3 * Copyright (c) 2009 Bartlomiej Wolowiec
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * IEC-61937 encapsulation of various formats, used by S/PDIF
25 * @author Bartlomiej Wolowiec
29 * Terminology used in specification:
30 * data-burst - IEC958 frame, contains header and encapsuled frame
31 * burst-preambule - IEC958 frame header, contains 16-bits words named Pa, Pb, Pc and Pd
32 * burst-payload - encapsuled frame
33 * Pa, Pb - syncword - 0xF872, 0x4E1F
34 * Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12)
35 * and bitstream number (bits 13-15)
36 * data-type - determines type of encapsuled frames
37 * Pd - length code (number of bits or bytes of encapsuled frame - according to data_type)
39 * IEC958 frames at normal usage start every specific count of bytes,
40 * dependent from data-type (spaces between packets are filled by zeros)
45 #include "libavcodec/ac3.h"
46 #include "libavcodec/dca.h"
47 #include "libavcodec/aacadtsdec.h"
49 typedef struct IEC958Context {
50 enum IEC958DataType data_type; ///< burst info - reference to type of payload of the data-burst
51 int length_code; ///< length code in bits or bytes, depending on data type
52 int pkt_offset; ///< data burst repetition period in bytes
53 uint8_t *buffer; ///< allocated buffer, used for swap bytes
54 int buffer_size; ///< size of allocated buffer
56 uint8_t *out_buf; ///< pointer to the outgoing data before byte-swapping
57 int out_bytes; ///< amount of outgoing bytes
59 uint8_t *hd_buf; ///< allocated buffer to concatenate hd audio frames
60 int hd_buf_size; ///< size of the hd audio buffer
61 int hd_buf_count; ///< number of frames in the hd audio buffer
62 int hd_buf_filled; ///< amount of bytes in the hd audio buffer
64 /// function, which generates codec dependent header information.
65 /// Sets data_type and pkt_offset, and length_code, out_bytes, out_buf if necessary
66 int (*header_info) (AVFormatContext *s, AVPacket *pkt);
70 static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
72 IEC958Context *ctx = s->priv_data;
73 int bitstream_mode = pkt->data[6] & 0x7;
75 ctx->data_type = IEC958_AC3 | (bitstream_mode << 8);
76 ctx->pkt_offset = AC3_FRAME_SIZE << 2;
80 static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)
82 IEC958Context *ctx = s->priv_data;
83 static const uint8_t eac3_repeat[4] = {6, 3, 2, 1};
86 if ((pkt->data[4] & 0xc0) != 0xc0) /* fscod */
87 repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */
89 ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size);
91 return AVERROR(ENOMEM);
93 memcpy(&ctx->hd_buf[ctx->hd_buf_filled], pkt->data, pkt->size);
95 ctx->hd_buf_filled += pkt->size;
96 if (++ctx->hd_buf_count < repeat){
100 ctx->data_type = IEC958_EAC3;
101 ctx->pkt_offset = 24576;
102 ctx->out_buf = ctx->hd_buf;
103 ctx->out_bytes = ctx->hd_buf_filled;
104 ctx->length_code = ctx->hd_buf_filled;
106 ctx->hd_buf_count = 0;
107 ctx->hd_buf_filled = 0;
111 static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
113 IEC958Context *ctx = s->priv_data;
114 uint32_t syncword_dts = AV_RB32(pkt->data);
117 switch (syncword_dts) {
118 case DCA_MARKER_RAW_BE:
119 blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
121 case DCA_MARKER_RAW_LE:
122 blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
124 case DCA_MARKER_14B_BE:
126 (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
128 case DCA_MARKER_14B_LE:
130 (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
133 av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
138 case 512 >> 5: ctx->data_type = IEC958_DTS1; break;
139 case 1024 >> 5: ctx->data_type = IEC958_DTS2; break;
140 case 2048 >> 5: ctx->data_type = IEC958_DTS3; break;
142 av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
146 ctx->pkt_offset = blocks << 7;
151 static const enum IEC958DataType mpeg_data_type[2][3] = {
152 // LAYER1 LAYER2 LAYER3
153 { IEC958_MPEG2_LAYER1_LSF, IEC958_MPEG2_LAYER2_LSF, IEC958_MPEG2_LAYER3_LSF }, //MPEG2 LSF
154 { IEC958_MPEG1_LAYER1, IEC958_MPEG1_LAYER23, IEC958_MPEG1_LAYER23 }, //MPEG1
157 static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
159 IEC958Context *ctx = s->priv_data;
160 int version = (pkt->data[1] >> 3) & 3;
161 int layer = 3 - ((pkt->data[1] >> 1) & 3);
162 int extension = pkt->data[2] & 1;
164 if (layer == 3 || version == 1) {
165 av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
168 av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
169 if (version == 2 && extension) {
170 ctx->data_type = IEC958_MPEG2_EXT;
171 ctx->pkt_offset = 4608;
173 ctx->data_type = mpeg_data_type [version & 1][layer];
174 ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer];
176 // TODO Data type dependant info (normal/karaoke, dynamic range control)
180 static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
182 IEC958Context *ctx = s->priv_data;
183 AACADTSHeaderInfo hdr;
187 init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
188 ret = ff_aac_parse_header(&gbc, &hdr);
190 av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
194 ctx->pkt_offset = hdr.samples << 2;
195 switch (hdr.num_aac_frames) {
197 ctx->data_type = IEC958_MPEG2_AAC;
200 ctx->data_type = IEC958_MPEG2_AAC_LSF_2048;
203 ctx->data_type = IEC958_MPEG2_AAC_LSF_4096;
206 av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
210 //TODO Data type dependent info (LC profile/SBR)
216 * It seems Dolby TrueHD frames have to be encapsulated in MAT frames before
217 * they can be encapsulated in IEC 61937.
218 * Here we encapsulate 24 TrueHD frames in a single MAT frame, padding them
219 * to achieve constant rate.
220 * The actual format of a MAT frame is unknown, but the below seems to work.
221 * However, it seems it is not actually necessary for the 24 TrueHD frames to
222 * be in an exact alignment with the MAT frame.
224 #define MAT_FRAME_SIZE 61424
225 #define TRUEHD_FRAME_OFFSET 2560
226 #define MAT_MIDDLE_CODE_OFFSET -4
228 static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)
230 IEC958Context *ctx = s->priv_data;
231 int mat_code_length = 0;
232 const char mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11 };
234 if (!ctx->hd_buf_count) {
235 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 };
236 mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE;
237 memcpy(ctx->hd_buf, mat_start_code, sizeof(mat_start_code));
239 } else if (ctx->hd_buf_count == 12) {
240 const char mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0 };
241 mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET;
242 memcpy(&ctx->hd_buf[12 * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + MAT_MIDDLE_CODE_OFFSET],
243 mat_middle_code, sizeof(mat_middle_code));
246 if (pkt->size > TRUEHD_FRAME_OFFSET - mat_code_length) {
247 /* if such frames exist, we'd need some more complex logic to
248 * distribute the TrueHD frames in the MAT frame */
249 av_log(s, AV_LOG_ERROR, "TrueHD frame too big, %d bytes\n", pkt->size);
250 av_log_ask_for_sample(s, NULL);
254 memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length],
255 pkt->data, pkt->size);
256 memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size],
257 0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length);
259 if (++ctx->hd_buf_count < 24){
263 memcpy(&ctx->hd_buf[MAT_FRAME_SIZE - sizeof(mat_end_code)], mat_end_code, sizeof(mat_end_code));
264 ctx->hd_buf_count = 0;
266 ctx->data_type = IEC958_TRUEHD;
267 ctx->pkt_offset = 61440;
268 ctx->out_buf = ctx->hd_buf;
269 ctx->out_bytes = MAT_FRAME_SIZE;
270 ctx->length_code = MAT_FRAME_SIZE;
274 static int spdif_write_header(AVFormatContext *s)
276 IEC958Context *ctx = s->priv_data;
278 switch (s->streams[0]->codec->codec_id) {
280 ctx->header_info = spdif_header_ac3;
283 ctx->header_info = spdif_header_eac3;
288 ctx->header_info = spdif_header_mpeg;
291 ctx->header_info = spdif_header_dts;
294 ctx->header_info = spdif_header_aac;
296 case CODEC_ID_TRUEHD:
297 ctx->header_info = spdif_header_truehd;
298 ctx->hd_buf = av_malloc(MAT_FRAME_SIZE);
300 return AVERROR(ENOMEM);
303 av_log(s, AV_LOG_ERROR, "codec not supported\n");
309 static int spdif_write_trailer(AVFormatContext *s)
311 IEC958Context *ctx = s->priv_data;
312 av_freep(&ctx->buffer);
313 av_freep(&ctx->hd_buf);
317 static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
319 IEC958Context *ctx = s->priv_data;
322 ctx->out_buf = pkt->data;
323 ctx->out_bytes = pkt->size;
324 ctx->length_code = FFALIGN(pkt->size, 2) << 3;
326 ret = ctx->header_info(s, pkt);
329 if (!ctx->pkt_offset)
332 padding = (ctx->pkt_offset - BURST_HEADER_SIZE - ctx->out_bytes) >> 1;
334 av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
338 put_le16(s->pb, SYNCWORD1); //Pa
339 put_le16(s->pb, SYNCWORD2); //Pb
340 put_le16(s->pb, ctx->data_type); //Pc
341 put_le16(s->pb, ctx->length_code);//Pd
344 put_buffer(s->pb, ctx->out_buf, ctx->out_bytes & ~1);
346 av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + FF_INPUT_BUFFER_PADDING_SIZE);
348 return AVERROR(ENOMEM);
349 ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)ctx->out_buf, ctx->out_bytes >> 1);
350 put_buffer(s->pb, ctx->buffer, ctx->out_bytes & ~1);
353 if (ctx->out_bytes & 1)
354 put_be16(s->pb, ctx->out_buf[ctx->out_bytes - 1]);
356 for (; padding > 0; padding--)
359 av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
360 ctx->data_type, ctx->out_bytes, ctx->pkt_offset);
362 put_flush_packet(s->pb);
366 AVOutputFormat spdif_muxer = {
368 NULL_IF_CONFIG_SMALL("IEC958 - S/PDIF (IEC-61937)"),
371 sizeof(IEC958Context),