// // 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 "info.h" #include #include #include #include #include #include // --- ICC profiles ------------------------------------------------------------ // v2 https://www.color.org/ICC_Minor_Revision_for_Web.pdf // v4 https://www.color.org/specification/ICC1v43_2010-12.pdf static jv parse_icc_mluc(jv o, const uint8_t *tag, uint32_t tag_length) { // v4 10.13 if (tag_length < 16) return add_warning(o, "invalid ICC 'mluc' structure length"); uint32_t count = u32be(tag + 8); if (count == 0) return add_warning(o, "unnamed ICC profile"); // There is no particularly good reason for us to iterate, take the first. const uint8_t *record = tag + 16 /* + i * u32be(tag + 12) */; uint32_t len = u32be(&record[4]); uint32_t off = u32be(&record[8]); if (off + len > tag_length) return add_warning(o, "invalid ICC 'mluc' structure record"); // Blindly assume simple ASCII, ensure NUL-termination. char name[len], *p = name; for (uint32_t i = 0; i < len / 2; i++) *p++ = tag[off + i * 2 + 1]; *p++ = 0; return jv_set(o, jv_string("ICC"), JV_OBJECT(jv_string("name"), jv_string(name), jv_string("version"), jv_number(4))); } static jv parse_icc_desc(jv o, const uint8_t *profile, size_t profile_len, uint32_t tag_offset, uint32_t tag_length) { const uint8_t *tag = profile + tag_offset; if (tag_offset + tag_length > profile_len) return add_warning(o, "unexpected end of ICC profile"); if (tag_length < 4) return add_warning(o, "invalid ICC tag structure length"); // v2 6.5.17 uint32_t sig = u32be(tag); if (sig == 0x6D6C7563 /* mluc */) return parse_icc_mluc(o, profile + tag_offset, tag_length); if (sig != 0x64657363 /* desc */) return add_warning(o, "invalid ICC 'desc' structure signature"); if (tag_length < 12) return add_warning(o, "invalid ICC 'desc' structure length"); uint32_t count = u32be(tag + 8); if (tag_length < 12 + count) return add_warning(o, "invalid ICC 'desc' structure length"); // Double-ensure a trailing NUL byte. char name[count + 1]; memcpy(name, tag + 12, count); name[count] = 0; return jv_set(o, jv_string("ICC"), JV_OBJECT(jv_string("name"), jv_string(name), jv_string("version"), jv_number(2))); } static jv parse_icc(jv o, const uint8_t *profile, size_t profile_len) { // v2 6, v4 7 if (profile_len < 132) return add_warning(o, "ICC profile too short"); if (u32be(profile) != profile_len) return add_warning(o, "ICC profile size mismatch"); // TODO(p): May decode more of the header fields, and validate them. // Need to check both v2 and v4, this is all fairly annoying. uint32_t count = u32be(profile + 128); if (132 + count * 12 > profile_len) return add_warning(o, "unexpected end of ICC profile"); for (uint32_t i = 0; i < count; i++) { const uint8_t *entry = profile + 132 + i * 12; uint32_t sig = u32be(&entry[0]); uint32_t off = u32be(&entry[4]); uint32_t len = u32be(&entry[8]); // v2 6.4.32, v4 9.2.41 if (sig == 0x64657363 /* desc */) return parse_icc_desc(o, profile, profile_len, off, len); } // The description is required, so this should be unreachable. return jv_set(o, jv_string("ICC"), jv_bool(true)); } // --- Multi-Picture Format ---------------------------------------------------- enum { MPF_MPFVersion = 45056, MPF_NumberOfImages = 45057, MPF_MPEntry = 45058, MPF_ImageUIDList = 45059, MPF_TotalFrames = 45060, MPF_MPIndividualNum = 45313, MPF_PanOrientation = 45569, MPF_PanOverlap_H = 45570, MPF_PanOverlap_V = 45571, MPF_BaseViewpointNum = 45572, MPF_ConvergenceAngle = 45573, MPF_BaselineLength = 45574, MPF_VerticalDivergence = 45575, MPF_AxisDistance_X = 45576, MPF_AxisDistance_Y = 45577, MPF_AxisDistance_Z = 45578, MPF_YawAngle = 45579, MPF_PitchAngle = 45580, MPF_RollAngle = 45581 }; static struct tiff_entry mpf_entries[] = { {"MP Format Version Number", MPF_MPFVersion, NULL}, {"Number of Images", MPF_NumberOfImages, NULL}, {"MP Entry", MPF_MPEntry, NULL}, {"Individual Image Unique ID List", MPF_ImageUIDList, NULL}, {"Total Number of Captured Frames", MPF_TotalFrames, NULL}, {"MP Individual Image Number", MPF_MPIndividualNum, NULL}, {"Panorama Scanning Orientation", MPF_PanOrientation, NULL}, {"Panorama Horizontal Overlap", MPF_PanOverlap_H, NULL}, {"Panorama Vertical Overlap", MPF_PanOverlap_V, NULL}, {"Base Viewpoint Number", MPF_BaseViewpointNum, NULL}, {"Convergence Angle", MPF_ConvergenceAngle, NULL}, {"Baseline Length", MPF_BaselineLength, NULL}, {"Divergence Angle", MPF_VerticalDivergence, NULL}, {"Horizontal Axis Distance", MPF_AxisDistance_X, NULL}, {"Vertical Axis Distance", MPF_AxisDistance_Y, NULL}, {"Collimation Axis Distance", MPF_AxisDistance_Z, NULL}, {"Yaw Angle", MPF_YawAngle, NULL}, {"Pitch Angle", MPF_PitchAngle, NULL}, {"Roll Angle", MPF_RollAngle, NULL}, {} }; static uint32_t parse_mpf_mpentry(jv *a, const uint8_t *p, struct tiffer *T) { uint32_t attrs = T->un->u32(p); uint32_t offset = T->un->u32(p + 8); uint32_t type_number = attrs & 0xFFFFFF; jv type = jv_number(type_number); switch (type_number) { break; case 0x030000: type = jv_string("Baseline MP Primary Image"); break; case 0x010001: type = jv_string("Large Thumbnail - VGA"); break; case 0x010002: type = jv_string("Large Thumbnail - Full HD"); break; case 0x020001: type = jv_string("Multi-Frame Image Panorama"); break; case 0x020002: type = jv_string("Multi-Frame Image Disparity"); break; case 0x020003: type = jv_string("Multi-Frame Image Multi-Angle"); break; case 0x000000: type = jv_string("Undefined"); } uint32_t format_number = (attrs >> 24) & 0x7; jv format = jv_number(format_number); if (format_number == 0) format = jv_string("JPEG"); *a = jv_array_append(*a, JV_OBJECT( jv_string("Individual Image Attribute"), JV_OBJECT( jv_string("Dependent Parent Image"), jv_bool((attrs >> 31) & 1), jv_string("Dependent Child Image"), jv_bool((attrs >> 30) & 1), jv_string("Representative Image"), jv_bool((attrs >> 29) & 1), jv_string("Reserved"), jv_number((attrs >> 27) & 0x3), jv_string("Image Data Format"), format, jv_string("MP Type Code"), type ), jv_string("Individual Image Size"), jv_number(T->un->u32(p + 4)), jv_string("Individual Image Data Offset"), jv_number(offset), jv_string("Dependent Image 1 Entry Number"), jv_number(T->un->u16(p + 12)), jv_string("Dependent Image 2 Entry Number"), jv_number(T->un->u16(p + 14)) )); // Don't report non-JPEGs, even though they're unlikely. return format_number == 0 ? offset : 0; } static jv parse_mpf_index_entry(jv o, const uint8_t ***offsets, struct tiffer *T, struct tiffer_entry *entry) { // 5.2.3.3. MP Entry if (entry->tag != MPF_MPEntry || entry->type != UNDEFINED || entry->remaining_count % 16) { return parse_exif_entry(o, T, entry, mpf_entries); } uint32_t count = entry->remaining_count / 16; jv a = jv_array_sized(count); const uint8_t **out = *offsets = calloc(sizeof *out, count + 1); for (uint32_t i = 0; i < count; i++) { uint32_t offset = parse_mpf_mpentry(&a, entry->p + i * 16, T); if (offset) *out++ = T->begin + offset; } return jv_set(o, jv_string("MP Entry"), a); } static jv parse_mpf_index_ifd(const uint8_t ***offsets, struct tiffer *T) { jv ifd = jv_object(); struct tiffer_entry entry = {}; while (tiffer_next_entry(T, &entry)) ifd = parse_mpf_index_entry(ifd, offsets, T, &entry); return ifd; } static jv parse_mpf(jv o, const uint8_t ***offsets, const uint8_t *p, size_t len) { struct tiffer T; if (!tiffer_init(&T, p, len) || !tiffer_next_ifd(&T)) return add_warning(o, "invalid MPF segment"); // First image: IFD0 is Index IFD, any IFD1 is Attribute IFD. // Other images: IFD0 is Attribute IFD, there is no Index IFD. if (!*offsets) { o = add_to_subarray(o, "MPF", parse_mpf_index_ifd(offsets, &T)); if (!tiffer_next_ifd(&T)) return o; } // This isn't optimal, but it will do. return add_to_subarray(o, "MPF", parse_exif_ifd(&T, mpf_entries)); } // --- JPEG -------------------------------------------------------------------- // Because the JPEG file format is simple, just do it manually. // 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", }; // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - struct data { bool ended; uint8_t *exif, *icc, *psir; size_t exif_len, icc_len, psir_len; int icc_sequence, icc_done; const uint8_t **mpf_offsets, **mpf_next; }; static void parse_append(uint8_t **buffer, size_t *buffer_len, const uint8_t *p, size_t len) { size_t buffer_longer = *buffer_len + len; *buffer = realloc(*buffer, buffer_longer); memcpy(*buffer + *buffer_len, p, len); *buffer_len = buffer_longer; } 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)) { // TODO(p): Handle Exifs independently--flush the last one. if ((data->mpf_next || (data->mpf_next = data->mpf_offsets)) && *data->mpf_next) return *data->mpf_next++; if (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("type"), jv_string(marker_descriptions[marker]), 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) 5.2 // http://fileformats.archiveteam.org/wiki/Multi-Picture_Format if (marker == APP2 && p - payload >= 8 && !memcmp(payload, "MPF\0", 4)) { payload += 4; *o = parse_mpf(*o, &data->mpf_offsets, payload, p - payload); } // CIPA DC-006 (Stereo Still Image Format for Digital Cameras) // 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]) )); } 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 // Adobe XMP Specification Part 3: Storage in Files, 2020/1, 1.1.3 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 Exif segments"); parse_append(&data->exif, &data->exif_len, payload, p - payload); } // 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; parse_append(&data->icc, &data->icc_len, payload, p - payload); data->icc_done = payload[-1] == data->icc_sequence; } // Adobe XMP Specification Part 3: Storage in Files, 2020/1, 1.1.3 + 3.1.3 // https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/ if (marker == APP13 && p - payload >= 14 && !memcmp(payload, "Photoshop 3.0\0", 14)) { payload += 14; parse_append(&data->psir, &data->psir_len, payload, p - payload); } 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) { if (!data.ended) 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) { o = parse_exif(o, data.exif, data.exif_len); free(data.exif); } if (data.icc) { if (data.icc_done) o = parse_icc(o, data.icc, data.icc_len); else o = add_warning(o, "bad ICC profile sequence"); free(data.icc); } if (data.psir) { o = parse_psir(o, data.psir, data.psir_len); free(data.psir); } free(data.mpf_offsets); return jv_set(o, jv_string("markers"), markers); } // --- I/O --------------------------------------------------------------------- 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; }