/*

 * Audio and Video frame extraction

 * Copyright (c) 2003 Fabrice Bellard

 * Copyright (c) 2003 Michael Niedermayer

 * Copyright (c) 2009 Alex Converse

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "adts_header.h"

#include "adts_parser.h"

#include "get_bits.h"

#include "mpeg4audio.h"

#include "libavutil/avassert.h"

int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr)

{

    int size, rdb, ch, sr;

    int aot, crc_abs;

    memset(hdr, 0, sizeof(*hdr));

    if (get_bits(gbc, 12) != 0xfff)

        return AAC_PARSE_ERROR_SYNC;

    skip_bits1(gbc);             /* id */

    skip_bits(gbc, 2);           /* layer */

    crc_abs = get_bits1(gbc);    /* protection_absent */

    aot     = get_bits(gbc, 2);  /* profile_objecttype */

    sr      = get_bits(gbc, 4);  /* sample_frequency_index */

    if (!ff_mpeg4audio_sample_rates[sr])

        return AAC_PARSE_ERROR_SAMPLE_RATE;

    skip_bits1(gbc);             /* private_bit */

    ch = get_bits(gbc, 3);       /* channel_configuration */

    skip_bits1(gbc);             /* original/copy */

    skip_bits1(gbc);             /* home */

    /* adts_variable_header */

    skip_bits1(gbc);             /* copyright_identification_bit */

    skip_bits1(gbc);             /* copyright_identification_start */

    size = get_bits(gbc, 13);    /* aac_frame_length */

    if (size < AV_AAC_ADTS_HEADER_SIZE)

        return AAC_PARSE_ERROR_FRAME_SIZE;

    skip_bits(gbc, 11);          /* adts_buffer_fullness */

    rdb = get_bits(gbc, 2);      /* number_of_raw_data_blocks_in_frame */

    hdr->object_type    = aot + 1;

    hdr->chan_config    = ch;

    hdr->crc_absent     = crc_abs;

    hdr->num_aac_frames = rdb + 1;

    hdr->sampling_index = sr;

    hdr->sample_rate    = ff_mpeg4audio_sample_rates[sr];

    hdr->samples        = (rdb + 1) * 1024;

    hdr->bit_rate       = size * 8 * hdr->sample_rate / hdr->samples;

    hdr->frame_length   = size;

    return size;

}

int ff_adts_header_parse_buf(const uint8_t buf[AV_AAC_ADTS_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE],

                             AACADTSHeaderInfo *hdr)

{

    GetBitContext gb;

    av_unused int ret = init_get_bits8(&gb, buf, AV_AAC_ADTS_HEADER_SIZE);

    av_assert1(ret >= 0);

    return ff_adts_header_parse(&gb, hdr);

}