void remove_systems_tracks(GF_ISOFile *file)
{
	u32 i, count;

	count = gf_isom_get_track_count(file);
	if (count==1) return;

	/*force PL rewrite*/
	gf_isom_set_pl_indication(file, GF_ISOM_PL_VISUAL, 0);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_AUDIO, 0);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_OD, 1);	/*the lib always remove IOD when no profiles are specified..*/

	for (i=0; i<gf_isom_get_track_count(file); i++) {
		switch (gf_isom_get_media_type(file, i+1)) {
		case GF_ISOM_MEDIA_VISUAL:
        case GF_ISOM_MEDIA_AUXV:
        case GF_ISOM_MEDIA_PICT:
		case GF_ISOM_MEDIA_AUDIO:
		case GF_ISOM_MEDIA_TEXT:
		case GF_ISOM_MEDIA_SUBT:
			gf_isom_remove_track_from_root_od(file, i+1);
			check_media_profile(file, i+1);
			break;
		/*only remove real systems tracks (eg, delaing with scene description & presentation)
		but keep meta & all unknown tracks*/
		case GF_ISOM_MEDIA_SCENE:
			switch (gf_isom_get_media_subtype(file, i+1, 1)) {
			case GF_ISOM_MEDIA_DIMS:
				gf_isom_remove_track_from_root_od(file, i+1);
				continue;
			default:
				break;
			}
		case GF_ISOM_MEDIA_OD:
		case GF_ISOM_MEDIA_OCR:
		case GF_ISOM_MEDIA_MPEGJ:
			gf_isom_remove_track(file, i+1);
			i--;
			break;
		default:
			break;
		}
	}
	/*none required*/
	if (!gf_isom_get_pl_indication(file, GF_ISOM_PL_AUDIO)) gf_isom_set_pl_indication(file, GF_ISOM_PL_AUDIO, 0xFF);
	if (!gf_isom_get_pl_indication(file, GF_ISOM_PL_VISUAL)) gf_isom_set_pl_indication(file, GF_ISOM_PL_VISUAL, 0xFF);

	gf_isom_set_pl_indication(file, GF_ISOM_PL_OD, 0xFF);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_SCENE, 0xFF);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_GRAPHICS, 0xFF);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_INLINE, 0);
}
void remove_systems_tracks(GF_ISOFile *file)
{
	u32 i, count;

	count = gf_isom_get_track_count(file);
	if (count==1) return;

	 
	gf_isom_set_pl_indication(file, GF_ISOM_PL_VISUAL, 0);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_AUDIO, 0);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_OD, 1);	 

	for (i=0; i<gf_isom_get_track_count(file); i++) {
		switch (gf_isom_get_media_type(file, i+1)) {
		case GF_ISOM_MEDIA_VISUAL:
        case GF_ISOM_MEDIA_AUXV:
        case GF_ISOM_MEDIA_PICT:
		case GF_ISOM_MEDIA_AUDIO:
		case GF_ISOM_MEDIA_TEXT:
		case GF_ISOM_MEDIA_SUBT:
			gf_isom_remove_track_from_root_od(file, i+1);
			check_media_profile(file, i+1);
			break;
		 
		case GF_ISOM_MEDIA_SCENE:
			switch (gf_isom_get_media_subtype(file, i+1, 1)) {
			case GF_ISOM_MEDIA_DIMS:
				gf_isom_remove_track_from_root_od(file, i+1);
				continue;
			default:
				break;
			}
		case GF_ISOM_MEDIA_OD:
		case GF_ISOM_MEDIA_OCR:
		case GF_ISOM_MEDIA_MPEGJ:
			gf_isom_remove_track(file, i+1);
			i--;
			break;
		default:
			break;
		}
	}
	 
	if (!gf_isom_get_pl_indication(file, GF_ISOM_PL_AUDIO)) gf_isom_set_pl_indication(file, GF_ISOM_PL_AUDIO, 0xFF);
	if (!gf_isom_get_pl_indication(file, GF_ISOM_PL_VISUAL)) gf_isom_set_pl_indication(file, GF_ISOM_PL_VISUAL, 0xFF);

	gf_isom_set_pl_indication(file, GF_ISOM_PL_OD, 0xFF);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_SCENE, 0xFF);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_GRAPHICS, 0xFF);
	gf_isom_set_pl_indication(file, GF_ISOM_PL_INLINE, 0);
}