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 Libav. 8 * 9 * Libav 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 * Libav 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 Libav; 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 "avformat.h" 48#include "avio_internal.h" 49#include "spdif.h" 50#include "libavcodec/ac3.h" 51#include "libavcodec/dca.h" 52#include "libavcodec/dcadata.h" 53#include "libavcodec/aacadtsdec.h" 54#include "libavutil/opt.h" 55 56typedef struct IEC61937Context { 57 const AVClass *av_class; 58 enum IEC61937DataType data_type;///< burst info - reference to type of payload of the data-burst 59 int length_code; ///< length code in bits or bytes, depending on data type 60 int pkt_offset; ///< data burst repetition period in bytes 61 uint8_t *buffer; ///< allocated buffer, used for swap bytes 62 int buffer_size; ///< size of allocated buffer 63 64 uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping 65 int out_bytes; ///< amount of outgoing bytes 66 67 int use_preamble; ///< preamble enabled (disabled for exactly pre-padded DTS) 68 int extra_bswap; ///< extra bswap for payload (for LE DTS => standard BE DTS) 69 70 uint8_t *hd_buf; ///< allocated buffer to concatenate hd audio frames 71 int hd_buf_size; ///< size of the hd audio buffer 72 int hd_buf_count; ///< number of frames in the hd audio buffer 73 int hd_buf_filled; ///< amount of bytes in the hd audio buffer 74 75 int dtshd_skip; ///< counter used for skipping DTS-HD frames 76 77 /* AVOptions: */ 78 int dtshd_rate; 79 int dtshd_fallback; 80#define SPDIF_FLAG_BIGENDIAN 0x01 81 int spdif_flags; 82 83 /// function, which generates codec dependent header information. 84 /// Sets data_type and pkt_offset, and length_code, out_bytes, out_buf if necessary 85 int (*header_info) (AVFormatContext *s, AVPacket *pkt); 86} IEC61937Context; 87 88static const AVOption options[] = { 89{ "spdif_flags", "IEC 61937 encapsulation flags", offsetof(IEC61937Context, spdif_flags), AV_OPT_TYPE_FLAGS, {.dbl = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" }, 90{ "be", "output in big-endian format (for use as s16be)", 0, AV_OPT_TYPE_CONST, {.dbl = SPDIF_FLAG_BIGENDIAN}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" }, 91{ "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, {.dbl = 0}, 0, 768000, AV_OPT_FLAG_ENCODING_PARAM }, 92{ "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, {.dbl = 60}, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM }, 93{ NULL }, 94}; 95 96static const AVClass class = { 97 .class_name = "spdif", 98 .item_name = av_default_item_name, 99 .option = options, 100 .version = LIBAVUTIL_VERSION_INT, 101}; 102 103static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt) 104{ 105 IEC61937Context *ctx = s->priv_data; 106 int bitstream_mode = pkt->data[5] & 0x7; 107 108 ctx->data_type = IEC61937_AC3 | (bitstream_mode << 8); 109 ctx->pkt_offset = AC3_FRAME_SIZE << 2; 110 return 0; 111} 112 113static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt) 114{ 115 IEC61937Context *ctx = s->priv_data; 116 static const uint8_t eac3_repeat[4] = {6, 3, 2, 1}; 117 int repeat = 1; 118 119 if ((pkt->data[4] & 0xc0) != 0xc0) /* fscod */ 120 repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */ 121 122 ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size); 123 if (!ctx->hd_buf) 124 return AVERROR(ENOMEM); 125 126 memcpy(&ctx->hd_buf[ctx->hd_buf_filled], pkt->data, pkt->size); 127 128 ctx->hd_buf_filled += pkt->size; 129 if (++ctx->hd_buf_count < repeat){ 130 ctx->pkt_offset = 0; 131 return 0; 132 } 133 ctx->data_type = IEC61937_EAC3; 134 ctx->pkt_offset = 24576; 135 ctx->out_buf = ctx->hd_buf; 136 ctx->out_bytes = ctx->hd_buf_filled; 137 ctx->length_code = ctx->hd_buf_filled; 138 139 ctx->hd_buf_count = 0; 140 ctx->hd_buf_filled = 0; 141 return 0; 142} 143 144/* 145 * DTS type IV (DTS-HD) can be transmitted with various frame repetition 146 * periods; longer repetition periods allow for longer packets and therefore 147 * higher bitrate. Longer repetition periods mean that the constant bitrate of 148 * the outputted IEC 61937 stream is higher. 149 * The repetition period is measured in IEC 60958 frames (4 bytes). 150 */ 151static int spdif_dts4_subtype(int period) 152{ 153 switch (period) { 154 case 512: return 0x0; 155 case 1024: return 0x1; 156 case 2048: return 0x2; 157 case 4096: return 0x3; 158 case 8192: return 0x4; 159 case 16384: return 0x5; 160 } 161 return -1; 162} 163 164static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size, 165 int sample_rate, int blocks) 166{ 167 IEC61937Context *ctx = s->priv_data; 168 static const char dtshd_start_code[10] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0xfe }; 169 int pkt_size = pkt->size; 170 int period; 171 int subtype; 172 173 if (!core_size) { 174 av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n"); 175 return AVERROR(EINVAL); 176 } 177 178 if (!sample_rate) { 179 av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n"); 180 return AVERROR_INVALIDDATA; 181 } 182 183 period = ctx->dtshd_rate * (blocks << 5) / sample_rate; 184 subtype = spdif_dts4_subtype(period); 185 186 if (subtype < 0) { 187 av_log(s, AV_LOG_ERROR, "Specified HD rate of %d Hz would require an " 188 "impossible repetition period of %d for the current DTS stream" 189 " (blocks = %d, sample rate = %d)\n", ctx->dtshd_rate, period, 190 blocks << 5, sample_rate); 191 return AVERROR(EINVAL); 192 } 193 194 /* set pkt_offset and DTS IV subtype according to the requested output 195 * rate */ 196 ctx->pkt_offset = period * 4; 197 ctx->data_type = IEC61937_DTSHD | subtype << 8; 198 199 /* If the bitrate is too high for transmitting at the selected 200 * repetition period setting, strip DTS-HD until a good amount 201 * of consecutive non-overflowing HD frames have been observed. 202 * This generally only happens if the caller is cramming a Master 203 * Audio stream into 192kHz IEC 60958 (which may or may not fit). */ 204 if (sizeof(dtshd_start_code) + 2 + pkt_size 205 > ctx->pkt_offset - BURST_HEADER_SIZE && core_size) { 206 if (!ctx->dtshd_skip) 207 av_log(s, AV_LOG_WARNING, "DTS-HD bitrate too high, " 208 "temporarily sending core only\n"); 209 if (ctx->dtshd_fallback > 0) 210 ctx->dtshd_skip = sample_rate * ctx->dtshd_fallback / (blocks << 5); 211 else 212 /* skip permanently (dtshd_fallback == -1) or just once 213 * (dtshd_fallback == 0) */ 214 ctx->dtshd_skip = 1; 215 } 216 if (ctx->dtshd_skip && core_size) { 217 pkt_size = core_size; 218 if (ctx->dtshd_fallback >= 0) 219 --ctx->dtshd_skip; 220 } 221 222 ctx->out_bytes = sizeof(dtshd_start_code) + 2 + pkt_size; 223 224 /* Align so that (length_code & 0xf) == 0x8. This is reportedly needed 225 * with some receivers, but the exact requirement is unconfirmed. */ 226 ctx->length_code = FFALIGN(ctx->out_bytes + 0x8, 0x10) - 0x8; 227 228 av_fast_malloc(&ctx->hd_buf, &ctx->hd_buf_size, ctx->out_bytes); 229 if (!ctx->hd_buf) 230 return AVERROR(ENOMEM); 231 232 ctx->out_buf = ctx->hd_buf; 233 234 memcpy(ctx->hd_buf, dtshd_start_code, sizeof(dtshd_start_code)); 235 AV_WB16(ctx->hd_buf + sizeof(dtshd_start_code), pkt_size); 236 memcpy(ctx->hd_buf + sizeof(dtshd_start_code) + 2, pkt->data, pkt_size); 237 238 return 0; 239} 240 241static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt) 242{ 243 IEC61937Context *ctx = s->priv_data; 244 uint32_t syncword_dts = AV_RB32(pkt->data); 245 int blocks; 246 int sample_rate = 0; 247 int core_size = 0; 248 249 if (pkt->size < 9) 250 return AVERROR_INVALIDDATA; 251 252 switch (syncword_dts) { 253 case DCA_MARKER_RAW_BE: 254 blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f; 255 core_size = ((AV_RB24(pkt->data + 5) >> 4) & 0x3fff) + 1; 256 sample_rate = dca_sample_rates[(pkt->data[8] >> 2) & 0x0f]; 257 break; 258 case DCA_MARKER_RAW_LE: 259 blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f; 260 ctx->extra_bswap = 1; 261 break; 262 case DCA_MARKER_14B_BE: 263 blocks = 264 (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2)); 265 break; 266 case DCA_MARKER_14B_LE: 267 blocks = 268 (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2)); 269 ctx->extra_bswap = 1; 270 break; 271 case DCA_HD_MARKER: 272 /* We only handle HD frames that are paired with core. However, 273 sometimes DTS-HD streams with core have a stray HD frame without 274 core in the beginning of the stream. */ 275 av_log(s, AV_LOG_ERROR, "stray DTS-HD frame\n"); 276 return AVERROR_INVALIDDATA; 277 default: 278 av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts); 279 return AVERROR_INVALIDDATA; 280 } 281 blocks++; 282 283 if (ctx->dtshd_rate) 284 /* DTS type IV output requested */ 285 return spdif_header_dts4(s, pkt, core_size, sample_rate, blocks); 286 287 switch (blocks) { 288 case 512 >> 5: ctx->data_type = IEC61937_DTS1; break; 289 case 1024 >> 5: ctx->data_type = IEC61937_DTS2; break; 290 case 2048 >> 5: ctx->data_type = IEC61937_DTS3; break; 291 default: 292 av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n", 293 blocks << 5); 294 return AVERROR(ENOSYS); 295 } 296 297 /* discard extraneous data by default */ 298 if (core_size && core_size < pkt->size) { 299 ctx->out_bytes = core_size; 300 ctx->length_code = core_size << 3; 301 } 302 303 ctx->pkt_offset = blocks << 7; 304 305 if (ctx->out_bytes == ctx->pkt_offset) { 306 /* The DTS stream fits exactly into the output stream, so skip the 307 * preamble as it would not fit in there. This is the case for dts 308 * discs and dts-in-wav. */ 309 ctx->use_preamble = 0; 310 } else if (ctx->out_bytes > ctx->pkt_offset - BURST_HEADER_SIZE) { 311 av_log_ask_for_sample(s, "Unrecognized large DTS frame."); 312 /* This will fail with a "bitrate too high" in the caller */ 313 } 314 315 return 0; 316} 317 318static const enum IEC61937DataType mpeg_data_type[2][3] = { 319 // LAYER1 LAYER2 LAYER3 320 { IEC61937_MPEG2_LAYER1_LSF, IEC61937_MPEG2_LAYER2_LSF, IEC61937_MPEG2_LAYER3_LSF },//MPEG2 LSF 321 { IEC61937_MPEG1_LAYER1, IEC61937_MPEG1_LAYER23, IEC61937_MPEG1_LAYER23 }, //MPEG1 322}; 323 324static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt) 325{ 326 IEC61937Context *ctx = s->priv_data; 327 int version = (pkt->data[1] >> 3) & 3; 328 int layer = 3 - ((pkt->data[1] >> 1) & 3); 329 int extension = pkt->data[2] & 1; 330 331 if (layer == 3 || version == 1) { 332 av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n"); 333 return AVERROR_INVALIDDATA; 334 } 335 av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension); 336 if (version == 2 && extension) { 337 ctx->data_type = IEC61937_MPEG2_EXT; 338 ctx->pkt_offset = 4608; 339 } else { 340 ctx->data_type = mpeg_data_type [version & 1][layer]; 341 ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer]; 342 } 343 // TODO Data type dependant info (normal/karaoke, dynamic range control) 344 return 0; 345} 346 347static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt) 348{ 349 IEC61937Context *ctx = s->priv_data; 350 AACADTSHeaderInfo hdr; 351 GetBitContext gbc; 352 int ret; 353 354 init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8); 355 ret = avpriv_aac_parse_header(&gbc, &hdr); 356 if (ret < 0) { 357 av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n"); 358 return AVERROR_INVALIDDATA; 359 } 360 361 ctx->pkt_offset = hdr.samples << 2; 362 switch (hdr.num_aac_frames) { 363 case 1: 364 ctx->data_type = IEC61937_MPEG2_AAC; 365 break; 366 case 2: 367 ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048; 368 break; 369 case 4: 370 ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096; 371 break; 372 default: 373 av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n", 374 hdr.samples); 375 return AVERROR(EINVAL); 376 } 377 //TODO Data type dependent info (LC profile/SBR) 378 return 0; 379} 380 381 382/* 383 * It seems Dolby TrueHD frames have to be encapsulated in MAT frames before 384 * they can be encapsulated in IEC 61937. 385 * Here we encapsulate 24 TrueHD frames in a single MAT frame, padding them 386 * to achieve constant rate. 387 * The actual format of a MAT frame is unknown, but the below seems to work. 388 * However, it seems it is not actually necessary for the 24 TrueHD frames to 389 * be in an exact alignment with the MAT frame. 390 */ 391#define MAT_FRAME_SIZE 61424 392#define TRUEHD_FRAME_OFFSET 2560 393#define MAT_MIDDLE_CODE_OFFSET -4 394 395static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt) 396{ 397 IEC61937Context *ctx = s->priv_data; 398 int mat_code_length = 0; 399 const char mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11 }; 400 401 if (!ctx->hd_buf_count) { 402 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 }; 403 mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE; 404 memcpy(ctx->hd_buf, mat_start_code, sizeof(mat_start_code)); 405 406 } else if (ctx->hd_buf_count == 12) { 407 const char mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0 }; 408 mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET; 409 memcpy(&ctx->hd_buf[12 * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + MAT_MIDDLE_CODE_OFFSET], 410 mat_middle_code, sizeof(mat_middle_code)); 411 } 412 413 if (pkt->size > TRUEHD_FRAME_OFFSET - mat_code_length) { 414 /* if such frames exist, we'd need some more complex logic to 415 * distribute the TrueHD frames in the MAT frame */ 416 av_log(s, AV_LOG_ERROR, "TrueHD frame too big, %d bytes\n", pkt->size); 417 av_log_ask_for_sample(s, NULL); 418 return AVERROR_INVALIDDATA; 419 } 420 421 memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length], 422 pkt->data, pkt->size); 423 memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size], 424 0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length); 425 426 if (++ctx->hd_buf_count < 24){ 427 ctx->pkt_offset = 0; 428 return 0; 429 } 430 memcpy(&ctx->hd_buf[MAT_FRAME_SIZE - sizeof(mat_end_code)], mat_end_code, sizeof(mat_end_code)); 431 ctx->hd_buf_count = 0; 432 433 ctx->data_type = IEC61937_TRUEHD; 434 ctx->pkt_offset = 61440; 435 ctx->out_buf = ctx->hd_buf; 436 ctx->out_bytes = MAT_FRAME_SIZE; 437 ctx->length_code = MAT_FRAME_SIZE; 438 return 0; 439} 440 441static int spdif_write_header(AVFormatContext *s) 442{ 443 IEC61937Context *ctx = s->priv_data; 444 445 switch (s->streams[0]->codec->codec_id) { 446 case CODEC_ID_AC3: 447 ctx->header_info = spdif_header_ac3; 448 break; 449 case CODEC_ID_EAC3: 450 ctx->header_info = spdif_header_eac3; 451 break; 452 case CODEC_ID_MP1: 453 case CODEC_ID_MP2: 454 case CODEC_ID_MP3: 455 ctx->header_info = spdif_header_mpeg; 456 break; 457 case CODEC_ID_DTS: 458 ctx->header_info = spdif_header_dts; 459 break; 460 case CODEC_ID_AAC: 461 ctx->header_info = spdif_header_aac; 462 break; 463 case CODEC_ID_TRUEHD: 464 ctx->header_info = spdif_header_truehd; 465 ctx->hd_buf = av_malloc(MAT_FRAME_SIZE); 466 if (!ctx->hd_buf) 467 return AVERROR(ENOMEM); 468 break; 469 default: 470 av_log(s, AV_LOG_ERROR, "codec not supported\n"); 471 return AVERROR_PATCHWELCOME; 472 } 473 return 0; 474} 475 476static int spdif_write_trailer(AVFormatContext *s) 477{ 478 IEC61937Context *ctx = s->priv_data; 479 av_freep(&ctx->buffer); 480 av_freep(&ctx->hd_buf); 481 return 0; 482} 483 484static av_always_inline void spdif_put_16(IEC61937Context *ctx, 485 AVIOContext *pb, unsigned int val) 486{ 487 if (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN) 488 avio_wb16(pb, val); 489 else 490 avio_wl16(pb, val); 491} 492 493static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt) 494{ 495 IEC61937Context *ctx = s->priv_data; 496 int ret, padding; 497 498 ctx->out_buf = pkt->data; 499 ctx->out_bytes = pkt->size; 500 ctx->length_code = FFALIGN(pkt->size, 2) << 3; 501 ctx->use_preamble = 1; 502 ctx->extra_bswap = 0; 503 504 ret = ctx->header_info(s, pkt); 505 if (ret < 0) 506 return ret; 507 if (!ctx->pkt_offset) 508 return 0; 509 510 padding = (ctx->pkt_offset - ctx->use_preamble * BURST_HEADER_SIZE - ctx->out_bytes) & ~1; 511 if (padding < 0) { 512 av_log(s, AV_LOG_ERROR, "bitrate is too high\n"); 513 return AVERROR(EINVAL); 514 } 515 516 if (ctx->use_preamble) { 517 spdif_put_16(ctx, s->pb, SYNCWORD1); //Pa 518 spdif_put_16(ctx, s->pb, SYNCWORD2); //Pb 519 spdif_put_16(ctx, s->pb, ctx->data_type); //Pc 520 spdif_put_16(ctx, s->pb, ctx->length_code);//Pd 521 } 522 523 if (ctx->extra_bswap ^ (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)) { 524 avio_write(s->pb, ctx->out_buf, ctx->out_bytes & ~1); 525 } else { 526 av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + FF_INPUT_BUFFER_PADDING_SIZE); 527 if (!ctx->buffer) 528 return AVERROR(ENOMEM); 529 ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)ctx->out_buf, ctx->out_bytes >> 1); 530 avio_write(s->pb, ctx->buffer, ctx->out_bytes & ~1); 531 } 532 533 /* a final lone byte has to be MSB aligned */ 534 if (ctx->out_bytes & 1) 535 spdif_put_16(ctx, s->pb, ctx->out_buf[ctx->out_bytes - 1] << 8); 536 537 ffio_fill(s->pb, 0, padding); 538 539 av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n", 540 ctx->data_type, ctx->out_bytes, ctx->pkt_offset); 541 542 avio_flush(s->pb); 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 = CODEC_ID_AC3, 552 .video_codec = 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 = &class, 558}; 559