shithub: aacdec

ref: 346020cc7ba14528f2d54b29cfc71f51d900aafc
dir: /common/mp4ff/mp4sample.c/

/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
**
** $Id: mp4sample.c,v 1.3 2003/11/25 13:16:09 menno Exp $
**/

#include <stdlib.h>
#include "mp4ffint.h"


static int32_t mp4ff_chunk_of_sample(const mp4ff_t *f, const int32_t track, const int32_t sample,
                                     int32_t *chunk_sample, int32_t *chunk)
{
    int32_t total_entries = 0;
    int32_t chunk2entry;
    int32_t chunk1, chunk2, chunk1samples, range_samples, total = 0;

    if (f->track[track] == NULL)
    {
        return -1;
    }

    total_entries = f->track[track]->stsc_entry_count;

    chunk1 = 1;
    chunk1samples = 0;
    chunk2entry = 0;

    do
    {
        chunk2 = f->track[track]->stsc_first_chunk[chunk2entry];
        *chunk = chunk2 - chunk1;
        range_samples = *chunk * chunk1samples;

        if (sample < total + range_samples) break;

        chunk1samples = f->track[track]->stsc_samples_per_chunk[chunk2entry];
        chunk1 = chunk2;

        if(chunk2entry < total_entries)
        {
            chunk2entry++;
            total += range_samples;
        }
    } while (chunk2entry < total_entries);

    if (chunk1samples)
        *chunk = (sample - total) / chunk1samples + chunk1;
    else
        *chunk = 1;

    *chunk_sample = total + (*chunk - chunk1) * chunk1samples;

    return 0;
}

static int32_t mp4ff_chunk_to_offset(const mp4ff_t *f, const int32_t track, const int32_t chunk)
{
    if (f->track[track]->stco_entry_count && (chunk > f->track[track]->stco_entry_count))
    {
        return f->track[track]->stco_chunk_offset[f->track[track]->stco_entry_count - 1];
    } else if (f->track[track]->stco_entry_count) {
        return f->track[track]->stco_chunk_offset[chunk - 1];
    } else {
        return 8;
    }
    
    return 0;
}

static int32_t mp4ff_sample_range_size(const mp4ff_t *f, const int32_t track,
                                       const int32_t chunk_sample, const int32_t sample)
{
    int32_t i, total;

    if (f->track[track]->stsz_sample_size)
    {
        return sample * f->track[track]->channelCount * f->track[track]->sampleSize/8;
    } else {
        for(i = chunk_sample, total = 0; i < sample; i++)
        {
            total += f->track[track]->stsz_table[i];
        }
    }

    return total;
}

static int32_t mp4ff_sample_to_offset(const mp4ff_t *f, const int32_t track, const int32_t sample)
{
    int32_t chunk, chunk_sample, chunk_offset1, chunk_offset2;

    mp4ff_chunk_of_sample(f, track, sample, &chunk_sample, &chunk);

    chunk_offset1 = mp4ff_chunk_to_offset(f, track, chunk);
    chunk_offset2 = chunk_offset1 + mp4ff_sample_range_size(f, track, chunk_sample, sample);

	return chunk_offset2;
}

int32_t mp4ff_audio_frame_size(const mp4ff_t *f, const int32_t track, const int32_t sample)
{
    int32_t bytes;

    if (f->track[track]->stsz_sample_size)
    {
        bytes = f->track[track]->stsz_sample_size;
    } else {
        bytes = f->track[track]->stsz_table[sample];
    }

    return bytes;
}

int32_t mp4ff_set_sample_position(mp4ff_t *f, const int32_t track, const int32_t sample)
{
    int32_t offset;

    offset = mp4ff_sample_to_offset(f, track, sample);
    mp4ff_set_position(f, offset);

    return 0;
}