1/* 2 * IEC958 muxer 3 * Copyright (c) 2009 Bartlomiej Wolowiec 4 * 5 * This file is part of FFmpeg. 6 * 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. 11 * 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. 16 * 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 20 */ 21 22/** 23 * @file 24 * IEC-61937 encapsulation of various formats, used by S/PDIF 25 * @author Bartlomiej Wolowiec 26 */ 27 28/* 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) 38 * 39 * IEC958 frames at normal usage start every specific count of bytes, 40 * dependent from data-type (spaces between packets are filled by zeros) 41 */ 42 43#include "avformat.h" 44#include "libavcodec/ac3.h" 45#include "libavcodec/dca.h" 46#include "libavcodec/aac_parser.h" 47 48#define SYNCWORD1 0xF872 49#define SYNCWORD2 0x4E1F 50#define BURST_HEADER_SIZE 0x8 51 52enum IEC958DataType { 53 IEC958_AC3 = 0x01, ///< AC-3 data 54 IEC958_MPEG1_LAYER1 = 0x04, ///< MPEG-1 layer 1 55 IEC958_MPEG1_LAYER23 = 0x05, ///< MPEG-1 layer 2 or 3 data or MPEG-2 without extension 56 IEC958_MPEG2_EXT = 0x06, ///< MPEG-2 data with extension 57 IEC958_MPEG2_AAC = 0x07, ///< MPEG-2 AAC ADTS 58 IEC958_MPEG2_LAYER1_LSF = 0x08, ///< MPEG-2, layer-1 low sampling frequency 59 IEC958_MPEG2_LAYER2_LSF = 0x09, ///< MPEG-2, layer-2 low sampling frequency 60 IEC958_MPEG2_LAYER3_LSF = 0x0A, ///< MPEG-2, layer-3 low sampling frequency 61 IEC958_DTS1 = 0x0B, ///< DTS type I (512 samples) 62 IEC958_DTS2 = 0x0C, ///< DTS type II (1024 samples) 63 IEC958_DTS3 = 0x0D, ///< DTS type III (2048 samples) 64 IEC958_MPEG2_AAC_LSF_2048 = 0x13, ///< MPEG-2 AAC ADTS half-rate low sampling frequency 65 IEC958_MPEG2_AAC_LSF_4096 = 0x13 | 0x20, ///< MPEG-2 AAC ADTS quarter-rate low sampling frequency 66}; 67 68typedef struct IEC958Context { 69 enum IEC958DataType data_type; ///< burst info - reference to type of payload of the data-burst 70 int pkt_size; ///< length code in bits 71 int pkt_offset; ///< data burst repetition period in bytes 72 uint8_t *buffer; ///< allocated buffer, used for swap bytes 73 int buffer_size; ///< size of allocated buffer 74 75 /// function, which generates codec dependent header information. 76 /// Sets data_type and data_offset 77 int (*header_info) (AVFormatContext *s, AVPacket *pkt); 78} IEC958Context; 79 80//TODO move to DSP 81static void bswap_buf16(uint16_t *dst, const uint16_t *src, int w) 82{ 83 int i; 84 85 for (i = 0; i + 8 <= w; i += 8) { 86 dst[i + 0] = bswap_16(src[i + 0]); 87 dst[i + 1] = bswap_16(src[i + 1]); 88 dst[i + 2] = bswap_16(src[i + 2]); 89 dst[i + 3] = bswap_16(src[i + 3]); 90 dst[i + 4] = bswap_16(src[i + 4]); 91 dst[i + 5] = bswap_16(src[i + 5]); 92 dst[i + 6] = bswap_16(src[i + 6]); 93 dst[i + 7] = bswap_16(src[i + 7]); 94 } 95 for (; i < w; i++) 96 dst[i + 0] = bswap_16(src[i + 0]); 97} 98 99static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt) 100{ 101 IEC958Context *ctx = s->priv_data; 102 int bitstream_mode = pkt->data[6] & 0x7; 103 104 ctx->data_type = IEC958_AC3 | (bitstream_mode << 8); 105 ctx->pkt_offset = AC3_FRAME_SIZE << 2; 106 return 0; 107} 108 109static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt) 110{ 111 IEC958Context *ctx = s->priv_data; 112 uint32_t syncword_dts = AV_RB32(pkt->data); 113 int blocks; 114 115 switch (syncword_dts) { 116 case DCA_MARKER_RAW_BE: 117 blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f; 118 break; 119 case DCA_MARKER_RAW_LE: 120 blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f; 121 break; 122 case DCA_MARKER_14B_BE: 123 blocks = 124 (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2)); 125 break; 126 case DCA_MARKER_14B_LE: 127 blocks = 128 (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2)); 129 break; 130 default: 131 av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts); 132 return -1; 133 } 134 blocks++; 135 switch (blocks) { 136 case 512 >> 5: ctx->data_type = IEC958_DTS1; break; 137 case 1024 >> 5: ctx->data_type = IEC958_DTS2; break; 138 case 2048 >> 5: ctx->data_type = IEC958_DTS3; break; 139 default: 140 av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n", 141 blocks << 5); 142 return -1; 143 } 144 ctx->pkt_offset = blocks << 7; 145 146 return 0; 147} 148 149static const enum IEC958DataType mpeg_data_type[2][3] = { 150 // LAYER1 LAYER2 LAYER3 151 { IEC958_MPEG2_LAYER1_LSF, IEC958_MPEG2_LAYER2_LSF, IEC958_MPEG2_LAYER3_LSF }, //MPEG2 LSF 152 { IEC958_MPEG1_LAYER1, IEC958_MPEG1_LAYER23, IEC958_MPEG1_LAYER23 }, //MPEG1 153}; 154 155static const uint16_t mpeg_pkt_offset[2][3] = { 156 //LAYER1 LAYER2 LAYER3 157 { 3072, 9216, 4608 }, // MPEG2 LSF 158 { 1536, 4608, 4608 }, // MPEG1 159}; 160 161static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt) 162{ 163 IEC958Context *ctx = s->priv_data; 164 int version = (pkt->data[1] >> 3) & 3; 165 int layer = 3 - ((pkt->data[1] >> 1) & 3); 166 int extension = pkt->data[2] & 1; 167 168 if (layer == 3 || version == 1) { 169 av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n"); 170 return -1; 171 } 172 av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension); 173 if (version == 2 && extension) { 174 ctx->data_type = IEC958_MPEG2_EXT; 175 ctx->pkt_offset = 4608; 176 } else { 177 ctx->data_type = mpeg_data_type [version & 1][layer]; 178 ctx->pkt_offset = mpeg_pkt_offset[version & 1][layer]; 179 } 180 // TODO Data type dependant info (normal/karaoke, dynamic range control) 181 return 0; 182} 183 184static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt) 185{ 186 IEC958Context *ctx = s->priv_data; 187 AACADTSHeaderInfo hdr; 188 GetBitContext gbc; 189 int ret; 190 191 init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8); 192 ret = ff_aac_parse_header(&gbc, &hdr); 193 if (ret < 0) { 194 av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n"); 195 return -1; 196 } 197 198 ctx->pkt_offset = hdr.samples << 2; 199 switch (hdr.num_aac_frames) { 200 case 1: 201 ctx->data_type = IEC958_MPEG2_AAC; 202 break; 203 case 2: 204 ctx->data_type = IEC958_MPEG2_AAC_LSF_2048; 205 break; 206 case 4: 207 ctx->data_type = IEC958_MPEG2_AAC_LSF_4096; 208 break; 209 default: 210 av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n", 211 hdr.samples); 212 return -1; 213 } 214 //TODO Data type dependent info (LC profile/SBR) 215 return 0; 216} 217 218static int spdif_write_header(AVFormatContext *s) 219{ 220 IEC958Context *ctx = s->priv_data; 221 222 switch (s->streams[0]->codec->codec_id) { 223 case CODEC_ID_AC3: 224 ctx->header_info = spdif_header_ac3; 225 break; 226 case CODEC_ID_MP1: 227 case CODEC_ID_MP2: 228 case CODEC_ID_MP3: 229 ctx->header_info = spdif_header_mpeg; 230 break; 231 case CODEC_ID_DTS: 232 ctx->header_info = spdif_header_dts; 233 break; 234 case CODEC_ID_AAC: 235 ctx->header_info = spdif_header_aac; 236 break; 237 default: 238 av_log(s, AV_LOG_ERROR, "codec not supported\n"); 239 return -1; 240 } 241 return 0; 242} 243 244static int spdif_write_trailer(AVFormatContext *s) 245{ 246 IEC958Context *ctx = s->priv_data; 247 av_freep(&ctx->buffer); 248 return 0; 249} 250 251static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt) 252{ 253 IEC958Context *ctx = s->priv_data; 254 int ret, padding; 255 256 ctx->pkt_size = FFALIGN(pkt->size, 2) << 3; 257 ret = ctx->header_info(s, pkt); 258 if (ret < 0) 259 return -1; 260 261 padding = (ctx->pkt_offset - BURST_HEADER_SIZE - pkt->size) >> 1; 262 if (padding < 0) { 263 av_log(s, AV_LOG_ERROR, "bitrate is too high\n"); 264 return -1; 265 } 266 267 put_le16(s->pb, SYNCWORD1); //Pa 268 put_le16(s->pb, SYNCWORD2); //Pb 269 put_le16(s->pb, ctx->data_type); //Pc 270 put_le16(s->pb, ctx->pkt_size); //Pd 271 272#if HAVE_BIGENDIAN 273 put_buffer(s->pb, pkt->data, pkt->size & ~1); 274#else 275 av_fast_malloc(&ctx->buffer, &ctx->buffer_size, pkt->size + FF_INPUT_BUFFER_PADDING_SIZE); 276 if (!ctx->buffer) 277 return AVERROR(ENOMEM); 278 bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)pkt->data, pkt->size >> 1); 279 put_buffer(s->pb, ctx->buffer, pkt->size & ~1); 280#endif 281 282 if (pkt->size & 1) 283 put_be16(s->pb, pkt->data[pkt->size - 1]); 284 285 for (; padding > 0; padding--) 286 put_be16(s->pb, 0); 287 288 av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n", 289 ctx->data_type, pkt->size, ctx->pkt_offset); 290 291 put_flush_packet(s->pb); 292 return 0; 293} 294 295AVOutputFormat spdif_muxer = { 296 "spdif", 297 NULL_IF_CONFIG_SMALL("IEC958 - S/PDIF (IEC-61937)"), 298 NULL, 299 "spdif", 300 sizeof(IEC958Context), 301 CODEC_ID_AC3, 302 CODEC_ID_NONE, 303 spdif_write_header, 304 spdif_write_packet, 305 spdif_write_trailer, 306}; 307