mp4atom.c

mpeg4 video codec mpeg4 video codec

    } else if (atom_type == ATOM_MP4V) {
        f->track[f->total_tracks - 1]->type = TRACK_VIDEO;
    } else if (atom_type == ATOM_MP4S) {
        f->track[f->total_tracks - 1]->type = TRACK_SYSTEM;
    } else {
        f->track[f->total_tracks - 1]->type = TRACK_UNKNOWN;
    }

    return 0;
}

static int32_t mp4ff_read_name(mp4ff_t *f, uint64_t size)
{
    uint8_t *data = malloc(size);
    mp4ff_read_data(f, data, size);

    if (f->track[f->total_tracks - 1]->p_drms != NULL)
    {
        drms_init(f->track[f->total_tracks - 1]->p_drms,
            DRMS_INIT_NAME, data, strlen(data) );
    }

    if (data)
        free(data);

    return 0;
}

static int32_t mp4ff_read_priv(mp4ff_t *f, uint64_t size)
{
    uint8_t *data = malloc(size);
    mp4ff_read_data(f, data, size);

    if (f->track[f->total_tracks - 1]->p_drms != 0)
    {
        drms_init(f->track[f->total_tracks - 1]->p_drms,
            DRMS_INIT_PRIV, data, size );
    }

    if (data)
        free(data);

    return 0;
}

static int32_t mp4ff_read_iviv(mp4ff_t *f, uint64_t size)
{
    uint8_t *data = malloc(size);
    mp4ff_read_data(f, data, size);

    if (f->track[f->total_tracks - 1]->p_drms != 0)
    {
        drms_init(f->track[f->total_tracks - 1]->p_drms,
            DRMS_INIT_IVIV, data, sizeof(uint32_t) * 4 );
    }

    if (data)
        free(data);

    return 0;
}
#endif

static int32_t mp4ff_read_stsd(mp4ff_t *f)
{
    int32_t i;
    uint8_t header_size = 0;

    mp4ff_read_char(f); /* version */
    mp4ff_read_int24(f); /* flags */

    f->track[f->total_tracks - 1]->stsd_entry_count = mp4ff_read_int32(f);

    for (i = 0; i < f->track[f->total_tracks - 1]->stsd_entry_count; i++)
    {
        uint64_t skip = mp4ff_position(f);
        uint64_t size;
        uint8_t atom_type = 0;
        size = mp4ff_atom_read_header(f, &atom_type, &header_size);
        skip += size;

        if (atom_type == ATOM_MP4A)
        {
            f->track[f->total_tracks - 1]->type = TRACK_AUDIO;
            mp4ff_read_mp4a(f);
        } else if (atom_type == ATOM_MP4V) {
            f->track[f->total_tracks - 1]->type = TRACK_VIDEO;
        } else if (atom_type == ATOM_MP4S) {
            f->track[f->total_tracks - 1]->type = TRACK_SYSTEM;
#ifdef ITUNES_DRM
        } else if (atom_type == ATOM_DRMS) {
            // track type is read from the "frma" atom
            f->track[f->total_tracks - 1]->type = TRACK_UNKNOWN;
            mp4ff_read_drms(f, skip-size+header_size);
#endif
        } else {
            f->track[f->total_tracks - 1]->type = TRACK_UNKNOWN;
        }

        mp4ff_set_position(f, skip);
    }

    return 0;
}

static int32_t mp4ff_read_stsc(mp4ff_t *f)
{
    int32_t i;

    mp4ff_read_char(f); /* version */ 
    mp4ff_read_int24(f); /* flags */ 
    f->track[f->total_tracks - 1]->stsc_entry_count = mp4ff_read_int32(f);

    f->track[f->total_tracks - 1]->stsc_first_chunk =
        (int32_t*)malloc(f->track[f->total_tracks - 1]->stsc_entry_count*sizeof(int32_t));
    f->track[f->total_tracks - 1]->stsc_samples_per_chunk =
        (int32_t*)malloc(f->track[f->total_tracks - 1]->stsc_entry_count*sizeof(int32_t));
    f->track[f->total_tracks - 1]->stsc_sample_desc_index =
        (int32_t*)malloc(f->track[f->total_tracks - 1]->stsc_entry_count*sizeof(int32_t));

    for (i = 0; i < f->track[f->total_tracks - 1]->stsc_entry_count; i++)
    {
        f->track[f->total_tracks - 1]->stsc_first_chunk[i] = mp4ff_read_int32(f);
        f->track[f->total_tracks - 1]->stsc_samples_per_chunk[i] = mp4ff_read_int32(f);
        f->track[f->total_tracks - 1]->stsc_sample_desc_index[i] = mp4ff_read_int32(f);
    }

    return 0;
}

static int32_t mp4ff_read_stco(mp4ff_t *f)
{
    int32_t i;

    mp4ff_read_char(f); /* version */
    mp4ff_read_int24(f); /* flags */
    f->track[f->total_tracks - 1]->stco_entry_count = mp4ff_read_int32(f);

    f->track[f->total_tracks - 1]->stco_chunk_offset =
        (int32_t*)malloc(f->track[f->total_tracks - 1]->stco_entry_count*sizeof(int32_t));

    for (i = 0; i < f->track[f->total_tracks - 1]->stco_entry_count; i++)
    {
        f->track[f->total_tracks - 1]->stco_chunk_offset[i] = mp4ff_read_int32(f);
    }

    return 0;
}

static int32_t mp4ff_read_ctts(mp4ff_t *f)
{
    int32_t i;
	mp4ff_track_t * p_track = f->track[f->total_tracks - 1];

	if (p_track->ctts_entry_count) return 0;

    mp4ff_read_char(f); /* version */
    mp4ff_read_int24(f); /* flags */
    p_track->ctts_entry_count = mp4ff_read_int32(f);

    p_track->ctts_sample_count = (int32_t*)malloc(p_track->ctts_entry_count * sizeof(int32_t));
    p_track->ctts_sample_offset = (int32_t*)malloc(p_track->ctts_entry_count * sizeof(int32_t));

	if (p_track->ctts_sample_count == 0 || p_track->ctts_sample_offset == 0)
	{
		if (p_track->ctts_sample_count) {free(p_track->ctts_sample_count);p_track->ctts_sample_count=0;}
		if (p_track->ctts_sample_offset) {free(p_track->ctts_sample_offset);p_track->ctts_sample_offset=0;}
		p_track->ctts_entry_count = 0;
		return 0;
	}
	else
	{
		for (i = 0; i < f->track[f->total_tracks - 1]->ctts_entry_count; i++)
		{
			p_track->ctts_sample_count[i] = mp4ff_read_int32(f);
			p_track->ctts_sample_offset[i] = mp4ff_read_int32(f);
		}
		return 1;
	}
}

static int32_t mp4ff_read_stts(mp4ff_t *f)
{
    int32_t i;
	mp4ff_track_t * p_track = f->track[f->total_tracks - 1];

	if (p_track->stts_entry_count) return 0;

    mp4ff_read_char(f); /* version */
    mp4ff_read_int24(f); /* flags */
    p_track->stts_entry_count = mp4ff_read_int32(f);

    p_track->stts_sample_count = (int32_t*)malloc(p_track->stts_entry_count * sizeof(int32_t));
    p_track->stts_sample_delta = (int32_t*)malloc(p_track->stts_entry_count * sizeof(int32_t));
	
	if (p_track->stts_sample_count == 0 || p_track->stts_sample_delta == 0)
	{
		if (p_track->stts_sample_count) {free(p_track->stts_sample_count);p_track->stts_sample_count=0;}
		if (p_track->stts_sample_delta) {free(p_track->stts_sample_delta);p_track->stts_sample_delta=0;}
		p_track->stts_entry_count = 0;
		return 0;
	}
	else
	{
		for (i = 0; i < f->track[f->total_tracks - 1]->stts_entry_count; i++)
		{
			p_track->stts_sample_count[i] = mp4ff_read_int32(f);
			p_track->stts_sample_delta[i] = mp4ff_read_int32(f);
		}
		return 1;
	}
}

static int32_t mp4ff_read_mvhd(mp4ff_t *f)
{
    int32_t i;

    mp4ff_read_char(f); /* version */
    mp4ff_read_int24(f); /* flags */
    /* creation_time */ mp4ff_read_int32(f);
    /* modification_time */ mp4ff_read_int32(f);
    f->time_scale = mp4ff_read_int32(f);
    f->duration = mp4ff_read_int32(f);
    /* preferred_rate */ mp4ff_read_int32(f); /*mp4ff_read_fixed32(f);*/
    /* preferred_volume */ mp4ff_read_int16(f); /*mp4ff_read_fixed16(f);*/
    for (i = 0; i < 10; i++)
    {
        /* reserved */ mp4ff_read_char(f);
    }
    for (i = 0; i < 9; i++)
    {
        mp4ff_read_int32(f); /* matrix */
    }
    /* preview_time */ mp4ff_read_int32(f);
    /* preview_duration */ mp4ff_read_int32(f);
    /* poster_time */ mp4ff_read_int32(f);
    /* selection_time */ mp4ff_read_int32(f);
    /* selection_duration */ mp4ff_read_int32(f);
    /* current_time */ mp4ff_read_int32(f);
    /* next_track_id */ mp4ff_read_int32(f);

    return 0;
}

#if 0
static int32_t mp4ff_read_tkhd(mp4ff_t *f)
{
	uint8_t version;
	uint32_t flags;
    version = mp4ff_read_char(f); /* version */
    flags = mp4ff_read_int24(f); /* flags */
	if (version==1)
	{
		mp4ff_read_int64(f);//creation-time
		mp4ff_read_int64(f);//modification-time
		mp4ff_read_int32(f);//track-id
		mp4ff_read_int32(f);//reserved
		f->track[f->total_tracks - 1]->duration = mp4ff_read_int64(f);//duration
	}
	else //version == 0
	{
		mp4ff_read_int32(f);//creation-time
		mp4ff_read_int32(f);//modification-time
		mp4ff_read_int32(f);//track-id
		mp4ff_read_int32(f);//reserved
		f->track[f->total_tracks - 1]->duration = mp4ff_read_int32(f);//duration
		if (f->track[f->total_tracks - 1]->duration == 0xFFFFFFFF)
			f->track[f->total_tracks - 1]->duration = 0xFFFFFFFFFFFFFFFF;

	}
	mp4ff_read_int32(f);//reserved
	mp4ff_read_int32(f);//reserved
	mp4ff_read_int16(f);//layer
	mp4ff_read_int16(f);//pre-defined
	mp4ff_read_int16(f);//volume
	mp4ff_read_int16(f);//reserved
	
	//matrix
	mp4ff_read_int32(f); mp4ff_read_int32(f); mp4ff_read_int32(f);
	mp4ff_read_int32(f); mp4ff_read_int32(f); mp4ff_read_int32(f);
	mp4ff_read_int32(f); mp4ff_read_int32(f); mp4ff_read_int32(f);
	mp4ff_read_int32(f);//width
	mp4ff_read_int32(f);//height
	return 1;
}
#endif

static int32_t mp4ff_read_mdhd(mp4ff_t *f)
{
	uint32_t version;

	version = mp4ff_read_int32(f);
	if (version==1)
	{
		mp4ff_read_int64(f);//creation-time
		mp4ff_read_int64(f);//modification-time
		f->track[f->total_tracks - 1]->timeScale = mp4ff_read_int32(f);//timescale
		f->track[f->total_tracks - 1]->duration = mp4ff_read_int64(f);//duration
	}
	else //version == 0
	{
		uint32_t temp;

		mp4ff_read_int32(f);//creation-time
		mp4ff_read_int32(f);//modification-time
		f->track[f->total_tracks - 1]->timeScale = mp4ff_read_int32(f);//timescale
		temp = mp4ff_read_int32(f);
		f->track[f->total_tracks - 1]->duration = (temp == (uint32_t)(-1)) ? (uint64_t)(-1) : (uint64_t)(temp);
	}
	mp4ff_read_int16(f);
	mp4ff_read_int16(f);
	return 1;
}
#ifdef USE_TAGGING
static int32_t mp4ff_read_meta(mp4ff_t *f, const uint64_t size)
{
    uint64_t subsize, sumsize = 0;
    uint8_t atom_type;
    uint8_t header_size = 0;

    mp4ff_read_char(f); /* version */
    mp4ff_read_int24(f); /* flags */

    while (sumsize < (size-12))
    {
        subsize = mp4ff_atom_read_header(f, &atom_type, &header_size);
        if (atom_type == ATOM_ILST)
        {
            mp4ff_parse_metadata(f, (uint32_t)(subsize-(header_size+4)));
        } else {
            mp4ff_set_position(f, mp4ff_position(f)+subsize-header_size);
        }
        sumsize += subsize;
    }

    return 0;
}
#endif

int32_t mp4ff_atom_read(mp4ff_t *f, const int32_t size, const uint8_t atom_type)
{
	uint64_t dest_position = mp4ff_position(f)+size-8;
    if (atom_type == ATOM_STSZ)
    {
        /* sample size box */
        mp4ff_read_stsz(f);
    } else if (atom_type == ATOM_STTS) {
        /* time to sample box */
        mp4ff_read_stts(f);
	} else if (atom_type == ATOM_CTTS) {
		/* composition offset box */
		mp4ff_read_ctts(f);
    } else if (atom_type == ATOM_STSC) {
        /* sample to chunk box */
        mp4ff_read_stsc(f);
    } else if (atom_type == ATOM_STCO) {
        /* chunk offset box */
        mp4ff_read_stco(f);
    } else if (atom_type == ATOM_STSD) {
        /* sample description box */
        mp4ff_read_stsd(f);
    } else if (atom_type == ATOM_MVHD) {
        /* movie header box */
        mp4ff_read_mvhd(f);
    } else if (atom_type == ATOM_MDHD) {
        /* track header */
        mp4ff_read_mdhd(f);
#ifdef ITUNES_DRM
    } else if (atom_type == ATOM_FRMA) {
        /* DRM track format */
        mp4ff_read_frma(f);
    } else if (atom_type == ATOM_IVIV) {
        mp4ff_read_iviv(f, size-8);
    } else if (atom_type == ATOM_NAME) {
        mp4ff_read_name(f, size-8);
    } else if (atom_type == ATOM_PRIV) {
        mp4ff_read_priv(f, size-8);
#endif
#ifdef USE_TAGGING
    } else if (atom_type == ATOM_META) {
        /* iTunes Metadata box */
        mp4ff_read_meta(f, size);
#endif
    }
     
    mp4ff_set_position(f, dest_position);


    return 0;
}