Add Cineform HD Decoder
[libav.git] / libavformat / spdifenc.c
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-preamble - IEC61937 frame header, contains 16-bit 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/dca_syncwords.h"
55 #include "libavcodec/aacadtsdec.h"
56 #include "libavutil/opt.h"
57
58 typedef struct IEC61937Context {
59 const AVClass *av_class;
60 enum IEC61937DataType data_type;///< burst info - reference to type of payload of the data-burst
61 int length_code; ///< length code in bits or bytes, depending on data type
62 int pkt_offset; ///< data burst repetition period in bytes
63 uint8_t *buffer; ///< allocated buffer, used for swap bytes
64 int buffer_size; ///< size of allocated buffer
65
66 uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping
67 int out_bytes; ///< amount of outgoing bytes
68
69 int use_preamble; ///< preamble enabled (disabled for exactly pre-padded DTS)
70 int extra_bswap; ///< extra bswap for payload (for LE DTS => standard BE DTS)
71
72 uint8_t *hd_buf; ///< allocated buffer to concatenate hd audio frames
73 int hd_buf_size; ///< size of the hd audio buffer
74 int hd_buf_count; ///< number of frames in the hd audio buffer
75 int hd_buf_filled; ///< amount of bytes in the hd audio buffer
76
77 int dtshd_skip; ///< counter used for skipping DTS-HD frames
78
79 /* AVOptions: */
80 int dtshd_rate;
81 int dtshd_fallback;
82 #define SPDIF_FLAG_BIGENDIAN 0x01
83 int spdif_flags;
84
85 /// function, which generates codec dependent header information.
86 /// Sets data_type and pkt_offset, and length_code, out_bytes, out_buf if necessary
87 int (*header_info) (AVFormatContext *s, AVPacket *pkt);
88 } IEC61937Context;
89
90 static const AVOption options[] = {
91 { "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" },
92 { "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" },
93 { "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 },
94 { "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 },
95 { NULL },
96 };
97
98 static const AVClass class = {
99 .class_name = "spdif",
100 .item_name = av_default_item_name,
101 .option = options,
102 .version = LIBAVUTIL_VERSION_INT,
103 };
104
105 static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
106 {
107 IEC61937Context *ctx = s->priv_data;
108 int bitstream_mode = pkt->data[5] & 0x7;
109
110 ctx->data_type = IEC61937_AC3 | (bitstream_mode << 8);
111 ctx->pkt_offset = AC3_FRAME_SIZE << 2;
112 return 0;
113 }
114
115 static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)
116 {
117 IEC61937Context *ctx = s->priv_data;
118 static const uint8_t eac3_repeat[4] = {6, 3, 2, 1};
119 int repeat = 1;
120
121 if ((pkt->data[4] & 0xc0) != 0xc0) /* fscod */
122 repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */
123
124 ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size);
125 if (!ctx->hd_buf)
126 return AVERROR(ENOMEM);
127
128 memcpy(&ctx->hd_buf[ctx->hd_buf_filled], pkt->data, pkt->size);
129
130 ctx->hd_buf_filled += pkt->size;
131 if (++ctx->hd_buf_count < repeat){
132 ctx->pkt_offset = 0;
133 return 0;
134 }
135 ctx->data_type = IEC61937_EAC3;
136 ctx->pkt_offset = 24576;
137 ctx->out_buf = ctx->hd_buf;
138 ctx->out_bytes = ctx->hd_buf_filled;
139 ctx->length_code = ctx->hd_buf_filled;
140
141 ctx->hd_buf_count = 0;
142 ctx->hd_buf_filled = 0;
143 return 0;
144 }
145
146 /*
147 * DTS type IV (DTS-HD) can be transmitted with various frame repetition
148 * periods; longer repetition periods allow for longer packets and therefore
149 * higher bitrate. Longer repetition periods mean that the constant bitrate of
150 * the output IEC 61937 stream is higher.
151 * The repetition period is measured in IEC 60958 frames (4 bytes).
152 */
153 static int spdif_dts4_subtype(int period)
154 {
155 switch (period) {
156 case 512: return 0x0;
157 case 1024: return 0x1;
158 case 2048: return 0x2;
159 case 4096: return 0x3;
160 case 8192: return 0x4;
161 case 16384: return 0x5;
162 }
163 return -1;
164 }
165
166 static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size,
167 int sample_rate, int blocks)
168 {
169 IEC61937Context *ctx = s->priv_data;
170 static const char dtshd_start_code[10] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0xfe };
171 int pkt_size = pkt->size;
172 int period;
173 int subtype;
174
175 if (!core_size) {
176 av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n");
177 return AVERROR(EINVAL);
178 }
179
180 if (!sample_rate) {
181 av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n");
182 return AVERROR_INVALIDDATA;
183 }
184
185 period = ctx->dtshd_rate * (blocks << 5) / sample_rate;
186 subtype = spdif_dts4_subtype(period);
187
188 if (subtype < 0) {
189 av_log(s, AV_LOG_ERROR, "Specified HD rate of %d Hz would require an "
190 "impossible repetition period of %d for the current DTS stream"
191 " (blocks = %d, sample rate = %d)\n", ctx->dtshd_rate, period,
192 blocks << 5, sample_rate);
193 return AVERROR(EINVAL);
194 }
195
196 /* set pkt_offset and DTS IV subtype according to the requested output
197 * rate */
198 ctx->pkt_offset = period * 4;
199 ctx->data_type = IEC61937_DTSHD | subtype << 8;
200
201 /* If the bitrate is too high for transmitting at the selected
202 * repetition period setting, strip DTS-HD until a good amount
203 * of consecutive non-overflowing HD frames have been observed.
204 * This generally only happens if the caller is cramming a Master
205 * Audio stream into 192kHz IEC 60958 (which may or may not fit). */
206 if (sizeof(dtshd_start_code) + 2 + pkt_size
207 > ctx->pkt_offset - BURST_HEADER_SIZE && core_size) {
208 if (!ctx->dtshd_skip)
209 av_log(s, AV_LOG_WARNING, "DTS-HD bitrate too high, "
210 "temporarily sending core only\n");
211 if (ctx->dtshd_fallback > 0)
212 ctx->dtshd_skip = sample_rate * ctx->dtshd_fallback / (blocks << 5);
213 else
214 /* skip permanently (dtshd_fallback == -1) or just once
215 * (dtshd_fallback == 0) */
216 ctx->dtshd_skip = 1;
217 }
218 if (ctx->dtshd_skip && core_size) {
219 pkt_size = core_size;
220 if (ctx->dtshd_fallback >= 0)
221 --ctx->dtshd_skip;
222 }
223
224 ctx->out_bytes = sizeof(dtshd_start_code) + 2 + pkt_size;
225
226 /* Align so that (length_code & 0xf) == 0x8. This is reportedly needed
227 * with some receivers, but the exact requirement is unconfirmed. */
228 ctx->length_code = FFALIGN(ctx->out_bytes + 0x8, 0x10) - 0x8;
229
230 av_fast_malloc(&ctx->hd_buf, &ctx->hd_buf_size, ctx->out_bytes);
231 if (!ctx->hd_buf)
232 return AVERROR(ENOMEM);
233
234 ctx->out_buf = ctx->hd_buf;
235
236 memcpy(ctx->hd_buf, dtshd_start_code, sizeof(dtshd_start_code));
237 AV_WB16(ctx->hd_buf + sizeof(dtshd_start_code), pkt_size);
238 memcpy(ctx->hd_buf + sizeof(dtshd_start_code) + 2, pkt->data, pkt_size);
239
240 return 0;
241 }
242
243 static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
244 {
245 IEC61937Context *ctx = s->priv_data;
246 uint32_t syncword_dts = AV_RB32(pkt->data);
247 int blocks;
248 int sample_rate = 0;
249 int core_size = 0;
250
251 if (pkt->size < 9)
252 return AVERROR_INVALIDDATA;
253
254 switch (syncword_dts) {
255 case DCA_SYNCWORD_CORE_BE:
256 blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
257 core_size = ((AV_RB24(pkt->data + 5) >> 4) & 0x3fff) + 1;
258 sample_rate = avpriv_dca_sample_rates[(pkt->data[8] >> 2) & 0x0f];
259 break;
260 case DCA_SYNCWORD_CORE_LE:
261 blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
262 ctx->extra_bswap = 1;
263 break;
264 case DCA_SYNCWORD_CORE_14B_BE:
265 blocks =
266 (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
267 break;
268 case DCA_SYNCWORD_CORE_14B_LE:
269 blocks =
270 (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
271 ctx->extra_bswap = 1;
272 break;
273 case DCA_SYNCWORD_SUBSTREAM:
274 /* We only handle HD frames that are paired with core. However,
275 sometimes DTS-HD streams with core have a stray HD frame without
276 core in the beginning of the stream. */
277 av_log(s, AV_LOG_ERROR, "stray DTS-HD frame\n");
278 return AVERROR_INVALIDDATA;
279 default:
280 av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%"PRIx32"\n", syncword_dts);
281 return AVERROR_INVALIDDATA;
282 }
283 blocks++;
284
285 if (ctx->dtshd_rate)
286 /* DTS type IV output requested */
287 return spdif_header_dts4(s, pkt, core_size, sample_rate, blocks);
288
289 switch (blocks) {
290 case 512 >> 5: ctx->data_type = IEC61937_DTS1; break;
291 case 1024 >> 5: ctx->data_type = IEC61937_DTS2; break;
292 case 2048 >> 5: ctx->data_type = IEC61937_DTS3; break;
293 default:
294 av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
295 blocks << 5);
296 return AVERROR(ENOSYS);
297 }
298
299 /* discard extraneous data by default */
300 if (core_size && core_size < pkt->size) {
301 ctx->out_bytes = core_size;
302 ctx->length_code = core_size << 3;
303 }
304
305 ctx->pkt_offset = blocks << 7;
306
307 if (ctx->out_bytes == ctx->pkt_offset) {
308 /* The DTS stream fits exactly into the output stream, so skip the
309 * preamble as it would not fit in there. This is the case for dts
310 * discs and dts-in-wav. */
311 ctx->use_preamble = 0;
312 } else if (ctx->out_bytes > ctx->pkt_offset - BURST_HEADER_SIZE) {
313 avpriv_request_sample(s, "Unrecognized large DTS frame");
314 /* This will fail with a "bitrate too high" in the caller */
315 }
316
317 return 0;
318 }
319
320 static const enum IEC61937DataType mpeg_data_type[2][3] = {
321 // LAYER1 LAYER2 LAYER3
322 { IEC61937_MPEG2_LAYER1_LSF, IEC61937_MPEG2_LAYER2_LSF, IEC61937_MPEG2_LAYER3_LSF }, // MPEG-2 LSF
323 { IEC61937_MPEG1_LAYER1, IEC61937_MPEG1_LAYER23, IEC61937_MPEG1_LAYER23 }, // MPEG-1
324 };
325
326 static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
327 {
328 IEC61937Context *ctx = s->priv_data;
329 int version = (pkt->data[1] >> 3) & 3;
330 int layer = 3 - ((pkt->data[1] >> 1) & 3);
331 int extension = pkt->data[2] & 1;
332
333 if (layer == 3 || version == 1) {
334 av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
335 return AVERROR_INVALIDDATA;
336 }
337 av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
338 if (version == 2 && extension) {
339 ctx->data_type = IEC61937_MPEG2_EXT;
340 ctx->pkt_offset = 4608;
341 } else {
342 ctx->data_type = mpeg_data_type [version & 1][layer];
343 ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer];
344 }
345 // TODO Data type dependent info (normal/karaoke, dynamic range control)
346 return 0;
347 }
348
349 static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
350 {
351 IEC61937Context *ctx = s->priv_data;
352 AACADTSHeaderInfo hdr;
353 GetBitContext gbc;
354 int ret;
355
356 init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
357 ret = avpriv_aac_parse_header(&gbc, &hdr);
358 if (ret < 0) {
359 av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
360 return AVERROR_INVALIDDATA;
361 }
362
363 ctx->pkt_offset = hdr.samples << 2;
364 switch (hdr.num_aac_frames) {
365 case 1:
366 ctx->data_type = IEC61937_MPEG2_AAC;
367 break;
368 case 2:
369 ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048;
370 break;
371 case 4:
372 ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096;
373 break;
374 default:
375 av_log(s, AV_LOG_ERROR,
376 "%"PRIu32" samples in AAC frame not supported\n", hdr.samples);
377 return AVERROR(EINVAL);
378 }
379 //TODO Data type dependent info (LC profile/SBR)
380 return 0;
381 }
382
383
384 /*
385 * It seems Dolby TrueHD frames have to be encapsulated in MAT frames before
386 * they can be encapsulated in IEC 61937.
387 * Here we encapsulate 24 TrueHD frames in a single MAT frame, padding them
388 * to achieve constant rate.
389 * The actual format of a MAT frame is unknown, but the below seems to work.
390 * However, it seems it is not actually necessary for the 24 TrueHD frames to
391 * be in an exact alignment with the MAT frame.
392 */
393 #define MAT_FRAME_SIZE 61424
394 #define TRUEHD_FRAME_OFFSET 2560
395 #define MAT_MIDDLE_CODE_OFFSET -4
396
397 static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)
398 {
399 IEC61937Context *ctx = s->priv_data;
400 int mat_code_length = 0;
401 static const char mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11 };
402
403 if (!ctx->hd_buf_count) {
404 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 };
405 mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE;
406 memcpy(ctx->hd_buf, mat_start_code, sizeof(mat_start_code));
407
408 } else if (ctx->hd_buf_count == 12) {
409 static const char mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0 };
410 mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET;
411 memcpy(&ctx->hd_buf[12 * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + MAT_MIDDLE_CODE_OFFSET],
412 mat_middle_code, sizeof(mat_middle_code));
413 }
414
415 if (pkt->size > TRUEHD_FRAME_OFFSET - mat_code_length) {
416 /* if such frames exist, we'd need some more complex logic to
417 * distribute the TrueHD frames in the MAT frame */
418 avpriv_request_sample(s, "Too large TrueHD frame of %d bytes",
419 pkt->size);
420 return AVERROR_PATCHWELCOME;
421 }
422
423 memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length],
424 pkt->data, pkt->size);
425 memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size],
426 0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length);
427
428 if (++ctx->hd_buf_count < 24){
429 ctx->pkt_offset = 0;
430 return 0;
431 }
432 memcpy(&ctx->hd_buf[MAT_FRAME_SIZE - sizeof(mat_end_code)], mat_end_code, sizeof(mat_end_code));
433 ctx->hd_buf_count = 0;
434
435 ctx->data_type = IEC61937_TRUEHD;
436 ctx->pkt_offset = 61440;
437 ctx->out_buf = ctx->hd_buf;
438 ctx->out_bytes = MAT_FRAME_SIZE;
439 ctx->length_code = MAT_FRAME_SIZE;
440 return 0;
441 }
442
443 static int spdif_write_header(AVFormatContext *s)
444 {
445 IEC61937Context *ctx = s->priv_data;
446
447 switch (s->streams[0]->codecpar->codec_id) {
448 case AV_CODEC_ID_AC3:
449 ctx->header_info = spdif_header_ac3;
450 break;
451 case AV_CODEC_ID_EAC3:
452 ctx->header_info = spdif_header_eac3;
453 break;
454 case AV_CODEC_ID_MP1:
455 case AV_CODEC_ID_MP2:
456 case AV_CODEC_ID_MP3:
457 ctx->header_info = spdif_header_mpeg;
458 break;
459 case AV_CODEC_ID_DTS:
460 ctx->header_info = spdif_header_dts;
461 break;
462 case AV_CODEC_ID_AAC:
463 ctx->header_info = spdif_header_aac;
464 break;
465 case AV_CODEC_ID_TRUEHD:
466 ctx->header_info = spdif_header_truehd;
467 ctx->hd_buf = av_malloc(MAT_FRAME_SIZE);
468 if (!ctx->hd_buf)
469 return AVERROR(ENOMEM);
470 break;
471 default:
472 avpriv_report_missing_feature(s, "Codec %d",
473 s->streams[0]->codecpar->codec_id);
474 return AVERROR_PATCHWELCOME;
475 }
476 return 0;
477 }
478
479 static int spdif_write_trailer(AVFormatContext *s)
480 {
481 IEC61937Context *ctx = s->priv_data;
482 av_freep(&ctx->buffer);
483 av_freep(&ctx->hd_buf);
484 return 0;
485 }
486
487 static av_always_inline void spdif_put_16(IEC61937Context *ctx,
488 AVIOContext *pb, unsigned int val)
489 {
490 if (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)
491 avio_wb16(pb, val);
492 else
493 avio_wl16(pb, val);
494 }
495
496 static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
497 {
498 IEC61937Context *ctx = s->priv_data;
499 int ret, padding;
500
501 ctx->out_buf = pkt->data;
502 ctx->out_bytes = pkt->size;
503 ctx->length_code = FFALIGN(pkt->size, 2) << 3;
504 ctx->use_preamble = 1;
505 ctx->extra_bswap = 0;
506
507 ret = ctx->header_info(s, pkt);
508 if (ret < 0)
509 return ret;
510 if (!ctx->pkt_offset)
511 return 0;
512
513 padding = (ctx->pkt_offset - ctx->use_preamble * BURST_HEADER_SIZE - ctx->out_bytes) & ~1;
514 if (padding < 0) {
515 av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
516 return AVERROR(EINVAL);
517 }
518
519 if (ctx->use_preamble) {
520 spdif_put_16(ctx, s->pb, SYNCWORD1); //Pa
521 spdif_put_16(ctx, s->pb, SYNCWORD2); //Pb
522 spdif_put_16(ctx, s->pb, ctx->data_type); //Pc
523 spdif_put_16(ctx, s->pb, ctx->length_code);//Pd
524 }
525
526 if (ctx->extra_bswap ^ (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)) {
527 avio_write(s->pb, ctx->out_buf, ctx->out_bytes & ~1);
528 } else {
529 av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + AV_INPUT_BUFFER_PADDING_SIZE);
530 if (!ctx->buffer)
531 return AVERROR(ENOMEM);
532 ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)ctx->out_buf, ctx->out_bytes >> 1);
533 avio_write(s->pb, ctx->buffer, ctx->out_bytes & ~1);
534 }
535
536 /* a final lone byte has to be MSB aligned */
537 if (ctx->out_bytes & 1)
538 spdif_put_16(ctx, s->pb, ctx->out_buf[ctx->out_bytes - 1] << 8);
539
540 ffio_fill(s->pb, 0, padding);
541
542 av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
543 ctx->data_type, ctx->out_bytes, ctx->pkt_offset);
544
545 return 0;
546 }
547
548 AVOutputFormat ff_spdif_muxer = {
549 .name = "spdif",
550 .long_name = NULL_IF_CONFIG_SMALL("IEC 61937 (used on S/PDIF - IEC958)"),
551 .extensions = "spdif",
552 .priv_data_size = sizeof(IEC61937Context),
553 .audio_codec = AV_CODEC_ID_AC3,
554 .video_codec = AV_CODEC_ID_NONE,
555 .write_header = spdif_write_header,
556 .write_packet = spdif_write_packet,
557 .write_trailer = spdif_write_trailer,
558 .flags = AVFMT_NOTIMESTAMPS,
559 .priv_class = &class,
560 };