/* parse root atoms */
static int32_t parse_atoms_int (mp4ff_t *f,int meta_only,int stop_on_mdat)
{
uint64_t size;
uint8_t atom_type = 0;
uint8_t header_size = 0;
int had_valid_atoms = 0;
f->file_size = 0;
while ((size = mp4ff_atom_read_header(f, &atom_type, &header_size)) != 0)
{
// FIXME: ATOM_UNKNOWN is returned both when a valid (but unknown) atom is encontered,
// and for invalid data. They need to be handled separately.
if (atom_type == ATOM_UNKNOWN && !had_valid_atoms && mp4ff_position(f)+size > 100) {
return -1;
}
had_valid_atoms = 1;
f->file_size += size;
f->last_atom = atom_type;
if (atom_type == ATOM_MDAT && f->moov_read)
{
/* moov atom is before mdat, we can stop reading when mdat is encountered */
/* file position will stay at beginning of mdat data */
if (!stop_on_mdat) {
break;
}
}
if (atom_type == ATOM_MOOV && size > header_size)
{
f->moov_read = 1;
f->moov_offset = mp4ff_position(f)-header_size;
f->moov_size = size;
}
/* parse subatoms */
if (meta_only && !need_parse_when_meta_only(atom_type))
{
mp4ff_set_position(f, mp4ff_position(f)+size-header_size);
} else if (atom_type < SUBATOMIC)
{
parse_sub_atoms(f, size-header_size,meta_only);
} else {
/* skip this atom */
mp4ff_set_position(f, mp4ff_position(f)+size-header_size);
}
}
return 0;
}
/* parse atoms that are sub atoms of other atoms */
int32_t parse_sub_atoms(mp4ff_t *f, const uint64_t total_size,int meta_only)
{
uint64_t size;
uint8_t atom_type = 0;
uint64_t counted_size = 0;
uint8_t header_size = 0;
while (counted_size < total_size)
{
size = mp4ff_atom_read_header(f, &atom_type, &header_size);
counted_size += size;
/* check for end of file */
if (size == 0)
break;
/* we're starting to read a new track, update index,
* so that all data and tables get written in the right place
*/
if (atom_type == ATOM_TRAK)
{
mp4ff_track_add(f);
}
/* parse subatoms */
if (meta_only && !need_parse_when_meta_only(atom_type))
{
mp4ff_set_position(f, mp4ff_position(f)+size-header_size);
} else if (atom_type < SUBATOMIC)
{
parse_sub_atoms(f, size-header_size,meta_only);
} else {
mp4ff_atom_read(f, (uint32_t)size, atom_type);
}
#if 0
if (atom_type == ATOM_TRAK)
{
trace ("mp4ff_track_create_chunks_index\n");
mp4ff_track_create_chunks_index (f, f->track[f->total_tracks-1]);
trace ("mp4ff_track_create_samples_index\n");
mp4ff_track_create_samples_index (f, f->track[f->total_tracks-1]);
}
#endif
}
return 0;
}
/* parse root atoms */
int32_t parse_atoms(mp4ff_t *f,int meta_only)
{
uint64_t size;
uint8_t atom_type = 0;
uint8_t header_size = 0;
f->file_size = 0;
while ((size = mp4ff_atom_read_header(f, &atom_type, &header_size)) != 0)
{
f->file_size += size;
f->last_atom = atom_type;
if (atom_type == ATOM_MDAT && f->moov_read)
{
/* moov atom is before mdat, we can stop reading when mdat is encountered */
/* file position will stay at beginning of mdat data */
// break;
}
if (atom_type == ATOM_MOOV && size > header_size)
{
f->moov_read = 1;
f->moov_offset = mp4ff_position(f)-header_size;
f->moov_size = size;
}
/* parse subatoms */
if (meta_only && !need_parse_when_meta_only(atom_type))
{
mp4ff_set_position(f, mp4ff_position(f)+size-header_size);
} else if (atom_type < SUBATOMIC)
{
parse_sub_atoms(f, size-header_size,meta_only);
} else {
/* skip this atom */
mp4ff_set_position(f, mp4ff_position(f)+size-header_size);
}
}
return 0;
}