jpeginfo: decode the main Exif subIFD

This commit is contained in:
Přemysl Eric Janouch 2021-12-05 14:05:06 +01:00
parent 55d8fdebf1
commit 1ae803a62e
Signed by: p
GPG Key ID: A0420B94F92B9493
1 changed files with 246 additions and 27 deletions

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@ -546,21 +546,234 @@ static struct tiff_entry tiff_entries[] = {
{}
};
// TODO(p): Consider if these can't be inlined into the above table.
static uint16_t tiff_subifd_tags[] = {
330, // SubIFDs
34665, // Exif IFD Pointer
34853, // GPS Info IFD Pointer
40965, // Interoperability IFD Pointer
0
// Exif 2.3 4.6.5
static struct tiff_entry exif_entries[] = {
{"ExposureTime", 33434, NULL},
{"FNumber", 33437, NULL},
{"ExposureProgram", 34850, (struct tiff_value[]) {
{"Not defined", 0},
{"Manual", 1},
{"Normal program", 2},
{"Aperture priority", 3},
{"Shutter priority", 4},
{"Creative program", 5},
{"Action program", 6},
{"Portrait mode", 7},
{"Landscape mode", 8},
{}
}},
{"SpectralSensitivity", 34852, NULL},
{"PhotographicSensitivity", 34855, NULL},
{"OECF", 34856, NULL},
{"SensitivityType", 34864, (struct tiff_value[]) {
{"Unknown", 0},
{"Standard output sensitivity", 1},
{"Recommended exposure index", 2},
{"ISO speed", 3},
{"SOS and REI", 4},
{"SOS and ISO speed", 5},
{"REI and ISO speed", 6},
{"SOS and REI and ISO speed", 7},
{}
}},
{"StandardOutputSensitivity", 34865, NULL},
{"RecommendedExposureIndex", 34866, NULL},
{"ISOSpeed", 34867, NULL},
{"ISOSpeedLatitudeyyy", 34868, NULL},
{"ISOSpeedLatitudezzz", 34869, NULL},
{"ExifVersion", 36864, NULL},
{"DateTimeOriginal", 36867, NULL},
{"DateTimeDigitized", 36868, NULL},
{"ComponentsConfiguration", 37121, (struct tiff_value[]) {
{"Does not exist", 0},
{"Y", 1},
{"Cb", 2},
{"Cr", 3},
{"R", 4},
{"G", 5},
{"B", 6},
{}
}},
{"CompressedBitsPerPixel", 37122, NULL},
{"ShutterSpeedValue", 37377, NULL},
{"ApertureValue", 37378, NULL},
{"BrightnessValue", 37379, NULL},
{"ExposureBiasValue", 37380, NULL},
{"MaxApertureValue", 37381, NULL},
{"SubjectDistance", 37382, NULL},
{"MeteringMode", 37383, (struct tiff_value[]) {
{"Unknown", 0},
{"Average", 1},
{"CenterWeightedAverage", 2},
{"Spot", 3},
{"MultiSpot", 4},
{"Pattern", 5},
{"Partial", 6},
{"Other", 255},
{}
}},
{"LightSource", 37384, (struct tiff_value[]) {
{"Unknown", 0},
{"Daylight", 1},
{"Fluorescent", 2},
{"Tungsten (incandescent light)", 3},
{"Flash", 4},
{"Fine weather", 9},
{"Cloudy weather", 10},
{"Shade", 11},
{"Daylight fluorescent (D 5700 - 7100K)", 12},
{"Day white fluorescent (N 4600 - 5500K)", 13},
{"Cool white fluorescent (W 3800 - 4500K)", 14},
{"White fluorescent (WW 3250 - 3800K)", 15},
{"Warm white fluorescent (L 2600 - 3250K)", 16},
{"Standard light A", 17},
{"Standard light B", 18},
{"Standard light C", 19},
{"D55", 20},
{"D65", 21},
{"D75", 22},
{"D50", 23},
{"ISO studio tungsten", 24},
{"Other light source", 255},
{}
}},
{"Flash", 37385, NULL},
{"FocalLength", 37386, NULL},
{"SubjectArea", 37396, NULL},
{"MakerNote", 37500, NULL},
// TODO(p): Decode.
{"UserComment", 37510, NULL},
{"SubSecTime", 37520, NULL},
{"SubSecTimeOriginal", 37521, NULL},
{"SubSecTimeDigitized", 37522, NULL},
{"FlashpixVersion", 40960, NULL},
{"ColorSpace", 40961, (struct tiff_value[]) {
{"sRGB", 1},
{"Uncalibrated", 0xFFFF},
{}
}},
{"PixelXDimension", 40962, NULL},
{"PixelYDimension", 40963, NULL},
{"RelatedSoundFile", 40964, NULL},
{"FlashEnergy", 41483, NULL},
{"SpatialFrequencyResponse", 41484, NULL},
{"FocalPlaneXResolution", 41486, NULL},
{"FocalPlaneYResolution", 41487, NULL},
{"FocalPlaneResolutionUnit", 41488, NULL},
{"SubjectLocation", 41492, NULL},
{"ExposureIndex", 41493, NULL},
{"SensingMethod", 41495, (struct tiff_value[]) {
{"Not defined", 1},
{"One-chip color area sensor", 2},
{"Two-chip color area sensor", 3},
{"Three-chip color area sensor", 4},
{"Color sequential area sensor", 5},
{"Trilinear sensor", 7},
{"Color sequential linear sensor", 8},
{}
}},
{"FileSource", 41728, (struct tiff_value[]) {
{"Others", 0},
{"Scanner of transparent type", 1},
{"Scanner of reflex type", 2},
{"DSC", 3},
{}
}},
{"SceneType", 41729, (struct tiff_value[]) {
{"Directly-photographed image", 1},
{}
}},
{"CFAPattern", 41730, NULL},
{"CustomRendered", 41985, (struct tiff_value[]) {
{"Normal process", 0},
{"Custom process", 1},
{}
}},
{"ExposureMode", 41986, (struct tiff_value[]) {
{"Auto exposure", 0},
{"Manual exposure", 1},
{"Auto bracket", 2},
{}
}},
{"WhiteBalance", 41987, (struct tiff_value[]) {
{"Auto white balance", 0},
{"Manual white balance", 1},
{}
}},
{"DigitalZoomRatio", 41988, NULL},
{"FocalLengthIn35mmFilm", 41989, NULL},
{"SceneCaptureType", 41990, (struct tiff_value[]) {
{"Standard", 0},
{"Landscape", 1},
{"Portrait", 2},
{"Night scene", 3},
{}
}},
{"GainControl", 41991, (struct tiff_value[]) {
{"None", 0},
{"Low gain up", 1},
{"High gain up", 2},
{"Low gain down", 3},
{"High gain down", 4},
{}
}},
{"Contrast", 41992, (struct tiff_value[]) {
{"Normal", 0},
{"Soft", 1},
{"Hard", 2},
{}
}},
{"Saturation", 41993, (struct tiff_value[]) {
{"Normal", 0},
{"Low", 1},
{"High", 2},
{}
}},
{"Sharpness", 41994, (struct tiff_value[]) {
{"Normal", 0},
{"Soft", 1},
{"Hard", 2},
{}
}},
{"DeviceSettingDescription", 41995, NULL},
{"SubjectDistanceRange", 41996, (struct tiff_value[]) {
{"Unknown", 0},
{"Macro", 1},
{"Close view", 2},
{"Distant view", 3},
{}
}},
{"ImageUniqueID", 42016, NULL},
{"CameraOwnerName", 42032, NULL},
{"BodySerialNumber", 42033, NULL},
{"LensSpecification", 42034, NULL},
{"LensMake", 42035, NULL},
{"LensModel", 42036, NULL},
{"LensSerialNumber", 42037, NULL},
{"Gamma", 42240, NULL},
{}
};
// TODO(p): Insert tags and values from other documentation,
// so far only tags and non-bit-field values from TIFF 6.0 and PM6 are present.
//
// TODO(p): Exif 2.3 4.6.5 and on.
// TODO(p): Exif 2.3 4.6.6 and on (note it starts at 0).
// sed 'N; s/\n/ /g' | sort -nk2 | awk '{print "\t{\"" $1 "\", " $2 ", NULL},"}'
static struct tiff_entry exif_gps_entries[] = {{}};
// TODO(p): Exif 2.3 4.6.7 and on (note it starts at 1, and collides with GPS).
static struct tiff_entry exif_interop_entries[] = {{}};
// TODO(p): Review Exif version history afterwards.
// TODO(p): Consider if these can't be inlined into `tiff_entries`.
static struct {
uint16_t tag;
struct tiff_entry *entries;
} tiff_subifds[] = {
{330, tiff_entries}, // SubIFDs
{34665, exif_entries}, // Exif IFD Pointer
{34853, exif_gps_entries}, // GPS Info IFD Pointer
{40965, exif_interop_entries}, // Interoperability IFD Pointer
{}
};
// --- Analysis ----------------------------------------------------------------
@ -589,10 +802,11 @@ add_error(jv o, const char *message)
// --- Exif --------------------------------------------------------------------
static jv parse_exif_ifd(struct tiffer *T);
static jv parse_exif_ifd(struct tiffer *T, const struct tiff_entry *info);
static jv
parse_exif_subifds(struct tiffer *T, const struct tiffer_entry *entry)
parse_exif_subifds(struct tiffer *T, const struct tiffer_entry *entry,
struct tiff_entry *info)
{
int64_t offset = 0;
struct tiffer subT = {};
@ -603,7 +817,7 @@ parse_exif_subifds(struct tiffer *T, const struct tiffer_entry *entry)
// The chain should correspond to the values in the entry,
// we are not going to verify it.
jv a = jv_array();
do a = jv_array_append(a, parse_exif_ifd(&subT));
do a = jv_array_append(a, parse_exif_ifd(&subT, info));
while (tiffer_next_ifd(&subT));
return a;
}
@ -663,26 +877,31 @@ parse_exif_extract_sole_array_element(jv a)
}
static jv
parse_exif_entry(jv o, struct tiffer *T, struct tiffer_entry *entry)
parse_exif_entry(jv o, struct tiffer *T, struct tiffer_entry *entry,
const struct tiff_entry *info)
{
const struct tiff_entry *info = tiff_entries;
if (!info)
info = (struct tiff_entry[]) {{}};
for (; info->name; info++)
if (info->tag == entry->tag)
break;
bool is_subifd = false;
for (const uint16_t *p = tiff_subifd_tags; *p; p++)
is_subifd |= *p == entry->tag;
struct tiff_entry *subentries = NULL;
for (size_t i = 0; tiff_subifds[i].tag; i++)
if (tiff_subifds[i].tag == entry->tag)
subentries = tiff_subifds[i].entries;
jv v = jv_true();
double real = 0;
if (!entry->remaining_count) {
v = jv_null();
} else if (entry->type == IFD || is_subifd) {
v = parse_exif_subifds(T, entry);
} else if (entry->type == IFD || subentries) {
v = parse_exif_subifds(T, entry, subentries);
} else if (entry->type == ASCII) {
v = parse_exif_extract_sole_array_element(parse_exif_ascii(entry));
} else if (entry->type == UNDEFINED) {
} else if (entry->type == UNDEFINED && !info->values) {
// Several Exif entries of UNDEFINED type contain single-byte numbers.
v = parse_exif_undefined(entry);
} else if (tiffer_real(T, entry, &real)) {
v = jv_array();
@ -697,12 +916,12 @@ parse_exif_entry(jv o, struct tiffer *T, struct tiffer_entry *entry)
}
static jv
parse_exif_ifd(struct tiffer *T)
parse_exif_ifd(struct tiffer *T, const struct tiff_entry *info)
{
jv ifd = jv_object();
struct tiffer_entry entry = {};
while (tiffer_next_entry(T, &entry))
ifd = parse_exif_entry(ifd, T, &entry);
ifd = parse_exif_entry(ifd, T, &entry, info);
return ifd;
}
@ -713,7 +932,7 @@ parse_exif(jv o, const uint8_t *p, size_t len)
if (!tiffer_init(&T, p, len))
return add_warning(o, "invalid Exif");
while (tiffer_next_ifd(&T))
o = add_to_subarray(o, "Exif", parse_exif_ifd(&T));
o = add_to_subarray(o, "Exif", parse_exif_ifd(&T, tiff_entries));
return o;
}
@ -1024,7 +1243,7 @@ parse_mpf_index_entry(
if (entry->tag != MPEntry || entry->type != UNDEFINED ||
entry->remaining_count % 16) {
// TODO(p): Parse the remaining special tags instead.
return parse_exif_entry(o, T, entry);
return parse_exif_entry(o, T, entry, NULL);
}
uint32_t count = entry->remaining_count / 16;
@ -1091,7 +1310,7 @@ static jv
parse_mpf_attribute_ifd(struct tiffer *T)
{
// TODO(p): Parse the special tags instead.
return parse_exif_ifd(T);
return parse_exif_ifd(T, NULL);
}
static jv