libavformat/spdif.c

   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 libavformat/spdif.c
  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
  52 enum 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
  68 typedef 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
  81 static 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
  99 static 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
 109 static 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
 149 static 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
 155 static 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
 161 static 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
 184 static 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
 218 static 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     put_le16(s->pb, 0);
 242     put_le16(s->pb, 0);
 243     put_le16(s->pb, 0);
 244     put_le16(s->pb, 0);
 245     return 0;
 246 }
 247
 248 static int spdif_write_trailer(AVFormatContext *s)
 249 {
 250     IEC958Context *ctx = s->priv_data;
 251     av_freep(&ctx->buffer);
 252     return 0;
 253 }
 254
 255 static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
 256 {
 257     IEC958Context *ctx = s->priv_data;
 258     int ret, padding;
 259
 260     ctx->pkt_size = FFALIGN(pkt->size, 2) << 3;
 261     ret = ctx->header_info(s, pkt);
 262     if (ret < 0)
 263         return -1;
 264
 265     padding = (ctx->pkt_offset - BURST_HEADER_SIZE - pkt->size) >> 1;
 266     if (padding < 0) {
 267         av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
 268         return -1;
 269     }
 270
 271     put_le16(s->pb, SYNCWORD1);      //Pa
 272     put_le16(s->pb, SYNCWORD2);      //Pb
 273     put_le16(s->pb, ctx->data_type); //Pc
 274     put_le16(s->pb, ctx->pkt_size);  //Pd
 275
 276 #if HAVE_BIGENDIAN
 277     put_buffer(s->pb, pkt->data, pkt->size & ~1);
 278 #else
 279     av_fast_malloc(&ctx->buffer, &ctx->buffer_size, pkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
 280     if (!ctx->buffer)
 281         return AVERROR(ENOMEM);
 282     bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)pkt->data, pkt->size >> 1);
 283     put_buffer(s->pb, ctx->buffer, pkt->size & ~1);
 284 #endif
 285
 286     if (pkt->size & 1)
 287         put_be16(s->pb, pkt->data[pkt->size - 1]);
 288
 289     for (; padding > 0; padding--)
 290         put_be16(s->pb, 0);
 291
 292     av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
 293            ctx->data_type, pkt->size, ctx->pkt_offset);
 294
 295     put_flush_packet(s->pb);
 296     return 0;
 297 }
 298
 299 AVOutputFormat spdif_muxer = {
 300     "spdif",
 301     NULL_IF_CONFIG_SMALL("IEC958 - S/PDIF (IEC-61937)"),
 302     NULL,
 303     "spdif",
 304     sizeof(IEC958Context),
 305     CODEC_ID_AC3,
 306     CODEC_ID_NONE,
 307     spdif_write_header,
 308     spdif_write_packet,
 309     spdif_write_trailer,
 310 };