip = 32;
325 }
326 
327 static av_cold int mpc7_decode_close(AVCodecContext *avctx)
328 {
329  MPCContext *c = avctx->priv_data;
330  av_freep(&c->bits);
331  c->buf_size = 0;
332  return 0;
333 }
334 
335 AVCodec ff_mpc7_decoder = {
336  .name = "mpc7",
337  .type = AVMEDIA_TYPE_AUDIO,
338  .id = AV_CODEC_ID_MUSEPACK7,
339  .priv_data_size = sizeof(MPCContext),
340  .init = mpc7_decode_init,
341  .close = mpc7_decode_close,
342  .decode = mpc7_decode_frame,
343  .flush = mpc7_decode_flush,
344  .capabilities = CODEC_CAP_DR1,
345  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
346  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
347  AV_SAMPLE_FMT_NONE },
348 };
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