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 pkt_size; ///< length code in bits
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 /// function, which generates codec dependent header information.
57 /// Sets data_type and data_offset
58 int (*header_info) (AVFormatContext *s, AVPacket *pkt);
62 static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
64 IEC958Context *ctx = s->priv_data;
65 int bitstream_mode = pkt->data[6] & 0x7;
67 ctx->data_type = IEC958_AC3 | (bitstream_mode << 8);
68 ctx->pkt_offset = AC3_FRAME_SIZE << 2;
72 static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
74 IEC958Context *ctx = s->priv_data;
75 uint32_t syncword_dts = AV_RB32(pkt->data);
78 switch (syncword_dts) {
79 case DCA_MARKER_RAW_BE:
80 blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
82 case DCA_MARKER_RAW_LE:
83 blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
85 case DCA_MARKER_14B_BE:
87 (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
89 case DCA_MARKER_14B_LE:
91 (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
94 av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
99 case 512 >> 5: ctx->data_type = IEC958_DTS1; break;
100 case 1024 >> 5: ctx->data_type = IEC958_DTS2; break;
101 case 2048 >> 5: ctx->data_type = IEC958_DTS3; break;
103 av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
107 ctx->pkt_offset = blocks << 7;
112 static const enum IEC958DataType mpeg_data_type[2][3] = {
113 // LAYER1 LAYER2 LAYER3
114 { IEC958_MPEG2_LAYER1_LSF, IEC958_MPEG2_LAYER2_LSF, IEC958_MPEG2_LAYER3_LSF }, //MPEG2 LSF
115 { IEC958_MPEG1_LAYER1, IEC958_MPEG1_LAYER23, IEC958_MPEG1_LAYER23 }, //MPEG1
118 static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
120 IEC958Context *ctx = s->priv_data;
121 int version = (pkt->data[1] >> 3) & 3;
122 int layer = 3 - ((pkt->data[1] >> 1) & 3);
123 int extension = pkt->data[2] & 1;
125 if (layer == 3 || version == 1) {
126 av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
129 av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
130 if (version == 2 && extension) {
131 ctx->data_type = IEC958_MPEG2_EXT;
132 ctx->pkt_offset = 4608;
134 ctx->data_type = mpeg_data_type [version & 1][layer];
135 ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer];
137 // TODO Data type dependant info (normal/karaoke, dynamic range control)
141 static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
143 IEC958Context *ctx = s->priv_data;
144 AACADTSHeaderInfo hdr;
148 init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
149 ret = ff_aac_parse_header(&gbc, &hdr);
151 av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
155 ctx->pkt_offset = hdr.samples << 2;
156 switch (hdr.num_aac_frames) {
158 ctx->data_type = IEC958_MPEG2_AAC;
161 ctx->data_type = IEC958_MPEG2_AAC_LSF_2048;
164 ctx->data_type = IEC958_MPEG2_AAC_LSF_4096;
167 av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
171 //TODO Data type dependent info (LC profile/SBR)
175 static int spdif_write_header(AVFormatContext *s)
177 IEC958Context *ctx = s->priv_data;
179 switch (s->streams[0]->codec->codec_id) {
181 ctx->header_info = spdif_header_ac3;
186 ctx->header_info = spdif_header_mpeg;
189 ctx->header_info = spdif_header_dts;
192 ctx->header_info = spdif_header_aac;
195 av_log(s, AV_LOG_ERROR, "codec not supported\n");
201 static int spdif_write_trailer(AVFormatContext *s)
203 IEC958Context *ctx = s->priv_data;
204 av_freep(&ctx->buffer);
208 static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
210 IEC958Context *ctx = s->priv_data;
213 ctx->pkt_size = FFALIGN(pkt->size, 2) << 3;
214 ret = ctx->header_info(s, pkt);
218 padding = (ctx->pkt_offset - BURST_HEADER_SIZE - pkt->size) >> 1;
220 av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
224 put_le16(s->pb, SYNCWORD1); //Pa
225 put_le16(s->pb, SYNCWORD2); //Pb
226 put_le16(s->pb, ctx->data_type); //Pc
227 put_le16(s->pb, ctx->pkt_size); //Pd
230 put_buffer(s->pb, pkt->data, pkt->size & ~1);
232 av_fast_malloc(&ctx->buffer, &ctx->buffer_size, pkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
234 return AVERROR(ENOMEM);
235 ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)pkt->data, pkt->size >> 1);
236 put_buffer(s->pb, ctx->buffer, pkt->size & ~1);
240 put_be16(s->pb, pkt->data[pkt->size - 1]);
242 for (; padding > 0; padding--)
245 av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
246 ctx->data_type, pkt->size, ctx->pkt_offset);
248 put_flush_packet(s->pb);
252 AVOutputFormat spdif_muxer = {
254 NULL_IF_CONFIG_SMALL("IEC958 - S/PDIF (IEC-61937)"),
257 sizeof(IEC958Context),