Sample files (numbers in parentheses show how many files per extension contain Exif metadata out of the total):
This page hosts a formal specification of Exchangeable image file format (Exif) using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
import kaitai_struct_nim_runtime
import options
type
Exif* = ref object of KaitaiStruct
`endianness`*: uint16
`body`*: Exif_ExifBody
`parent`*: KaitaiStruct
Exif_FieldType* = enum
byte = 1
ascii = 2
short = 3
long = 4
rational = 5
sbyte = 6
undefined = 7
sshort = 8
slong = 9
srational = 10
float = 11
double = 12
ifd = 13
utf8 = 129
Exif_GpsTag* = enum
gps_version_id = 0
gps_latitude_ref = 1
gps_latitude = 2
gps_longitude_ref = 3
gps_longitude = 4
gps_altitude_ref = 5
gps_altitude = 6
gps_time_stamp = 7
gps_satellites = 8
gps_status = 9
gps_measure_mode = 10
gps_dop = 11
gps_speed_ref = 12
gps_speed = 13
gps_track_ref = 14
gps_track = 15
gps_img_direction_ref = 16
gps_img_direction = 17
gps_map_datum = 18
gps_dest_latitude_ref = 19
gps_dest_latitude = 20
gps_dest_longitude_ref = 21
gps_dest_longitude = 22
gps_dest_bearing_ref = 23
gps_dest_bearing = 24
gps_dest_distance_ref = 25
gps_dest_distance = 26
gps_processing_method = 27
gps_area_information = 28
gps_date_stamp = 29
gps_differential = 30
gps_h_positioning_error = 31
Exif_Tag* = enum
interop_index = 1
interop_version = 2
image_width = 256
image_height = 257
bits_per_sample = 258
compression = 259
photometric_interpretation = 262
thresholding = 263
cell_width = 264
cell_length = 265
fill_order = 266
document_name = 269
image_description = 270
make = 271
model = 272
strip_offsets = 273
orientation = 274
samples_per_pixel = 277
rows_per_strip = 278
strip_byte_counts = 279
min_sample_value = 280
max_sample_value = 281
x_resolution = 282
y_resolution = 283
planar_configuration = 284
page_name = 285
x_position = 286
y_position = 287
free_offsets = 288
free_byte_counts = 289
gray_response_unit = 290
gray_response_curve = 291
t4_options = 292
t6_options = 293
resolution_unit = 296
page_number = 297
color_response_unit = 300
transfer_function = 301
software = 305
modify_date = 306
artist = 315
host_computer = 316
predictor = 317
white_point = 318
primary_chromaticities = 319
color_map = 320
halftone_hints = 321
tile_width = 322
tile_length = 323
tile_offsets = 324
tile_byte_counts = 325
bad_fax_lines = 326
clean_fax_data = 327
consecutive_bad_fax_lines = 328
sub_ifd = 330
ink_set = 332
ink_names = 333
numberof_inks = 334
dot_range = 336
target_printer = 337
extra_samples = 338
sample_format = 339
s_min_sample_value = 340
s_max_sample_value = 341
transfer_range = 342
clip_path = 343
x_clip_path_units = 344
y_clip_path_units = 345
indexed = 346
jpeg_tables = 347
opi_proxy = 351
global_parameters_ifd = 400
profile_type = 401
fax_profile = 402
coding_methods = 403
version_year = 404
mode_number = 405
decode = 433
default_image_color = 434
t82_options = 435
jpeg_tables2 = 437
jpeg_proc = 512
thumbnail_offset = 513
thumbnail_length = 514
jpeg_restart_interval = 515
jpeg_lossless_predictors = 517
jpeg_point_transforms = 518
jpegq_tables = 519
jpegdc_tables = 520
jpegac_tables = 521
y_cb_cr_coefficients = 529
y_cb_cr_sub_sampling = 530
y_cb_cr_positioning = 531
reference_black_white = 532
strip_row_counts = 559
application_notes = 700
uspto_miscellaneous = 999
related_image_file_format = 4096
related_image_width = 4097
related_image_height = 4098
rating = 18246
xp_dip_xml = 18247
stitch_info = 18248
rating_percent = 18249
sony_raw_file_type = 28672
light_falloff_params = 28722
chromatic_aberration_corr_params = 28725
distortion_corr_params = 28727
image_id = 32781
wang_tag1 = 32931
wang_annotation = 32932
wang_tag3 = 32933
wang_tag4 = 32934
image_reference_points = 32953
region_xform_tack_point = 32954
warp_quadrilateral = 32955
affine_transform_mat = 32956
matteing = 32995
data_type = 32996
image_depth = 32997
tile_depth = 32998
image_full_width = 33300
image_full_height = 33301
texture_format = 33302
wrap_modes = 33303
fov_cot = 33304
matrix_world_to_screen = 33305
matrix_world_to_camera = 33306
model2 = 33405
cfa_repeat_pattern_dim = 33421
cfa_pattern2 = 33422
battery_level = 33423
kodak_ifd = 33424
copyright = 33432
exposure_time = 33434
f_number = 33437
md_file_tag = 33445
md_scale_pixel = 33446
md_color_table = 33447
md_lab_name = 33448
md_sample_info = 33449
md_prep_date = 33450
md_prep_time = 33451
md_file_units = 33452
pixel_scale = 33550
advent_scale = 33589
advent_revision = 33590
uic1_tag = 33628
uic2_tag = 33629
uic3_tag = 33630
uic4_tag = 33631
iptc_naa = 33723
intergraph_packet_data = 33918
intergraph_flag_registers = 33919
intergraph_matrix = 33920
ingr_reserved = 33921
model_tie_point = 33922
site = 34016
color_sequence = 34017
it8_header = 34018
raster_padding = 34019
bits_per_run_length = 34020
bits_per_extended_run_length = 34021
color_table = 34022
image_color_indicator = 34023
background_color_indicator = 34024
image_color_value = 34025
background_color_value = 34026
pixel_intensity_range = 34027
transparency_indicator = 34028
color_characterization = 34029
hc_usage = 34030
trap_indicator = 34031
cmyk_equivalent = 34032
sem_info = 34118
afcp_iptc = 34152
pixel_magic_jbig_options = 34232
jpl_carto_ifd = 34263
model_transform = 34264
wb_grgb_levels = 34306
leaf_data = 34310
photoshop_settings = 34377
exif_offset = 34665
icc_profile = 34675
tiff_fx_extensions = 34687
multi_profiles = 34688
shared_data = 34689
t88_options = 34690
image_layer = 34732
geo_tiff_directory = 34735
geo_tiff_double_params = 34736
geo_tiff_ascii_params = 34737
jbig_options = 34750
exposure_program = 34850
spectral_sensitivity = 34852
gps_info = 34853
iso = 34855
opto_electric_conv_factor = 34856
interlace = 34857
time_zone_offset = 34858
self_timer_mode = 34859
sensitivity_type = 34864
standard_output_sensitivity = 34865
recommended_exposure_index = 34866
iso_speed = 34867
iso_speed_latitudeyyy = 34868
iso_speed_latitudezzz = 34869
fax_recv_params = 34908
fax_sub_address = 34909
fax_recv_time = 34910
fedex_edr = 34929
leaf_sub_ifd = 34954
exif_version = 36864
date_time_original = 36867
create_date = 36868
google_plus_upload_code = 36873
offset_time = 36880
offset_time_original = 36881
offset_time_digitized = 36882
components_configuration = 37121
compressed_bits_per_pixel = 37122
shutter_speed_value = 37377
aperture_value = 37378
brightness_value = 37379
exposure_compensation = 37380
max_aperture_value = 37381
subject_distance = 37382
metering_mode = 37383
light_source = 37384
flash = 37385
focal_length = 37386
flash_energy = 37387
spatial_frequency_response = 37388
noise = 37389
focal_plane_x_resolution = 37390
focal_plane_y_resolution = 37391
focal_plane_resolution_unit = 37392
image_number = 37393
security_classification = 37394
image_history = 37395
subject_area = 37396
exposure_index = 37397
tiff_ep_standard_id = 37398
sensing_method = 37399
cip3_data_file = 37434
cip3_sheet = 37435
cip3_side = 37436
sto_nits = 37439
maker_note = 37500
user_comment = 37510
sub_sec_time = 37520
sub_sec_time_original = 37521
sub_sec_time_digitized = 37522
ms_document_text = 37679
ms_property_set_storage = 37680
ms_document_text_position = 37681
image_source_data = 37724
ambient_temperature = 37888
humidity = 37889
pressure = 37890
water_depth = 37891
acceleration = 37892
camera_elevation_angle = 37893
xp_title = 40091
xp_comment = 40092
xp_author = 40093
xp_keywords = 40094
xp_subject = 40095
flashpix_version = 40960
color_space = 40961
exif_image_width = 40962
exif_image_height = 40963
related_sound_file = 40964
interop_offset = 40965
samsung_raw_pointers_offset = 40976
samsung_raw_pointers_length = 40977
samsung_raw_byte_order = 41217
samsung_raw_unknown = 41218
flash_energy2 = 41483
spatial_frequency_response2 = 41484
noise2 = 41485
focal_plane_x_resolution2 = 41486
focal_plane_y_resolution2 = 41487
focal_plane_resolution_unit2 = 41488
image_number2 = 41489
security_classification2 = 41490
image_history2 = 41491
subject_location = 41492
exposure_index2 = 41493
tiff_ep_standard_id2 = 41494
sensing_method2 = 41495
file_source = 41728
scene_type = 41729
cfa_pattern = 41730
custom_rendered = 41985
exposure_mode = 41986
white_balance = 41987
digital_zoom_ratio = 41988
focal_length_in35mm_format = 41989
scene_capture_type = 41990
gain_control = 41991
contrast = 41992
saturation = 41993
sharpness = 41994
device_setting_description = 41995
subject_distance_range = 41996
image_unique_id = 42016
owner_name = 42032
serial_number = 42033
lens_info = 42034
lens_make = 42035
lens_model = 42036
lens_serial_number = 42037
gdal_metadata = 42112
gdal_no_data = 42113
gamma = 42240
expand_software = 44992
expand_lens = 44993
expand_film = 44994
expand_filter_lens = 44995
expand_scanner = 44996
expand_flash_lamp = 44997
pixel_format = 48129
transformation = 48130
uncompressed = 48131
image_type = 48132
image_width2 = 48256
image_height2 = 48257
width_resolution = 48258
height_resolution = 48259
image_offset = 48320
image_byte_count = 48321
alpha_offset = 48322
alpha_byte_count = 48323
image_data_discard = 48324
alpha_data_discard = 48325
oce_scanjob_desc = 50215
oce_application_selector = 50216
oce_id_number = 50217
oce_image_logic = 50218
annotations = 50255
print_im = 50341
original_file_name = 50547
uspto_original_content_type = 50560
dng_version = 50706
dng_backward_version = 50707
unique_camera_model = 50708
localized_camera_model = 50709
cfa_plane_color = 50710
cfa_layout = 50711
linearization_table = 50712
black_level_repeat_dim = 50713
black_level = 50714
black_level_delta_h = 50715
black_level_delta_v = 50716
white_level = 50717
default_scale = 50718
default_crop_origin = 50719
default_crop_size = 50720
color_matrix1 = 50721
color_matrix2 = 50722
camera_calibration1 = 50723
camera_calibration2 = 50724
reduction_matrix1 = 50725
reduction_matrix2 = 50726
analog_balance = 50727
as_shot_neutral = 50728
as_shot_white_xy = 50729
baseline_exposure = 50730
baseline_noise = 50731
baseline_sharpness = 50732
bayer_green_split = 50733
linear_response_limit = 50734
camera_serial_number = 50735
dng_lens_info = 50736
chroma_blur_radius = 50737
anti_alias_strength = 50738
shadow_scale = 50739
sr2_private = 50740
maker_note_safety = 50741
raw_image_segmentation = 50752
calibration_illuminant1 = 50778
calibration_illuminant2 = 50779
best_quality_scale = 50780
raw_data_unique_id = 50781
alias_layer_metadata = 50784
original_raw_file_name = 50827
original_raw_file_data = 50828
active_area = 50829
masked_areas = 50830
as_shot_icc_profile = 50831
as_shot_pre_profile_matrix = 50832
current_icc_profile = 50833
current_pre_profile_matrix = 50834
colorimetric_reference = 50879
s_raw_type = 50885
panasonic_title = 50898
panasonic_title2 = 50899
camera_calibration_sig = 50931
profile_calibration_sig = 50932
profile_ifd = 50933
as_shot_profile_name = 50934
noise_reduction_applied = 50935
profile_name = 50936
profile_hue_sat_map_dims = 50937
profile_hue_sat_map_data1 = 50938
profile_hue_sat_map_data2 = 50939
profile_tone_curve = 50940
profile_embed_policy = 50941
profile_copyright = 50942
forward_matrix1 = 50964
forward_matrix2 = 50965
preview_application_name = 50966
preview_application_version = 50967
preview_settings_name = 50968
preview_settings_digest = 50969
preview_color_space = 50970
preview_date_time = 50971
raw_image_digest = 50972
original_raw_file_digest = 50973
sub_tile_block_size = 50974
row_interleave_factor = 50975
profile_look_table_dims = 50981
profile_look_table_data = 50982
opcode_list1 = 51008
opcode_list2 = 51009
opcode_list3 = 51022
noise_profile = 51041
time_codes = 51043
frame_rate = 51044
t_stop = 51058
reel_name = 51081
original_default_final_size = 51089
original_best_quality_size = 51090
original_default_crop_size = 51091
camera_label = 51105
profile_hue_sat_map_encoding = 51107
profile_look_table_encoding = 51108
baseline_exposure_offset = 51109
default_black_render = 51110
new_raw_image_digest = 51111
raw_to_preview_gain = 51112
default_user_crop = 51125
padding = 59932
offset_schema = 59933
owner_name2 = 65000
serial_number2 = 65001
lens = 65002
kdc_ifd = 65024
raw_file = 65100
converter = 65101
white_balance2 = 65102
exposure = 65105
shadows = 65106
brightness = 65107
contrast2 = 65108
saturation2 = 65109
sharpness2 = 65110
smoothness = 65111
moire_filter = 65112
Exif_ExifBody* = ref object of KaitaiStruct
`magic`*: uint16
`ofsIfd0`*: uint32
`parent`*: Exif
`ifd0Inst`: Exif_ExifBody_Ifd
`ifd0InstFlag`: bool
isLe: bool
Exif_ExifBody_AsciiString* = ref object of KaitaiStruct
`value`*: seq[byte]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Doubles* = ref object of KaitaiStruct
`values`*: seq[float64]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Floats* = ref object of KaitaiStruct
`values`*: seq[float32]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Ifd* = ref object of KaitaiStruct
`numFields`*: uint16
`fields`*: seq[Exif_ExifBody_IfdField]
`ofsNextIfd`*: uint32
`isGpsIfd`*: bool
`parent`*: KaitaiStruct
`rawFields`*: seq[seq[byte]]
`nextIfdInst`: Exif_ExifBody_Ifd
`nextIfdInstFlag`: bool
isLe: bool
Exif_ExifBody_IfdField* = ref object of KaitaiStruct
`tagRaw`*: uint16
`fieldType`*: Exif_FieldType
`numValues`*: uint32
`ofsData`*: uint32
`parent`*: Exif_ExifBody_Ifd
`rawDataInst`*: seq[byte]
`bytesPerValueInst`: int8
`bytesPerValueInstFlag`: bool
`dataInst`: KaitaiStruct
`dataInstFlag`: bool
`gpsTagInst`: Exif_GpsTag
`gpsTagInstFlag`: bool
`hasImmediateDataInst`: bool
`hasImmediateDataInstFlag`: bool
`lenDataInst`: int
`lenDataInstFlag`: bool
`subIfdInst`: Exif_ExifBody_Ifd
`subIfdInstFlag`: bool
`tagInst`: Exif_Tag
`tagInstFlag`: bool
isLe: bool
Exif_ExifBody_Longs* = ref object of KaitaiStruct
`values`*: seq[uint32]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Rational* = ref object of KaitaiStruct
`valueNum`*: uint32
`valueDen`*: uint32
`parent`*: Exif_ExifBody_Rationals
`valueInst`: float64
`valueInstFlag`: bool
isLe: bool
Exif_ExifBody_Rationals* = ref object of KaitaiStruct
`values`*: seq[Exif_ExifBody_Rational]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Sbytes* = ref object of KaitaiStruct
`values`*: seq[int8]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Shorts* = ref object of KaitaiStruct
`values`*: seq[uint16]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Slongs* = ref object of KaitaiStruct
`values`*: seq[int32]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Srational* = ref object of KaitaiStruct
`valueNum`*: int32
`valueDen`*: int32
`parent`*: Exif_ExifBody_Srationals
`valueInst`: float64
`valueInstFlag`: bool
isLe: bool
Exif_ExifBody_Srationals* = ref object of KaitaiStruct
`values`*: seq[Exif_ExifBody_Srational]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Sshorts* = ref object of KaitaiStruct
`values`*: seq[int16]
`parent`*: Exif_ExifBody_IfdField
isLe: bool
Exif_ExifBody_Utf8String* = ref object of KaitaiStruct
`value`*: string
`parent`*: Exif_ExifBody_IfdField
isLe: bool
proc read*(_: typedesc[Exif], io: KaitaiStream, root: KaitaiStruct, parent: KaitaiStruct): Exif
proc read*(_: typedesc[Exif_ExifBody], io: KaitaiStream, root: KaitaiStruct, parent: Exif): Exif_ExifBody
proc read*(_: typedesc[Exif_ExifBody_AsciiString], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_AsciiString
proc read*(_: typedesc[Exif_ExifBody_Doubles], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Doubles
proc read*(_: typedesc[Exif_ExifBody_Floats], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Floats
proc read*(_: typedesc[Exif_ExifBody_Ifd], io: KaitaiStream, root: KaitaiStruct, parent: KaitaiStruct, isGpsIfd: any): Exif_ExifBody_Ifd
proc read*(_: typedesc[Exif_ExifBody_IfdField], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_Ifd): Exif_ExifBody_IfdField
proc read*(_: typedesc[Exif_ExifBody_Longs], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Longs
proc read*(_: typedesc[Exif_ExifBody_Rational], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_Rationals): Exif_ExifBody_Rational
proc read*(_: typedesc[Exif_ExifBody_Rationals], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Rationals
proc read*(_: typedesc[Exif_ExifBody_Sbytes], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Sbytes
proc read*(_: typedesc[Exif_ExifBody_Shorts], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Shorts
proc read*(_: typedesc[Exif_ExifBody_Slongs], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Slongs
proc read*(_: typedesc[Exif_ExifBody_Srational], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_Srationals): Exif_ExifBody_Srational
proc read*(_: typedesc[Exif_ExifBody_Srationals], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Srationals
proc read*(_: typedesc[Exif_ExifBody_Sshorts], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Sshorts
proc read*(_: typedesc[Exif_ExifBody_Utf8String], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Utf8String
proc ifd0*(this: Exif_ExifBody): Exif_ExifBody_Ifd
proc nextIfd*(this: Exif_ExifBody_Ifd): Exif_ExifBody_Ifd
proc bytesPerValue*(this: Exif_ExifBody_IfdField): int8
proc data*(this: Exif_ExifBody_IfdField): KaitaiStruct
proc gpsTag*(this: Exif_ExifBody_IfdField): Exif_GpsTag
proc hasImmediateData*(this: Exif_ExifBody_IfdField): bool
proc lenData*(this: Exif_ExifBody_IfdField): int
proc subIfd*(this: Exif_ExifBody_IfdField): Exif_ExifBody_Ifd
proc tag*(this: Exif_ExifBody_IfdField): Exif_Tag
proc value*(this: Exif_ExifBody_Rational): float64
proc value*(this: Exif_ExifBody_Srational): float64
##[
Sample files (numbers in parentheses show how many files per extension contain
Exif metadata out of the total):
* <https://github.com/ianare/exif-py/tree/a69bf74770caf6b333221658f5092ed69f99faac/tests/resources/jpg> (84/93 .jpg, 1/1 .jpeg)
* <https://github.com/exiftool/exiftool/tree/2200871d9cef988051d2a99d67df3bda6cbb30a8/t/images> (34/41 .jpg, 0/1 .png)
* <https://github.com/Exiv2/exiv2/tree/648ada43dcb35ce6077f38183ace52d5e2071f64/test/data> (85/155 .jpg, 5/23 .png)
* <https://github.com/python-pillow/Pillow/tree/807d689a83738027b6f6e0f219a6a6dd30e01c08/Tests/images> (36/55 .jpg, 3/420 .png)
* <https://github.com/drewnoakes/metadata-extractor-images/tree/651ad0e67aa8d43d358ad05f9bc07b52d8b9ac6e/jpg> (335/430 .jpg)
* <https://github.com/libexif/libexif-testsuite/tree/8c1f5bbc18d2cbc80b01b3f9b3eb29546310acf2> (15/18 .jpg)
@see <a href="https://www.cipa.jp/std/documents/download_e.html?CIPA_DC-008-2026-E">Exif Version 3.1</a>
@see <a href="https://www.cipa.jp/std/documents/download_e.html?CIPA_DC-008-2024-E">Exif Version 3.0</a>
@see <a href="https://web.archive.org/web/20190624045241id_/https://www.cipa.jp/std/documents/e/DC-008-Translation-2019-E.pdf">Exif Version 2.32</a>
@see <a href="https://web.archive.org/web/20190712232333id_/https://www.cipa.jp/std/documents/e/DC-008-Translation-2016-E.pdf">Exif Version 2.31</a>
@see <a href="https://www.cipa.jp/std/documents/e/DC-008-2012_E_C.pdf">Exif Version 2.3 (with Corrigendum at the end)</a>
@see <a href="https://web.archive.org/web/20051228234707id_/https://tsc.jeita.or.jp/avs/data/cp3451_1.pdf">Exif Version 2.21 (2003 draft)</a>
@see <a href="https://web.archive.org/web/20131018091152id_/https://exif.org/Exif2-2.PDF">Exif Version 2.2</a>
@see <a href="https://web.archive.org/web/20131111073619id_/https://exif.org/Exif2-1.PDF">Exif Version 2.1</a>
]##
proc read*(_: typedesc[Exif], io: KaitaiStream, root: KaitaiStruct, parent: KaitaiStruct): Exif =
template this: untyped = result
this = new(Exif)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
let endiannessExpr = this.io.readU2le()
this.endianness = endiannessExpr
let bodyExpr = Exif_ExifBody.read(this.io, this.root, this)
this.body = bodyExpr
proc fromFile*(_: typedesc[Exif], filename: string): Exif =
Exif.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody) =
let magicExpr = this.io.readU2le()
this.magic = magicExpr
let ofsIfd0Expr = this.io.readU4le()
this.ofsIfd0 = ofsIfd0Expr
proc readBe(this: Exif_ExifBody) =
let magicExpr = this.io.readU2be()
this.magic = magicExpr
let ofsIfd0Expr = this.io.readU4be()
this.ofsIfd0 = ofsIfd0Expr
proc read*(_: typedesc[Exif_ExifBody], io: KaitaiStream, root: KaitaiStruct, parent: Exif): Exif_ExifBody =
template this: untyped = result
this = new(Exif_ExifBody)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = false
block:
let on = Exif(this.root).endianness
if on == 18761:
let isLeExpr = bool(true)
this.isLe = isLeExpr
elif on == 19789:
let isLeExpr = bool(false)
this.isLe = isLeExpr
if this.isLe:
readLe(this)
else:
readBe(this)
proc ifd0(this: Exif_ExifBody): Exif_ExifBody_Ifd =
if this.ifd0InstFlag:
return this.ifd0Inst
let pos = this.io.pos()
this.io.seek(int(this.ofsIfd0))
if this.isLe:
let ifd0InstExpr = Exif_ExifBody_Ifd.read(this.io, this.root, this, false)
this.ifd0Inst = ifd0InstExpr
else:
let ifd0InstExpr = Exif_ExifBody_Ifd.read(this.io, this.root, this, false)
this.ifd0Inst = ifd0InstExpr
this.io.seek(pos)
this.ifd0InstFlag = true
return this.ifd0Inst
proc fromFile*(_: typedesc[Exif_ExifBody], filename: string): Exif_ExifBody =
Exif_ExifBody.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_AsciiString) =
##[
According to the core Exif standard, this should be ASCII, but in
practice, this is not always the case. From
[ExifTool FAQ](https://exiftool.sourceforge.net/faq.html#Q10):
> However, it is not uncommon for applications to write UTF-8 or
other encodings where ASCII is expected.
Therefore, this field is a byte array, not a string. This is to
avoid non-ASCII characters being treated as errors in some target
languages, such as Python. The only assumption is that a null byte
terminates the value (although sometimes the null byte is missing,
which we tolerate thanks to the `eos-error: false` setting).
Here is a sample JPEG file with a `tag::image_description` IFD
field of type `field_type::ascii` that actually contains UTF-8:
<https://github.com/Exiv2/exiv2/blob/2cd987a731236037b6b78cbff897d08685a8ef49/test/data/exiv2-bug501.jpg>
It seems that most modern applications (e.g. GIMP 3.0.6) always
use UTF-8 when storing Exif metadata. However, there are also
files with a non-UTF-8 encoding, for example
<https://github.com/drewnoakes/metadata-extractor-images/blob/651ad0e67aa8d43d358ad05f9bc07b52d8b9ac6e/jpg/Ricoh%20DC-3Z%20(low%20res).jpg>
has a `tag::copyright` IFD field with a value encoded in
ISO-8859-1 (Latin-1).
]##
let valueExpr = this.io.readBytesTerm(0, false, true, false)
this.value = valueExpr
proc readBe(this: Exif_ExifBody_AsciiString) =
##[
According to the core Exif standard, this should be ASCII, but in
practice, this is not always the case. From
[ExifTool FAQ](https://exiftool.sourceforge.net/faq.html#Q10):
> However, it is not uncommon for applications to write UTF-8 or
other encodings where ASCII is expected.
Therefore, this field is a byte array, not a string. This is to
avoid non-ASCII characters being treated as errors in some target
languages, such as Python. The only assumption is that a null byte
terminates the value (although sometimes the null byte is missing,
which we tolerate thanks to the `eos-error: false` setting).
Here is a sample JPEG file with a `tag::image_description` IFD
field of type `field_type::ascii` that actually contains UTF-8:
<https://github.com/Exiv2/exiv2/blob/2cd987a731236037b6b78cbff897d08685a8ef49/test/data/exiv2-bug501.jpg>
It seems that most modern applications (e.g. GIMP 3.0.6) always
use UTF-8 when storing Exif metadata. However, there are also
files with a non-UTF-8 encoding, for example
<https://github.com/drewnoakes/metadata-extractor-images/blob/651ad0e67aa8d43d358ad05f9bc07b52d8b9ac6e/jpg/Ricoh%20DC-3Z%20(low%20res).jpg>
has a `tag::copyright` IFD field with a value encoded in
ISO-8859-1 (Latin-1).
]##
let valueExpr = this.io.readBytesTerm(0, false, true, false)
this.value = valueExpr
proc read*(_: typedesc[Exif_ExifBody_AsciiString], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_AsciiString =
template this: untyped = result
this = new(Exif_ExifBody_AsciiString)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_AsciiString], filename: string): Exif_ExifBody_AsciiString =
Exif_ExifBody_AsciiString.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Doubles) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readF8le()
this.values.add(it)
proc readBe(this: Exif_ExifBody_Doubles) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readF8be()
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Doubles], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Doubles =
template this: untyped = result
this = new(Exif_ExifBody_Doubles)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Doubles], filename: string): Exif_ExifBody_Doubles =
Exif_ExifBody_Doubles.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Floats) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readF4le()
this.values.add(it)
proc readBe(this: Exif_ExifBody_Floats) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readF4be()
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Floats], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Floats =
template this: untyped = result
this = new(Exif_ExifBody_Floats)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Floats], filename: string): Exif_ExifBody_Floats =
Exif_ExifBody_Floats.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Ifd) =
let numFieldsExpr = this.io.readU2le()
this.numFields = numFieldsExpr
for i in 0 ..< int(this.numFields):
let buf = this.io.readBytes(int(12))
this.rawFields.add(buf)
let rawFieldsIo = newKaitaiStream(buf)
let it = Exif_ExifBody_IfdField.read(rawFieldsIo, this.root, this)
this.fields.add(it)
let ofsNextIfdExpr = this.io.readU4le()
this.ofsNextIfd = ofsNextIfdExpr
proc readBe(this: Exif_ExifBody_Ifd) =
let numFieldsExpr = this.io.readU2be()
this.numFields = numFieldsExpr
for i in 0 ..< int(this.numFields):
let buf = this.io.readBytes(int(12))
this.rawFields.add(buf)
let rawFieldsIo = newKaitaiStream(buf)
let it = Exif_ExifBody_IfdField.read(rawFieldsIo, this.root, this)
this.fields.add(it)
let ofsNextIfdExpr = this.io.readU4be()
this.ofsNextIfd = ofsNextIfdExpr
proc read*(_: typedesc[Exif_ExifBody_Ifd], io: KaitaiStream, root: KaitaiStruct, parent: KaitaiStruct, isGpsIfd: any): Exif_ExifBody_Ifd =
template this: untyped = result
this = new(Exif_ExifBody_Ifd)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
let isGpsIfdExpr = bool(isGpsIfd)
this.isGpsIfd = isGpsIfdExpr
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc nextIfd(this: Exif_ExifBody_Ifd): Exif_ExifBody_Ifd =
if this.nextIfdInstFlag:
return this.nextIfdInst
if this.ofsNextIfd != 0:
let pos = this.io.pos()
this.io.seek(int(this.ofsNextIfd))
if this.isLe:
let nextIfdInstExpr = Exif_ExifBody_Ifd.read(this.io, this.root, this, this.isGpsIfd)
this.nextIfdInst = nextIfdInstExpr
else:
let nextIfdInstExpr = Exif_ExifBody_Ifd.read(this.io, this.root, this, this.isGpsIfd)
this.nextIfdInst = nextIfdInstExpr
this.io.seek(pos)
this.nextIfdInstFlag = true
return this.nextIfdInst
proc fromFile*(_: typedesc[Exif_ExifBody_Ifd], filename: string): Exif_ExifBody_Ifd =
Exif_ExifBody_Ifd.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_IfdField) =
##[
Raw numeric tag. Don't read this field - access `tag` or `gps_tag`
instead.
]##
let tagRawExpr = this.io.readU2le()
this.tagRaw = tagRawExpr
let fieldTypeExpr = Exif_FieldType(this.io.readU2le())
this.fieldType = fieldTypeExpr
let numValuesExpr = this.io.readU4le()
this.numValues = numValuesExpr
if not(this.hasImmediateData):
let ofsDataExpr = this.io.readU4le()
this.ofsData = ofsDataExpr
proc readBe(this: Exif_ExifBody_IfdField) =
##[
Raw numeric tag. Don't read this field - access `tag` or `gps_tag`
instead.
]##
let tagRawExpr = this.io.readU2be()
this.tagRaw = tagRawExpr
let fieldTypeExpr = Exif_FieldType(this.io.readU2be())
this.fieldType = fieldTypeExpr
let numValuesExpr = this.io.readU4be()
this.numValues = numValuesExpr
if not(this.hasImmediateData):
let ofsDataExpr = this.io.readU4be()
this.ofsData = ofsDataExpr
proc read*(_: typedesc[Exif_ExifBody_IfdField], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_Ifd): Exif_ExifBody_IfdField =
template this: untyped = result
this = new(Exif_ExifBody_IfdField)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc bytesPerValue(this: Exif_ExifBody_IfdField): int8 =
##[
Size in bytes of a single value of type `field_type`, or 0 if
`field_type` is not one of the known types (in which case the size
cannot be determined and `data` will be empty).
@see <a href="https://www.media.mit.edu/pia/Research/deepview/exif.html#DataForm">Source</a>
]##
if this.bytesPerValueInstFlag:
return this.bytesPerValueInst
let bytesPerValueInstExpr = int8((if ((this.fieldType == exif.byte) or (this.fieldType == exif.ascii) or (this.fieldType == exif.sbyte) or (this.fieldType == exif.undefined) or (this.fieldType == exif.utf8)) : 1 else: (if ((this.fieldType == exif.short) or (this.fieldType == exif.sshort)) : 2 else: (if ((this.fieldType == exif.long) or (this.fieldType == exif.slong) or (this.fieldType == exif.float) or (this.fieldType == exif.ifd)) : 4 else: (if ((this.fieldType == exif.rational) or (this.fieldType == exif.srational) or (this.fieldType == exif.double)) : 8 else: 0)))))
this.bytesPerValueInst = bytesPerValueInstExpr
this.bytesPerValueInstFlag = true
return this.bytesPerValueInst
proc data(this: Exif_ExifBody_IfdField): KaitaiStruct =
if this.dataInstFlag:
return this.dataInst
let io = (if this.hasImmediateData: this.io else: Exif(this.root).io)
let pos = io.pos()
io.seek(int((if this.hasImmediateData: 8 else: this.ofsData)))
if this.isLe:
block:
let on = this.fieldType
if on == exif.ascii:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_AsciiString.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.double:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Doubles.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.float:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Floats.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.ifd:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Longs.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.long:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Longs.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.rational:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Rationals.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.sbyte:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Sbytes.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.short:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Shorts.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.slong:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Slongs.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.srational:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Srationals.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.sshort:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Sshorts.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.utf8:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Utf8String.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
else:
let dataInstExpr = io.readBytes(int(this.lenData))
this.dataInst = dataInstExpr
else:
block:
let on = this.fieldType
if on == exif.ascii:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_AsciiString.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.double:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Doubles.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.float:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Floats.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.ifd:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Longs.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.long:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Longs.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.rational:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Rationals.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.sbyte:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Sbytes.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.short:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Shorts.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.slong:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Slongs.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.srational:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Srationals.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.sshort:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Sshorts.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
elif on == exif.utf8:
let rawDataInstExpr = io.readBytes(int(this.lenData))
this.rawDataInst = rawDataInstExpr
let rawDataInstIo = newKaitaiStream(rawDataInstExpr)
let dataInstExpr = Exif_ExifBody_Utf8String.read(rawDataInstIo, this.root, this)
this.dataInst = dataInstExpr
else:
let dataInstExpr = io.readBytes(int(this.lenData))
this.dataInst = dataInstExpr
io.seek(pos)
this.dataInstFlag = true
return this.dataInst
proc gpsTag(this: Exif_ExifBody_IfdField): Exif_GpsTag =
if this.gpsTagInstFlag:
return this.gpsTagInst
if this.parent.isGpsIfd:
let gpsTagInstExpr = Exif_GpsTag(Exif_GpsTag(this.tagRaw))
this.gpsTagInst = gpsTagInstExpr
this.gpsTagInstFlag = true
return this.gpsTagInst
proc hasImmediateData(this: Exif_ExifBody_IfdField): bool =
if this.hasImmediateDataInstFlag:
return this.hasImmediateDataInst
let hasImmediateDataInstExpr = bool(this.lenData <= 4)
this.hasImmediateDataInst = hasImmediateDataInstExpr
this.hasImmediateDataInstFlag = true
return this.hasImmediateDataInst
proc lenData(this: Exif_ExifBody_IfdField): int =
if this.lenDataInstFlag:
return this.lenDataInst
let lenDataInstExpr = int(this.bytesPerValue * this.numValues)
this.lenDataInst = lenDataInstExpr
this.lenDataInstFlag = true
return this.lenDataInst
proc subIfd(this: Exif_ExifBody_IfdField): Exif_ExifBody_Ifd =
##[
All the "IFD Pointer" tags (as the core Exif standard calls them),
i.e. `ExifOffset`, `InteropOffset` and `GPSInfo` (using the
[ExifTool's
names](https://exiftool.sourceforge.net/TagNames/EXIF.html)),
should be of type `LONG` (`field_type::long`). However, the type
`SLONG` (`field_type::slong`) type has also been observed:
<https://github.com/Exiv2/exiv2/blob/2cd987a731236037b6b78cbff897d08685a8ef49/test/data/FurnaceCreekInn.jpg>
Both ExifTool and Exiv2 accept `LONG`, `SLONG` and also `IFD`.
Exiv2 specifically supports only these three types - see
<https://github.com/Exiv2/exiv2/blob/2cd987a731236037b6b78cbff897d08685a8ef49/src/tiffvisitor_int.cpp#L1141>
(Git tag "v0.28.8"). ExifTool is more lenient - it even accepts
any integer type. In practice, real files most likely only use one
of the three types supported by Exiv2, so we stick with that.
]##
if this.subIfdInstFlag:
return this.subIfdInst
if ((this.numValues == 1) and ( ((this.fieldType == exif.long) or (this.fieldType == exif.ifd) or ( ((this.fieldType == exif.slong) and ((Exif_ExifBody_Slongs(this.data)).values[0] >= 0)) )) ) and ( ((this.tag == exif.exif_offset) or (this.tag == exif.interop_offset) or (this.tag == exif.gps_info)) )) :
let io = Exif(this.root).io
let pos = io.pos()
io.seek(int((if this.fieldType == exif.slong: (uint32((Exif_ExifBody_Slongs(this.data)).values[0])) else: (Exif_ExifBody_Longs(this.data)).values[0])))
if this.isLe:
let subIfdInstExpr = Exif_ExifBody_Ifd.read(io, this.root, this, this.tag == exif.gps_info)
this.subIfdInst = subIfdInstExpr
else:
let subIfdInstExpr = Exif_ExifBody_Ifd.read(io, this.root, this, this.tag == exif.gps_info)
this.subIfdInst = subIfdInstExpr
io.seek(pos)
this.subIfdInstFlag = true
return this.subIfdInst
proc tag(this: Exif_ExifBody_IfdField): Exif_Tag =
if this.tagInstFlag:
return this.tagInst
if not(this.parent.isGpsIfd):
let tagInstExpr = Exif_Tag(Exif_Tag(this.tagRaw))
this.tagInst = tagInstExpr
this.tagInstFlag = true
return this.tagInst
proc fromFile*(_: typedesc[Exif_ExifBody_IfdField], filename: string): Exif_ExifBody_IfdField =
Exif_ExifBody_IfdField.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Longs) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readU4le()
this.values.add(it)
proc readBe(this: Exif_ExifBody_Longs) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readU4be()
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Longs], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Longs =
template this: untyped = result
this = new(Exif_ExifBody_Longs)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Longs], filename: string): Exif_ExifBody_Longs =
Exif_ExifBody_Longs.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Rational) =
##[
Numerator
]##
let valueNumExpr = this.io.readU4le()
this.valueNum = valueNumExpr
##[
Denominator
]##
let valueDenExpr = this.io.readU4le()
this.valueDen = valueDenExpr
proc readBe(this: Exif_ExifBody_Rational) =
##[
Numerator
]##
let valueNumExpr = this.io.readU4be()
this.valueNum = valueNumExpr
##[
Denominator
]##
let valueDenExpr = this.io.readU4be()
this.valueDen = valueDenExpr
proc read*(_: typedesc[Exif_ExifBody_Rational], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_Rationals): Exif_ExifBody_Rational =
template this: untyped = result
this = new(Exif_ExifBody_Rational)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc value(this: Exif_ExifBody_Rational): float64 =
##[
If denominator is zero, this instance is disabled to prevent
`ZeroDivisionError` in Python.
Here's a sample file with a zero denominator in the IFD fields
`tag::x_resolution` and `tag::y_resolution` (both of which are of
type `field_type::rational`):
<https://github.com/python-pillow/Pillow/blob/807d689a83738027b6f6e0f219a6a6dd30e01c08/Tests/images/exif-dpi-zerodivision.jpg>
]##
if this.valueInstFlag:
return this.valueInst
if this.valueDen != 0:
let valueInstExpr = float64((this.valueNum + 0.0) div this.valueDen)
this.valueInst = valueInstExpr
this.valueInstFlag = true
return this.valueInst
proc fromFile*(_: typedesc[Exif_ExifBody_Rational], filename: string): Exif_ExifBody_Rational =
Exif_ExifBody_Rational.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Rationals) =
for i in 0 ..< int(this.parent.numValues):
let it = Exif_ExifBody_Rational.read(this.io, this.root, this)
this.values.add(it)
proc readBe(this: Exif_ExifBody_Rationals) =
for i in 0 ..< int(this.parent.numValues):
let it = Exif_ExifBody_Rational.read(this.io, this.root, this)
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Rationals], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Rationals =
template this: untyped = result
this = new(Exif_ExifBody_Rationals)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Rationals], filename: string): Exif_ExifBody_Rationals =
Exif_ExifBody_Rationals.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Sbytes) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readS1()
this.values.add(it)
proc readBe(this: Exif_ExifBody_Sbytes) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readS1()
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Sbytes], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Sbytes =
template this: untyped = result
this = new(Exif_ExifBody_Sbytes)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Sbytes], filename: string): Exif_ExifBody_Sbytes =
Exif_ExifBody_Sbytes.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Shorts) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readU2le()
this.values.add(it)
proc readBe(this: Exif_ExifBody_Shorts) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readU2be()
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Shorts], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Shorts =
template this: untyped = result
this = new(Exif_ExifBody_Shorts)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Shorts], filename: string): Exif_ExifBody_Shorts =
Exif_ExifBody_Shorts.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Slongs) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readS4le()
this.values.add(it)
proc readBe(this: Exif_ExifBody_Slongs) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readS4be()
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Slongs], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Slongs =
template this: untyped = result
this = new(Exif_ExifBody_Slongs)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Slongs], filename: string): Exif_ExifBody_Slongs =
Exif_ExifBody_Slongs.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Srational) =
##[
Numerator
]##
let valueNumExpr = this.io.readS4le()
this.valueNum = valueNumExpr
##[
Denominator
]##
let valueDenExpr = this.io.readS4le()
this.valueDen = valueDenExpr
proc readBe(this: Exif_ExifBody_Srational) =
##[
Numerator
]##
let valueNumExpr = this.io.readS4be()
this.valueNum = valueNumExpr
##[
Denominator
]##
let valueDenExpr = this.io.readS4be()
this.valueDen = valueDenExpr
proc read*(_: typedesc[Exif_ExifBody_Srational], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_Srationals): Exif_ExifBody_Srational =
template this: untyped = result
this = new(Exif_ExifBody_Srational)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc value(this: Exif_ExifBody_Srational): float64 =
##[
If denominator is zero, this instance is disabled to prevent
`ZeroDivisionError` in Python.
Here's a sample file with a zero denominator in the IFD field
`tag::exposure_compensation` of type `field_type::srational`:
<https://github.com/drewnoakes/metadata-extractor-images/blob/651ad0e67aa8d43d358ad05f9bc07b52d8b9ac6e/jpg/Reconyx%20Hyperfire%20HP4K.jpg>
]##
if this.valueInstFlag:
return this.valueInst
if this.valueDen != 0:
let valueInstExpr = float64((this.valueNum + 0.0) div this.valueDen)
this.valueInst = valueInstExpr
this.valueInstFlag = true
return this.valueInst
proc fromFile*(_: typedesc[Exif_ExifBody_Srational], filename: string): Exif_ExifBody_Srational =
Exif_ExifBody_Srational.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Srationals) =
for i in 0 ..< int(this.parent.numValues):
let it = Exif_ExifBody_Srational.read(this.io, this.root, this)
this.values.add(it)
proc readBe(this: Exif_ExifBody_Srationals) =
for i in 0 ..< int(this.parent.numValues):
let it = Exif_ExifBody_Srational.read(this.io, this.root, this)
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Srationals], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Srationals =
template this: untyped = result
this = new(Exif_ExifBody_Srationals)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Srationals], filename: string): Exif_ExifBody_Srationals =
Exif_ExifBody_Srationals.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Sshorts) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readS2le()
this.values.add(it)
proc readBe(this: Exif_ExifBody_Sshorts) =
for i in 0 ..< int(this.parent.numValues):
let it = this.io.readS2be()
this.values.add(it)
proc read*(_: typedesc[Exif_ExifBody_Sshorts], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Sshorts =
template this: untyped = result
this = new(Exif_ExifBody_Sshorts)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Sshorts], filename: string): Exif_ExifBody_Sshorts =
Exif_ExifBody_Sshorts.read(newKaitaiFileStream(filename), nil, nil)
proc readLe(this: Exif_ExifBody_Utf8String) =
let valueExpr = encode(this.io.readBytesTerm(0, false, true, false), "UTF-8")
this.value = valueExpr
proc readBe(this: Exif_ExifBody_Utf8String) =
let valueExpr = encode(this.io.readBytesTerm(0, false, true, false), "UTF-8")
this.value = valueExpr
proc read*(_: typedesc[Exif_ExifBody_Utf8String], io: KaitaiStream, root: KaitaiStruct, parent: Exif_ExifBody_IfdField): Exif_ExifBody_Utf8String =
template this: untyped = result
this = new(Exif_ExifBody_Utf8String)
let root = if root == nil: cast[Exif](this) else: cast[Exif](root)
this.io = io
this.root = root
this.parent = parent
this.isLe = this.parent.isLe
if this.isLe:
readLe(this)
else:
readBe(this)
proc fromFile*(_: typedesc[Exif_ExifBody_Utf8String], filename: string): Exif_ExifBody_Utf8String =
Exif_ExifBody_Utf8String.read(newKaitaiFileStream(filename), nil, nil)