FFmpeg: libavformat/spdifenc.c Source File

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libavformat

spdifenc.c

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1 /*

2 * IEC 61937 muxer

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 /**

25 * @file

26 * IEC-61937 encapsulation of various formats, used by S/PDIF

27 * @author Bartlomiej Wolowiec

28 * @author Anssi Hannula

29 * @author Carl Eugen Hoyos

30 */

32 /*

33 * Terminology used in specification:

34 * data-burst - IEC61937 frame, contains header and encapsuled frame

35 * burst-preambule - IEC61937 frame header, contains 16-bits words named Pa, Pb, Pc and Pd

36 * burst-payload - encapsuled frame

37 * Pa, Pb - syncword - 0xF872, 0x4E1F

38 * Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12)

39 * and bitstream number (bits 13-15)

40 * data-type - determines type of encapsuled frames

41 * Pd - length code (number of bits or bytes of encapsuled frame - according to data_type)

42 *

43 * IEC 61937 frames at normal usage start every specific count of bytes,

44 * dependent from data-type (spaces between packets are filled by zeros)

45 */

47 #include <inttypes.h>

49 #include "avformat.h"

50 #include "avio_internal.h"

51 #include "spdif.h"

52 #include "libavcodec/ac3.h"

53 #include "libavcodec/dca.h"

54 #include "libavcodec/dca_syncwords.h"

55 #include "libavcodec/aacadtsdec.h"

56 #include "libavutil/opt.h"

58 typedef struct IEC61937Context {

59 const AVClass *av_class;

60 enum IEC61937DataType data_type;///< burst info - reference to type of payload of the data-burst

61 int length_code; ///< length code in bits or bytes, depending on data type

62 int pkt_offset; ///< data burst repetition period in bytes

63 uint8_t *buffer; ///< allocated buffer, used for swap bytes

64 int buffer_size; ///< size of allocated buffer

66 uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping

67 int out_bytes; ///< amount of outgoing bytes

69 int use_preamble; ///< preamble enabled (disabled for exactly pre-padded DTS)

70 int extra_bswap; ///< extra bswap for payload (for LE DTS => standard BE DTS)

72 uint8_t *hd_buf; ///< allocated buffer to concatenate hd audio frames

73 int hd_buf_size; ///< size of the hd audio buffer

74 int hd_buf_count; ///< number of frames in the hd audio buffer

75 int hd_buf_filled; ///< amount of bytes in the hd audio buffer

77 int dtshd_skip; ///< counter used for skipping DTS-HD frames

79 /* AVOptions: */

80 int dtshd_rate;

81 int dtshd_fallback;

82 #define SPDIF_FLAG_BIGENDIAN 0x01

83 int spdif_flags;

85 /// function, which generates codec dependent header information.

86 /// Sets data_type and pkt_offset, and length_code, out_bytes, out_buf if necessary

87 int (*header_info) (AVFormatContext *s, AVPacket *pkt);

88 } IEC61937Context;

90 static const AVOption options[] = {

91 { "spdif_flags", "IEC 61937 encapsulation flags", offsetof(IEC61937Context, spdif_flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" },

92 { "be", "output in big-endian format (for use as s16be)", 0, AV_OPT_TYPE_CONST, {.i64 = SPDIF_FLAG_BIGENDIAN}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" },

93 { "dtshd_rate", "mux complete DTS frames in HD mode at the specified IEC958 rate (in Hz, default 0=disabled)", offsetof(IEC61937Context, dtshd_rate), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 768000, AV_OPT_FLAG_ENCODING_PARAM },

94 { "dtshd_fallback_time", "min secs to strip HD for after an overflow (-1: till the end, default 60)", offsetof(IEC61937Context, dtshd_fallback), AV_OPT_TYPE_INT, {.i64 = 60}, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },

95 { NULL },

96 };

98 static const AVClass spdif_class = {

99 .class_name = "spdif",

100 .item_name = av_default_item_name,

101 .option = options,

102 .version = LIBAVUTIL_VERSION_INT,

103 };

104

105 static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)

106 {

107 IEC61937Context *ctx = s->priv_data;

108 int bitstream_mode = pkt->data[5] & 0x7;

109

110 ctx->data_type = IEC61937_AC3 | (bitstream_mode << 8);

111 ctx->pkt_offset = AC3_FRAME_SIZE << 2;

112 return 0;

113 }

114

115 static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)

116 {

117 IEC61937Context *ctx = s->priv_data;

118 static const uint8_t eac3_repeat[4] = {6, 3, 2, 1};

119 int repeat = 1;

120

121 if ((pkt->data[4] & 0xc0) != 0xc0) /* fscod */

122 repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */

123

124 ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size);

125 if (!ctx->hd_buf)

126 return AVERROR(ENOMEM);

127

128 memcpy(&ctx->hd_buf[ctx->hd_buf_filled], pkt->data, pkt->size);

129

130 ctx->hd_buf_filled += pkt->size;

131 if (++ctx->hd_buf_count < repeat){

132 ctx->pkt_offset = 0;

133 return 0;

134 }

135 ctx->data_type = IEC61937_EAC3;

136 ctx->pkt_offset = 24576;

137 ctx->out_buf = ctx->hd_buf;

138 ctx->out_bytes = ctx->hd_buf_filled;

139 ctx->length_code = ctx->hd_buf_filled;

140

141 ctx->hd_buf_count = 0;

142 ctx->hd_buf_filled = 0;

143 return 0;

144 }

145

146 /*

147 * DTS type IV (DTS-HD) can be transmitted with various frame repetition

148 * periods; longer repetition periods allow for longer packets and therefore

149 * higher bitrate. Longer repetition periods mean that the constant bitrate of

150 * the outputted IEC 61937 stream is higher.

151 * The repetition period is measured in IEC 60958 frames (4 bytes).

152 */

153 static int spdif_dts4_subtype(int period)

154 {

155 switch (period) {

156 case 512: return 0x0;

157 case 1024: return 0x1;

158 case 2048: return 0x2;

159 case 4096: return 0x3;

160 case 8192: return 0x4;

161 case 16384: return 0x5;

162 }

163 return -1;

164 }

165

166 static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size,

167 int sample_rate, int blocks)

168 {

169 IEC61937Context *ctx = s->priv_data;

170 static const char dtshd_start_code[10] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0xfe };

171 int pkt_size = pkt->size;

172 int period;

173 int subtype;

174

175 if (!core_size) {

176 av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n");

177 return AVERROR(EINVAL);

178 }

179

180 if (!sample_rate) {

181 av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n");

182 return AVERROR_INVALIDDATA;

183 }

184

185 period = ctx->dtshd_rate * (blocks << 5) / sample_rate;

186 subtype = spdif_dts4_subtype(period);

187

188 if (subtype < 0) {

189 av_log(s, AV_LOG_ERROR, "Specified HD rate of %d Hz would require an "

190 "impossible repetition period of %d for the current DTS stream"

191 " (blocks = %d, sample rate = %d)\n", ctx->dtshd_rate, period,

192 blocks << 5, sample_rate);

193 return AVERROR(EINVAL);

194 }

195

196 /* set pkt_offset and DTS IV subtype according to the requested output

197 * rate */

198 ctx->pkt_offset = period * 4;

199 ctx->data_type = IEC61937_DTSHD | subtype << 8;

200

201 /* If the bitrate is too high for transmitting at the selected

202 * repetition period setting, strip DTS-HD until a good amount

203 * of consecutive non-overflowing HD frames have been observed.

204 * This generally only happens if the caller is cramming a Master

205 * Audio stream into 192kHz IEC 60958 (which may or may not fit). */

206 if (sizeof(dtshd_start_code) + 2 + pkt_size

207 > ctx->pkt_offset - BURST_HEADER_SIZE && core_size) {

208 if (!ctx->dtshd_skip)

209 av_log(s, AV_LOG_WARNING, "DTS-HD bitrate too high, "

210 "temporarily sending core only\n");

211 if (ctx->dtshd_fallback > 0)

212 ctx->dtshd_skip = sample_rate * ctx->dtshd_fallback / (blocks << 5);

213 else

214 /* skip permanently (dtshd_fallback == -1) or just once

215 * (dtshd_fallback == 0) */

216 ctx->dtshd_skip = 1;

217 }

218 if (ctx->dtshd_skip && core_size) {

219 pkt_size = core_size;

220 if (ctx->dtshd_fallback >= 0)

221 --ctx->dtshd_skip;

222 }

223

224 ctx->out_bytes = sizeof(dtshd_start_code) + 2 + pkt_size;

225

226 /* Align so that (length_code & 0xf) == 0x8. This is reportedly needed

227 * with some receivers, but the exact requirement is unconfirmed. */

228 ctx->length_code = FFALIGN(ctx->out_bytes + 0x8, 0x10) - 0x8;

229

230 av_fast_malloc(&ctx->hd_buf, &ctx->hd_buf_size, ctx->out_bytes);

231 if (!ctx->hd_buf)

232 return AVERROR(ENOMEM);

233

234 ctx->out_buf = ctx->hd_buf;

235

236 memcpy(ctx->hd_buf, dtshd_start_code, sizeof(dtshd_start_code));

237 AV_WB16(ctx->hd_buf + sizeof(dtshd_start_code), pkt_size);

238 memcpy(ctx->hd_buf + sizeof(dtshd_start_code) + 2, pkt->data, pkt_size);

239

240 return 0;

241 }

242

243 static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)

244 {

245 IEC61937Context *ctx = s->priv_data;

246 uint32_t syncword_dts = AV_RB32(pkt->data);

247 int blocks;

248 int sample_rate = 0;

249 int core_size = 0;

250

251 if (pkt->size < 9)

252 return AVERROR_INVALIDDATA;

253

254 switch (syncword_dts) {

255 case DCA_SYNCWORD_CORE_BE:

256 blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;

257 core_size = ((AV_RB24(pkt->data + 5) >> 4) & 0x3fff) + 1;

258 sample_rate = avpriv_dca_sample_rates[(pkt->data[8] >> 2) & 0x0f];

259 break;

260 case DCA_SYNCWORD_CORE_LE:

261 blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;

262 ctx->extra_bswap = 1;

263 break;

264 case DCA_SYNCWORD_CORE_14B_BE:

265 blocks =

266 (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));

267 break;

268 case DCA_SYNCWORD_CORE_14B_LE:

269 blocks =

270 (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));

271 ctx->extra_bswap = 1;

272 break;

273 case DCA_SYNCWORD_SUBSTREAM:

274 /* We only handle HD frames that are paired with core. However,

275 sometimes DTS-HD streams with core have a stray HD frame without

276 core in the beginning of the stream. */

277 av_log(s, AV_LOG_ERROR, "stray DTS-HD frame\n");

278 return AVERROR_INVALIDDATA;

279 default:

280 av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%"PRIx32"\n", syncword_dts);

281 return AVERROR_INVALIDDATA;

282 }

283 blocks++;

284

285 if (ctx->dtshd_rate)

286 /* DTS type IV output requested */

287 return spdif_header_dts4(s, pkt, core_size, sample_rate, blocks);

288

289 switch (blocks) {

290 case 512 >> 5: ctx->data_type = IEC61937_DTS1; break;

291 case 1024 >> 5: ctx->data_type = IEC61937_DTS2; break;

292 case 2048 >> 5: ctx->data_type = IEC61937_DTS3; break;

293 default:

294 av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",

295 blocks << 5);

296 return AVERROR(ENOSYS);

297 }

298

299 /* discard extraneous data by default */

300 if (core_size && core_size < pkt->size) {

301 ctx->out_bytes = core_size;

302 ctx->length_code = core_size << 3;

303 }

304

305 ctx->pkt_offset = blocks << 7;

306

307 if (ctx->out_bytes == ctx->pkt_offset) {

308 /* The DTS stream fits exactly into the output stream, so skip the

309 * preamble as it would not fit in there. This is the case for dts

310 * discs and dts-in-wav. */

311 ctx->use_preamble = 0;

312 } else if (ctx->out_bytes > ctx->pkt_offset - BURST_HEADER_SIZE) {

313 avpriv_request_sample(s, "Unrecognized large DTS frame");

314 /* This will fail with a "bitrate too high" in the caller */

315 }

316

317 return 0;

318 }

319

320 static const enum IEC61937DataType mpeg_data_type[2][3] = {

321 // LAYER1 LAYER2 LAYER3

322 { IEC61937_MPEG2_LAYER1_LSF, IEC61937_MPEG2_LAYER2_LSF, IEC61937_MPEG2_LAYER3_LSF },//MPEG2 LSF

323 { IEC61937_MPEG1_LAYER1, IEC61937_MPEG1_LAYER23, IEC61937_MPEG1_LAYER23 }, //MPEG1

324 };

325

326 static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)

327 {

328 IEC61937Context *ctx = s->priv_data;

329 int version = (pkt->data[1] >> 3) & 3;

330 int layer = 3 - ((pkt->data[1] >> 1) & 3);

331 int extension = pkt->data[2] & 1;

332

333 if (layer == 3 || version == 1) {

334 av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");

335 return AVERROR_INVALIDDATA;

336 }

337 av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);

338 if (version == 2 && extension) {

339 ctx->data_type = IEC61937_MPEG2_EXT;

340 ctx->pkt_offset = 4608;

341 } else {

342 ctx->data_type = mpeg_data_type [version & 1][layer];

343 ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer];

344 }

345 // TODO Data type dependent info (normal/karaoke, dynamic range control)

346 return 0;

347 }

348

349 static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)

350 {

351 IEC61937Context *ctx = s->priv_data;

352 AACADTSHeaderInfo hdr;

353 GetBitContext gbc;

354 int ret;

355

356 init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);

357 ret = avpriv_aac_parse_header(&gbc, &hdr);

358 if (ret < 0) {

359 av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");

360 return AVERROR_INVALIDDATA;

361 }

362

363 ctx->pkt_offset = hdr.samples << 2;

364 switch (hdr.num_aac_frames) {

365 case 1:

366 ctx->data_type = IEC61937_MPEG2_AAC;

367 break;

368 case 2:

369 ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048;

370 break;

371 case 4:

372 ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096;

373 break;

374 default:

375 av_log(s, AV_LOG_ERROR,

376 "%"PRIu32" samples in AAC frame not supported\n", hdr.samples);

377 return AVERROR(EINVAL);

378 }

379 //TODO Data type dependent info (LC profile/SBR)

380 return 0;

381 }

382

383

384 /*

385 * It seems Dolby TrueHD frames have to be encapsulated in MAT frames before

386 * they can be encapsulated in IEC 61937.

387 * Here we encapsulate 24 TrueHD frames in a single MAT frame, padding them

388 * to achieve constant rate.

389 * The actual format of a MAT frame is unknown, but the below seems to work.

390 * However, it seems it is not actually necessary for the 24 TrueHD frames to

391 * be in an exact alignment with the MAT frame.

392 */

393 #define MAT_FRAME_SIZE 61424

394 #define TRUEHD_FRAME_OFFSET 2560

395 #define MAT_MIDDLE_CODE_OFFSET -4

396

397 static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)

398 {

399 IEC61937Context *ctx = s->priv_data;

400 int mat_code_length = 0;

401 static const char mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11 };

402

403 if (!ctx->hd_buf_count) {

404 static const char mat_start_code[20] = { 0x07, 0x9E, 0x00, 0x03, 0x84, 0x01, 0x01, 0x01, 0x80, 0x00, 0x56, 0xA5, 0x3B, 0xF4, 0x81, 0x83, 0x49, 0x80, 0x77, 0xE0 };

405 mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE;

406 memcpy(ctx->hd_buf, mat_start_code, sizeof(mat_start_code));

407

408 } else if (ctx->hd_buf_count == 12) {

409 static const char mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0 };

410 mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET;

411 memcpy(&ctx->hd_buf[12 * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + MAT_MIDDLE_CODE_OFFSET],

412 mat_middle_code, sizeof(mat_middle_code));

413 }

414

415 if (pkt->size > TRUEHD_FRAME_OFFSET - mat_code_length) {

416 /* if such frames exist, we'd need some more complex logic to