From 9c77aac640e11ca5df144e3c943f48dfeab8485a Mon Sep 17 00:00:00 2001 From: Přemysl Eric Janouch Date: Mon, 29 Nov 2021 22:23:41 +0100 Subject: Add a tool to extract information from JPEG images --- tools/.gitignore | 1 + tools/Makefile | 2 +- tools/jpeginfo.c | 463 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 465 insertions(+), 1 deletion(-) create mode 100644 tools/jpeginfo.c diff --git a/tools/.gitignore b/tools/.gitignore index 8463b6e..5888ef6 100644 --- a/tools/.gitignore +++ b/tools/.gitignore @@ -1 +1,2 @@ /pnginfo +/jpeginfo diff --git a/tools/Makefile b/tools/Makefile index c7fa1a5..a60c17d 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -4,7 +4,7 @@ CFLAGS = -g -O2 -Wall -Wextra `pkg-config --cflags $(deps)` LDLIBS = -ljq `pkg-config --libs $(deps)` deps = libpng -targets = pnginfo +targets = pnginfo jpeginfo all: $(targets) clean: diff --git a/tools/jpeginfo.c b/tools/jpeginfo.c new file mode 100644 index 0000000..fcfda0e --- /dev/null +++ b/tools/jpeginfo.c @@ -0,0 +1,463 @@ +// +// jpeginfo.c: acquire information about JPEG files in JSON format +// +// Copyright (c) 2021, Přemysl Eric Janouch +// +// 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 + +#include +#include +#include +#include +#include + +// --- JPEG -------------------------------------------------------------------- +// See: https://www.w3.org/Graphics/JPEG/itu-t81.pdf + +enum { + TEM = 0x01, + SOF0 = 0xC0, SOF1, SOF2, SOF3, + DHT = 0xC4, + SOF5, SOF6, SOF7, + JPG = 0xC8, + SOF9, SOF10, SOF11, + DAC = 0xCC, + SOF13, SOF14, SOF15, + + RST0 = 0xD0, RST1, RST2, RST3, RST4, RST5, RST6, RST7, + + SOI = 0xD8, + EOI = 0xD9, + SOS = 0xDA, + DQT = 0xDB, + DNL = 0xDC, + DRI = 0xDD, + DHP = 0xDE, + EXP = 0xDF, + + APP0 = 0xE0, APP1, APP2, APP3, APP4, APP5, APP6, APP7, + APP8, APP9, APP10, APP11, APP12, APP13, APP14, APP15, + + JPG0 = 0xF0, JPG1, JPG2, JPG3, JPG4, JPG5, JPG6, JPG7, + JPG8, JPG9, JPG10, JPG11, JPG12, JPG13, + + COM = 0xFE +}; + +// The rest is "RES (Reserved)", except for 0xFF (filler) and 0x00 (invalid). +static const char *marker_ids[0xFF] = { + [TEM] = "TEM", + [SOF0] = "SOF0", [SOF1] = "SOF1", [SOF2] = "SOF2", [SOF3] = "SOF3", + [DHT] = "DHT", [SOF5] = "SOF5", [SOF6] = "SOF6", [SOF7] = "SOF7", + [JPG] = "JPG", [SOF9] = "SOF9", [SOF10] = "SOF10", [SOF11] = "SOF11", + [DAC] = "DAC", [SOF13] = "SOF13", [SOF14] = "SOF14", [SOF15] = "SOF15", + [RST0] = "RST0", [RST1] = "RST1", [RST2] = "RST2", [RST3] = "RST3", + [RST4] = "RST4", [RST5] = "RST5", [RST6] = "RST6", [RST7] = "RST7", + [SOI] = "SOI", [EOI] = "EOI", [SOS] = "SOS", [DQT] = "DQT", + [DNL] = "DNL", [DRI] = "DRI", [DHP] = "DHP", [EXP] = "EXP", + [APP0] = "APP0", [APP1] = "APP1", [APP2] = "APP2", [APP3] = "APP3", + [APP4] = "APP4", [APP5] = "APP5", [APP6] = "APP6", [APP7] = "APP7", + [APP8] = "APP8", [APP9] = "APP9", [APP10] = "APP10", [APP11] = "APP11", + [APP12] = "APP12", [APP13] = "APP13", [APP14] = "APP14", [APP15] = "APP15", + [JPG0] = "JPG0", [JPG1] = "JPG1", [JPG2] = "JPG2", [JPG3] = "JPG3", + [JPG4] = "JPG4", [JPG5] = "JPG5", [JPG6] = "JPG6", [JPG7] = "JPG7", + [JPG8] = "JPG8", [JPG9] = "JPG9", [JPG10] = "JPG10", [JPG11] = "JPG11", + [JPG12] = "JPG12", [JPG13] = "JPG13", [COM] = "COM" +}; + +/* +// The rest is "RES (Reserved)", except for 0xFF (filler) and 0x00 (invalid). +static const char *marker_descriptions[0xFF] = { + [TEM] = "For temporary private use in arithmetic coding", + [SOF0] = "Baseline DCT", + [SOF1] = "Extended sequential DCT", + [SOF2] = "Progressive DCT", + [SOF3] = "Lossless (sequential)", + [DHT] = "Define Huffman table(s)", + [SOF5] = "Differential sequential DCT", + [SOF6] = "Differential progressive DCT", + [SOF7] = "Differential lossless (sequential)", + [JPG] = "Reserved for JPEG extensions", + [SOF9] = "Extended sequential DCT", + [SOF10] = "Progressive DCT", + [SOF11] = "Lossless (sequential)", + [DAC] = "Define arithmetic coding conditioning(s)", + [SOF13] = "Differential sequential DCT", + [SOF14] = "Differential progressive DCT", + [SOF15] = "Differential lossless (sequential)", + [RST0] = "Restart with module 8 count 0", + [RST1] = "Restart with module 8 count 1", + [RST2] = "Restart with module 8 count 2", + [RST3] = "Restart with module 8 count 3", + [RST4] = "Restart with module 8 count 4", + [RST5] = "Restart with module 8 count 5", + [RST6] = "Restart with module 8 count 6", + [RST7] = "Restart with module 8 count 7", + [SOI] = "Start of image", + [EOI] = "End of image", + [SOS] = "Start of scan", + [DQT] = "Define quantization table(s)", + [DNL] = "Define number of lines", + [DRI] = "Define restart interval", + [DHP] = "Define hierarchical progression", + [EXP] = "Expand reference component(s)", + [APP0] = "Reserved for application segments, 0", + [APP1] = "Reserved for application segments, 1", + [APP2] = "Reserved for application segments, 2", + [APP3] = "Reserved for application segments, 3", + [APP4] = "Reserved for application segments, 4", + [APP5] = "Reserved for application segments, 5", + [APP6] = "Reserved for application segments, 6", + [APP7] = "Reserved for application segments, 7", + [APP8] = "Reserved for application segments, 8", + [APP9] = "Reserved for application segments, 9", + [APP10] = "Reserved for application segments, 10", + [APP11] = "Reserved for application segments, 11", + [APP12] = "Reserved for application segments, 12", + [APP13] = "Reserved for application segments, 13", + [APP14] = "Reserved for application segments, 14", + [APP15] = "Reserved for application segments, 15", + [JPG0] = "Reserved for JPEG extensions, 0", + [JPG1] = "Reserved for JPEG extensions, 1", + [JPG2] = "Reserved for JPEG extensions, 2", + [JPG3] = "Reserved for JPEG extensions, 3", + [JPG4] = "Reserved for JPEG extensions, 4", + [JPG5] = "Reserved for JPEG extensions, 5", + [JPG6] = "Reserved for JPEG extensions, 6", + [JPG7] = "Reserved for JPEG extensions, 7", + [JPG8] = "Reserved for JPEG extensions, 8", + [JPG9] = "Reserved for JPEG extensions, 9", + [JPG10] = "Reserved for JPEG extensions, 10", + [JPG11] = "Reserved for JPEG extensions, 11", + [JPG12] = "Reserved for JPEG extensions, 12", + [JPG13] = "Reserved for JPEG extensions, 13", + [COM] = "Comment", +}; +*/ + +// --- Analysis ---------------------------------------------------------------- +// Because the JPEG file format is simple, just do it manually. + +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(). + jv a = jv_object_get(jv_copy(o), jv_string(key)); + return jv_set(o, jv_string(key), + jv_is_valid(jv_copy(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)); +} + +struct data { + bool ended; + char *exif, *icc; + size_t exif_len, icc_len; + int icc_sequence, icc_done; +}; + +static const uint8_t * +parse_marker(uint8_t marker, const uint8_t *p, const uint8_t *end, + struct data *data, jv *o) +{ + // Suspected: MJPEG? Undetected format recursion, e.g., thumbnails? + // Found: Random metadata! Multi-Picture Format! + if ((data->ended = marker == EOI) && p != end) + *o = add_warning(*o, "trailing data"); + + // These markers stand alone, not starting a marker segment. + switch (marker) { + case RST0: + case RST1: + case RST2: + case RST3: + case RST4: + case RST5: + case RST6: + case RST7: + *o = add_warning(*o, "unexpected restart marker"); + // Fall-through + case SOI: + case EOI: + case TEM: + return p; + } + + uint16_t length = p[0] << 8 | p[1]; + const uint8_t *payload = p + 2; + if ((p += length) > end) { + *o = add_error(*o, "runaway marker segment"); + return NULL; + } + + switch (marker) { + case SOF0: + case SOF1: + case SOF2: + case SOF3: + case SOF5: + case SOF6: + case SOF7: + case SOF9: + case SOF10: + case SOF11: + case SOF13: + case SOF14: + case SOF15: + case DHP: // B.2.2 and B.3.2. + // As per B.2.5, Y can be zero, then there needs to be a DNL segment. + *o = add_to_subarray(*o, "info", JV_OBJECT( + jv_string("bits"), jv_number(payload[0]), + jv_string("height"), jv_number(payload[1] << 8 | payload[2]), + jv_string("width"), jv_number(payload[3] << 8 | payload[4]), + jv_string("components"), jv_number(payload[5]) + )); + return p; + } + + // See B.1.1.5, we can brute-force our way through the entropy-coded data. + if (marker == SOS) { + while (p + 2 <= end && (p[0] != 0xFF || p[1] < 0xC0 || p[1] > 0xFE || + (p[1] >= RST0 && p[1] <= RST7))) + p++; + return p; + } + + // "The interpretation is left to the application." + if (marker == COM) { + int superascii = 0; + char *buf = calloc(3, p - payload), *bufp = buf; + for (const uint8_t *q = payload; q < p; q++) { + if (*q < 128) { + *bufp++ = *q; + } else { + superascii++; + *bufp++ = 0xC0 | (*q >> 6); + *bufp++ = 0x80 | (*q & 0x3F); + } + } + *bufp++ = 0; + *o = add_to_subarray(*o, "comments", jv_string(buf)); + free(buf); + + if (superascii) + *o = add_warning(*o, "super-ASCII comments"); + } + + // These mostly contain an ASCII string header, following JPEG FIF: + // + // "Application-specific APP0 marker segments are identified + // by a zero terminated string which identifies the application + // (not 'JFIF' or 'JFXX')." + if (marker >= APP0 && marker <= APP15) { + const uint8_t *nul = memchr(payload, 0, p - payload); + int unprintable = !nul; + if (nul) { + for (const uint8_t *q = payload; q < nul; q++) + unprintable += *q < 32 || *q >= 127; + } + *o = add_to_subarray(*o, "apps", + unprintable ? jv_null() : jv_string((const char *) payload)); + } + + // CIPA DC-007 (Multi-Picture Format) + // http://fileformats.archiveteam.org/wiki/Multi-Picture_Format + // TODO(p): Handle by properly skipping trailing data (use MPF offsets). + + // CIPA DC-006 (Stereo Still Image Format for Digital Cameras) + // http://fileformats.archiveteam.org/wiki/Multi-Picture_Format + // TODO(p): Handle by properly skipping trailing data (use Stim offsets). + + // https://www.w3.org/Graphics/JPEG/jfif3.pdf + if (marker == APP0 && p - payload >= 14 && !memcmp(payload, "JFIF\0", 5)) { + payload += 5; + + jv units = jv_number(payload[2]); + switch (payload[2]) { + break; case 0: units = jv_null(); + break; case 1: units = jv_string("DPI"); + break; case 2: units = jv_string("dots per cm"); + } + + // The rest is picture data. + *o = add_to_subarray(*o, "JFIF", JV_OBJECT( + jv_string("version"), jv_number(payload[0] * 100 + payload[1]), + jv_string("units"), units, + jv_string("density-x"), jv_number(payload[3] << 8 | payload[4]), + jv_string("density-y"), jv_number(payload[5] << 8 | payload[6]), + jv_string("thumbnail-w"), jv_number(payload[7]), + jv_string("thumbnail-h"), jv_number(payload[8]) + )); + } + + // https://www.w3.org/Graphics/JPEG/jfif3.pdf + if (marker == APP0 && p - payload >= 6 && !memcmp(payload, "JFXX\0", 5)) { + payload += 5; + + jv extension = jv_number(payload[0]); + switch (payload[0]) { + break; case 0x10: extension = jv_string("JPEG thumbnail"); + break; case 0x11: extension = jv_string("Paletted thumbnail"); + break; case 0x13: extension = jv_string("RGB thumbnail"); + } + + // The rest is picture data. + *o = add_to_subarray(*o, "JFXX", + JV_OBJECT(jv_string("extension"), extension)); + } + + // https://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf 4.7.2 + if (marker == APP1 && p - payload >= 6 && !memcmp(payload, "Exif\0", 5)) { + payload += 6; + + if (payload[-1] != 0) + *o = add_warning(*o, "weirdly padded Exif header"); + + if (data->exif) { + *o = add_warning(*o, "multiple Exifs"); + } else { + data->exif = realloc(data->exif, (data->exif_len = p - payload)); + memcpy(data->exif, payload, data->exif_len); + } + } + + // https://www.color.org/specification/ICC1v43_2010-12.pdf B.4 + if (marker == APP2 && p - payload >= 14 && + !memcmp(payload, "ICC_PROFILE\0", 12) && !data->icc_done && + payload[12] == ++data->icc_sequence && payload[13] >= payload[12]) { + payload += 14; + + size_t icc_longer = data->icc_len + (p - payload); + data->icc = realloc(data->icc, icc_longer); + memcpy(data->icc + data->icc_len, payload, p - payload); + data->icc_len = icc_longer; + + data->icc_done = payload[-1] == data->icc_sequence; + } + return p; +} + +static jv +parse_jpeg(jv o, const uint8_t *p, size_t len) +{ + struct data data = {}; + const uint8_t *end = p + len; + jv markers = jv_array(); + while (p) { + // This is an expectable condition, use a simple warning. + if (p + 2 > end) { + if (!data.ended) + o = add_warning(o, "unexpected EOF"); + break; + } + if (*p++ != 0xFF || *p == 0) { + o = add_error(o, "no marker found where one was expected"); + break; + } + + // Markers may be preceded by fill bytes. + if (*p == 0xFF) { + o = jv_object_set(o, jv_string("fillers"), jv_bool(true)); + continue; + } + + uint8_t marker = *p++; + markers = jv_array_append(markers, + jv_string(marker_ids[marker] ? marker_ids[marker] : "RES")); + p = parse_marker(marker, p, end, &data, &o); + } + + if (data.exif) { + // TODO(p): Decode. + free(data.exif); + } + + if (data.icc) { + if (data.icc_done) { + // TODO(p): Decode. + } else { + o = add_warning(o, "bad ICC profile sequence"); + } + free(data.icc); + } + + return jv_set(o, jv_string("markers"), markers); +} + +static jv +do_file(const char *filename, jv o) +{ + const char *err = NULL; + FILE *fp = fopen(filename, "rb"); + if (!fp) { + err = strerror(errno); + goto error; + } + + uint8_t *data = NULL, buf[256 << 10]; + size_t n, len = 0; + while ((n = fread(buf, sizeof *buf, sizeof buf / sizeof *buf, fp))) { + data = realloc(data, len + n); + memcpy(data + len, buf, n); + len += n; + } + if (ferror(fp)) { + err = strerror(errno); + goto error_read; + } + +#if 0 + // Not sure if I want to ensure their existence... + o = jv_object_set(o, jv_string("info"), jv_array()); + o = jv_object_set(o, jv_string("warnings"), jv_array()); +#endif + + o = parse_jpeg(o, data, len); +error_read: + fclose(fp); + free(data); +error: + if (err) + o = add_error(o, err); + return o; +} + +int +main(int argc, char *argv[]) +{ + // XXX: Can't use `xargs -P0`, there's a risk of non-atomic writes. + // Usage: find . -iname *.png -print0 | xargs -0 ./pnginfo + for (int i = 1; i < argc; i++) { + const char *filename = argv[i]; + + jv o = jv_object(); + o = jv_object_set(o, jv_string("filename"), jv_string(filename)); + o = do_file(filename, o); + jv_dumpf(o, stdout, 0 /* Might consider JV_PRINT_SORTED. */); + fputc('\n', stdout); + } + return 0; +} -- cgit v1.2.3-70-g09d2