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/aacadtsdec.h"

55 #include "libavutil/opt.h"

57 typedef struct IEC61937Context {

58 const AVClass *av_class;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

78 /* AVOptions: */

79 int dtshd_rate;

80 int dtshd_fallback;

81 #define SPDIF_FLAG_BIGENDIAN 0x01

82 int spdif_flags;

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

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

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

87 } IEC61937Context;

89 static const AVOption options[] = {

90 { "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" },

91 { "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" },

92 { "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 },

93 { "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 },

94 { NULL },

95 };

97 static const AVClass spdif_class = {

98 .class_name = "spdif",

99 .item_name = av_default_item_name,

100 .option = options,

101 .version = LIBAVUTIL_VERSION_INT,

102 };

103

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

105 {

106 IEC61937Context *ctx = s->priv_data;

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

108

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

110 ctx->pkt_offset = AC3_FRAME_SIZE << 2;

111 return 0;

112 }

113

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

115 {

116 IEC61937Context *ctx = s->priv_data;

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

118 int repeat = 1;

119

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

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

122

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

124 if (!ctx->hd_buf)

125 return AVERROR(ENOMEM);

126

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

128

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

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

131 ctx->pkt_offset = 0;

132 return 0;

133 }

134 ctx->data_type = IEC61937_EAC3;

135 ctx->pkt_offset = 24576;

136 ctx->out_buf = ctx->hd_buf;

137 ctx->out_bytes = ctx->hd_buf_filled;

138 ctx->length_code = ctx->hd_buf_filled;

139

140 ctx->hd_buf_count = 0;

141 ctx->hd_buf_filled = 0;

142 return 0;

143 }

144

145 /*

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

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

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

149 * the outputted IEC 61937 stream is higher.

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

151 */

152 static int spdif_dts4_subtype(int period)

153 {

154 switch (period) {

155 case 512: return 0x0;

156 case 1024: return 0x1;

157 case 2048: return 0x2;

158 case 4096: return 0x3;

159 case 8192: return 0x4;

160 case 16384: return 0x5;

161 }

162 return -1;

163 }

164

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

166 int sample_rate, int blocks)

167 {

168 IEC61937Context *ctx = s->priv_data;

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

170 int pkt_size = pkt->size;

171 int period;

172 int subtype;

173

174 if (!core_size) {

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

176 return AVERROR(EINVAL);

177 }

178

179 if (!sample_rate) {

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

181 return AVERROR_INVALIDDATA;

182 }

183

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

185 subtype = spdif_dts4_subtype(period);

186

187 if (subtype < 0) {

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

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

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

191 blocks << 5, sample_rate);

192 return AVERROR(EINVAL);

193 }

194

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

196 * rate */

197 ctx->pkt_offset = period * 4;

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

199

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

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

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

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

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

205 if (sizeof(dtshd_start_code) + 2 + pkt_size

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

207 if (!ctx->dtshd_skip)

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

209 "temporarily sending core only\n");

210 if (ctx->dtshd_fallback > 0)

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

212 else

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

214 * (dtshd_fallback == 0) */

215 ctx->dtshd_skip = 1;

216 }

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

218 pkt_size = core_size;

219 if (ctx->dtshd_fallback >= 0)

220 --ctx->dtshd_skip;

221 }

222

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

224

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

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

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

228

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

230 if (!ctx->hd_buf)

231 return AVERROR(ENOMEM);

232

233 ctx->out_buf = ctx->hd_buf;

234

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

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

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

238

239 return 0;

240 }

241

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

243 {

244 IEC61937Context *ctx = s->priv_data;

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

246 int blocks;

247 int sample_rate = 0;

248 int core_size = 0;

249

250 if (pkt->size < 9)

251 return AVERROR_INVALIDDATA;

252

253 switch (syncword_dts) {

254 case DCA_MARKER_RAW_BE:

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

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

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

258 break;

259 case DCA_MARKER_RAW_LE:

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

261 ctx->extra_bswap = 1;

262 break;

263 case DCA_MARKER_14B_BE:

264 blocks =

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

266 break;

267 case DCA_MARKER_14B_LE:

268 blocks =

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

270 ctx->extra_bswap = 1;

271 break;

272 case DCA_HD_MARKER:

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

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

275 core in the beginning of the stream. */

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

277 return AVERROR_INVALIDDATA;

278 default:

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

280 return AVERROR_INVALIDDATA;

281 }

282 blocks++;

283

284 if (ctx->dtshd_rate)

285 /* DTS type IV output requested */

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

287

288 switch (blocks) {

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

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

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

292 default:

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

294 blocks << 5);

295 return AVERROR(ENOSYS);

296 }

297

298 /* discard extraneous data by default */

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

300 ctx->out_bytes = core_size;

301 ctx->length_code = core_size << 3;

302 }

303

304 ctx->pkt_offset = blocks << 7;

305

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

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

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

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

310 ctx->use_preamble = 0;

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

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

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

314 }

315

316 return 0;

317 }

318

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

320 // LAYER1 LAYER2 LAYER3

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

322 { IEC61937_MPEG1_LAYER1, IEC61937_MPEG1_LAYER23, IEC61937_MPEG1_LAYER23 }, //MPEG1

323 };

324

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

326 {

327 IEC61937Context *ctx = s->priv_data;

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

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

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

331

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

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

334 return AVERROR_INVALIDDATA;

335 }

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

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

338 ctx->data_type = IEC61937_MPEG2_EXT;

339 ctx->pkt_offset = 4608;

340 } else {

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

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

343 }

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

345 return 0;

346 }

347

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

349 {

350 IEC61937Context *ctx = s->priv_data;

351 AACADTSHeaderInfo hdr;

352 GetBitContext gbc;

353 int ret;

354

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

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

357 if (ret < 0) {

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

359 return AVERROR_INVALIDDATA;

360 }

361

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

363 switch (hdr.num_aac_frames) {

364 case 1:

365 ctx->data_type = IEC61937_MPEG2_AAC;

366 break;

367 case 2:

368 ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048;

369 break;

370 case 4:

371 ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096;

372 break;

373 default:

374 av_log(s, AV_LOG_ERROR,

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

376 return AVERROR(EINVAL);

377 }

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

379 return 0;

380 }

381

382

383 /*

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

385 * they can be encapsulated in IEC 61937.

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

387 * to achieve constant rate.

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

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

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

391 */

392 #define MAT_FRAME_SIZE 61424

393 #define TRUEHD_FRAME_OFFSET 2560

394 #define MAT_MIDDLE_CODE_OFFSET -4

395

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

397 {

398 IEC61937Context *ctx = s->priv_data;

399 int mat_code_length = 0;

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

401

402 if (!ctx->hd_buf_count) {

403 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 };

404 mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE;

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

406

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

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

409 mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET;

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

411 mat_middle_code, sizeof(mat_middle_code));

412 }

413

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

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