GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/ac3_parser.c Lines: 108 111 97.3 %
Date: 2019-11-22 03:34:36 Branches: 45 52 86.5 %

Line Branch Exec Source
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/*
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 * AC-3 parser
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 * Copyright (c) 2003 Fabrice Bellard
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 * Copyright (c) 2003 Michael Niedermayer
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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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#include "config.h"
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#include "libavutil/channel_layout.h"
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#include "parser.h"
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#include "ac3_parser.h"
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#include "ac3_parser_internal.h"
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#include "aac_ac3_parser.h"
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#include "get_bits.h"
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#define AC3_HEADER_SIZE 7
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#if CONFIG_AC3_PARSER
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static const uint8_t eac3_blocks[4] = {
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    1, 2, 3, 6
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};
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/**
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 * Table for center mix levels
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 * reference: Section 5.4.2.4 cmixlev
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 */
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static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
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/**
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 * Table for surround mix levels
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 * reference: Section 5.4.2.5 surmixlev
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 */
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static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
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56656
int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
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{
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    int frame_size_code;
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56656
    memset(hdr, 0, sizeof(*hdr));
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56656
    hdr->sync_word = get_bits(gbc, 16);
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56656
    if(hdr->sync_word != 0x0B77)
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38405
        return AAC_AC3_PARSE_ERROR_SYNC;
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    /* read ahead to bsid to distinguish between AC-3 and E-AC-3 */
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18251
    hdr->bitstream_id = show_bits_long(gbc, 29) & 0x1F;
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18251
    if(hdr->bitstream_id > 16)
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        return AAC_AC3_PARSE_ERROR_BSID;
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    hdr->num_blocks = 6;
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    /* set default mix levels */
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15493
    hdr->center_mix_level   = 5;  // -4.5dB
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15493
    hdr->surround_mix_level = 6;  // -6.0dB
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    /* set default dolby surround mode */
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15493
    hdr->dolby_surround_mode = AC3_DSURMOD_NOTINDICATED;
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15493
    if(hdr->bitstream_id <= 10) {
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        /* Normal AC-3 */
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7370
        hdr->crc1 = get_bits(gbc, 16);
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7370
        hdr->sr_code = get_bits(gbc, 2);
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7370
        if(hdr->sr_code == 3)
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            return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
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        frame_size_code = get_bits(gbc, 6);
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        if(frame_size_code > 37)
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            return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
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7016
        skip_bits(gbc, 5); // skip bsid, already got it
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7016
        hdr->bitstream_mode = get_bits(gbc, 3);
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7016
        hdr->channel_mode = get_bits(gbc, 3);
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        if(hdr->channel_mode == AC3_CHMODE_STEREO) {
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            hdr->dolby_surround_mode = get_bits(gbc, 2);
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        } else {
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            if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
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                hdr->  center_mix_level =   center_levels[get_bits(gbc, 2)];
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            if(hdr->channel_mode & 4)
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3922
                hdr->surround_mix_level = surround_levels[get_bits(gbc, 2)];
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        }
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7016
        hdr->lfe_on = get_bits1(gbc);
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7016
        hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8;
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7016
        hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
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7016
        hdr->bit_rate = (ff_ac3_bitrate_tab[frame_size_code>>1] * 1000) >> hdr->sr_shift;
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7016
        hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
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7016
        hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
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7016
        hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
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7016
        hdr->substreamid = 0;
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    } else {
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        /* Enhanced AC-3 */
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        hdr->crc1 = 0;
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8123
        hdr->frame_type = get_bits(gbc, 2);
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        if(hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
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            return AAC_AC3_PARSE_ERROR_FRAME_TYPE;
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        hdr->substreamid = get_bits(gbc, 3);
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8049
        hdr->frame_size = (get_bits(gbc, 11) + 1) << 1;
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        if(hdr->frame_size < AC3_HEADER_SIZE)
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            return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
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        hdr->sr_code = get_bits(gbc, 2);
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8047
        if (hdr->sr_code == 3) {
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            int sr_code2 = get_bits(gbc, 2);
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            if(sr_code2 == 3)
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                return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
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            hdr->sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
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            hdr->sr_shift = 1;
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        } else {
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            hdr->num_blocks = eac3_blocks[get_bits(gbc, 2)];
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            hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code];
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            hdr->sr_shift = 0;
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        }
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        hdr->channel_mode = get_bits(gbc, 3);
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        hdr->lfe_on = get_bits1(gbc);
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8023
        hdr->bit_rate = 8LL * hdr->frame_size * hdr->sample_rate /
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                        (hdr->num_blocks * 256);
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        hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
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    }
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15039
    hdr->channel_layout = avpriv_ac3_channel_layout_tab[hdr->channel_mode];
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15039
    if (hdr->lfe_on)
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        hdr->channel_layout |= AV_CH_LOW_FREQUENCY;
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15039
    return 0;
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}
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// TODO: Better way to pass AC3HeaderInfo fields to mov muxer.
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int avpriv_ac3_parse_header(AC3HeaderInfo **phdr, const uint8_t *buf,
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                            size_t size)
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{
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    GetBitContext gb;
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    AC3HeaderInfo *hdr;
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    int err;
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    if (!*phdr)
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        *phdr = av_mallocz(sizeof(AC3HeaderInfo));
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    if (!*phdr)
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        return AVERROR(ENOMEM);
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    hdr = *phdr;
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    err = init_get_bits8(&gb, buf, size);
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    if (err < 0)
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        return AVERROR_INVALIDDATA;
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    err = ff_ac3_parse_header(&gb, hdr);
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    if (err < 0)
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        return AVERROR_INVALIDDATA;
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    return get_bits_count(&gb);
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}
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23224
int av_ac3_parse_header(const uint8_t *buf, size_t size,
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                        uint8_t *bitstream_id, uint16_t *frame_size)
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{
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    GetBitContext gb;
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    AC3HeaderInfo hdr;
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    int err;
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    init_get_bits8(&gb, buf, size);
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    err = ff_ac3_parse_header(&gb, &hdr);
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    if (err < 0)
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        return AVERROR_INVALIDDATA;
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7498
    *bitstream_id = hdr.bitstream_id;
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    *frame_size   = hdr.frame_size;
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    return 0;
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}
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static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
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        int *need_next_header, int *new_frame_start)
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{
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    int err;
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    union {
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        uint64_t u64;
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        uint8_t  u8[8 + AV_INPUT_BUFFER_PADDING_SIZE];
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    } tmp = { av_be2ne64(state) };
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    AC3HeaderInfo hdr;
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    GetBitContext gbc;
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30042
    init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54);
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    err = ff_ac3_parse_header(&gbc, &hdr);
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30042
    if(err < 0)
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        return 0;
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4152
    hdr_info->sample_rate = hdr.sample_rate;
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4152
    hdr_info->bit_rate = hdr.bit_rate;
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4152
    hdr_info->channels = hdr.channels;
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    hdr_info->channel_layout = hdr.channel_layout;
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    hdr_info->samples = hdr.num_blocks * 256;
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4152
    hdr_info->service_type = hdr.bitstream_mode;
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    if (hdr.bitstream_mode == 0x7 && hdr.channels > 1)
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        hdr_info->service_type = AV_AUDIO_SERVICE_TYPE_KARAOKE;
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    if(hdr.bitstream_id>10)
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        hdr_info->codec_id = AV_CODEC_ID_EAC3;
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1501
    else if (hdr_info->codec_id == AV_CODEC_ID_NONE)
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        hdr_info->codec_id = AV_CODEC_ID_AC3;
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4152
    *new_frame_start  = (hdr.frame_type != EAC3_FRAME_TYPE_DEPENDENT);
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4152
    *need_next_header = *new_frame_start || (hdr.frame_type != EAC3_FRAME_TYPE_AC3_CONVERT);
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    return hdr.frame_size;
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}
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static av_cold int ac3_parse_init(AVCodecParserContext *s1)
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{
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    AACAC3ParseContext *s = s1->priv_data;
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    s->header_size = AC3_HEADER_SIZE;
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    s->sync = ac3_sync;
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    return 0;
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}
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AVCodecParser ff_ac3_parser = {
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    .codec_ids      = { AV_CODEC_ID_AC3, AV_CODEC_ID_EAC3 },
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    .priv_data_size = sizeof(AACAC3ParseContext),
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    .parser_init    = ac3_parse_init,
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    .parser_parse   = ff_aac_ac3_parse,
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    .parser_close   = ff_parse_close,
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};
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#else
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int avpriv_ac3_parse_header(AC3HeaderInfo **phdr, const uint8_t *buf,
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                            size_t size)
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{
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    return AVERROR(ENOSYS);
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}
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int av_ac3_parse_header(const uint8_t *buf, size_t size,
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                        uint8_t *bitstream_id, uint16_t *frame_size)
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{
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    return AVERROR(ENOSYS);
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}
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#endif