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Diffstat (limited to 'tools/info.h')
| -rw-r--r-- | tools/info.h | 1265 |
1 files changed, 1265 insertions, 0 deletions
diff --git a/tools/info.h b/tools/info.h new file mode 100644 index 0000000..1872345 --- /dev/null +++ b/tools/info.h @@ -0,0 +1,1265 @@ +// +// info.h: metadata extraction utilities +// +// Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name> +// +// Permission to use, copy, modify, and/or distribute this software for any +// purpose with or without fee is hereby granted. +// +// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY +// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION +// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN +// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +// + +#include <jv.h> + +#include <stdlib.h> +#include <string.h> +#include <stdbool.h> + +// --- Utilities --------------------------------------------------------------- + +static char * +binhex(const uint8_t *data, size_t len) +{ + static const char *alphabet = "0123456789abcdef"; + char *buf = calloc(1, len * 2 + 1), *p = buf; + for (size_t i = 0; i < len; i++) { + *p++ = alphabet[data[i] >> 4]; + *p++ = alphabet[data[i] & 0xF]; + } + return buf; +} + +static uint32_t +u32be(const uint8_t *p) +{ + return (uint32_t) p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3]; +} + +static uint16_t +u16be(const uint8_t *p) +{ + return (uint16_t) p[0] << 8 | p[1]; +} + +static uint32_t +u32le(const uint8_t *p) +{ + return (uint32_t) p[3] << 24 | p[2] << 16 | p[1] << 8 | p[0]; +} + +static uint16_t +u16le(const uint8_t *p) +{ + return (uint16_t) p[1] << 8 | p[0]; +} + +// --- TIFF -------------------------------------------------------------------- +// TIFF Revision 6.0 (1992) +// https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFF6.pdf +// +// TIFF Technical Note 1: TIFF Trees (1993) +// https://download.osgeo.org/libtiff/old/TTN1.ps +// +// DRAFT TIFF Technical Note 2 (1995) +// https://www.awaresystems.be/imaging/tiff/specification/TIFFTechNote2.txt +// +// Adobe PageMaker 6.0 TIFF Technical Notes (1995) [includes TTN1] +// https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFFPM6.pdf +// +// Adobe Photoshop TIFF Technical Notes (2002) +// https://www.adobe.io/content/dam/udp/en/open/standards/tiff/TIFFphotoshop.pdf +// - Note that ImageSourceData 8BIM frames are specified differently +// from how Adobe XMP Specification Part 3 defines them. +// - The document places a condition on SubIFDs, without further explanation. +// +// Adobe Photoshop TIFF Technical Note 3 (2005) +// http://chriscox.org/TIFFTN3d1.pdf +// +// Exif Version 2.3 (2012) +// https://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf +// +// Exif Version 2.32 (2019) +// https://www.cipa.jp/e/std/std-sec.html +// +// libtiff is a mess, and the format is not particularly complicated. +// Exiv2 is senselessly copylefted, and cannot do much. +// libexif is only marginally better. +// ExifTool is too user-oriented. + +static struct un { + uint32_t (*u32) (const uint8_t *); + uint16_t (*u16) (const uint8_t *); +} unbe = {u32be, u16be}, unle = {u32le, u16le}; + +struct tiffer { + struct un *un; + const uint8_t *begin, *p, *end; + uint16_t remaining_fields; +}; + +static bool +tiffer_u32(struct tiffer *self, uint32_t *u) +{ + if (self->p + 4 > self->end) + return false; + *u = self->un->u32(self->p); + self->p += 4; + return true; +} + +static bool +tiffer_u16(struct tiffer *self, uint16_t *u) +{ + if (self->p + 2 > self->end) + return false; + *u = self->un->u16(self->p); + self->p += 2; + return true; +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +static bool +tiffer_init(struct tiffer *self, const uint8_t *tiff, size_t len) +{ + self->un = NULL; + self->begin = self->p = tiff; + self->end = tiff + len; + self->remaining_fields = 0; + + const uint8_t + le[4] = {'I', 'I', 42, 0}, + be[4] = {'M', 'M', 0, 42}; + + if (tiff + 8 > self->end) + return false; + else if (!memcmp(tiff, le, sizeof le)) + self->un = &unle; + else if (!memcmp(tiff, be, sizeof be)) + self->un = &unbe; + else + return false; + + self->p = tiff + 4; + // The first IFD needs to be read by caller explicitly, + // even though it's required to be present by TIFF 6.0. + return true; +} + +/// Read the next IFD in a sequence. +static bool +tiffer_next_ifd(struct tiffer *self) +{ + // All fields from any previous IFD need to be read first. + if (self->remaining_fields) + return false; + + uint32_t ifd_offset = 0; + if (!tiffer_u32(self, &ifd_offset)) + return false; + + // There is nothing more to read, this chain has terminated. + if (!ifd_offset) + return false; + + // Note that TIFF 6.0 requires there to be at least one entry, + // but there is no need for us to check it. + self->p = self->begin + ifd_offset; + return tiffer_u16(self, &self->remaining_fields); +} + +/// Initialize a derived TIFF reader for a subIFD at the given location. +static bool +tiffer_subifd(struct tiffer *self, uint32_t offset, struct tiffer *subreader) +{ + *subreader = *self; + subreader->p = subreader->begin + offset; + return tiffer_u16(subreader, &subreader->remaining_fields); +} + +enum tiffer_type { + BYTE = 1, ASCII, SHORT, LONG, RATIONAL, + SBYTE, UNDEFINED, SSHORT, SLONG, SRATIONAL, FLOAT, DOUBLE, + IFD // This last type from TIFF Technical Note 1 isn't really used much. +}; + +static size_t +tiffer_value_size(enum tiffer_type type) +{ + switch (type) { + case BYTE: + case SBYTE: + case ASCII: + case UNDEFINED: + return 1; + case SHORT: + case SSHORT: + return 2; + case LONG: + case SLONG: + case FLOAT: + case IFD: + return 4; + case RATIONAL: + case SRATIONAL: + case DOUBLE: + return 8; + default: + return 0; + } +} + +/// A lean iterator for values within entries. +struct tiffer_entry { + uint16_t tag; + enum tiffer_type type; + // For {S,}BYTE, ASCII, UNDEFINED, use these fields directly. + const uint8_t *p; + uint32_t remaining_count; +}; + +static bool +tiffer_next_value(struct tiffer_entry *entry) +{ + if (!entry->remaining_count) + return false; + + entry->p += tiffer_value_size(entry->type); + entry->remaining_count--; + return true; +} + +static bool +tiffer_integer( + const struct tiffer *self, const struct tiffer_entry *entry, int64_t *out) +{ + if (!entry->remaining_count) + return false; + + // Somewhat excessively lenient, intended for display. + // TIFF 6.0 only directly suggests that a reader is should accept + // any of BYTE/SHORT/LONG for unsigned integers. + switch (entry->type) { + case BYTE: + case ASCII: + case UNDEFINED: + *out = *entry->p; + return true; + case SBYTE: + *out = (int8_t) *entry->p; + return true; + case SHORT: + *out = self->un->u16(entry->p); + return true; + case SSHORT: + *out = (int16_t) self->un->u16(entry->p); + return true; + case LONG: + case IFD: + *out = self->un->u32(entry->p); + return true; + case SLONG: + *out = (int32_t) self->un->u32(entry->p); + return true; + default: + return false; + } +} + +static bool +tiffer_rational(const struct tiffer *self, const struct tiffer_entry *entry, + int64_t *numerator, int64_t *denominator) +{ + if (!entry->remaining_count) + return false; + + // Somewhat excessively lenient, intended for display. + switch (entry->type) { + case RATIONAL: + *numerator = self->un->u32(entry->p); + *denominator = self->un->u32(entry->p + 4); + return true; + case SRATIONAL: + *numerator = (int32_t) self->un->u32(entry->p); + *denominator = (int32_t) self->un->u32(entry->p + 4); + return true; + default: + if (tiffer_integer(self, entry, numerator)) { + *denominator = 1; + return true; + } + return false; + } +} + +static bool +tiffer_real( + const struct tiffer *self, const struct tiffer_entry *entry, double *out) +{ + if (!entry->remaining_count) + return false; + + // Somewhat excessively lenient, intended for display. + // Assuming the host architecture uses IEEE 754. + switch (entry->type) { + int64_t numerator, denominator; + case FLOAT: + *out = *(float *) entry->p; + return true; + case DOUBLE: + *out = *(double *) entry->p; + return true; + default: + if (tiffer_rational(self, entry, &numerator, &denominator)) { + *out = (double) numerator / denominator; + return true; + } + return false; + } +} + +static bool +tiffer_next_entry(struct tiffer *self, struct tiffer_entry *entry) +{ + if (!self->remaining_fields) + return false; + + uint16_t type = entry->type = 0xFFFF; + if (!tiffer_u16(self, &entry->tag) || !tiffer_u16(self, &type) || + !tiffer_u32(self, &entry->remaining_count)) + return false; + + // Short values may and will be inlined, rather than pointed to. + size_t values_size = tiffer_value_size(type) * entry->remaining_count; + uint32_t offset = 0; + if (values_size <= sizeof offset) { + entry->p = self->p; + self->p += sizeof offset; + } else if (tiffer_u32(self, &offset)) { + entry->p = self->begin + offset; + } else { + return false; + } + + // All entries are pre-checked not to overflow. + if (entry->p + values_size > self->end) + return false; + + // Setting it at the end may provide an indication while debugging. + entry->type = type; + self->remaining_fields--; + return true; +} + +// --- TIFF/Exif tags ---------------------------------------------------------- + +struct tiff_value { + const char *name; + uint16_t value; +}; + +struct tiff_entry { + const char *name; + uint16_t tag; + struct tiff_value *values; +}; + +static struct tiff_entry tiff_entries[] = { + {"NewSubfileType", 254, NULL}, + {"SubfileType", 255, (struct tiff_value[]) { + {"Full-resolution image data", 1}, + {"Reduced-resolution image data", 2}, + {"Page of a multi-page image", 3}, + {} + }}, + {"ImageWidth", 256, NULL}, + {"ImageLength", 257, NULL}, + {"BitsPerSample", 258, NULL}, + {"Compression", 259, (struct tiff_value[]) { + {"Uncompressed", 1}, + {"CCITT 1D", 2}, + {"Group 3 Fax", 3}, + {"Group 4 Fax", 4}, + {"LZW", 5}, + {"JPEG", 6}, + {"JPEG datastream", 7}, // DRAFT TIFF Technical Note 2 + TIFFphotoshop + {"Deflate/zlib", 8}, // Adobe Photoshop TIFF Technical Notes + {"PackBits", 32773}, + {"Deflate/zlib", 32946}, // Adobe Photoshop TIFF Technical Notes + {} + }}, + {"PhotometricInterpretation", 262, (struct tiff_value[]) { + {"WhiteIsZero", 0}, + {"BlackIsZero", 1}, + {"RGB", 2}, + {"RGB Palette", 3}, + {"Transparency mask", 4}, + {"CMYK", 5}, + {"YCbCr", 6}, + {"CIELab", 8}, + {"ICCLab", 9}, // Adobe PageMaker 6.0 TIFF Technical Notes + {} + }}, + {"Threshholding", 263, (struct tiff_value[]) { + {"No dithering or halftoning", 1}, + {"Ordered dither or halftoning", 2}, + {"Randomized process", 3}, + {} + }}, + {"CellWidth", 264, NULL}, + {"CellLength", 265, NULL}, + {"FillOrder", 266, (struct tiff_value[]) { + {"MSB-first", 1}, + {"LSB-first", 2}, + {} + }}, + {"DocumentName", 269, NULL}, + {"ImageDescription", 270, NULL}, + {"Make", 271, NULL}, + {"Model", 272, NULL}, + {"StripOffsets", 273, NULL}, + {"Orientation", 274, (struct tiff_value[]) { + {"TopLeft", 1}, + {"TopRight", 2}, + {"BottomRight", 3}, + {"BottomLeft", 4}, + {"LeftTop", 5}, + {"RightTop", 6}, + {"RightBottom", 7}, + {"LeftBottom", 8}, + {} + }}, + {"SamplesPerPixel", 277, NULL}, + {"RowsPerStrip", 278, NULL}, + {"StripByteCounts", 279, NULL}, + {"MinSampleValue", 280, NULL}, + {"MaxSampleValue", 281, NULL}, + {"XResolution", 282, NULL}, + {"YResolution", 283, NULL}, + {"PlanarConfiguration", 284, (struct tiff_value[]) { + {"Chunky", 1}, + {"Planar", 2}, + {} + }}, + {"PageName", 285, NULL}, + {"XPosition", 286, NULL}, + {"YPosition", 287, NULL}, + {"FreeOffsets", 288, NULL}, + {"FreeByteCounts", 289, NULL}, + {"GrayResponseUnit", 290, (struct tiff_value[]) { + {"1/10", 1}, + {"1/100", 2}, + {"1/1000", 3}, + {"1/10000", 4}, + {"1/100000", 5}, + {} + }}, + {"GrayResponseCurve", 291, NULL}, + {"T4Options", 292, NULL}, + {"T6Options", 293, NULL}, + {"ResolutionUnit", 296, (struct tiff_value[]) { + {"None", 1}, + {"Inch", 2}, + {"Centimeter", 3}, + {} + }}, + {"PageNumber", 297, NULL}, + {"TransferFunction", 301, NULL}, + {"Software", 305, NULL}, + {"DateTime", 306, NULL}, + {"Artist", 315, NULL}, + {"HostComputer", 316, NULL}, + {"Predictor", 317, (struct tiff_value[]) { + {"None", 1}, + {"Horizontal", 2}, + {"Floating point", 3}, // Adobe Photoshop TIFF Technical Note 3 + {} + }}, + {"WhitePoint", 318, NULL}, + {"PrimaryChromaticities", 319, NULL}, + {"ColorMap", 320, NULL}, + {"HalftoneHints", 321, NULL}, + {"TileWidth", 322, NULL}, + {"TileLength", 323, NULL}, + {"TileOffsets", 324, NULL}, + {"TileByteCounts", 325, NULL}, + {"SubIFDs", 330, NULL}, // TIFF Technical Note 1: TIFF Trees + {"InkSet", 332, (struct tiff_value[]) { + {"CMYK", 1}, + {"Non-CMYK", 2}, + {} + }}, + {"InkNames", 333, NULL}, + {"NumberOfInks", 334, NULL}, + {"DotRange", 336, NULL}, + {"TargetPrinter", 337, NULL}, + {"ExtraSamples", 338, (struct tiff_value[]) { + {"Unspecified", 0}, + {"Associated alpha", 1}, + {"Unassociated alpha", 2}, + {} + }}, + {"SampleFormat", 339, (struct tiff_value[]) { + {"Unsigned integer", 1}, + {"Two's complement signed integer", 2}, + {"IEEE floating-point", 3}, + {"Undefined", 4}, + {} + }}, + {"SMinSampleValue", 340, NULL}, + {"SMaxSampleValue", 341, NULL}, + {"TransferRange", 342, NULL}, + {"ClipPath", 343, NULL}, // TIFF Technical Note 2: Clipping Path + {"XClipPathUnits", 344, NULL}, // TIFF Technical Note 2: Clipping Path + {"YClipPathUnits", 345, NULL}, // TIFF Technical Note 2: Clipping Path + {"Indexed", 346, NULL}, // TIFF Technical Note 3: Indexed Images + {"JPEGTables", 347, NULL}, // DRAFT TIFF Technical Note 2 + TIFFphotoshop + {"OPIProxy", 351, NULL}, // Adobe PageMaker 6.0 TIFF Technical Notes + {"JPEGProc", 512, (struct tiff_value[]) { + {"Baseline sequential", 1}, + {"Lossless Huffman", 14}, + {} + }}, + {"JPEGInterchangeFormat", 513, NULL}, + {"JPEGInterchangeFormatLength", 514, NULL}, + {"JPEGRestartInterval", 515, NULL}, + {"JPEGLosslessPredictors", 517, (struct tiff_value[]) { + {"A", 1}, + {"B", 2}, + {"C", 3}, + {"A+B+C", 4}, + {"A+((B-C)/2)", 5}, + {"B+((A-C)/2)", 6}, + {"(A+B)/2", 7}, + {} + }}, + {"JPEGPointTransforms", 518, NULL}, + {"JPEGQTables", 519, NULL}, + {"JPEGDCTables", 520, NULL}, + {"JPEGACTables", 521, NULL}, + {"YCbCrCoefficients", 529, NULL}, + {"YCbCrSubSampling", 530, NULL}, + {"YCbCrPositioning", 531, (struct tiff_value[]) { + {"Centered", 1}, + {"Co-sited", 2}, + {} + }}, + {"ReferenceBlackWhite", 532, NULL}, + {"ImageID", 32781, NULL}, // Adobe PageMaker 6.0 TIFF Technical Notes + {"Copyright", 33432, NULL}, + // TODO(p): Extract PSIRs, like we do directly with the JPEG segment. + {"Photoshop", 34377, NULL}, // Adobe XMP Specification Part 3 Table 12/39 + {"Exif IFD Pointer", 34665, NULL}, // Exif 2.3 + {"GPS Info IFD Pointer", 34853, NULL}, // Exif 2.3 + // TODO(p): Extract IPTC DataSets, like we do directly with PSIRs. + {"IPTC", 37723, NULL}, // Adobe XMP Specification Part 3 Table 12/39 + {"ImageSourceData", 37724, NULL}, // Adobe Photoshop TIFF Technical Notes + {} +}; + +// 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}, + {"OffsetTime", 36880, NULL}, // 2.31 + {"OffsetTimeOriginal", 36881, NULL}, // 2.31 + {"OffsetTimeDigitized", 36882, NULL}, // 2.31 + {"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}, + {"Temperature", 37888, NULL}, // 2.31 + {"Humidity", 37889, NULL}, // 2.31 + {"Pressure", 37890, NULL}, // 2.31 + {"WaterDepth", 37891, NULL}, // 2.31 + {"Acceleration", 37892, NULL}, // 2.31 + {"CameraElevationAngle", 37893, NULL}, // 2.31 + {"FlashpixVersion", 40960, NULL}, + {"ColorSpace", 40961, (struct tiff_value[]) { + {"sRGB", 1}, + {"Uncalibrated", 0xFFFF}, + {} + }}, + {"PixelXDimension", 40962, NULL}, + {"PixelYDimension", 40963, NULL}, + {"RelatedSoundFile", 40964, NULL}, + {"Interoperability IFD Pointer", 40965, 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}, + {"CompositeImage", 42080, NULL}, // 2.32 + {"SourceImageNumberOfCompositeImage", 42081, NULL}, // 2.32 + {"SourceExposureTimesOfCompositeImage", 42082, NULL}, // 2.32 + {"Gamma", 42240, NULL}, + {} +}; + +// Exif 2.3 4.6.6 (Notice it starts at 0.) +static struct tiff_entry exif_gps_entries[] = { + {"GPSVersionID", 0, NULL}, + {"GPSLatitudeRef", 1, NULL}, + {"GPSLatitude", 2, NULL}, + {"GPSLongitudeRef", 3, NULL}, + {"GPSLongitude", 4, NULL}, + {"GPSAltitudeRef", 5, (struct tiff_value[]) { + {"Sea level", 0}, + {"Sea level reference (negative value)", 1}, + {} + }}, + {"GPSAltitude", 6, NULL}, + {"GPSTimeStamp", 7, NULL}, + {"GPSSatellites", 8, NULL}, + {"GPSStatus", 9, NULL}, + {"GPSMeasureMode", 10, NULL}, + {"GPSDOP", 11, NULL}, + {"GPSSpeedRef", 12, NULL}, + {"GPSSpeed", 13, NULL}, + {"GPSTrackRef", 14, NULL}, + {"GPSTrack", 15, NULL}, + {"GPSImgDirectionRef", 16, NULL}, + {"GPSImgDirection", 17, NULL}, + {"GPSMapDatum", 18, NULL}, + {"GPSDestLatitudeRef", 19, NULL}, + {"GPSDestLatitude", 20, NULL}, + {"GPSDestLongitudeRef", 21, NULL}, + {"GPSDestLongitude", 22, NULL}, + {"GPSDestBearingRef", 23, NULL}, + {"GPSDestBearing", 24, NULL}, + {"GPSDestDistanceRef", 25, NULL}, + {"GPSDestDistance", 26, NULL}, + {"GPSProcessingMethod", 27, NULL}, + {"GPSAreaInformation", 28, NULL}, + {"GPSDateStamp", 29, NULL}, + {"GPSDifferential", 30, (struct tiff_value[]) { + {"Measurement without differential correction", 0}, + {"Differential correction applied", 1}, + {} + }}, + {"GPSHPositioningError", 31, NULL}, + {} +}; + +// Exif 2.3 4.6.7 (Notice it starts at 1, and collides with GPS.) +static struct tiff_entry exif_interop_entries[] = { + {"InteroperabilityIndex", 1, NULL}, + {} +}; + +// 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 ---------------------------------------------------------------- + +static jv +add_to_subarray(jv o, const char *key, jv value) +{ + // Invalid values are not allocated, and we use up any valid one. + // Beware that jv_get() returns jv_null() rather than jv_invalid(). + // Also, the header comment is lying, jv_is_valid() doesn't unreference. + jv a = jv_object_get(jv_copy(o), jv_string(key)); + return jv_set(o, jv_string(key), + jv_is_valid(a) ? jv_array_append(a, value) : JV_ARRAY(value)); +} + +static jv +add_warning(jv o, const char *message) +{ + return add_to_subarray(o, "warnings", jv_string(message)); +} + +static jv +add_error(jv o, const char *message) +{ + return jv_object_set(o, jv_string("error"), jv_string(message)); +} + +// --- Exif -------------------------------------------------------------------- + +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, + struct tiff_entry *info) +{ + int64_t offset = 0; + struct tiffer subT = {}; + if (!tiffer_integer(T, entry, &offset) || + offset < 0 || offset > UINT32_MAX || !tiffer_subifd(T, offset, &subT)) + return jv_null(); + + // 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, info)); + while (tiffer_next_ifd(&subT)); + return a; +} + +static jv +parse_exif_ascii(struct tiffer_entry *entry) +{ + // Adobe XMP Specification Part 3: Storage in Files, 2020/1, 2.4.2 + // The text may in practice contain any 8-bit encoding, but likely UTF-8. + // TODO(p): Validate UTF-8, and assume Latin 1 if unsuccessful. + jv a = jv_array(); + uint8_t *nul = 0; + while ((nul = memchr(entry->p, 0, entry->remaining_count))) { + size_t len = nul - entry->p; + a = jv_array_append(a, jv_string_sized((const char *) entry->p, len)); + entry->remaining_count -= len + 1; + entry->p += len + 1; + } + + // Trailing NULs are required, but let's extract everything. + if (entry->remaining_count) { + a = jv_array_append(a, + jv_string_sized((const char *) entry->p, entry->remaining_count)); + } + return a; +} + +static jv +parse_exif_undefined(struct tiffer_entry *entry) +{ + // Sometimes, it can be ASCII, but the safe bet is to hex-encode it. + char *buf = binhex(entry->p, entry->remaining_count); + jv s = jv_string(buf); + free(buf); + return s; +} + +static jv +parse_exif_value(const struct tiff_value *values, double real) +{ + if (values) { + for (; values->name; values++) + if (values->value == real) + return jv_string(values->name); + } + return jv_number(real); +} +static jv +parse_exif_extract_sole_array_element(jv a) +{ + return jv_array_length(jv_copy(a)) == 1 ? jv_array_get(a, 0) : a; +} + +static jv +parse_exif_entry(jv o, struct tiffer *T, struct tiffer_entry *entry, + const struct tiff_entry *info) +{ + if (!info) + info = (struct tiff_entry[]) {{}}; + + for (; info->name; info++) + if (info->tag == entry->tag) + break; + + 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 || 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 && !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(); + do v = jv_array_append(v, parse_exif_value(info->values, real)); + while (tiffer_next_value(entry) && tiffer_real(T, entry, &real)); + v = parse_exif_extract_sole_array_element(v); + } + + if (info->name) + return jv_set(o, jv_string(info->name), v); + return jv_set(o, jv_string_fmt("%u", entry->tag), v); +} + +static jv +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, info); + return ifd; +} + +static jv +parse_exif(jv o, const uint8_t *p, size_t len) +{ + struct tiffer T = {}; + 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, tiff_entries)); + return o; +} + +// --- Photoshop Image Resources ----------------------------------------------- +// Adobe XMP Specification Part 3: Storage in Files, 2020/1, 1.1.3 + 3.1.3 +// https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/ +// Unless otherwise noted, the descriptions are derived from the above document. + +static struct { + uint16_t id; + const char *description; +} psir_descriptions[] = { + {1000, "Number of channels, rows, columns, depth, mode"}, + {1001, "Macintosh print manager print info record"}, + {1002, "Macintosh page format information"}, + {1003, "Indexed color table"}, + {1005, "Resolution information"}, + {1006, "Names of alpha channels (Pascal strings)"}, + {1007, "Display information"}, + {1008, "Caption (Pascal string)"}, // XMP Part 3 3.3.3 + {1009, "Border information"}, + {1010, "Background color"}, + {1011, "Print flags"}, + {1012, "Grayscale and multichannel halftoning information"}, + {1013, "Color halftoning information"}, + {1014, "Duotone halftoning information"}, + {1015, "Grayscale and multichannel transfer function"}, + {1016, "Color transfer functions"}, + {1017, "Duotone transfer functions"}, + {1018, "Duotone image information"}, + {1019, "Effective B/W values for the dot range"}, + {1020, "Caption"}, // XMP Part 3 3.3.3 + {1021, "EPS options"}, + {1022, "Quick Mask information"}, + {1023, "(Obsolete)"}, + {1024, "Layer state information"}, + {1025, "Working path (not saved)"}, + {1026, "Layers group information"}, + {1027, "(Obsolete)"}, + {1028, "IPTC DataSets"}, // XMP Part 3 3.3.3 + {1029, "Image mode for raw format files"}, + {1030, "JPEG quality"}, + {1032, "Grid and guides information"}, + {1033, "Thumbnail resource"}, + {1034, "Copyright flag"}, + {1035, "Copyright information URL"}, // XMP Part 3 3.3.3 + {1036, "Thumbnail resource"}, + {1037, "Global lighting angle for effects layer"}, + {1038, "Color samplers information"}, + {1039, "ICC profile"}, + {1040, "Watermark"}, + {1041, "ICC untagged profile flag"}, + {1042, "Effects visible flag"}, + {1043, "Spot halftone"}, + {1044, "Document-specific IDs seed number"}, + {1045, "Unicode alpha names"}, + {1046, "Indexed color table count"}, + {1047, "Transparent color index"}, + {1049, "Global altitude"}, + {1050, "Slices"}, + {1051, "Workflow URL"}, + {1052, "Jump To XPEP"}, + {1053, "Alpha identifiers"}, + {1054, "URL list"}, + {1057, "Version info"}, + {1058, "Exif metadata 1"}, + {1059, "Exif metadata 3"}, + {1060, "XMP metadata"}, + {1061, "MD5 digest of IPTC data"}, // XMP Part 3 3.3.3 + {1062, "Print scale"}, + {1064, "Pixel aspect ratio"}, + {1065, "Layer comps"}, + {1066, "Alternate duotone colors"}, + {1067, "Alternate spot colors"}, + {1069, "Layer selection IDs"}, + {1070, "HDR toning information"}, + {1071, "Print info"}, + {1072, "Layer group(s) enabled ID"}, + {1073, "Color samplers"}, + {1074, "Measurement scale"}, + {1075, "Timeline information"}, + {1076, "Sheet disclosure"}, + {1077, "Display information to support floating point colors"}, + {1078, "Onion skins"}, + {1080, "Count information"}, + {1082, "Print information"}, + {1083, "Print style"}, + {1084, "Macintosh NSPrintInfo"}, + {1085, "Windows DEVMODE"}, + {1086, "Autosave file path"}, + {1087, "Autosave format"}, + {1088, "Path selection state"}, + // {2000-2997, "Saved paths"}, + {2999, "Name of clipping path"}, + {3000, "Origin path information"}, + // {4000-4999, "Plug-in resource"}, + {7000, "Image Ready variables"}, + {7001, "Image Ready data sets"}, + {7002, "Image Ready default selected state"}, + {7003, "Image Ready 7 rollover expanded state"}, + {7004, "Image Ready rollover expanded state"}, + {7005, "Image Ready save layer settings"}, + {7006, "Image Ready version"}, + {8000, "Lightroom workflow"}, + {10000, "Print flags"}, + {} +}; + +static jv +process_psir_thumbnail(jv res, const uint8_t *data, size_t len) +{ + uint32_t format_number = u32be(data + 0); + uint32_t compressed_size = u32be(data + 20); + + // TODO(p): Recurse into the thumbnail if it's a JPEG. + jv format = jv_number(format_number); + switch (format_number) { + break; case 0: format = jv_string("kJpegRGB"); + break; case 1: format = jv_string("kRawRGB"); + } + + res = jv_object_merge(res, JV_OBJECT( + jv_string("Format"), format, + jv_string("Width"), jv_number(u32be(data + 4)), + jv_string("Height"), jv_number(u32be(data + 8)), + jv_string("Stride"), jv_number(u32be(data + 12)), + jv_string("TotalSize"), jv_number(u32be(data + 16)), + jv_string("CompressedSize"), jv_number(compressed_size), + jv_string("BitsPerPixel"), jv_number(u16be(data + 24)), + jv_string("Planes"), jv_number(u16be(data + 26)) + )); + if (28 + compressed_size <= len) { + char *buf = binhex(data + 28, compressed_size); + res = jv_set(res, jv_string("Data"), jv_string(buf)); + free(buf); + } + return res; +} + +static const char * +process_iptc_dataset(jv *a, const uint8_t **p, size_t len) +{ + const uint8_t *header = *p; + if (len < 5) + return "unexpected end of IPTC data"; + if (*header != 0x1c) + return "invalid tag marker"; + + uint8_t record = header[1]; + uint8_t dataset = header[2]; + uint16_t byte_count = header[3] << 8 | header[4]; + + // TODO(p): Although highly unlikely to appear, we could decode it. + if (byte_count & 0x8000) + return "unsupported extended DataSet"; + if (len - 5 < byte_count) + return "data overrun"; + + char *buf = binhex(header + 5, byte_count); + *p += 5 + byte_count; + *a = jv_array_append(*a, JV_OBJECT( + jv_string("DataSet"), jv_string_fmt("%u:%u", record, dataset), + jv_string("Data"), jv_string(buf) + )); + free(buf); + return NULL; +} + +static jv +process_psir_iptc(jv res, const uint8_t *data, size_t len) +{ + // https://iptc.org/standards/iim/ + // https://iptc.org/std/IIM/4.2/specification/IIMV4.2.pdf + jv a = jv_array(); + const uint8_t *end = data + len; + while (data < end) { + const char *err = process_iptc_dataset(&a, &data, end - data); + if (err) { + a = jv_array_append(a, jv_string(err)); + break; + } + } + return jv_set(res, jv_string("DataSets"), a); +} + +static jv +process_psir(jv o, uint16_t resource_id, const char *name, + const uint8_t *data, size_t len) +{ + const char *description = NULL; + if (resource_id >= 2000 && resource_id <= 2997) + description = "Saved paths"; + if (resource_id >= 4000 && resource_id <= 4999) + description = "Plug-in resource"; + for (size_t i = 0; psir_descriptions[i].id; i++) + if (psir_descriptions[i].id == resource_id) + description = psir_descriptions[i].description; + + jv res = JV_OBJECT( + jv_string("name"), jv_string(name), + jv_string("id"), jv_number(resource_id), + jv_string("description"), + description ? jv_string(description) : jv_null(), + jv_string("size"), jv_number(len) + ); + + // Both are thumbnails, older is BGR, newer is RGB. + if ((resource_id == 1033 || resource_id == 1036) && len >= 28) + res = process_psir_thumbnail(res, data, len); + if (resource_id == 1028) + res = process_psir_iptc(res, data, len); + + return add_to_subarray(o, "PSIR", res); +} + +static jv +parse_psir_block(jv o, const uint8_t *p, size_t len, size_t *advance) +{ + *advance = 0; + if (len < 8 || memcmp(p, "8BIM", 4)) + return add_warning(o, "bad PSIR block header"); + + uint16_t resource_id = u16be(p + 4); + uint8_t name_len = p[6]; + const uint8_t *name = &p[7]; + + // Add one byte for the Pascal-ish string length prefix, + // then another one for padding to make the length even. + size_t name_len_full = (name_len + 2) & ~1U; + + size_t resource_len_offset = 6 + name_len_full, + header_len = resource_len_offset + 4; + if (len < header_len) + return add_warning(o, "bad PSIR block header"); + + uint32_t resource_len = u32be(p + resource_len_offset); + size_t resource_len_padded = (resource_len + 1) & ~1U; + if (resource_len_padded < resource_len || + len < header_len + resource_len_padded) + return add_warning(o, "runaway PSIR block"); + + char *cname = calloc(1, name_len_full); + strncpy(cname, (const char *) name, name_len); + o = process_psir(o, resource_id, cname, p + header_len, resource_len); + free(cname); + + *advance = header_len + resource_len_padded; + return o; +} + +static jv +parse_psir(jv o, const uint8_t *p, size_t len) +{ + if (len == 0) + return add_warning(o, "empty PSIR data"); + + size_t advance = 0; + while (len && (o = parse_psir_block(o, p, len, &advance), advance)) { + p += advance; + len -= advance; + } + return o; +} |