FFmpeg: libavcodec/metasound.c Source File

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metasound.c

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1 /*

2 * Voxware MetaSound decoder

4 * based on TwinVQ decoder

6 *

7 * This file is part of FFmpeg.

8 *

9 * FFmpeg is free software; you can redistribute it and/or

10 * modify it under the terms of the GNU Lesser General Public

11 * License as published by the Free Software Foundation; either

12 * version 2.1 of the License, or (at your option) any later version.

13 *

14 * FFmpeg is distributed in the hope that it will be useful,

15 * but WITHOUT ANY WARRANTY; without even the implied warranty of

16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

17 * Lesser General Public License for more details.

18 *

19 * You should have received a copy of the GNU Lesser General Public

20 * License along with FFmpeg; if not, write to the Free Software

21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

22 */

24 #include <math.h>

25 #include <stdint.h>

27 #define BITSTREAM_READER_LE

28 #include "libavutil/channel_layout.h"

29 #include "libavutil/float_dsp.h"

30 #include "avcodec.h"

31 #include "get_bits.h"

32 #include "fft.h"

33 #include "internal.h"

34 #include "lsp.h"

35 #include "sinewin.h"

37 #include "twinvq.h"

38 #include "metasound_data.h"

40 static void add_peak(float period, int width, const float *shape,

41 float ppc_gain, float *speech, int len)

42 {

43 int i, j, center;

44 const float *shape_end = shape + len;

46 // First peak centered around zero

47 for (i = 0; i < width / 2; i++)

48 speech[i] += ppc_gain * *shape++;

50 for (i = 1; i < ROUNDED_DIV(len, width); i++) {

51 center = (int)(i * period + 0.5);

52 for (j = -width / 2; j < (width + 1) / 2; j++)

53 speech[j + center] += ppc_gain * *shape++;

54 }

56 // For the last block, be careful not to go beyond the end of the buffer

57 center = (int)(i * period + 0.5);

58 for (j = -width / 2; j < (width + 1) / 2 && shape < shape_end; j++)

59 speech[j + center] += ppc_gain * *shape++;

60 }

62 static void decode_ppc(TwinVQContext *tctx, int period_coef, int g_coef,

63 const float *shape, float *speech)

64 {

65 const TwinVQModeTab *mtab = tctx->mtab;

66 int isampf = tctx->avctx->sample_rate / 1000;

67 int ibps = tctx->avctx->bit_rate / (1000 * tctx->avctx->channels);

68 int width;

70 float ratio = (float)mtab->size / isampf;

71 float min_period, max_period, period_range, period;

72 float some_mult;

74 float pgain_base, pgain_step, ppc_gain;

76 if (tctx->avctx->channels == 1) {

77 min_period = log2(ratio * 0.2);

78 max_period = min_period + log2(6);

79 } else {

80 min_period = (int)(ratio * 0.2 * 400 + 0.5) / 400.0;

81 max_period = (int)(ratio * 0.2 * 400 * 6 + 0.5) / 400.0;

82 }

83 period_range = max_period - min_period;

84 period = min_period + period_coef * period_range /

85 ((1 << mtab->ppc_period_bit) - 1);

86 if (tctx->avctx->channels == 1)

87 period = powf(2.0, period);

88 else

89 period = (int)(period * 400 + 0.5) / 400.0;

91 switch (isampf) {

92 case 8: some_mult = 2.0; break;

93 case 11: some_mult = 3.0; break;

94 case 16: some_mult = 3.0; break;

95 case 22: some_mult = ibps == 32 ? 2.0 : 4.0; break;

96 case 44: some_mult = 8.0; break;

97 default: some_mult = 4.0;

98 }

100 width = (int)(some_mult / (mtab->size / period) * mtab->ppc_shape_len);

101 if (isampf == 22 && ibps == 32)

102 width = (int)((2.0 / period + 1) * width + 0.5);

103

104 pgain_base = tctx->avctx->channels == 2 ? 25000.0 : 20000.0;

105 pgain_step = pgain_base / ((1 << mtab->pgain_bit) - 1);

106 ppc_gain = 1.0 / 8192 *

107 twinvq_mulawinv(pgain_step * g_coef + pgain_step / 2,

108 pgain_base, TWINVQ_PGAIN_MU);

109

110 add_peak(period, width, shape, ppc_gain, speech, mtab->ppc_shape_len);

111 }

112

113 static void dec_bark_env(TwinVQContext *tctx, const uint8_t *in, int use_hist,

114 int ch, float *out, float gain,

115 enum TwinVQFrameType ftype)

116 {

117 const TwinVQModeTab *mtab = tctx->mtab;

118 int i, j;

119 float *hist = tctx->bark_hist[ftype][ch];

120 float val = ((const float []) { 0.4, 0.35, 0.28 })[ftype];

121 int bark_n_coef = mtab->fmode[ftype].bark_n_coef;

122 int fw_cb_len = mtab->fmode[ftype].bark_env_size / bark_n_coef;

123 int idx = 0;

124

125 if (tctx->avctx->channels == 1)

126 val = 0.5;

127 for (i = 0; i < fw_cb_len; i++)

128 for (j = 0; j < bark_n_coef; j++, idx++) {

129 float tmp2 = mtab->fmode[ftype].bark_cb[fw_cb_len * in[j] + i] *

130 (1.0 / 2048);

131 float st;

132

133 if (tctx->avctx->channels == 1)

134 st = use_hist ?

135 tmp2 + val * hist[idx] + 1.0 : tmp2 + 1.0;

136 else

137 st = use_hist ? (1.0 - val) * tmp2 + val * hist[idx] + 1.0

138 : tmp2 + 1.0;

139

140 hist[idx] = tmp2;

141 if (st < 0.1)

142 st = 0.1;

143

144 twinvq_memset_float(out, st * gain,

145 mtab->fmode[ftype].bark_tab[idx]);

146 out += mtab->fmode[ftype].bark_tab[idx];

147 }

148 }

149

150 static void read_cb_data(TwinVQContext *tctx, GetBitContext *gb,

151 uint8_t *dst, enum TwinVQFrameType ftype)

152 {

153 int i;

154

155 for (i = 0; i < tctx->n_div[ftype]; i++) {

156 int bs_second_part = (i >= tctx->bits_main_spec_change[ftype]);

157

158 *dst++ = get_bits(gb, tctx->bits_main_spec[0][ftype][bs_second_part]);

159 *dst++ = get_bits(gb, tctx->bits_main_spec[1][ftype][bs_second_part]);

160 }

161 }

162

163 static int metasound_read_bitstream(AVCodecContext *avctx, TwinVQContext *tctx,

164 const uint8_t *buf, int buf_size)

165 {

166 TwinVQFrameData *bits = &tctx->bits;

167 const TwinVQModeTab *mtab = tctx->mtab;

168 int channels = tctx->avctx->channels;

169 int sub;

170 GetBitContext gb;

171 int i, j, k;

172

173 init_get_bits(&gb, buf, buf_size * 8);

174

175 bits->window_type = get_bits(&gb, TWINVQ_WINDOW_TYPE_BITS);

176

177 if (bits->window_type > 8) {

178 av_log(avctx, AV_LOG_ERROR, "Invalid window type, broken sample?\n");

179 return AVERROR_INVALIDDATA;

180 }

181

182 bits->ftype = ff_twinvq_wtype_to_ftype_table[tctx->bits.window_type];

183

184 sub = mtab->fmode[bits->ftype].sub;

185

186 if (bits->ftype != TWINVQ_FT_SHORT)

187 get_bits(&gb, 2);

188

189 read_cb_data(tctx, &gb, bits->main_coeffs, bits->ftype);

190

191 for (i = 0; i < channels; i++)

192 for (j = 0; j < sub; j++)

193 for (k = 0; k < mtab->fmode[bits->ftype].bark_n_coef; k++)

194 bits->bark1[i][j][k] =

195 get_bits(&gb, mtab->fmode[bits->ftype].bark_n_bit);

196

197 for (i = 0; i < channels; i++)

198 for (j = 0; j < sub; j++)

199 bits->bark_use_hist[i][j] = get_bits1(&gb);

200

201 if (bits->ftype == TWINVQ_FT_LONG) {

202 for (i = 0; i < channels; i++)

203 bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);

204 } else {

205 for (i = 0; i < channels; i++) {

206 bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);

207 for (j = 0; j < sub; j++)

208 bits->sub_gain_bits[i * sub + j] =

209 get_bits(&gb, TWINVQ_SUB_GAIN_BITS);

210 }

211 }

212

213 for (i = 0; i < channels; i++) {

214 bits->lpc_hist_idx[i] = get_bits(&gb, mtab->lsp_bit0);

215 bits->lpc_idx1[i] = get_bits(&gb, mtab->lsp_bit1);

216

217 for (j = 0; j < mtab->lsp_split; j++)

218 bits->lpc_idx2[i][j] = get_bits(&gb, mtab->lsp_bit2);

219 }

220

221 if (bits->ftype == TWINVQ_FT_LONG) {

222 read_cb_data(tctx, &gb, bits->ppc_coeffs, 3);

223 for (i = 0; i < channels; i++) {

224 bits->p_coef[i] = get_bits(&gb, mtab->ppc_period_bit);

225 bits->g_coef[i] = get_bits(&gb, mtab->pgain_bit);

226 }

227 }

228

229 return (get_bits_count(&gb) + 7) / 8;

230 }

231

232 typedef struct MetasoundProps {

233 uint32_t tag;

234 int bit_rate;

235 int channels;

236 int sample_rate;

237 } MetasoundProps;

238

239 static const MetasoundProps codec_props[] = {

240 { MKTAG('V','X','0','3'), 6, 1, 8000 },

241 { MKTAG('V','X','0','4'), 12, 2, 8000 },

242

243 { MKTAG('V','O','X','i'), 8, 1, 8000 },

244 { MKTAG('V','O','X','j'), 10, 1, 11025 },

245 { MKTAG('V','O','X','k'), 16, 1, 16000 },

246 { MKTAG('V','O','X','L'), 24, 1, 22050 },

247 { MKTAG('V','O','X','q'), 32, 1, 44100 },

248 { MKTAG('V','O','X','r'), 40, 1, 44100 },

249 { MKTAG('V','O','X','s'), 48, 1, 44100 },

250 { MKTAG('V','O','X','t'), 16, 2, 8000 },

251 { MKTAG('V','O','X','u'), 20, 2, 11025 },

252 { MKTAG('V','O','X','v'), 32, 2, 16000 },

253 { MKTAG('V','O','X','w'), 48, 2, 22050 },

254 { MKTAG('V','O','X','x'), 64, 2, 44100 },

255 { MKTAG('V','O','X','y'), 80, 2, 44100 },

256 { MKTAG('V','O','X','z'), 96, 2, 44100 },

257

258 { 0, 0, 0, 0 }

259 };

260

261 static av_cold int metasound_decode_init(AVCodecContext *avctx)

262 {

263 int isampf, ibps;

264 TwinVQContext *tctx = avctx->priv_data;

265 uint32_t tag;

266 const MetasoundProps *props = codec_props;

267

268 if (!avctx->extradata || avctx->extradata_size < 16) {

269 av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n");

270 return AVERROR_INVALIDDATA;

271 }

272

273 tag = AV_RL32(avctx->extradata + 12);

274

275 for (;;) {

276 if (!props->tag) {

277 av_log(avctx, AV_LOG_ERROR, "Could not find tag %08X\n", tag);

278 return AVERROR_INVALIDDATA;

279 }

280 if (props->tag == tag) {

281 avctx->sample_rate = props->sample_rate;

282 avctx->channels = props->channels;

283 avctx->bit_rate = props->bit_rate * 1000;

284 isampf = avctx->sample_rate / 1000;

285 break;

286 }

287 props++;

288 }

289

290 if (avctx->channels <= 0 || avctx->channels > TWINVQ_CHANNELS_MAX) {

291 av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",

292 avctx->channels);

293 return AVERROR_INVALIDDATA;

294 }

295 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO

296 : AV_CH_LAYOUT_STEREO;

297

298 ibps = avctx->bit_rate / (1000 * avctx->channels);

299

300 switch ((avctx->channels << 16) + (isampf << 8) + ibps) {

301 case (1 << 16) + ( 8 << 8) + 8:

302 tctx->mtab = &ff_metasound_mode0808;

303 break;

304 case (1 << 16) + (16 << 8) + 16:

305 tctx->mtab = &ff_metasound_mode1616;

306 break;

307 case (1 << 16) + (44 << 8) + 32:

308 tctx->mtab = &ff_metasound_mode4432;

309 break;

310 case (2 << 16) + (44 << 8) + 48:

311 tctx->mtab = &ff_metasound_mode4448s;

312 break;

313 default:

314 av_log(avctx, AV_LOG_ERROR,

315 "This version does not support %d kHz - %d kbit/s/ch mode.\n",

316 isampf, isampf);

317 return AVERROR(ENOSYS);

318 }

319

320 avctx->block_align = (avctx->bit_rate * tctx->mtab->size

321 / avctx->sample_rate + 7) / 8;

322

323 tctx->codec = TWINVQ_CODEC_METASOUND;

324 tctx->read_bitstream = metasound_read_bitstream;

325 tctx->dec_bark_env = dec_bark_env;

326 tctx->decode_ppc = decode_ppc;

327

328 return ff_twinvq_decode_init(avctx);

329 }

330

331 AVCodec ff_metasound_decoder = {

332 .name = "metasound",

333 .long_name = NULL_IF_CONFIG_SMALL("Voxware MetaSound"),

334 .type = AVMEDIA_TYPE_AUDIO,

335 .id = AV_CODEC_ID_METASOUND,

336 .priv_data_size = sizeof(TwinVQContext),

337 .init = metasound_decode_init,

338 .close = ff_twinvq_decode_close,

339 .decode = ff_twinvq_decode_frame,

340 .capabilities = CODEC_CAP_DR1,

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

342 AV_SAMPLE_FMT_NONE },

343 };

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