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libavformat/spdifenc.c

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00001 /*
00002  * IEC 61937 muxer
00003  * Copyright (c) 2009 Bartlomiej Wolowiec
00004  * Copyright (c) 2010 Anssi Hannula
00005  * Copyright (c) 2010 Carl Eugen Hoyos
00006  *
00007  * This file is part of FFmpeg.
00008  *
00009  * FFmpeg is free software; you can redistribute it and/or
00010  * modify it under the terms of the GNU Lesser General Public
00011  * License as published by the Free Software Foundation; either
00012  * version 2.1 of the License, or (at your option) any later version.
00013  *
00014  * FFmpeg is distributed in the hope that it will be useful,
00015  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00016  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00017  * Lesser General Public License for more details.
00018  *
00019  * You should have received a copy of the GNU Lesser General Public
00020  * License along with FFmpeg; if not, write to the Free Software
00021  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00022  */
00023 
00032 /*
00033  * Terminology used in specification:
00034  * data-burst - IEC61937 frame, contains header and encapsuled frame
00035  * burst-preambule - IEC61937 frame header, contains 16-bits words named Pa, Pb, Pc and Pd
00036  * burst-payload - encapsuled frame
00037  * Pa, Pb - syncword - 0xF872, 0x4E1F
00038  * Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12)
00039  *      and bitstream number (bits 13-15)
00040  * data-type - determines type of encapsuled frames
00041  * Pd - length code (number of bits or bytes of encapsuled frame - according to data_type)
00042  *
00043  * IEC 61937 frames at normal usage start every specific count of bytes,
00044  *      dependent from data-type (spaces between packets are filled by zeros)
00045  */
00046 
00047 #include "avformat.h"
00048 #include "avio_internal.h"
00049 #include "spdif.h"
00050 #include "libavcodec/ac3.h"
00051 #include "libavcodec/dca.h"
00052 #include "libavcodec/dcadata.h"
00053 #include "libavcodec/aacadtsdec.h"
00054 #include "libavutil/opt.h"
00055 
00056 typedef struct IEC61937Context {
00057     const AVClass *av_class;
00058     enum IEC61937DataType data_type;
00059     int length_code;                
00060     int pkt_offset;                 
00061     uint8_t *buffer;                
00062     int buffer_size;                
00063 
00064     uint8_t *out_buf;               
00065     int out_bytes;                  
00066 
00067     int use_preamble;               
00068     int extra_bswap;                
00069 
00070     uint8_t *hd_buf;                
00071     int hd_buf_size;                
00072     int hd_buf_count;               
00073     int hd_buf_filled;              
00074 
00075     int dtshd_skip;                 
00076 
00077     /* AVOptions: */
00078     int dtshd_rate;
00079     int dtshd_fallback;
00080 #define SPDIF_FLAG_BIGENDIAN    0x01
00081     int spdif_flags;
00082 
00085     int (*header_info) (AVFormatContext *s, AVPacket *pkt);
00086 } IEC61937Context;
00087 
00088 static const AVOption options[] = {
00089 { "spdif_flags", "IEC 61937 encapsulation flags", offsetof(IEC61937Context, spdif_flags), FF_OPT_TYPE_FLAGS, {.dbl = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" },
00090 { "be", "output in big-endian format (for use as s16be)", 0, FF_OPT_TYPE_CONST, {.dbl = SPDIF_FLAG_BIGENDIAN},  0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "spdif_flags" },
00091 { "dtshd_rate", "mux complete DTS frames in HD mode at the specified IEC958 rate (in Hz, default 0=disabled)", offsetof(IEC61937Context, dtshd_rate), FF_OPT_TYPE_INT, {.dbl = 0}, 0, 768000, AV_OPT_FLAG_ENCODING_PARAM },
00092 { "dtshd_fallback_time", "min secs to strip HD for after an overflow (-1: till the end, default 60)", offsetof(IEC61937Context, dtshd_fallback), FF_OPT_TYPE_INT, {.dbl = 60}, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
00093 { NULL },
00094 };
00095 
00096 static const AVClass class = {
00097     .class_name     = "spdif",
00098     .item_name      = av_default_item_name,
00099     .option         = options,
00100     .version        = LIBAVUTIL_VERSION_INT,
00101 };
00102 
00103 static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
00104 {
00105     IEC61937Context *ctx = s->priv_data;
00106     int bitstream_mode = pkt->data[5] & 0x7;
00107 
00108     ctx->data_type  = IEC61937_AC3 | (bitstream_mode << 8);
00109     ctx->pkt_offset = AC3_FRAME_SIZE << 2;
00110     return 0;
00111 }
00112 
00113 static int spdif_header_eac3(AVFormatContext *s, AVPacket *pkt)
00114 {
00115     IEC61937Context *ctx = s->priv_data;
00116     static const uint8_t eac3_repeat[4] = {6, 3, 2, 1};
00117     int repeat = 1;
00118 
00119     if ((pkt->data[4] & 0xc0) != 0xc0) /* fscod */
00120         repeat = eac3_repeat[(pkt->data[4] & 0x30) >> 4]; /* numblkscod */
00121 
00122     ctx->hd_buf = av_fast_realloc(ctx->hd_buf, &ctx->hd_buf_size, ctx->hd_buf_filled + pkt->size);
00123     if (!ctx->hd_buf)
00124         return AVERROR(ENOMEM);
00125 
00126     memcpy(&ctx->hd_buf[ctx->hd_buf_filled], pkt->data, pkt->size);
00127 
00128     ctx->hd_buf_filled += pkt->size;
00129     if (++ctx->hd_buf_count < repeat){
00130         ctx->pkt_offset = 0;
00131         return 0;
00132     }
00133     ctx->data_type   = IEC61937_EAC3;
00134     ctx->pkt_offset  = 24576;
00135     ctx->out_buf     = ctx->hd_buf;
00136     ctx->out_bytes   = ctx->hd_buf_filled;
00137     ctx->length_code = ctx->hd_buf_filled;
00138 
00139     ctx->hd_buf_count  = 0;
00140     ctx->hd_buf_filled = 0;
00141     return 0;
00142 }
00143 
00144 /*
00145  * DTS type IV (DTS-HD) can be transmitted with various frame repetition
00146  * periods; longer repetition periods allow for longer packets and therefore
00147  * higher bitrate. Longer repetition periods mean that the constant bitrate of
00148  * the outputted IEC 61937 stream is higher.
00149  * The repetition period is measured in IEC 60958 frames (4 bytes).
00150  */
00151 static int spdif_dts4_subtype(int period)
00152 {
00153     switch (period) {
00154     case 512:   return 0x0;
00155     case 1024:  return 0x1;
00156     case 2048:  return 0x2;
00157     case 4096:  return 0x3;
00158     case 8192:  return 0x4;
00159     case 16384: return 0x5;
00160     }
00161     return -1;
00162 }
00163 
00164 static int spdif_header_dts4(AVFormatContext *s, AVPacket *pkt, int core_size,
00165                              int sample_rate, int blocks)
00166 {
00167     IEC61937Context *ctx = s->priv_data;
00168     static const char dtshd_start_code[10] = { 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfe, 0xfe };
00169     int pkt_size = pkt->size;
00170     int period;
00171     int subtype;
00172 
00173     if (!core_size) {
00174         av_log(s, AV_LOG_ERROR, "HD mode not supported for this format\n");
00175         return AVERROR(EINVAL);
00176     }
00177 
00178     if (!sample_rate) {
00179         av_log(s, AV_LOG_ERROR, "Unknown DTS sample rate for HD\n");
00180         return AVERROR_INVALIDDATA;
00181     }
00182 
00183     period = ctx->dtshd_rate * (blocks << 5) / sample_rate;
00184     subtype = spdif_dts4_subtype(period);
00185 
00186     if (subtype < 0) {
00187         av_log(s, AV_LOG_ERROR, "Specified HD rate of %d Hz would require an "
00188                "impossible repetition period of %d for the current DTS stream"
00189                " (blocks = %d, sample rate = %d)\n", ctx->dtshd_rate, period,
00190                blocks << 5, sample_rate);
00191         return AVERROR(EINVAL);
00192     }
00193 
00194     /* set pkt_offset and DTS IV subtype according to the requested output
00195      * rate */
00196     ctx->pkt_offset = period * 4;
00197     ctx->data_type = IEC61937_DTSHD | subtype << 8;
00198 
00199     /* If the bitrate is too high for transmitting at the selected
00200      * repetition period setting, strip DTS-HD until a good amount
00201      * of consecutive non-overflowing HD frames have been observed.
00202      * This generally only happens if the caller is cramming a Master
00203      * Audio stream into 192kHz IEC 60958 (which may or may not fit). */
00204     if (sizeof(dtshd_start_code) + 2 + pkt_size
00205             > ctx->pkt_offset - BURST_HEADER_SIZE && core_size) {
00206         if (!ctx->dtshd_skip)
00207             av_log(s, AV_LOG_WARNING, "DTS-HD bitrate too high, "
00208                                       "temporarily sending core only\n");
00209         if (ctx->dtshd_fallback > 0)
00210             ctx->dtshd_skip = sample_rate * ctx->dtshd_fallback / (blocks << 5);
00211         else
00212             /* skip permanently (dtshd_fallback == -1) or just once
00213              * (dtshd_fallback == 0) */
00214             ctx->dtshd_skip = 1;
00215     }
00216     if (ctx->dtshd_skip && core_size) {
00217         pkt_size = core_size;
00218         if (ctx->dtshd_fallback >= 0)
00219             --ctx->dtshd_skip;
00220     }
00221 
00222     ctx->out_bytes   = sizeof(dtshd_start_code) + 2 + pkt_size;
00223     ctx->length_code = ctx->out_bytes;
00224 
00225     av_fast_malloc(&ctx->hd_buf, &ctx->hd_buf_size, ctx->out_bytes);
00226     if (!ctx->hd_buf)
00227         return AVERROR(ENOMEM);
00228 
00229     ctx->out_buf = ctx->hd_buf;
00230 
00231     memcpy(ctx->hd_buf, dtshd_start_code, sizeof(dtshd_start_code));
00232     AV_WB16(ctx->hd_buf + sizeof(dtshd_start_code), pkt_size);
00233     memcpy(ctx->hd_buf + sizeof(dtshd_start_code) + 2, pkt->data, pkt_size);
00234 
00235     return 0;
00236 }
00237 
00238 static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
00239 {
00240     IEC61937Context *ctx = s->priv_data;
00241     uint32_t syncword_dts = AV_RB32(pkt->data);
00242     int blocks;
00243     int sample_rate = 0;
00244     int core_size = 0;
00245 
00246     if (pkt->size < 9)
00247         return AVERROR_INVALIDDATA;
00248 
00249     switch (syncword_dts) {
00250     case DCA_MARKER_RAW_BE:
00251         blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
00252         core_size = ((AV_RB24(pkt->data + 5) >> 4) & 0x3fff) + 1;
00253         sample_rate = dca_sample_rates[(pkt->data[8] >> 2) & 0x0f];
00254         break;
00255     case DCA_MARKER_RAW_LE:
00256         blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
00257         ctx->extra_bswap = 1;
00258         break;
00259     case DCA_MARKER_14B_BE:
00260         blocks =
00261             (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
00262         break;
00263     case DCA_MARKER_14B_LE:
00264         blocks =
00265             (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
00266         ctx->extra_bswap = 1;
00267         break;
00268     case DCA_HD_MARKER:
00269         /* We only handle HD frames that are paired with core. However,
00270            sometimes DTS-HD streams with core have a stray HD frame without
00271            core in the beginning of the stream. */
00272         av_log(s, AV_LOG_ERROR, "stray DTS-HD frame\n");
00273         return AVERROR_INVALIDDATA;
00274     default:
00275         av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
00276         return AVERROR_INVALIDDATA;
00277     }
00278     blocks++;
00279 
00280     if (ctx->dtshd_rate)
00281         /* DTS type IV output requested */
00282         return spdif_header_dts4(s, pkt, core_size, sample_rate, blocks);
00283 
00284     switch (blocks) {
00285     case  512 >> 5: ctx->data_type = IEC61937_DTS1; break;
00286     case 1024 >> 5: ctx->data_type = IEC61937_DTS2; break;
00287     case 2048 >> 5: ctx->data_type = IEC61937_DTS3; break;
00288     default:
00289         av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
00290                blocks << 5);
00291         return AVERROR(ENOSYS);
00292     }
00293 
00294     /* discard extraneous data by default */
00295     if (core_size && core_size < pkt->size) {
00296         ctx->out_bytes = core_size;
00297         ctx->length_code = core_size << 3;
00298     }
00299 
00300     ctx->pkt_offset = blocks << 7;
00301 
00302     if (ctx->out_bytes == ctx->pkt_offset) {
00303         /* The DTS stream fits exactly into the output stream, so skip the
00304          * preamble as it would not fit in there. This is the case for dts
00305          * discs and dts-in-wav. */
00306         ctx->use_preamble = 0;
00307     } else if (ctx->out_bytes > ctx->pkt_offset - BURST_HEADER_SIZE) {
00308         av_log_ask_for_sample(s, "Unrecognized large DTS frame.");
00309         /* This will fail with a "bitrate too high" in the caller */
00310     }
00311 
00312     return 0;
00313 }
00314 
00315 static const enum IEC61937DataType mpeg_data_type[2][3] = {
00316     //     LAYER1                      LAYER2                  LAYER3
00317     { IEC61937_MPEG2_LAYER1_LSF, IEC61937_MPEG2_LAYER2_LSF, IEC61937_MPEG2_LAYER3_LSF },//MPEG2 LSF
00318     { IEC61937_MPEG1_LAYER1,     IEC61937_MPEG1_LAYER23,    IEC61937_MPEG1_LAYER23 },   //MPEG1
00319 };
00320 
00321 static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
00322 {
00323     IEC61937Context *ctx = s->priv_data;
00324     int version =      (pkt->data[1] >> 3) & 3;
00325     int layer   = 3 - ((pkt->data[1] >> 1) & 3);
00326     int extension = pkt->data[2] & 1;
00327 
00328     if (layer == 3 || version == 1) {
00329         av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
00330         return AVERROR_INVALIDDATA;
00331     }
00332     av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
00333     if (version == 2 && extension) {
00334         ctx->data_type  = IEC61937_MPEG2_EXT;
00335         ctx->pkt_offset = 4608;
00336     } else {
00337         ctx->data_type  = mpeg_data_type [version & 1][layer];
00338         ctx->pkt_offset = spdif_mpeg_pkt_offset[version & 1][layer];
00339     }
00340     // TODO Data type dependant info (normal/karaoke, dynamic range control)
00341     return 0;
00342 }
00343 
00344 static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
00345 {
00346     IEC61937Context *ctx = s->priv_data;
00347     AACADTSHeaderInfo hdr;
00348     GetBitContext gbc;
00349     int ret;
00350 
00351     init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
00352     ret = ff_aac_parse_header(&gbc, &hdr);
00353     if (ret < 0) {
00354         av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
00355         return AVERROR_INVALIDDATA;
00356     }
00357 
00358     ctx->pkt_offset = hdr.samples << 2;
00359     switch (hdr.num_aac_frames) {
00360     case 1:
00361         ctx->data_type = IEC61937_MPEG2_AAC;
00362         break;
00363     case 2:
00364         ctx->data_type = IEC61937_MPEG2_AAC_LSF_2048;
00365         break;
00366     case 4:
00367         ctx->data_type = IEC61937_MPEG2_AAC_LSF_4096;
00368         break;
00369     default:
00370         av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
00371                hdr.samples);
00372         return AVERROR(EINVAL);
00373     }
00374     //TODO Data type dependent info (LC profile/SBR)
00375     return 0;
00376 }
00377 
00378 
00379 /*
00380  * It seems Dolby TrueHD frames have to be encapsulated in MAT frames before
00381  * they can be encapsulated in IEC 61937.
00382  * Here we encapsulate 24 TrueHD frames in a single MAT frame, padding them
00383  * to achieve constant rate.
00384  * The actual format of a MAT frame is unknown, but the below seems to work.
00385  * However, it seems it is not actually necessary for the 24 TrueHD frames to
00386  * be in an exact alignment with the MAT frame.
00387  */
00388 #define MAT_FRAME_SIZE          61424
00389 #define TRUEHD_FRAME_OFFSET     2560
00390 #define MAT_MIDDLE_CODE_OFFSET  -4
00391 
00392 static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)
00393 {
00394     IEC61937Context *ctx = s->priv_data;
00395     int mat_code_length = 0;
00396     const char mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11 };
00397 
00398     if (!ctx->hd_buf_count) {
00399         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 };
00400         mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE;
00401         memcpy(ctx->hd_buf, mat_start_code, sizeof(mat_start_code));
00402 
00403     } else if (ctx->hd_buf_count == 12) {
00404         const char mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0 };
00405         mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET;
00406         memcpy(&ctx->hd_buf[12 * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + MAT_MIDDLE_CODE_OFFSET],
00407                mat_middle_code, sizeof(mat_middle_code));
00408     }
00409 
00410     if (pkt->size > TRUEHD_FRAME_OFFSET - mat_code_length) {
00411         /* if such frames exist, we'd need some more complex logic to
00412          * distribute the TrueHD frames in the MAT frame */
00413         av_log(s, AV_LOG_ERROR, "TrueHD frame too big, %d bytes\n", pkt->size);
00414         av_log_ask_for_sample(s, NULL);
00415         return AVERROR_INVALIDDATA;
00416     }
00417 
00418     memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length],
00419            pkt->data, pkt->size);
00420     memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size],
00421            0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length);
00422 
00423     if (++ctx->hd_buf_count < 24){
00424         ctx->pkt_offset = 0;
00425         return 0;
00426     }
00427     memcpy(&ctx->hd_buf[MAT_FRAME_SIZE - sizeof(mat_end_code)], mat_end_code, sizeof(mat_end_code));
00428     ctx->hd_buf_count = 0;
00429 
00430     ctx->data_type   = IEC61937_TRUEHD;
00431     ctx->pkt_offset  = 61440;
00432     ctx->out_buf     = ctx->hd_buf;
00433     ctx->out_bytes   = MAT_FRAME_SIZE;
00434     ctx->length_code = MAT_FRAME_SIZE;
00435     return 0;
00436 }
00437 
00438 static int spdif_write_header(AVFormatContext *s)
00439 {
00440     IEC61937Context *ctx = s->priv_data;
00441 
00442     switch (s->streams[0]->codec->codec_id) {
00443     case CODEC_ID_AC3:
00444         ctx->header_info = spdif_header_ac3;
00445         break;
00446     case CODEC_ID_EAC3:
00447         ctx->header_info = spdif_header_eac3;
00448         break;
00449     case CODEC_ID_MP1:
00450     case CODEC_ID_MP2:
00451     case CODEC_ID_MP3:
00452         ctx->header_info = spdif_header_mpeg;
00453         break;
00454     case CODEC_ID_DTS:
00455         ctx->header_info = spdif_header_dts;
00456         break;
00457     case CODEC_ID_AAC:
00458         ctx->header_info = spdif_header_aac;
00459         break;
00460     case CODEC_ID_TRUEHD:
00461         ctx->header_info = spdif_header_truehd;
00462         ctx->hd_buf = av_malloc(MAT_FRAME_SIZE);
00463         if (!ctx->hd_buf)
00464             return AVERROR(ENOMEM);
00465         break;
00466     default:
00467         av_log(s, AV_LOG_ERROR, "codec not supported\n");
00468         return AVERROR_PATCHWELCOME;
00469     }
00470     return 0;
00471 }
00472 
00473 static int spdif_write_trailer(AVFormatContext *s)
00474 {
00475     IEC61937Context *ctx = s->priv_data;
00476     av_freep(&ctx->buffer);
00477     av_freep(&ctx->hd_buf);
00478     return 0;
00479 }
00480 
00481 static av_always_inline void spdif_put_16(IEC61937Context *ctx,
00482                                           AVIOContext *pb, unsigned int val)
00483 {
00484     if (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)
00485         avio_wb16(pb, val);
00486     else
00487         avio_wl16(pb, val);
00488 }
00489 
00490 static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
00491 {
00492     IEC61937Context *ctx = s->priv_data;
00493     int ret, padding;
00494 
00495     ctx->out_buf = pkt->data;
00496     ctx->out_bytes = pkt->size;
00497     ctx->length_code = FFALIGN(pkt->size, 2) << 3;
00498     ctx->use_preamble = 1;
00499     ctx->extra_bswap = 0;
00500 
00501     ret = ctx->header_info(s, pkt);
00502     if (ret < 0)
00503         return ret;
00504     if (!ctx->pkt_offset)
00505         return 0;
00506 
00507     padding = (ctx->pkt_offset - ctx->use_preamble * BURST_HEADER_SIZE - ctx->out_bytes) & ~1;
00508     if (padding < 0) {
00509         av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
00510         return AVERROR(EINVAL);
00511     }
00512 
00513     if (ctx->use_preamble) {
00514         spdif_put_16(ctx, s->pb, SYNCWORD1);       //Pa
00515         spdif_put_16(ctx, s->pb, SYNCWORD2);       //Pb
00516         spdif_put_16(ctx, s->pb, ctx->data_type);  //Pc
00517         spdif_put_16(ctx, s->pb, ctx->length_code);//Pd
00518     }
00519 
00520     if (ctx->extra_bswap ^ (ctx->spdif_flags & SPDIF_FLAG_BIGENDIAN)) {
00521     avio_write(s->pb, ctx->out_buf, ctx->out_bytes & ~1);
00522     } else {
00523     av_fast_malloc(&ctx->buffer, &ctx->buffer_size, ctx->out_bytes + FF_INPUT_BUFFER_PADDING_SIZE);
00524     if (!ctx->buffer)
00525         return AVERROR(ENOMEM);
00526     ff_spdif_bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)ctx->out_buf, ctx->out_bytes >> 1);
00527     avio_write(s->pb, ctx->buffer, ctx->out_bytes & ~1);
00528     }
00529 
00530     /* a final lone byte has to be MSB aligned */
00531     if (ctx->out_bytes & 1)
00532         spdif_put_16(ctx, s->pb, ctx->out_buf[ctx->out_bytes - 1] << 8);
00533 
00534     ffio_fill(s->pb, 0, padding);
00535 
00536     av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
00537            ctx->data_type, ctx->out_bytes, ctx->pkt_offset);
00538 
00539     avio_flush(s->pb);
00540     return 0;
00541 }
00542 
00543 AVOutputFormat ff_spdif_muxer = {
00544     "spdif",
00545     NULL_IF_CONFIG_SMALL("IEC 61937 (used on S/PDIF - IEC958)"),
00546     NULL,
00547     "spdif",
00548     sizeof(IEC61937Context),
00549     CODEC_ID_AC3,
00550     CODEC_ID_NONE,
00551     spdif_write_header,
00552     spdif_write_packet,
00553     spdif_write_trailer,
00554     .flags = AVFMT_NOTIMESTAMPS,
00555     .priv_class = &class,
00556 };

Generated on Fri Feb 22 2013 07:24:32 for FFmpeg by  doxygen 1.7.1