FFmpeg: libavcodec/mpc7.c Source File

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libavcodec

mpc7.c

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1 /*

2 * Musepack SV7 decoder

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 */

22 /**

23 * @file

24 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples

25 * divided into 32 subbands.

26 */

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"

37 #include "mpc.h"

38 #include "mpc7data.h"

40 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];

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 };

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;

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];

62 /* Musepack SV7 is always stereo */

63 if (avctx->channels != 2) {

64 avpriv_request_sample(avctx, "%d channels", avctx->channels);

65 return AVERROR_PATCHWELCOME;

66 }

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);

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;

94 avctx->sample_fmt = AV_SAMPLE_FMT_S16P;

95 avctx->channel_layout = AV_CH_LAYOUT_STEREO;

97 if(vlc_initialized) return 0;

98 av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");

99 scfi_vlc.table = scfi_table;

100 scfi_vlc.table_allocated = 1 << MPC7_SCFI_BITS;

101 if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,

102 &mpc7_scfi[1], 2, 1,

103 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){

104 av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");

105 return -1;

106 }

107 dscf_vlc.table = dscf_table;

108 dscf_vlc.table_allocated = 1 << MPC7_DSCF_BITS;

109 if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,

110 &mpc7_dscf[1], 2, 1,

111 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){

112 av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");

113 return -1;

114 }

115 hdr_vlc.table = hdr_table;

116 hdr_vlc.table_allocated = 1 << MPC7_HDR_BITS;

117 if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,

118 &mpc7_hdr[1], 2, 1,

119 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_NEW_STATIC)){

120 av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");

121 return -1;

122 }

123 for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){

124 for(j = 0; j < 2; j++){

125 quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];

126 quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];

127 if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],

128 &mpc7_quant_vlc[i][j][1], 4, 2,

129 &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC)){

130 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);

131 return -1;

132 }

133 }

134 }

135 vlc_initialized = 1;

136

137 return 0;

138 }

139

140 /**

141 * Fill samples for given subband

142 */

143 static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)

144 {

145 int i, i1, t;

146 switch(idx){

147 case -1:

148 for(i = 0; i < SAMPLES_PER_BAND; i++){

149 *dst++ = (av_lfg_get(&c->rnd) & 0x3FC) - 510;

150 }

151 break;

152 case 1:

153 i1 = get_bits1(gb);

154 for(i = 0; i < SAMPLES_PER_BAND/3; i++){

155 t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);

156 *dst++ = mpc7_idx30[t];

157 *dst++ = mpc7_idx31[t];

158 *dst++ = mpc7_idx32[t];

159 }

160 break;

161 case 2:

162 i1 = get_bits1(gb);

163 for(i = 0; i < SAMPLES_PER_BAND/2; i++){

164 t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);

165 *dst++ = mpc7_idx50[t];

166 *dst++ = mpc7_idx51[t];

167 }

168 break;

169 case 3: case 4: case 5: case 6: case 7:

170 i1 = get_bits1(gb);

171 for(i = 0; i < SAMPLES_PER_BAND; i++)

172 *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];

173 break;

174 case 8: case 9: case 10: case 11: case 12:

175 case 13: case 14: case 15: case 16: case 17:

176 t = (1 << (idx - 2)) - 1;

177 for(i = 0; i < SAMPLES_PER_BAND; i++)

178 *dst++ = get_bits(gb, idx - 1) - t;

179 break;

180 default: // case 0 and -2..-17

181 return;

182 }

183 }

184

185 static int get_scale_idx(GetBitContext *gb, int ref)

186 {

187 int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;

188 if (t == 8)

189 return get_bits(gb, 6);

190 return ref + t;

191 }

192

193 static int mpc7_decode_frame(AVCodecContext * avctx, void *data,

194 int *got_frame_ptr, AVPacket *avpkt)

195 {

196 AVFrame *frame = data;

197 const uint8_t *buf = avpkt->data;

198 int buf_size;

199 MPCContext *c = avctx->priv_data;

200 GetBitContext gb;

201 int i, ch;

202 int mb = -1;

203 Band *bands = c->bands;

204 int off, ret, last_frame, skip;

205 int bits_used, bits_avail;

206

207 memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));

208

209 buf_size = avpkt->size & ~3;

210 if (buf_size <= 0) {

211 av_log(avctx, AV_LOG_ERROR, "packet size is too small (%i bytes)\n",

212 avpkt->size);

213 return AVERROR_INVALIDDATA;

214 }

215 if (buf_size != avpkt->size) {

216 av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "

217 "extra bytes at the end will be skipped.\n");

218 }

219

220 skip = buf[0];

221 last_frame = buf[1];

222 buf += 4;

223 buf_size -= 4;

224

225 /* get output buffer */

226 frame->nb_samples = MPC_FRAME_SIZE;

227 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

228 return ret;

229

230 av_fast_padded_malloc(&c->bits, &c->buf_size, buf_size);

231 if (!c->bits)

232 return AVERROR(ENOMEM);

233 c->dsp.bswap_buf((uint32_t *)c->bits, (const uint32_t *)buf, buf_size >> 2);

234 init_get_bits(&gb, c->bits, buf_size * 8);

235 skip_bits_long(&gb, skip);

236

237 /* read subband indexes */

238 for(i = 0; i <= c->maxbands; i++){

239 for(ch = 0; ch < 2; ch++){

240 int t = 4;

241 if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;

242 if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);

243 else bands[i].res[ch] = bands[i-1].res[ch] + t;

244 if (bands[i].res[ch] < -1 || bands[i].res[ch] > 17) {

245 av_log(avctx, AV_LOG_ERROR, "subband index invalid\n");

246 return AVERROR_INVALIDDATA;

247 }

248 }

249

250 if(bands[i].res[0] || bands[i].res[1]){

251 mb = i;

252 if(c->MSS) bands[i].msf = get_bits1(&gb);

253 }

254 }

255 /* get scale indexes coding method */

256 for(i = 0; i <= mb; i++)

257 for(ch = 0; ch < 2; ch++)

258 if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);

259 /* get scale indexes */

260 for(i = 0; i <= mb; i++){

261 for(ch = 0; ch < 2; ch++){

262 if(bands[i].res[ch]){

263 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];

264 bands[i].scf_idx[ch][0] = get_scale_idx(&gb, bands[i].scf_idx[ch][2]);

265 switch(bands[i].scfi[ch]){

266 case 0:

267 bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);

268 bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);

269 break;

270 case 1:

271 bands[i].scf_idx[ch][1] = get_scale_idx(&gb, bands[i].scf_idx[ch][0]);

272 bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];

273 break;

274 case 2:

275 bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];

276 bands[i].scf_idx[ch][2] = get_scale_idx(&gb, bands[i].scf_idx[ch][1]);

277 break;

278 case 3:

279 bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];

280 break;

281 }

282 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];

283 }

284 }

285 }

286 /* get quantizers */

287 memset(c->Q, 0, sizeof(c->Q));

288 off = 0;

289 for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)

290 for(ch = 0; ch < 2; ch++)

291 idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);

292

293 ff_mpc_dequantize_and_synth(c, mb, (int16_t **)frame->extended_data, 2);

294 if(last_frame)

295 frame->nb_samples = c->lastframelen;

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

314 static void mpc7_decode_flush(AVCodecContext *avctx)

315 {

316 MPCContext *c = avctx->priv_data;

317

318 memset(c->oldDSCF, 0, sizeof(c->oldDSCF));

319 c->frames_to_skip = 32;

320 }

321

322 static av_cold int mpc7_decode_close(AVCodecContext *avctx)

323 {

324 MPCContext *c = avctx->priv_data;

325 av_freep(&c->bits);

326 c->buf_size = 0;

327 return 0;

328 }

329

330 AVCodec ff_mpc7_decoder = {

331 .name = "mpc7",

332 .type = AVMEDIA_TYPE_AUDIO,

333 .id = AV_CODEC_ID_MUSEPACK7,

334 .priv_data_size = sizeof(MPCContext),

335 .init = mpc7_decode_init,

336 .close = mpc7_decode_close,

337 .decode = mpc7_decode_frame,

338 .flush = mpc7_decode_flush,

339 .capabilities = CODEC_CAP_DR1,

340 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV7"),

341 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,

342 AV_SAMPLE_FMT_NONE },

343 };

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