3 * Copyright (c) 2009 Bartlomiej Wolowiec
4 * Copyright (c) 2010 Anssi Hannula
5 * Copyright (c) 2010 Carl Eugen Hoyos
7 * This file is part of FFmpeg.
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.
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.
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
26 * IEC-61937 encapsulation of various formats, used by S/PDIF
27 * @author Bartlomiej Wolowiec
28 * @author Anssi Hannula
29 * @author Carl Eugen Hoyos
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)
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)
48 #include "avio_internal.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"
56 typedef 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
64 uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping
65 int out_bytes; ///< amount of outgoing bytes
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)
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
75 int dtshd_skip; ///< counter used for skipping DTS-HD frames
80 #define SPDIF_FLAG_BIGENDIAN 0x01
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);
88 static 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 },
96 static const AVClass class = {
97 .class_name = "spdif",
98 .item_name = av_default_item_name,
100 .version = LIBAVUTIL_VERSION_INT,
103 static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
105 IEC61937Context *ctx = s->priv_data;
106 int bitstream_mode = pkt->data[5] & 0x7;
108 ctx->data_type = IEC61937_AC3 | (bitstream_mode << 8);
109 ctx->pkt_offset = AC3_FRAME_SIZE << 2;
113 static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)
115 IEC61937Context *ctx = s->priv_data;
116 static const uint8_t eac3_repeat[4] = {6, 3, 2, 1};
119 if ((pkt->data[4] & 0xc0) != 0xc0) /* fscod */
120 repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */
122 ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size);
124 return AVERROR(ENOMEM);
126 memcpy(&ctx->hd_buf[ctx->hd_buf_filled], pkt->data, pkt->size);
128 ctx->hd_buf_filled += pkt->size;
129 if (++ctx->hd_buf_count < repeat){
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;
139 ctx->hd_buf_count = 0;
140 ctx->hd_buf_filled = 0;
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).
151 static int spdif_dts4_subtype(int 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;
164 static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size,
165 int sample_rate, int blocks)
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;
174 av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n");
175 return AVERROR(EINVAL);
179 av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n");
180 return AVERROR_INVALIDDATA;
183 period = ctx->dtshd_rate * (blocks << 5) / sample_rate;
184 subtype = spdif_dts4_subtype(period);
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);
194 /* set pkt_offset and DTS IV subtype according to the requested output
196 ctx->pkt_offset = period * 4;
197 ctx->data_type = IEC61937_DTSHD | subtype << 8;
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);
212 /* skip permanently (dtshd_fallback == -1) or just once
213 * (dtshd_fallback == 0) */
216 if (ctx->dtshd_skip && core_size) {
217 pkt_size = core_size;
218 if (ctx->dtshd_fallback >= 0)
222 ctx->out_bytes = sizeof(dtshd_start_code) + 2 + pkt_size;
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;
228 av_fast_malloc(&ctx->hd_buf, &ctx->hd_buf_size, ctx->out_bytes);
230 return AVERROR(ENOMEM);
232 ctx->out_buf = ctx->hd_buf;
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);
241 static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
243 IEC61937Context *ctx = s->priv_data;
244 uint32_t syncword_dts = AV_RB32(pkt->data);
250 return AVERROR_INVALIDDATA;
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];
258 case DCA_MARKER_RAW_LE:
259 blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
260 ctx->extra_bswap = 1;
262 case DCA_MARKER_14B_BE:
264 (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
266 case DCA_MARKER_14B_LE:
268 (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
269 ctx->extra_bswap = 1;
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;
278 av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
279 return AVERROR_INVALIDDATA;
284 /* DTS type IV output requested */
285 return spdif_header_dts4(s, pkt, core_size, sample_rate, 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;
292 av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
294 return AVERROR(ENOSYS);
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;
303 ctx->pkt_offset = blocks << 7;
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 */
318 static 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
324 static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
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;
331 if (layer == 3 || version == 1) {
332 av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
333 return AVERROR_INVALIDDATA;
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;
340 ctx->data_type = mpeg_data_type [version & 1][layer];
341 ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer];
343 // TODO Data type dependant info (normal/karaoke, dynamic range control)
347 static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
349 IEC61937Context *ctx = s->priv_data;
350 AACADTSHeaderInfo hdr;
354 init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
355 ret = avpriv_aac_parse_header(&gbc, &hdr);
357 av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
358 return AVERROR_INVALIDDATA;
361 ctx->pkt_offset = hdr.samples << 2;
362 switch (hdr.num_aac_frames) {
364 ctx->data_type = IEC61937_MPEG2_AAC;
367 ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048;
370 ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096;
373 av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
375 return AVERROR(EINVAL);
377 //TODO Data type dependent info (LC profile/SBR)
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.
391 #define MAT_FRAME_SIZE 61424
392 #define TRUEHD_FRAME_OFFSET 2560
393 #define MAT_MIDDLE_CODE_OFFSET -4
395 static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)
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 };
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));
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));
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;
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);
426 if (++ctx->hd_buf_count < 24){
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;
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;
441 static int spdif_write_header(AVFormatContext *s)
443 IEC61937Context *ctx = s->priv_data;
445 switch (s->streams[0]->codec->codec_id) {
447 ctx->header_info = spdif_header_ac3;
450 ctx->header_info = spdif_header_eac3;
455 ctx->header_info = spdif_header_mpeg;
458 ctx->header_info = spdif_header_dts;
461 ctx->header_info = spdif_header_aac;
463 case CODEC_ID_TRUEHD:
464 ctx->header_info = spdif_header_truehd;
465 ctx->hd_buf = av_malloc(MAT_FRAME_SIZE);
467 return AVERROR(ENOMEM);
470 av_log(s, AV_LOG_ERROR, "codec not supported\n");
471 return AVERROR_PATCHWELCOME;
476 static int spdif_write_trailer(AVFormatContext *s)
478 IEC61937Context *ctx = s->priv_data;
479 av_freep(&ctx->buffer);
480 av_freep(&ctx->hd_buf);
484 static av_always_inline void spdif_put_16(IEC61937Context *ctx,
485 AVIOContext *pb, unsigned int val)
487 if (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)
493 static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
495 IEC61937Context *ctx = s->priv_data;
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;
504 ret = ctx->header_info(s, pkt);
507 if (!ctx->pkt_offset)
510 padding = (ctx->pkt_offset - ctx->use_preamble * BURST_HEADER_SIZE - ctx->out_bytes) & ~1;
512 av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
513 return AVERROR(EINVAL);
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
523 if (ctx->extra_bswap ^ (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)) {
524 avio_write(s->pb, ctx->out_buf, ctx->out_bytes & ~1);
526 av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + FF_INPUT_BUFFER_PADDING_SIZE);
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);
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);
537 ffio_fill(s->pb, 0, padding);
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);
546 AVOutputFormat ff_spdif_muxer = {
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,