/* * IEC 61937 muxer * Copyright (c) 2009 Bartlomiej Wolowiec * Copyright (c) 2010, 2020 Anssi Hannula * Copyright (c) 2010 Carl Eugen Hoyos * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * IEC-61937 encapsulation of various formats, used by S/PDIF * @author Bartlomiej Wolowiec * @author Anssi Hannula * @author Carl Eugen Hoyos */ /* * Terminology used in specification: * data-burst - IEC61937 frame, contains header and encapsuled frame * burst-preamble - IEC61937 frame header, contains 16-bit words named Pa, Pb, Pc and Pd * burst-payload - encapsuled frame * Pa, Pb - syncword - 0xF872, 0x4E1F * Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12) * and bitstream number (bits 13-15) * data-type - determines type of encapsuled frames * Pd - length code (number of bits or bytes of encapsuled frame - according to data_type) * * IEC 61937 frames at normal usage start every specific count of bytes, * dependent from data-type (spaces between packets are filled by zeros) */ #include <inttypes.h> #include "avformat.h" #include "avio_internal.h" #include "spdif.h" #include "libavcodec/ac3.h" #include "libavcodec/adts_parser.h" #include "libavcodec/dca.h" #include "libavcodec/dca_syncwords.h" #include "libavutil/opt.h" typedef struct IEC61937Context { const AVClass *av_class; enum IEC61937DataType data_type;///< burst info - reference to type of payload of the data-burst int length_code; ///< length code in bits or bytes, depending on data type int pkt_offset; ///< data burst repetition period in bytes uint8_t *buffer; ///< allocated buffer, used for swap bytes int buffer_size; ///< size of allocated buffer uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping int out_bytes; ///< amount of outgoing bytes int use_preamble; ///< preamble enabled (disabled for exactly pre-padded DTS) int extra_bswap; ///< extra bswap for payload (for LE DTS => standard BE DTS) uint8_t *hd_buf[2]; ///< allocated buffers to concatenate hd audio frames int hd_buf_size; ///< size of the hd audio buffer (eac3, dts4) int hd_buf_count; ///< number of frames in the hd audio buffer (eac3) int hd_buf_filled; ///< amount of bytes in the hd audio buffer (eac3, truehd) int hd_buf_idx; ///< active hd buffer index (truehd) int dtshd_skip; ///< counter used for skipping DTS-HD frames uint16_t truehd_prev_time; ///< input_timing from the last frame int truehd_prev_size; ///< previous frame size in bytes, including any MAT codes int truehd_samples_per_frame; ///< samples per frame for padding calculation /* AVOptions: */ int dtshd_rate; int dtshd_fallback; #define SPDIF_FLAG_BIGENDIAN 0x01 int spdif_flags; /// function, which generates codec dependent header information. /// Sets data_type and pkt_offset, and length_code, out_bytes, out_buf if necessary int (*header_info) (AVFormatContext *s, AVPacket *pkt); } IEC61937Context; static const AVOption options[] = { { "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" }, { "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" }, { "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 }, { "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 }, { NULL }, }; static const AVClass spdif_class = { .class_name = "spdif", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt) { IEC61937Context *ctx = s->priv_data; int bitstream_mode = pkt->data[5] & 0x7; ctx->data_type = IEC61937_AC3 | (bitstream_mode << 8); ctx->pkt_offset = AC3_FRAME_SIZE << 2; return 0; } static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt) { IEC61937Context *ctx = s->priv_data; static const uint8_t eac3_repeat[4] = {6, 3, 2, 1}; int repeat = 1; int bsid = pkt->data[5] >> 3; if (bsid > 10 && (pkt->data[4] & 0xc0) != 0xc0) /* fscod */ repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */ ctx->hd_buf[0] = av_fast_realloc(ctx->hd_buf[0], &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size); if (!ctx->hd_buf[0]) return AVERROR(ENOMEM); memcpy(&ctx->hd_buf[0][ctx->hd_buf_filled], pkt->data, pkt->size); ctx->hd_buf_filled += pkt->size; if (++ctx->hd_buf_count < repeat){ ctx->pkt_offset = 0; return 0; } ctx->data_type = IEC61937_EAC3; ctx->pkt_offset = 24576; ctx->out_buf = ctx->hd_buf[0]; ctx->out_bytes = ctx->hd_buf_filled; ctx->length_code = ctx->hd_buf_filled; ctx->hd_buf_count = 0; ctx->hd_buf_filled = 0; return 0; } /* * DTS type IV (DTS-HD) can be transmitted with various frame repetition * periods; longer repetition periods allow for longer packets and therefore * higher bitrate. Longer repetition periods mean that the constant bitrate of * the output IEC 61937 stream is higher. * The repetition period is measured in IEC 60958 frames (4 bytes). */ static int spdif_dts4_subtype(int period) { switch (period) { case 512: return 0x0; case 1024: return 0x1; case 2048: return 0x2; case 4096: return 0x3; case 8192: return 0x4; case 16384: return 0x5; } return -1; } static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size, int sample_rate, int blocks) { IEC61937Context *ctx = s->priv_data; static const char dtshd_start_code[10] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0xfe }; int pkt_size = pkt->size; int period; int subtype; if (!core_size) { av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n"); return AVERROR(EINVAL); } if (!sample_rate) { av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n"); return AVERROR_INVALIDDATA; } period = ctx->dtshd_rate * (blocks << 5) / sample_rate; subtype = spdif_dts4_subtype(period); if (subtype < 0) { av_log(s, AV_LOG_ERROR, "Specified HD rate of %d Hz would require an " "impossible repetition period of %d for the current DTS stream" " (blocks = %d, sample rate = %d)\n", ctx->dtshd_rate, period, blocks << 5, sample_rate); return AVERROR(EINVAL); } /* set pkt_offset and DTS IV subtype according to the requested output * rate */ ctx->pkt_offset = period * 4; ctx->data_type = IEC61937_DTSHD | subtype << 8; /* If the bitrate is too high for transmitting at the selected * repetition period setting, strip DTS-HD until a good amount * of consecutive non-overflowing HD frames have been observed. * This generally only happens if the caller is cramming a Master * Audio stream into 192kHz IEC 60958 (which may or may not fit). */ if (sizeof(dtshd_start_code) + 2 + pkt_size > ctx->pkt_offset - BURST_HEADER_SIZE && core_size) { if (!ctx->dtshd_skip) av_log(s, AV_LOG_WARNING, "DTS-HD bitrate too high, " "temporarily sending core only\n"); if (ctx->dtshd_fallback > 0) ctx->dtshd_skip = sample_rate * ctx->dtshd_fallback / (blocks << 5); else /* skip permanently (dtshd_fallback == -1) or just once * (dtshd_fallback == 0) */ ctx->dtshd_skip = 1; } if (ctx->dtshd_skip && core_size) { pkt_size = core_size; if (ctx->dtshd_fallback >= 0) --ctx->dtshd_skip; } ctx->out_bytes = sizeof(dtshd_start_code) + 2 + pkt_size; /* Align so that (length_code & 0xf) == 0x8. This is reportedly needed * with some receivers, but the exact requirement is unconfirmed. */ ctx->length_code = FFALIGN(ctx->out_bytes + 0x8, 0x10) - 0x8; av_fast_malloc(&ctx->hd_buf[0], &ctx->hd_buf_size, ctx->out_bytes); if (!ctx->hd_buf[0]) return AVERROR(ENOMEM); ctx->out_buf = ctx->hd_buf[0]; memcpy(ctx->hd_buf[0], dtshd_start_code, sizeof(dtshd_start_code)); AV_WB16(ctx->hd_buf[0] + sizeof(dtshd_start_code), pkt_size); memcpy(ctx->hd_buf[0] + sizeof(dtshd_start_code) + 2, pkt->data, pkt_size); return 0; } static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt) { IEC61937Context *ctx = s->priv_data; uint32_t syncword_dts = AV_RB32(pkt->data); int blocks; int sample_rate = 0; int core_size = 0; if (pkt->size < 9) return AVERROR_INVALIDDATA; switch (syncword_dts) { case DCA_SYNCWORD_CORE_BE: blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f; core_size = ((AV_RB24(pkt->data + 5) >> 4) & 0x3fff) + 1; sample_rate = avpriv_dca_sample_rates[(pkt->data[8] >> 2) & 0x0f]; break; case DCA_SYNCWORD_CORE_LE: blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f; ctx->extra_bswap = 1; break; case DCA_SYNCWORD_CORE_14B_BE: blocks = (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2)); break; case DCA_SYNCWORD_CORE_14B_LE: blocks = (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2)); ctx->extra_bswap = 1; break; case DCA_SYNCWORD_SUBSTREAM: /* We only handle HD frames that are paired with core. However, sometimes DTS-HD streams with core have a stray HD frame without core in the beginning of the stream. */ av_log(s, AV_LOG_ERROR, "stray DTS-HD frame\n"); return AVERROR_INVALIDDATA; default: av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%"PRIx32"\n", syncword_dts); return AVERROR_INVALIDDATA; } blocks++; if (ctx->dtshd_rate) /* DTS type IV output requested */ return spdif_header_dts4(s, pkt, core_size, sample_rate, blocks); switch (blocks) { case 512 >> 5: ctx->data_type = IEC61937_DTS1; break; case 1024 >> 5: ctx->data_type = IEC61937_DTS2; break; case 2048 >> 5: ctx->data_type = IEC61937_DTS3; break; default: av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n", blocks << 5); return AVERROR(ENOSYS); } /* discard extraneous data by default */ if (core_size && core_size < pkt->size) { ctx->out_bytes = core_size; ctx->length_code = core_size << 3; } ctx->pkt_offset = blocks << 7; if (ctx->out_bytes == ctx->pkt_offset) { /* The DTS stream fits exactly into the output stream, so skip the * preamble as it would not fit in there. This is the case for dts * discs and dts-in-wav. */ ctx->use_preamble = 0; } else if (ctx->out_bytes > ctx->pkt_offset - BURST_HEADER_SIZE) { avpriv_request_sample(s, "Unrecognized large DTS frame"); /* This will fail with a "bitrate too high" in the caller */ } return 0; } static const enum IEC61937DataType mpeg_data_type[2][3] = { // LAYER1 LAYER2 LAYER3 { IEC61937_MPEG2_LAYER1_LSF, IEC61937_MPEG2_LAYER2_LSF, IEC61937_MPEG2_LAYER3_LSF }, // MPEG-2 LSF { IEC61937_MPEG1_LAYER1, IEC61937_MPEG1_LAYER23, IEC61937_MPEG1_LAYER23 }, // MPEG-1 }; static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt) { IEC61937Context *ctx = s->priv_data; int version = (pkt->data[1] >> 3) & 3; int layer = 3 - ((pkt->data[1] >> 1) & 3); int extension = pkt->data[2] & 1; if (layer == 3 || version == 1) { av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n"); return AVERROR_INVALIDDATA; } av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension); if (version == 2 && extension) { ctx->data_type = IEC61937_MPEG2_EXT; ctx->pkt_offset = 4608; } else { ctx->data_type = mpeg_data_type [version & 1][layer]; ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer]; } // TODO Data type dependent info (normal/karaoke, dynamic range control) return 0; } static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt) { IEC61937Context *ctx = s->priv_data; uint32_t samples; uint8_t frames; int ret; ret = av_adts_header_parse(pkt->data, &samples, &frames); if (ret < 0) { av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n"); return ret; } ctx->pkt_offset = samples << 2; switch (frames) { case 1: ctx->data_type = IEC61937_MPEG2_AAC; break; case 2: ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048; break; case 4: ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096; break; default: av_log(s, AV_LOG_ERROR, "%"PRIu32" samples in AAC frame not supported\n", samples); return AVERROR(EINVAL); } //TODO Data type dependent info (LC profile/SBR) return 0; } /* * It seems Dolby TrueHD frames have to be encapsulated in MAT frames before * they can be encapsulated in IEC 61937. */ #define MAT_PKT_OFFSET 61440 #define MAT_FRAME_SIZE 61424 static const uint8_t mat_start_code[20] = { 0x07, 0x9E, 0x00, 0x03, 0x84, 0x01, 0x01, 0x01, 0x80, 0x00, 0x56, 0xA5, 0x3B, 0xF4, 0x81, 0x83, 0x49, 0x80, 0x77, 0xE0, }; static const uint8_t mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0, }; static const uint8_t mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11, }; #define MAT_CODE(position, data) { .pos = position, .code = data, .len = sizeof(data) } static const struct { unsigned int pos; const uint8_t *code; unsigned int len; } mat_codes[] = { MAT_CODE(0, mat_start_code), MAT_CODE(30708, mat_middle_code), MAT_CODE(MAT_FRAME_SIZE - sizeof(mat_end_code), mat_end_code), }; static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt) { IEC61937Context *ctx = s->priv_data; uint8_t *hd_buf = ctx->hd_buf[ctx->hd_buf_idx]; int ratebits; int padding_remaining = 0; uint16_t input_timing; int total_frame_size = pkt->size; const uint8_t *dataptr = pkt->data; int data_remaining = pkt->size; int have_pkt = 0; int next_code_idx; if (pkt->size < 10) return AVERROR_INVALIDDATA; if (AV_RB24(pkt->data + 4) == 0xf8726f) { /* major sync unit, fetch sample rate */ if (pkt->data[7] == 0xba) ratebits = pkt->data[8] >> 4; else if (pkt->data[7] == 0xbb) ratebits = pkt->data[9] >> 4; else return AVERROR_INVALIDDATA; ctx->truehd_samples_per_frame = 40 << (ratebits & 3); av_log(s, AV_LOG_TRACE, "TrueHD samples per frame: %d\n", ctx->truehd_samples_per_frame); } if (!ctx->truehd_samples_per_frame) return AVERROR_INVALIDDATA; input_timing = AV_RB16(pkt->data + 2); if (ctx->truehd_prev_size) { uint16_t delta_samples = input_timing - ctx->truehd_prev_time; /* * One multiple-of-48kHz frame is 1/1200 sec and the IEC 61937 rate * is 768kHz = 768000*4 bytes/sec. * The nominal space per frame is therefore * (768000*4 bytes/sec) * (1/1200 sec) = 2560 bytes. * For multiple-of-44.1kHz frames: 1/1102.5 sec, 705.6kHz, 2560 bytes. * * 2560 is divisible by truehd_samples_per_frame. */ int delta_bytes = delta_samples * 2560 / ctx->truehd_samples_per_frame; /* padding needed before this frame */ padding_remaining = delta_bytes - ctx->truehd_prev_size; av_log(s, AV_LOG_TRACE, "delta_samples: %"PRIu16", delta_bytes: %d\n", delta_samples, delta_bytes); /* sanity check */ if (padding_remaining < 0 || padding_remaining >= MAT_FRAME_SIZE / 2) { avpriv_request_sample(s, "Unusual frame timing: %"PRIu16" => %"PRIu16", %d samples/frame", ctx->truehd_prev_time, input_timing, ctx->truehd_samples_per_frame); padding_remaining = 0; } } for (next_code_idx = 0; next_code_idx < FF_ARRAY_ELEMS(mat_codes); next_code_idx++) if (ctx->hd_buf_filled <= mat_codes[next_code_idx].pos) break; if (next_code_idx >= FF_ARRAY_ELEMS(mat_codes)) return AVERROR_BUG; while (padding_remaining || data_remaining || mat_codes[next_code_idx].pos == ctx->hd_buf_filled) { if (mat_codes[next_code_idx].pos == ctx->hd_buf_filled) { /* time to insert MAT code */ int code_len = mat_codes[next_code_idx].len; int code_len_remaining = code_len; memcpy(hd_buf + mat_codes[next_code_idx].pos, mat_codes[next_code_idx].code, code_len); ctx->hd_buf_filled += code_len; next_code_idx++; if (next_code_idx == FF_ARRAY_ELEMS(mat_codes)) { next_code_idx = 0; /* this was the last code, move to the next MAT frame */ have_pkt = 1; ctx->out_buf = hd_buf; ctx->hd_buf_idx ^= 1; hd_buf = ctx->hd_buf[ctx->hd_buf_idx]; ctx->hd_buf_filled = 0; /* inter-frame gap has to be counted as well, add it */ code_len_remaining += MAT_PKT_OFFSET - MAT_FRAME_SIZE; } if (padding_remaining) { /* consider the MAT code as padding */ int counted_as_padding = FFMIN(padding_remaining, code_len_remaining); padding_remaining -= counted_as_padding; code_len_remaining -= counted_as_padding; } /* count the remainder of the code as part of frame size */ if (code_len_remaining) total_frame_size += code_len_remaining; } if (padding_remaining) { int padding_to_insert = FFMIN(mat_codes[next_code_idx].pos - ctx->hd_buf_filled, padding_remaining); memset(hd_buf + ctx->hd_buf_filled, 0, padding_to_insert); ctx->hd_buf_filled += padding_to_insert; padding_remaining -= padding_to_insert; if (padding_remaining) continue; /* time to insert MAT code */ } if (data_remaining) { int data_to_insert = FFMIN(mat_codes[next_code_idx].pos - ctx->hd_buf_filled, data_remaining); memcpy(hd_buf + ctx->hd_buf_filled, dataptr, data_to_insert); ctx->hd_buf_filled += data_to_insert; dataptr += data_to_insert; data_remaining -= data_to_insert; } } ctx->truehd_prev_size = total_frame_size; ctx->truehd_prev_time = input_timing; av_log(s, AV_LOG_TRACE, "TrueHD frame inserted, total size %d, buffer position %d\n", total_frame_size, ctx->hd_buf_filled); if (!have_pkt) { ctx->pkt_offset = 0; return 0; } ctx->data_type = IEC61937_TRUEHD; ctx->pkt_offset = MAT_PKT_OFFSET; ctx->out_bytes = MAT_FRAME_SIZE; ctx->length_code = MAT_FRAME_SIZE; return 0; } static int spdif_write_header(AVFormatContext *s) { IEC61937Context *ctx = s->priv_data; switch (s->streams[0]->codecpar->codec_id) { case AV_CODEC_ID_AC3: ctx->header_info = spdif_header_ac3; break; case AV_CODEC_ID_EAC3: ctx->header_info = spdif_header_eac3; break; case AV_CODEC_ID_MP1: case AV_CODEC_ID_MP2: case AV_CODEC_ID_MP3: ctx->header_info = spdif_header_mpeg; break; case AV_CODEC_ID_DTS: ctx->header_info = spdif_header_dts; break; case AV_CODEC_ID_AAC: ctx->header_info = spdif_header_aac; break; case AV_CODEC_ID_TRUEHD: case AV_CODEC_ID_MLP: ctx->header_info = spdif_header_truehd; for (int i = 0; i < FF_ARRAY_ELEMS(ctx->hd_buf); i++) { ctx->hd_buf[i] = av_malloc(MAT_FRAME_SIZE); if (!ctx->hd_buf[i]) return AVERROR(ENOMEM); } break; default: avpriv_report_missing_feature(s, "Codec %d", s->streams[0]->codecpar->codec_id); return AVERROR_PATCHWELCOME; } return 0; } static void spdif_deinit(AVFormatContext *s) { IEC61937Context *ctx = s->priv_data; av_freep(&ctx->buffer); for (int i = 0; i < FF_ARRAY_ELEMS(ctx->hd_buf); i++) av_freep(&ctx->hd_buf[i]); } static av_always_inline void spdif_put_16(IEC61937Context *ctx, AVIOContext *pb, unsigned int val) { if (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN) avio_wb16(pb, val); else avio_wl16(pb, val); } static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt) { IEC61937Context *ctx = s->priv_data; int ret, padding; ctx->out_buf = pkt->data; ctx->out_bytes = pkt->size; ctx->length_code = FFALIGN(pkt->size, 2) << 3; ctx->use_preamble = 1; ctx->extra_bswap = 0; ret = ctx->header_info(s, pkt); if (ret < 0) return ret; if (!ctx->pkt_offset) return 0; padding = (ctx->pkt_offset - ctx->use_preamble * BURST_HEADER_SIZE - ctx->out_bytes) & ~1; if (padding < 0) { av_log(s, AV_LOG_ERROR, "bitrate is too high\n"); return AVERROR(EINVAL); } if (ctx->use_preamble) { spdif_put_16(ctx, s->pb, SYNCWORD1); //Pa spdif_put_16(ctx, s->pb, SYNCWORD2); //Pb spdif_put_16(ctx, s->pb, ctx->data_type); //Pc spdif_put_16(ctx, s->pb, ctx->length_code);//Pd } if (ctx->extra_bswap ^ (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)) { avio_write(s->pb, ctx->out_buf, ctx->out_bytes & ~1); } else { av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + AV_INPUT_BUFFER_PADDING_SIZE); if (!ctx->buffer) return AVERROR(ENOMEM); ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)ctx->out_buf, ctx->out_bytes >> 1); avio_write(s->pb, ctx->buffer, ctx->out_bytes & ~1); } /* a final lone byte has to be MSB aligned */ if (ctx->out_bytes & 1) spdif_put_16(ctx, s->pb, ctx->out_buf[ctx->out_bytes - 1] << 8); ffio_fill(s->pb, 0, padding); av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n", ctx->data_type, ctx->out_bytes, ctx->pkt_offset); return 0; } AVOutputFormat ff_spdif_muxer = { .name = "spdif", .long_name = NULL_IF_CONFIG_SMALL("IEC 61937 (used on S/PDIF - IEC958)"), .extensions = "spdif", .priv_data_size = sizeof(IEC61937Context), .audio_codec = AV_CODEC_ID_AC3, .video_codec = AV_CODEC_ID_NONE, .write_header = spdif_write_header, .write_packet = spdif_write_packet, .deinit = spdif_deinit, .flags = AVFMT_NOTIMESTAMPS, .priv_class = &spdif_class, };