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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/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 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
41 
42 static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
43 {
44  0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
45  5636, 6164, 6676, 7224
46 };
47 
48 
49 static av_cold int mpc7_decode_init(AVCodecContext * avctx)
50 {
51  int i, j;
52  MPCContext *c = avctx->priv_data;
53  GetBitContext gb;
54  LOCAL_ALIGNED_16(uint8_t, buf, [16]);
55  static int vlc_initialized = 0;
56 
57  static VLC_TYPE scfi_table[1 << MPC7_SCFI_BITS][2];
58  static VLC_TYPE dscf_table[1 << MPC7_DSCF_BITS][2];
59  static VLC_TYPE hdr_table[1 << MPC7_HDR_BITS][2];
60  static VLC_TYPE quant_tables[7224][2];
61 
62  /* Musepack SV7 is always stereo */
63  if (avctx->channels != 2) {
64  av_log_ask_for_sample(avctx, "Unsupported number of channels: %d\n",
65  avctx->channels);
66  return AVERROR_PATCHWELCOME;
67  }
68 
69  if(avctx->extradata_size < 16){
70  av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
71  return -1;
72  }
73  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
74  av_lfg_init(&c->rnd, 0xDEADBEEF);
75  ff_dsputil_init(&c->dsp, avctx);
76  ff_mpadsp_init(&c->mpadsp);
77  c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);
78  ff_mpc_init();
79  init_get_bits(&gb, buf, 128);
80 
81  c->IS = get_bits1(&gb);
82  c->MSS = get_bits1(&gb);
83  c->maxbands = get_bits(&gb, 6);
84  if(c->maxbands >= BANDS){
85  av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);
86  return -1;
87  }
88  skip_bits_long(&gb, 88);
89  c->gapless = get_bits1(&gb);
90  c->lastframelen = get_bits(&gb, 11);
91  av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",
92  c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);
93  c->frames_to_skip = 0;
94 
95  avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
96  avctx->channel_layout = AV_CH_LAYOUT_STEREO;
97 
98  if(vlc_initialized) return 0;
99  av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
100  scfi_vlc.table = scfi_table;
101  scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;
102  if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,
103  &mpc7_scfi[1], 2, 1,
104  &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
105  av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");
106  return -1;
107  }
108  dscf_vlc.table = dscf_table;
109  dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;
110  if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
111  &mpc7_dscf[1], 2, 1,
112  &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
113  av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");
114  return -1;
115  }
116  hdr_vlc.table = hdr_table;
117  hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;
118  if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
119  &mpc7_hdr[1], 2, 1,
120  &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){
121  av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");
122  return -1;
123  }
124  for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
125  for(j = 0; j < 2; j++){
126  quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
127  quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
128  if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
129  &mpc7_quant_vlc[i][j][1], 4, 2,
130  &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){
131  av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);
132  return -1;
133  }
134  }
135  }
136  vlc_initialized = 1;
137 
138  return 0;
139 }
140 
141 /**
142  * Fill samples for given subband
143  */
144 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)
145 {
146  int i, i1, t;
147  switch(idx){
148  case -1:
149  for(i = 0; i < SAMPLES_PER_BAND; i++){
150  *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
151  }
152  break;
153  case 1:
154  i1 = get_bits1(gb);
155  for(i = 0; i < SAMPLES_PER_BAND/3; i++){
156  t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);
157  *dst++ = mpc7_idx30[t];
158  *dst++ = mpc7_idx31[t];
159  *dst++ = mpc7_idx32[t];
160  }
161  break;
162  case 2:
163  i1 = get_bits1(gb);
164  for(i = 0; i < SAMPLES_PER_BAND/2; i++){
165  t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);
166  *dst++ = mpc7_idx50[t];
167  *dst++ = mpc7_idx51[t];
168  }
169  break;
170  case 3: case 4: case 5: case 6: case 7:
171  i1 = get_bits1(gb);
172  for(i = 0; i < SAMPLES_PER_BAND; i++)
173  *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
174  break;
175  case 8: case 9: case 10: case 11: case 12:
176  case 13: case 14: case 15: case 16: case 17:
177  t = (1 << (idx - 2)) - 1;
178  for(i = 0; i < SAMPLES_PER_BAND; i++)
179  *dst++ = get_bits(gb, idx - 1) - t;
180  break;
181  default: // case 0 and -2..-17
182  return;
183  }
184 }
185 
186 static int get_scale_idx(GetBitContext *gb, int ref)
187 {
188  int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
189  if (t == 8)
190  return get_bits(gb, 6);
191  return ref + t;
192 }
193 
194 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
195  int *got_frame_ptr, AVPacket *avpkt)
196 {
197  AVFrame *frame = data;
198  const uint8_t *buf = avpkt->data;
199  int buf_size;
200  MPCContext *c = avctx->priv_data;
201  GetBitContext gb;
202  int i, ch;
203  int mb = -1;
204  Band *bands = c->bands;
205  int off, ret, last_frame, skip;
206  int bits_used, bits_avail;
207 
208  memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
209 
210  buf_size = avpkt->size & ~3;
211  if (buf_size <= 0) {
212  av_log(avctx, AV_LOG_ERROR, "packet size is too small (%i bytes)\n",
213  avpkt->size);
214  return AVERROR_INVALIDDATA;
215  }
216  if (buf_size != avpkt->size) {
217  av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
218  "extra bytes at the end will be skipped.\n");
219  }
220 
221  skip = buf[0];
222  last_frame = buf[1];
223  buf += 4;
224  buf_size -= 4;
225 
226  /* get output buffer */
227  frame->nb_samples = MPC_FRAME_SIZE;
228  if ((ret = ff_get_buffer(avctx, frame)) < 0) {
229  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
230  return ret;
231  }
232 
233  av_fast_padded_malloc(&c->bits, &c->buf_size, buf_size);
234  if (!c->bits)
235  return AVERROR(ENOMEM);
236  c->dsp.bswap_buf((uint32_t *)c->bits, (const uint32_t *)buf, buf_size >> 2);
237  init_get_bits(&gb, c->bits, buf_size * 8);
238  skip_bits_long(&gb, skip);
239 
240  /* read subband indexes */
241  for(i = 0; i <= c->maxbands; i++){
242  for(ch = 0; ch < 2; ch++){
243  int t = 4;
244  if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
245  if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
246  else bands[i].res[ch] = bands[i-1].res[ch] + t;
247  if (bands[i].res[ch] < -1 || bands[i].res[ch] > 17) {
248  av_log(avctx, AV_LOG_ERROR, "subband index invalid\n");
249  return AVERROR_INVALIDDATA;
250  }
251  }
252 
253  if(bands[i].res[0] || bands[i].res[1]){
254  mb = i;
255  if(c->MSS) bands[i].msf = get_bits1(&gb);
256  }
257  }
258  /* get scale indexes coding method */
259  for(i = 0; i <= mb; i++)
260  for(ch = 0; ch < 2; ch++)
261  if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);
262  /* get scale indexes */
263  for(i = 0; i <= mb; i++){
264  for(ch = 0; ch < 2; ch++){
265  if(bands[i].res[ch]){
266  bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];
267  bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);
268  switch(bands[i].scfi[ch]){
269  case 0:
270  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
271  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
272  break;
273  case 1:
274  bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);
275  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];
276  break;
277  case 2:
278  bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
279  bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);
280  break;
281  case 3:
282  bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];
283  break;
284  }
285  c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];
286  }
287  }
288  }
289  /* get quantizers */
290  memset(c->Q, 0, sizeof(c->Q));
291  off = 0;
292  for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)
293  for(ch = 0; ch < 2; ch++)
294  idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);
295 
296  ff_mpc_dequantize_and_synth(c, mb, (int16_t **)frame->extended_data, 2);
297  if(last_frame)
298  frame->nb_samples = c->lastframelen;
299 
300  bits_used = get_bits_count(&gb);
301  bits_avail = buf_size * 8;
302  if (!last_frame && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))) {
303  av_log(avctx, AV_LOG_ERROR, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
304  return -1;
305  }
306  if(c->frames_to_skip){
307  c->frames_to_skip--;
308  *got_frame_ptr = 0;
309  return avpkt->size;
310  }
311 
312  *got_frame_ptr = 1;
313 
314  return avpkt->size;
315 }
316 
317 static void mpc7_decode_flush(AVCodecContext *avctx)
318 {
319  MPCContext *c = avctx->priv_data;
320 
321  memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
322  c->frames_to_skip = 32;
323 }
324 
325 static av_cold int mpc7_decode_close(AVCodecContext *avctx)
326 {
327  MPCContext *c = avctx->priv_data;
328  av_freep(&c->bits);
329  c->buf_size = 0;
330  return 0;
331 }
332 
333 AVCodec ff_mpc7_decoder = {
334  .name = "mpc7",
335  .type = AVMEDIA_TYPE_AUDIO,
336  .id = AV_CODEC_ID_MUSEPACK7,
337  .priv_data_size = sizeof(MPCContext),
338  .init = mpc7_decode_init,
339  .close = mpc7_decode_close,
340  .decode = mpc7_decode_frame,
341  .flush = mpc7_decode_flush,
342  .capabilities = CODEC_CAP_DR1,
343  .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),
344  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
345  AV_SAMPLE_FMT_NONE },
346 };
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