1/* 2 * IEC 61937 muxer 3 * Copyright (c) 2009 Bartlomiej Wolowiec 4 * Copyright (c) 2010 Anssi Hannula 5 * Copyright (c) 2010 Carl Eugen Hoyos 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 */ 23 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 */ 31 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 */ 46 47#include <inttypes.h> 48 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" 56 57typedef 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 64 65 uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping 66 int out_bytes; ///< amount of outgoing bytes 67 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) 70 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 75 76 int dtshd_skip; ///< counter used for skipping DTS-HD frames 77 78 /* AVOptions: */ 79 int dtshd_rate; 80 int dtshd_fallback; 81#define SPDIF_FLAG_BIGENDIAN 0x01 82 int spdif_flags; 83 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; 88 89static 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}; 96 97static 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 104static 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 114static 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 */ 152static 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 165static 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 242static 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 319static 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 325static 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 348static 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 396static 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 416 * distribute the TrueHD frames in the MAT frame */ 417 avpriv_request_sample(s, "Too large TrueHD frame of %d bytes", 418 pkt->size); 419 return AVERROR_PATCHWELCOME; 420 } 421 422 memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length], 423 pkt->data, pkt->size); 424 memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size], 425 0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length); 426 427 if (++ctx->hd_buf_count < 24){ 428 ctx->pkt_offset = 0; 429 return 0; 430 } 431 memcpy(&ctx->hd_buf[MAT_FRAME_SIZE - sizeof(mat_end_code)], mat_end_code, sizeof(mat_end_code)); 432 ctx->hd_buf_count = 0; 433 434 ctx->data_type = IEC61937_TRUEHD; 435 ctx->pkt_offset = 61440; 436 ctx->out_buf = ctx->hd_buf; 437 ctx->out_bytes = MAT_FRAME_SIZE; 438 ctx->length_code = MAT_FRAME_SIZE; 439 return 0; 440} 441 442static int spdif_write_header(AVFormatContext *s) 443{ 444 IEC61937Context *ctx = s->priv_data; 445 446 switch (s->streams[0]->codec->codec_id) { 447 case AV_CODEC_ID_AC3: 448 ctx->header_info = spdif_header_ac3; 449 break; 450 case AV_CODEC_ID_EAC3: 451 ctx->header_info = spdif_header_eac3; 452 break; 453 case AV_CODEC_ID_MP1: 454 case AV_CODEC_ID_MP2: 455 case AV_CODEC_ID_MP3: 456 ctx->header_info = spdif_header_mpeg; 457 break; 458 case AV_CODEC_ID_DTS: 459 ctx->header_info = spdif_header_dts; 460 break; 461 case AV_CODEC_ID_AAC: 462 ctx->header_info = spdif_header_aac; 463 break; 464 case AV_CODEC_ID_TRUEHD: 465 ctx->header_info = spdif_header_truehd; 466 ctx->hd_buf = av_malloc(MAT_FRAME_SIZE); 467 if (!ctx->hd_buf) 468 return AVERROR(ENOMEM); 469 break; 470 default: 471 av_log(s, AV_LOG_ERROR, "codec not supported\n"); 472 return AVERROR_PATCHWELCOME; 473 } 474 return 0; 475} 476 477static int spdif_write_trailer(AVFormatContext *s) 478{ 479 IEC61937Context *ctx = s->priv_data; 480 av_freep(&ctx->buffer); 481 av_freep(&ctx->hd_buf); 482 return 0; 483} 484 485static av_always_inline void spdif_put_16(IEC61937Context *ctx, 486 AVIOContext *pb, unsigned int val) 487{ 488 if (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN) 489 avio_wb16(pb, val); 490 else 491 avio_wl16(pb, val); 492} 493 494static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt) 495{ 496 IEC61937Context *ctx = s->priv_data; 497 int ret, padding; 498 499 ctx->out_buf = pkt->data; 500 ctx->out_bytes = pkt->size; 501 ctx->length_code = FFALIGN(pkt->size, 2) << 3; 502 ctx->use_preamble = 1; 503 ctx->extra_bswap = 0; 504 505 ret = ctx->header_info(s, pkt); 506 if (ret < 0) 507 return ret; 508 if (!ctx->pkt_offset) 509 return 0; 510 511 padding = (ctx->pkt_offset - ctx->use_preamble * BURST_HEADER_SIZE - ctx->out_bytes) & ~1; 512 if (padding < 0) { 513 av_log(s, AV_LOG_ERROR, "bitrate is too high\n"); 514 return AVERROR(EINVAL); 515 } 516 517 if (ctx->use_preamble) { 518 spdif_put_16(ctx, s->pb, SYNCWORD1); //Pa 519 spdif_put_16(ctx, s->pb, SYNCWORD2); //Pb 520 spdif_put_16(ctx, s->pb, ctx->data_type); //Pc 521 spdif_put_16(ctx, s->pb, ctx->length_code);//Pd 522 } 523 524 if (ctx->extra_bswap ^ (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)) { 525 avio_write(s->pb, ctx->out_buf, ctx->out_bytes & ~1); 526 } else { 527 av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + FF_INPUT_BUFFER_PADDING_SIZE); 528 if (!ctx->buffer) 529 return AVERROR(ENOMEM); 530 ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)ctx->out_buf, ctx->out_bytes >> 1); 531 avio_write(s->pb, ctx->buffer, ctx->out_bytes & ~1); 532 } 533 534 /* a final lone byte has to be MSB aligned */ 535 if (ctx->out_bytes & 1) 536 spdif_put_16(ctx, s->pb, ctx->out_buf[ctx->out_bytes - 1] << 8); 537 538 ffio_fill(s->pb, 0, padding); 539 540 av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n", 541 ctx->data_type, ctx->out_bytes, ctx->pkt_offset); 542 543 return 0; 544} 545 546AVOutputFormat ff_spdif_muxer = { 547 .name = "spdif", 548 .long_name = NULL_IF_CONFIG_SMALL("IEC 61937 (used on S/PDIF - IEC958)"), 549 .extensions = "spdif", 550 .priv_data_size = sizeof(IEC61937Context), 551 .audio_codec = AV_CODEC_ID_AC3, 552 .video_codec = AV_CODEC_ID_NONE, 553 .write_header = spdif_write_header, 554 .write_packet = spdif_write_packet, 555 .write_trailer = spdif_write_trailer, 556 .flags = AVFMT_NOTIMESTAMPS, 557 .priv_class = &spdif_class, 558}; 559