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/*
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 * IEC958 muxer
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 * Copyright (c) 2009 Bartlomiej Wolowiec
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * IEC-61937 encapsulation of various formats, used by S/PDIF
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 * @author Bartlomiej Wolowiec
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 */
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/*
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 * Terminology used in specification:
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 * data-burst - IEC958 frame, contains header and encapsuled frame
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 * burst-preambule - IEC958 frame header, contains 16-bits words named Pa, Pb, Pc and Pd
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 * burst-payload - encapsuled frame
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 * Pa, Pb - syncword - 0xF872, 0x4E1F
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 * Pc - burst-info, contains data-type (bits 0-6), error flag (bit 7), data-type-dependent info (bits 8-12)
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 *      and bitstream number (bits 13-15)
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 * data-type - determines type of encapsuled frames
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 * Pd - length code (number of bits or bytes of encapsuled frame - according to data_type)
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 *
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 * IEC958 frames at normal usage start every specific count of bytes,
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 *      dependent from data-type (spaces between packets are filled by zeros)
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 */
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#include "avformat.h"
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#include "libavcodec/ac3.h"
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#include "libavcodec/dca.h"
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#include "libavcodec/aacadtsdec.h"
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#define SYNCWORD1 0xF872
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#define SYNCWORD2 0x4E1F
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#define BURST_HEADER_SIZE 0x8
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enum IEC958DataType {
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    IEC958_AC3                = 0x01,          ///< AC-3 data
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    IEC958_MPEG1_LAYER1       = 0x04,          ///< MPEG-1 layer 1
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    IEC958_MPEG1_LAYER23      = 0x05,          ///< MPEG-1 layer 2 or 3 data or MPEG-2 without extension
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    IEC958_MPEG2_EXT          = 0x06,          ///< MPEG-2 data with extension
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    IEC958_MPEG2_AAC          = 0x07,          ///< MPEG-2 AAC ADTS
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    IEC958_MPEG2_LAYER1_LSF   = 0x08,          ///< MPEG-2, layer-1 low sampling frequency
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    IEC958_MPEG2_LAYER2_LSF   = 0x09,          ///< MPEG-2, layer-2 low sampling frequency
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    IEC958_MPEG2_LAYER3_LSF   = 0x0A,          ///< MPEG-2, layer-3 low sampling frequency
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    IEC958_DTS1               = 0x0B,          ///< DTS type I   (512 samples)
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    IEC958_DTS2               = 0x0C,          ///< DTS type II  (1024 samples)
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    IEC958_DTS3               = 0x0D,          ///< DTS type III (2048 samples)
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    IEC958_ATRAC              = 0x0E,          ///< Atrac data
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    IEC958_ATRAC3             = 0x0F,          ///< Atrac 3 data
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    IEC958_ATRACX             = 0x10,          ///< Atrac 3 plus data
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    IEC958_DTSHD              = 0x11,          ///< DTS HD data
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    IEC958_WMAPRO             = 0x12,          ///< WMA 9 Professional data
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    IEC958_MPEG2_AAC_LSF_2048 = 0x13,          ///< MPEG-2 AAC ADTS half-rate low sampling frequency
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    IEC958_MPEG2_AAC_LSF_4096 = 0x13 | 0x20,   ///< MPEG-2 AAC ADTS quarter-rate low sampling frequency
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    IEC958_EAC3               = 0x15,          ///< E-AC-3 data
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    IEC958_TRUEHD             = 0x16,          ///< TrueHD data
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};
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typedef struct IEC958Context {
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    enum IEC958DataType data_type;  ///< burst info - reference to type of payload of the data-burst
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    int pkt_size;                   ///< length code in bits
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    int pkt_offset;                 ///< data burst repetition period in bytes
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    uint8_t *buffer;                ///< allocated buffer, used for swap bytes
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    int buffer_size;                ///< size of allocated buffer
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    /// function, which generates codec dependent header information.
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    /// Sets data_type and data_offset
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    int (*header_info) (AVFormatContext *s, AVPacket *pkt);
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} IEC958Context;
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//TODO move to DSP
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static void bswap_buf16(uint16_t *dst, const uint16_t *src, int w)
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{
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    int i;
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    for (i = 0; i + 8 <= w; i += 8) {
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        dst[i + 0] = av_bswap16(src[i + 0]);
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        dst[i + 1] = av_bswap16(src[i + 1]);
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        dst[i + 2] = av_bswap16(src[i + 2]);
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        dst[i + 3] = av_bswap16(src[i + 3]);
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        dst[i + 4] = av_bswap16(src[i + 4]);
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        dst[i + 5] = av_bswap16(src[i + 5]);
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        dst[i + 6] = av_bswap16(src[i + 6]);
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        dst[i + 7] = av_bswap16(src[i + 7]);
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    }
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    for (; i < w; i++)
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        dst[i + 0] = av_bswap16(src[i + 0]);
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}
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static int spdif_header_ac3(AVFormatContext *s, AVPacket *pkt)
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{
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    IEC958Context *ctx = s->priv_data;
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    int bitstream_mode = pkt->data[6] & 0x7;
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    ctx->data_type  = IEC958_AC3 | (bitstream_mode << 8);
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    ctx->pkt_offset = AC3_FRAME_SIZE << 2;
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    return 0;
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}
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static int spdif_header_dts(AVFormatContext *s, AVPacket *pkt)
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{
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    IEC958Context *ctx = s->priv_data;
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    uint32_t syncword_dts = AV_RB32(pkt->data);
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    int blocks;
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    switch (syncword_dts) {
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    case DCA_MARKER_RAW_BE:
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        blocks = (AV_RB16(pkt->data + 4) >> 2) & 0x7f;
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        break;
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    case DCA_MARKER_RAW_LE:
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        blocks = (AV_RL16(pkt->data + 4) >> 2) & 0x7f;
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        break;
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    case DCA_MARKER_14B_BE:
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        blocks =
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            (((pkt->data[5] & 0x07) << 4) | ((pkt->data[6] & 0x3f) >> 2));
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        break;
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    case DCA_MARKER_14B_LE:
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        blocks =
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            (((pkt->data[4] & 0x07) << 4) | ((pkt->data[7] & 0x3f) >> 2));
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        break;
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    default:
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        av_log(s, AV_LOG_ERROR, "bad DTS syncword 0x%x\n", syncword_dts);
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        return -1;
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    }
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    blocks++;
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    switch (blocks) {
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    case  512 >> 5: ctx->data_type = IEC958_DTS1; break;
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    case 1024 >> 5: ctx->data_type = IEC958_DTS2; break;
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    case 2048 >> 5: ctx->data_type = IEC958_DTS3; break;
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    default:
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        av_log(s, AV_LOG_ERROR, "%i samples in DTS frame not supported\n",
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               blocks << 5);
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        return -1;
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    }
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    ctx->pkt_offset = blocks << 7;
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    return 0;
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}
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static const enum IEC958DataType mpeg_data_type[2][3] = {
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    //     LAYER1                      LAYER2                  LAYER3
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    { IEC958_MPEG2_LAYER1_LSF, IEC958_MPEG2_LAYER2_LSF, IEC958_MPEG2_LAYER3_LSF },  //MPEG2 LSF
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    { IEC958_MPEG1_LAYER1,     IEC958_MPEG1_LAYER23,    IEC958_MPEG1_LAYER23 },     //MPEG1
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};
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static const uint16_t mpeg_pkt_offset[2][3] = {
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    //LAYER1  LAYER2  LAYER3
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    { 3072,    9216,   4608 }, // MPEG2 LSF
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    { 1536,    4608,   4608 }, // MPEG1
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};
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static int spdif_header_mpeg(AVFormatContext *s, AVPacket *pkt)
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{
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    IEC958Context *ctx = s->priv_data;
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    int version =      (pkt->data[1] >> 3) & 3;
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    int layer   = 3 - ((pkt->data[1] >> 1) & 3);
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    int extension = pkt->data[2] & 1;
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    if (layer == 3 || version == 1) {
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        av_log(s, AV_LOG_ERROR, "Wrong MPEG file format\n");
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        return -1;
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    }
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    av_log(s, AV_LOG_DEBUG, "version: %i layer: %i extension: %i\n", version, layer, extension);
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    if (version == 2 && extension) {
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        ctx->data_type  = IEC958_MPEG2_EXT;
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        ctx->pkt_offset = 4608;
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    } else {
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        ctx->data_type  = mpeg_data_type [version & 1][layer];
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        ctx->pkt_offset = mpeg_pkt_offset[version & 1][layer];
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    }
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    // TODO Data type dependant info (normal/karaoke, dynamic range control)
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    return 0;
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}
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static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)
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{
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    IEC958Context *ctx = s->priv_data;
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    AACADTSHeaderInfo hdr;
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    GetBitContext gbc;
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    int ret;
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    init_get_bits(&gbc, pkt->data, AAC_ADTS_HEADER_SIZE * 8);
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    ret = ff_aac_parse_header(&gbc, &hdr);
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    if (ret < 0) {
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        av_log(s, AV_LOG_ERROR, "Wrong AAC file format\n");
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        return -1;
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    }
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    ctx->pkt_offset = hdr.samples << 2;
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    switch (hdr.num_aac_frames) {
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    case 1:
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        ctx->data_type = IEC958_MPEG2_AAC;
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        break;
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    case 2:
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        ctx->data_type = IEC958_MPEG2_AAC_LSF_2048;
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        break;
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    case 4:
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        ctx->data_type = IEC958_MPEG2_AAC_LSF_4096;
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        break;
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    default:
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        av_log(s, AV_LOG_ERROR, "%i samples in AAC frame not supported\n",
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               hdr.samples);
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        return -1;
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    }
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    //TODO Data type dependent info (LC profile/SBR)
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    return 0;
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}
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static int spdif_write_header(AVFormatContext *s)
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{
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    IEC958Context *ctx = s->priv_data;
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    switch (s->streams[0]->codec->codec_id) {
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    case CODEC_ID_AC3:
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        ctx->header_info = spdif_header_ac3;
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        break;
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    case CODEC_ID_MP1:
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    case CODEC_ID_MP2:
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    case CODEC_ID_MP3:
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        ctx->header_info = spdif_header_mpeg;
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        break;
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    case CODEC_ID_DTS:
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        ctx->header_info = spdif_header_dts;
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        break;
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    case CODEC_ID_AAC:
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        ctx->header_info = spdif_header_aac;
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        break;
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    default:
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        av_log(s, AV_LOG_ERROR, "codec not supported\n");
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        return -1;
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    }
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    return 0;
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}
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static int spdif_write_trailer(AVFormatContext *s)
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{
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    IEC958Context *ctx = s->priv_data;
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    av_freep(&ctx->buffer);
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    return 0;
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}
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static int spdif_write_packet(struct AVFormatContext *s, AVPacket *pkt)
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{
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    IEC958Context *ctx = s->priv_data;
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    int ret, padding;
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    ctx->pkt_size = FFALIGN(pkt->size, 2) << 3;
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    ret = ctx->header_info(s, pkt);
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    if (ret < 0)
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        return -1;
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    padding = (ctx->pkt_offset - BURST_HEADER_SIZE - pkt->size) >> 1;
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    if (padding < 0) {
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        av_log(s, AV_LOG_ERROR, "bitrate is too high\n");
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        return -1;
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    }
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    put_le16(s->pb, SYNCWORD1);      //Pa
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    put_le16(s->pb, SYNCWORD2);      //Pb
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    put_le16(s->pb, ctx->data_type); //Pc
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    put_le16(s->pb, ctx->pkt_size);  //Pd
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#if HAVE_BIGENDIAN
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    put_buffer(s->pb, pkt->data, pkt->size & ~1);
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#else
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    av_fast_malloc(&ctx->buffer, &ctx->buffer_size, pkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
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    if (!ctx->buffer)
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        return AVERROR(ENOMEM);
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    bswap_buf16((uint16_t *)ctx->buffer, (uint16_t *)pkt->data, pkt->size >> 1);
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    put_buffer(s->pb, ctx->buffer, pkt->size & ~1);
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#endif
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    if (pkt->size & 1)
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        put_be16(s->pb, pkt->data[pkt->size - 1]);
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    for (; padding > 0; padding--)
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        put_be16(s->pb, 0);
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    av_log(s, AV_LOG_DEBUG, "type=%x len=%i pkt_offset=%i\n",
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           ctx->data_type, pkt->size, ctx->pkt_offset);
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    put_flush_packet(s->pb);
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    return 0;
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}
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AVOutputFormat spdif_muxer = {
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    "spdif",
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    NULL_IF_CONFIG_SMALL("IEC958 - S/PDIF (IEC-61937)"),
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    NULL,
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    "spdif",
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    sizeof(IEC958Context),
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    CODEC_ID_AC3,
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    CODEC_ID_NONE,
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    spdif_write_header,
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    spdif_write_packet,
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    spdif_write_trailer,
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};