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libavformat/spdif.c

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00001 /*
00002  * IEC958 muxer
00003  * Copyright (c) 2009 Bartlomiej Wolowiec
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 /*
00029  * Terminology used in specification:
00030  * data-burst - IEC958 frame, contains header and encapsuled frame
00031  * burst-preambule - IEC958 frame header, contains 16-bits words named Pa, Pb, Pc and Pd
00032  * burst-payload - encapsuled frame
00033  * Pa, Pb - syncword - 0xF872, 0x4E1F
00034  * Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12)
00035  *      and bitstream number (bits 13-15)
00036  * data-type - determines type of encapsuled frames
00037  * Pd - length code (number of bits or bytes of encapsuled frame - according to data_type)
00038  *
00039  * IEC958 frames at normal usage start every specific count of bytes,
00040  *      dependent from data-type (spaces between packets are filled by zeros)
00041  */
00042 
00043 #include "avformat.h"
00044 #include "libavcodec/ac3.h"
00045 #include "libavcodec/dca.h"
00046 #include "libavcodec/aac_parser.h"
00047 
00048 #define SYNCWORD1 0xF872
00049 #define SYNCWORD2 0x4E1F
00050 #define BURST_HEADER_SIZE 0x8
00051 
00052 enum IEC958DataType {
00053     IEC958_AC3                = 0x01,          
00054     IEC958_MPEG1_LAYER1       = 0x04,          
00055     IEC958_MPEG1_LAYER23      = 0x05,          
00056     IEC958_MPEG2_EXT          = 0x06,          
00057     IEC958_MPEG2_AAC          = 0x07,          
00058     IEC958_MPEG2_LAYER1_LSF   = 0x08,          
00059     IEC958_MPEG2_LAYER2_LSF   = 0x09,          
00060     IEC958_MPEG2_LAYER3_LSF   = 0x0A,          
00061     IEC958_DTS1               = 0x0B,          
00062     IEC958_DTS2               = 0x0C,          
00063     IEC958_DTS3               = 0x0D,          
00064     IEC958_MPEG2_AAC_LSF_2048 = 0x13,          
00065     IEC958_MPEG2_AAC_LSF_4096 = 0x13 | 0x20,   
00066 };
00067 
00068 typedef struct IEC958Context {
00069     enum IEC958DataType data_type;  
00070     int pkt_size;                   
00071     int pkt_offset;                 
00072     uint8_t *buffer;                
00073     int buffer_size;                
00074 
00077     int (*header_info) (AVFormatContext *s, AVPacket *pkt);
00078 } IEC958Context;
00079 
00080 //TODO move to DSP
00081 static void bswap_buf16(uint16_t *dst, const uint16_t *src, int w)
00082 {
00083     int i;
00084 
00085     for (i = 0; i + 8 <= w; i += 8) {
00086         dst[i + 0] = bswap_16(src[i + 0]);
00087         dst[i + 1] = bswap_16(src[i + 1]);
00088         dst[i + 2] = bswap_16(src[i + 2]);
00089         dst[i + 3] = bswap_16(src[i + 3]);
00090         dst[i + 4] = bswap_16(src[i + 4]);
00091         dst[i + 5] = bswap_16(src[i + 5]);
00092         dst[i + 6] = bswap_16(src[i + 6]);
00093         dst[i + 7] = bswap_16(src[i + 7]);
00094     }
00095     for (; i < w; i++)
00096         dst[i + 0] = bswap_16(src[i + 0]);
00097 }
00098 
00099 static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
00100 {
00101     IEC958Context *ctx = s->priv_data;
00102     int bitstream_mode = pkt->data[6] & 0x7;
00103 
00104     ctx->data_type  = IEC958_AC3 | (bitstream_mode << 8);
00105     ctx->pkt_offset = AC3_FRAME_SIZE << 2;
00106     return 0;
00107 }
00108 
00109 static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
00110 {
00111     IEC958Context *ctx = s->priv_data;
00112     uint32_t syncword_dts = AV_RB32(pkt->data);
00113     int blocks;
00114 
00115     switch (syncword_dts) {
00116     case DCA_MARKER_RAW_BE:
00117         blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
00118         break;
00119     case DCA_MARKER_RAW_LE:
00120         blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
00121         break;
00122     case DCA_MARKER_14B_BE:
00123         blocks =
00124             (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
00125         break;
00126     case DCA_MARKER_14B_LE:
00127         blocks =
00128             (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
00129         break;
00130     default:
00131         av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
00132         return -1;
00133     }
00134     blocks++;
00135     switch (blocks) {
00136     case  512 >> 5: ctx->data_type = IEC958_DTS1; break;
00137     case 1024 >> 5: ctx->data_type = IEC958_DTS2; break;
00138     case 2048 >> 5: ctx->data_type = IEC958_DTS3; break;
00139     default:
00140         av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
00141                blocks << 5);
00142         return -1;
00143     }
00144     ctx->pkt_offset = blocks << 7;
00145 
00146     return 0;
00147 }
00148 
00149 static const enum IEC958DataType mpeg_data_type[2][3] = {
00150     //     LAYER1                      LAYER2                  LAYER3
00151     { IEC958_MPEG2_LAYER1_LSF, IEC958_MPEG2_LAYER2_LSF, IEC958_MPEG2_LAYER3_LSF },  //MPEG2 LSF
00152     { IEC958_MPEG1_LAYER1,     IEC958_MPEG1_LAYER23,    IEC958_MPEG1_LAYER23 },     //MPEG1
00153 };
00154 
00155 static const uint16_t mpeg_pkt_offset[2][3] = {
00156     //LAYER1  LAYER2  LAYER3
00157     { 3072,    9216,   4608 }, // MPEG2 LSF
00158     { 1536,    4608,   4608 }, // MPEG1
00159 };
00160 
00161 static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
00162 {
00163     IEC958Context *ctx = s->priv_data;
00164     int version =      (pkt->data[1] >> 3) & 3;
00165     int layer   = 3 - ((pkt->data[1] >> 1) & 3);
00166     int extension = pkt->data[2] & 1;
00167 
00168     if (layer == 3 || version == 1) {
00169         av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
00170         return -1;
00171     }
00172     av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
00173     if (version == 2 && extension) {
00174         ctx->data_type  = IEC958_MPEG2_EXT;
00175         ctx->pkt_offset = 4608;
00176     } else {
00177         ctx->data_type  = mpeg_data_type [version & 1][layer];
00178         ctx->pkt_offset = mpeg_pkt_offset[version & 1][layer];
00179     }
00180     // TODO Data type dependant info (normal/karaoke, dynamic range control)
00181     return 0;
00182 }
00183 
00184 static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
00185 {
00186     IEC958Context *ctx = s->priv_data;
00187     AACADTSHeaderInfo hdr;
00188     GetBitContext gbc;
00189     int ret;
00190 
00191     init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
00192     ret = ff_aac_parse_header(&gbc, &hdr);
00193     if (ret < 0) {
00194         av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
00195         return -1;
00196     }
00197 
00198     ctx->pkt_offset = hdr.samples << 2;
00199     switch (hdr.num_aac_frames) {
00200     case 1:
00201         ctx->data_type = IEC958_MPEG2_AAC;
00202         break;
00203     case 2:
00204         ctx->data_type = IEC958_MPEG2_AAC_LSF_2048;
00205         break;
00206     case 4:
00207         ctx->data_type = IEC958_MPEG2_AAC_LSF_4096;
00208         break;
00209     default:
00210         av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
00211                hdr.samples);
00212         return -1;
00213     }
00214     //TODO Data type dependent info (LC profile/SBR)
00215     return 0;
00216 }
00217 
00218 static int spdif_write_header(AVFormatContext *s)
00219 {
00220     IEC958Context *ctx = s->priv_data;
00221 
00222     switch (s->streams[0]->codec->codec_id) {
00223     case CODEC_ID_AC3:
00224         ctx->header_info = spdif_header_ac3;
00225         break;
00226     case CODEC_ID_MP1:
00227     case CODEC_ID_MP2:
00228     case CODEC_ID_MP3:
00229         ctx->header_info = spdif_header_mpeg;
00230         break;
00231     case CODEC_ID_DTS:
00232         ctx->header_info = spdif_header_dts;
00233         break;
00234     case CODEC_ID_AAC:
00235         ctx->header_info = spdif_header_aac;
00236         break;
00237     default:
00238         av_log(s, AV_LOG_ERROR, "codec not supported\n");
00239         return -1;
00240     }
00241     return 0;
00242 }
00243 
00244 static int spdif_write_trailer(AVFormatContext *s)
00245 {
00246     IEC958Context *ctx = s->priv_data;
00247     av_freep(&ctx->buffer);
00248     return 0;
00249 }
00250 
00251 static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
00252 {
00253     IEC958Context *ctx = s->priv_data;
00254     int ret, padding;
00255 
00256     ctx->pkt_size = FFALIGN(pkt->size, 2) << 3;
00257     ret = ctx->header_info(s, pkt);
00258     if (ret < 0)
00259         return -1;
00260 
00261     padding = (ctx->pkt_offset - BURST_HEADER_SIZE - pkt->size) >> 1;
00262     if (padding < 0) {
00263         av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
00264         return -1;
00265     }
00266 
00267     put_le16(s->pb, SYNCWORD1);      //Pa
00268     put_le16(s->pb, SYNCWORD2);      //Pb
00269     put_le16(s->pb, ctx->data_type); //Pc
00270     put_le16(s->pb, ctx->pkt_size);  //Pd
00271 
00272 #if HAVE_BIGENDIAN
00273     put_buffer(s->pb, pkt->data, pkt->size & ~1);
00274 #else
00275     av_fast_malloc(&ctx->buffer, &ctx->buffer_size, pkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
00276     if (!ctx->buffer)
00277         return AVERROR(ENOMEM);
00278     bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)pkt->data, pkt->size >> 1);
00279     put_buffer(s->pb, ctx->buffer, pkt->size & ~1);
00280 #endif
00281 
00282     if (pkt->size & 1)
00283         put_be16(s->pb, pkt->data[pkt->size - 1]);
00284 
00285     for (; padding > 0; padding--)
00286         put_be16(s->pb, 0);
00287 
00288     av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
00289            ctx->data_type, pkt->size, ctx->pkt_offset);
00290 
00291     put_flush_packet(s->pb);
00292     return 0;
00293 }
00294 
00295 AVOutputFormat spdif_muxer = {
00296     "spdif",
00297     NULL_IF_CONFIG_SMALL("IEC958 - S/PDIF (IEC-61937)"),
00298     NULL,
00299     "spdif",
00300     sizeof(IEC958Context),
00301     CODEC_ID_AC3,
00302     CODEC_ID_NONE,
00303     spdif_write_header,
00304     spdif_write_packet,
00305     spdif_write_trailer,
00306 };

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