FFmpeg: libavcodec/truespeech.c Source File

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libavcodec

truespeech.c

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1 /*

2 * DSP Group TrueSpeech compatible 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 #include "libavutil/channel_layout.h"

23 #include "libavutil/intreadwrite.h"

24 #include "avcodec.h"

25 #include "dsputil.h"

26 #include "get_bits.h"

27 #include "internal.h"

29 #include "truespeech_data.h"

30 /**

31 * @file

32 * TrueSpeech decoder.

33 */

35 /**

36 * TrueSpeech decoder context

37 */

38 typedef struct {

39 DSPContext dsp;

40 /* input data */

41 DECLARE_ALIGNED(16, uint8_t, buffer)[32];

42 int16_t vector[8]; ///< input vector: 5/5/4/4/4/3/3/3

43 int offset1[2]; ///< 8-bit value, used in one copying offset

44 int offset2[4]; ///< 7-bit value, encodes offsets for copying and for two-point filter

45 int pulseoff[4]; ///< 4-bit offset of pulse values block

46 int pulsepos[4]; ///< 27-bit variable, encodes 7 pulse positions

47 int pulseval[4]; ///< 7x2-bit pulse values

48 int flag; ///< 1-bit flag, shows how to choose filters

49 /* temporary data */

50 int filtbuf[146]; // some big vector used for storing filters

51 int prevfilt[8]; // filter from previous frame

52 int16_t tmp1[8]; // coefficients for adding to out

53 int16_t tmp2[8]; // coefficients for adding to out

54 int16_t tmp3[8]; // coefficients for adding to out

55 int16_t cvector[8]; // correlated input vector

56 int filtval; // gain value for one function

57 int16_t newvec[60]; // tmp vector

58 int16_t filters[32]; // filters for every subframe

59 } TSContext;

61 static av_cold int truespeech_decode_init(AVCodecContext * avctx)

62 {

63 TSContext *c = avctx->priv_data;

65 if (avctx->channels != 1) {

66 avpriv_request_sample(avctx, "Channel count %d", avctx->channels);

67 return AVERROR_PATCHWELCOME;

68 }

70 avctx->channel_layout = AV_CH_LAYOUT_MONO;

71 avctx->sample_fmt = AV_SAMPLE_FMT_S16;

73 ff_dsputil_init(&c->dsp, avctx);

75 return 0;

76 }

78 static void truespeech_read_frame(TSContext *dec, const uint8_t *input)

79 {

80 GetBitContext gb;

82 dec->dsp.bswap_buf((uint32_t *)dec->buffer, (const uint32_t *)input, 8);

83 init_get_bits(&gb, dec->buffer, 32 * 8);

85 dec->vector[7] = ts_codebook[7][get_bits(&gb, 3)];

86 dec->vector[6] = ts_codebook[6][get_bits(&gb, 3)];

87 dec->vector[5] = ts_codebook[5][get_bits(&gb, 3)];

88 dec->vector[4] = ts_codebook[4][get_bits(&gb, 4)];

89 dec->vector[3] = ts_codebook[3][get_bits(&gb, 4)];

90 dec->vector[2] = ts_codebook[2][get_bits(&gb, 4)];

91 dec->vector[1] = ts_codebook[1][get_bits(&gb, 5)];

92 dec->vector[0] = ts_codebook[0][get_bits(&gb, 5)];

93 dec->flag = get_bits1(&gb);

95 dec->offset1[0] = get_bits(&gb, 4) << 4;

96 dec->offset2[3] = get_bits(&gb, 7);

97 dec->offset2[2] = get_bits(&gb, 7);

98 dec->offset2[1] = get_bits(&gb, 7);

99 dec->offset2[0] = get_bits(&gb, 7);

100

101 dec->offset1[1] = get_bits(&gb, 4);

102 dec->pulseval[1] = get_bits(&gb, 14);

103 dec->pulseval[0] = get_bits(&gb, 14);

104

105 dec->offset1[1] |= get_bits(&gb, 4) << 4;

106 dec->pulseval[3] = get_bits(&gb, 14);

107 dec->pulseval[2] = get_bits(&gb, 14);

108

109 dec->offset1[0] |= get_bits1(&gb);

110 dec->pulsepos[0] = get_bits_long(&gb, 27);

111 dec->pulseoff[0] = get_bits(&gb, 4);

112

113 dec->offset1[0] |= get_bits1(&gb) << 1;

114 dec->pulsepos[1] = get_bits_long(&gb, 27);

115 dec->pulseoff[1] = get_bits(&gb, 4);

116

117 dec->offset1[0] |= get_bits1(&gb) << 2;

118 dec->pulsepos[2] = get_bits_long(&gb, 27);

119 dec->pulseoff[2] = get_bits(&gb, 4);

120

121 dec->offset1[0] |= get_bits1(&gb) << 3;

122 dec->pulsepos[3] = get_bits_long(&gb, 27);

123 dec->pulseoff[3] = get_bits(&gb, 4);

124 }

125

126 static void truespeech_correlate_filter(TSContext *dec)

127 {

128 int16_t tmp[8];

129 int i, j;

130

131 for(i = 0; i < 8; i++){

132 if(i > 0){

133 memcpy(tmp, dec->cvector, i * sizeof(*tmp));

134 for(j = 0; j < i; j++)

135 dec->cvector[j] = ((tmp[i - j - 1] * dec->vector[i]) +

136 (dec->cvector[j] << 15) + 0x4000) >> 15;

137 }

138 dec->cvector[i] = (8 - dec->vector[i]) >> 3;

139 }

140 for(i = 0; i < 8; i++)

141 dec->cvector[i] = (dec->cvector[i] * ts_decay_994_1000[i]) >> 15;

142

143 dec->filtval = dec->vector[0];

144 }

145

146 static void truespeech_filters_merge(TSContext *dec)

147 {

148 int i;

149

150 if(!dec->flag){

151 for(i = 0; i < 8; i++){

152 dec->filters[i + 0] = dec->prevfilt[i];

153 dec->filters[i + 8] = dec->prevfilt[i];

154 }

155 }else{

156 for(i = 0; i < 8; i++){

157 dec->filters[i + 0]=(dec->cvector[i] * 21846 + dec->prevfilt[i] * 10923 + 16384) >> 15;

158 dec->filters[i + 8]=(dec->cvector[i] * 10923 + dec->prevfilt[i] * 21846 + 16384) >> 15;

159 }

160 }

161 for(i = 0; i < 8; i++){

162 dec->filters[i + 16] = dec->cvector[i];

163 dec->filters[i + 24] = dec->cvector[i];

164 }

165 }

166

167 static void truespeech_apply_twopoint_filter(TSContext *dec, int quart)

168 {

169 int16_t tmp[146 + 60], *ptr0, *ptr1;

170 const int16_t *filter;

171 int i, t, off;

172

173 t = dec->offset2[quart];

174 if(t == 127){

175 memset(dec->newvec, 0, 60 * sizeof(*dec->newvec));

176 return;

177 }

178 for(i = 0; i < 146; i++)

179 tmp[i] = dec->filtbuf[i];

180 off = (t / 25) + dec->offset1[quart >> 1] + 18;

181 off = av_clip(off, 0, 145);

182 ptr0 = tmp + 145 - off;

183 ptr1 = tmp + 146;

184 filter = ts_order2_coeffs + (t % 25) * 2;

185 for(i = 0; i < 60; i++){

186 t = (ptr0[0] * filter[0] + ptr0[1] * filter[1] + 0x2000) >> 14;

187 ptr0++;

188 dec->newvec[i] = t;

189 ptr1[i] = t;

190 }

191 }

192

193 static void truespeech_place_pulses(TSContext *dec, int16_t *out, int quart)

194 {

195 int16_t tmp[7];

196 int i, j, t;

197 const int16_t *ptr1;

198 int16_t *ptr2;

199 int coef;

200

201 memset(out, 0, 60 * sizeof(*out));

202 for(i = 0; i < 7; i++) {

203 t = dec->pulseval[quart] & 3;

204 dec->pulseval[quart] >>= 2;

205 tmp[6 - i] = ts_pulse_scales[dec->pulseoff[quart] * 4 + t];

206 }

207

208 coef = dec->pulsepos[quart] >> 15;

209 ptr1 = ts_pulse_values + 30;

210 ptr2 = tmp;

211 for(i = 0, j = 3; (i < 30) && (j > 0); i++){

212 t = *ptr1++;

213 if(coef >= t)

214 coef -= t;

215 else{

216 out[i] = *ptr2++;

217 ptr1 += 30;

218 j--;

219 }

220 }

221 coef = dec->pulsepos[quart] & 0x7FFF;

222 ptr1 = ts_pulse_values;

223 for(i = 30, j = 4; (i < 60) && (j > 0); i++){

224 t = *ptr1++;

225 if(coef >= t)

226 coef -= t;

227 else{

228 out[i] = *ptr2++;

229 ptr1 += 30;

230 j--;

231 }

232 }

233

234 }

235

236 static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)

237 {

238 int i;

239

240 memmove(dec->filtbuf, &dec->filtbuf[60], 86 * sizeof(*dec->filtbuf));

241 for(i = 0; i < 60; i++){

242 dec->filtbuf[i + 86] = out[i] + dec->newvec[i] - (dec->newvec[i] >> 3);

243 out[i] += dec->newvec[i];

244 }

245 }

246

247 static void truespeech_synth(TSContext *dec, int16_t *out, int quart)

248 {

249 int i,k;

250 int t[8];

251 int16_t *ptr0, *ptr1;

252

253 ptr0 = dec->tmp1;

254 ptr1 = dec->filters + quart * 8;

255 for(i = 0; i < 60; i++){

256 int sum = 0;

257 for(k = 0; k < 8; k++)

258 sum += ptr0[k] * ptr1[k];

259 sum = (sum + (out[i] << 12) + 0x800) >> 12;

260 out[i] = av_clip(sum, -0x7FFE, 0x7FFE);

261 for(k = 7; k > 0; k--)

262 ptr0[k] = ptr0[k - 1];

263 ptr0[0] = out[i];

264 }

265

266 for(i = 0; i < 8; i++)

267 t[i] = (ts_decay_35_64[i] * ptr1[i]) >> 15;

268

269 ptr0 = dec->tmp2;

270 for(i = 0; i < 60; i++){

271 int sum = 0;

272 for(k = 0; k < 8; k++)

273 sum += ptr0[k] * t[k];

274 for(k = 7; k > 0; k--)

275 ptr0[k] = ptr0[k - 1];

276 ptr0[0] = out[i];

277 out[i] = ((out[i] << 12) - sum) >> 12;

278 }

279

280 for(i = 0; i < 8; i++)

281 t[i] = (ts_decay_3_4[i] * ptr1[i]) >> 15;

282

283 ptr0 = dec->tmp3;

284 for(i = 0; i < 60; i++){

285 int sum = out[i] << 12;

286 for(k = 0; k < 8; k++)

287 sum += ptr0[k] * t[k];

288 for(k = 7; k > 0; k--)

289 ptr0[k] = ptr0[k - 1];

290 ptr0[0] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);

291

292 sum = ((ptr0[1] * (dec->filtval - (dec->filtval >> 2))) >> 4) + sum;

293 sum = sum - (sum >> 3);

294 out[i] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);

295 }

296 }

297

298 static void truespeech_save_prevvec(TSContext *c)

299 {

300 int i;

301

302 for(i = 0; i < 8; i++)

303 c->prevfilt[i] = c->cvector[i];

304 }

305

306 static int truespeech_decode_frame(AVCodecContext *avctx, void *data,

307 int *got_frame_ptr, AVPacket *avpkt)

308 {

309 AVFrame *frame = data;

310 const uint8_t *buf = avpkt->data;

311 int buf_size = avpkt->size;

312 TSContext *c = avctx->priv_data;

313

314 int i, j;

315 int16_t *samples;

316 int iterations, ret;

317

318 iterations = buf_size / 32;

319

320 if (!iterations) {

321 av_log(avctx, AV_LOG_ERROR,

322 "Too small input buffer (%d bytes), need at least 32 bytes\n", buf_size);

323 return -1;

324 }

325

326 /* get output buffer */

327 frame->nb_samples = iterations * 240;

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

329 return ret;

330 samples = (int16_t *)frame->data[0];

331

332 memset(samples, 0, iterations * 240 * sizeof(*samples));

333

334 for(j = 0; j < iterations; j++) {

335 truespeech_read_frame(c, buf);

336 buf += 32;

337

338 truespeech_correlate_filter(c);

339 truespeech_filters_merge(c);

340

341 for(i = 0; i < 4; i++) {

342 truespeech_apply_twopoint_filter(c, i);

343 truespeech_place_pulses (c, samples, i);

344 truespeech_update_filters(c, samples, i);

345 truespeech_synth (c, samples, i);

346 samples += 60;

347 }

348

349 truespeech_save_prevvec(c);

350 }

351

352 *got_frame_ptr = 1;

353

354 return buf_size;

355 }

356

357 AVCodec ff_truespeech_decoder = {

358 .name = "truespeech",

359 .type = AVMEDIA_TYPE_AUDIO,

360 .id = AV_CODEC_ID_TRUESPEECH,

361 .priv_data_size = sizeof(TSContext),

362 .init = truespeech_decode_init,

363 .decode = truespeech_decode_frame,

364 .capabilities = CODEC_CAP_DR1,

365 .long_name = NULL_IF_CONFIG_SMALL("DSP Group TrueSpeech"),

366 };

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