/* * GStreamer * Copyright 2007 Edgard Lima * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. * * Alternatively, the contents of this file may be used under the * GNU Lesser General Public License Version 2.1 (the "LGPL"), in * which case the following provisions apply instead of the ones * mentioned above: * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /* * SECTION: metadatamuxpng * @short_description: This module provides functions to parse PNG files in * order to write metadata to it. * * This module parses a PNG stream to find the places in which XMP metadata * chunks would be written. It also wraps metadata chunks with PNG marks * according to the specification. * * * * #metadatamux_png_init must be called before any other function in this * module and must be paired with a call to #metadatamux_png_dispose. * #metadatamux_png_parse is used to parse the stream (find the place * metadata chunks should be written to). * #metadatamux_png_lazy_update do nothing. * * * EXIF chunks will always be the first chunk (replaces JFIF). IPTC and XMP * chunks will be placed or second chunk (after JFIF or EXIF) or third chunk * if both (IPTC and XMP) are written to the file. * * * When a EXIF chunk is written to the PNG stream, if there is a JFIF chunk * as the first chunk, it will be stripped out. * * * * Last reviewed on 2008-01-24 (0.10.15) */ /* * includes */ #include "metadatamuxpng.h" #include /* * defines and macros */ #define READ(buf, size) ( (size)--, *((buf)++) ) /* * static global vars */ static const guint32 metadatamux_crc_table[256] = { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d }; /* * static helper functions declaration */ static MetadataParsingReturn metadatamux_png_reading (PngMuxData * png_data, guint8 ** buf, guint32 * bufsize, const guint32 offset, const guint8 * step_buf, guint8 ** next_start, guint32 * next_size); static guint32 metadatamux_update_crc (guint32 crc, guint8 * buf, guint32 len); static guint32 metadatamux_calc_crc (guint8 * buf, guint32 len); static void metadatamux_wrap_xmp_chunk (MetadataChunk * chunk); /* * extern functions implementations */ /* * metadatamux_png_init: * @png_data: [in] png data handler to be inited * @strip_chunks: Array of chunks (offset and size) marked for removal * @inject_chunks: Array of chunks (offset, data, size) marked for injection * adapter (@exif_adpt, @iptc_adpt, @xmp_adpt). Or FALSE if should also put * them on @strip_chunks. * * Init png data handle. * This function must be called before any other function from this module. * This function must not be called twice without call to * #metadatamux_png_dispose beteween them. * @see_also: #metadatamux_png_dispose #metadatamux_png_parse * * Returns: nothing */ void metadatamux_png_init (PngMuxData * png_data, MetadataChunkArray * strip_chunks, MetadataChunkArray * inject_chunks) { png_data->state = PNG_MUX_NULL; png_data->strip_chunks = strip_chunks; png_data->inject_chunks = inject_chunks; } /* * metadatamux_png_dispose: * png_data: [in] png data handler to be freed * * Call this function to free any resource allocated by #metadatamux_png_init * @see_also: #metadatamux_png_init * * Returns: nothing */ void metadatamux_png_dispose (PngMuxData * png_data) { png_data->strip_chunks = NULL; png_data->inject_chunks = NULL; png_data->state = PNG_MUX_NULL; } /* * metadatamux_png_parse: * @png_data: [in] png data handle * @buf: [in] data to be parsed * @bufsize: [in] size of @buf in bytes * @offset: is the offset where @buf starts from the beginnig of the whole * stream * @next_start: is a pointer after @buf which indicates where @buf should start * on the next call to this function. It means, that after returning, this * function has consumed *@next_start - @buf bytes. Which also means * that @offset should also be incremanted by (*@next_start - @buf) for the * next time. * @next_size: [out] number of minimal bytes in @buf for the next call to this * function * * This function is used to parse a PNG stream step-by-step incrementally. * Basically this function works like a state machine, that will run in a loop * while there is still bytes in @buf to be read or it has finished parsing. * If the it hasn't parsed yet and there is no more data in @buf, then the * current state is saved and a indication will be make about the buffer to * be passed by the caller function. * @see_also: #metadatamux_png_init * * Returns: * * %META_PARSING_ERROR * * %META_PARSING_DONE if parse has finished. Now strip and * inject chunks has been found * * %META_PARSING_NEED_MORE_DATA if this function should be * called again (look @next_start and @next_size) * * */ MetadataParsingReturn metadatamux_png_parse (PngMuxData * png_data, guint8 * buf, guint32 * bufsize, const guint32 offset, guint8 ** next_start, guint32 * next_size) { int ret = META_PARSING_DONE; guint8 mark[8]; const guint8 *step_buf = buf; *next_start = buf; if (png_data->state == PNG_MUX_NULL) { if (*bufsize < 8) { *next_size = (buf - *next_start) + 8; ret = META_PARSING_NEED_MORE_DATA; goto done; } mark[0] = READ (buf, *bufsize); mark[1] = READ (buf, *bufsize); mark[2] = READ (buf, *bufsize); mark[3] = READ (buf, *bufsize); mark[4] = READ (buf, *bufsize); mark[5] = READ (buf, *bufsize); mark[6] = READ (buf, *bufsize); mark[7] = READ (buf, *bufsize); if (mark[0] != 0x89 || mark[1] != 0x50 || mark[2] != 0x4E || mark[3] != 0x47 || mark[4] != 0x0D || mark[5] != 0x0A || mark[6] != 0x1A || mark[7] != 0x0A) { ret = META_PARSING_ERROR; goto done; } png_data->state = PNG_MUX_READING; } while (ret == META_PARSING_DONE) { switch (png_data->state) { case PNG_MUX_READING: ret = metadatamux_png_reading (png_data, &buf, bufsize, offset, step_buf, next_start, next_size); break; case PNG_MUX_DONE: goto done; break; default: ret = META_PARSING_ERROR; break; } } done: return ret; } /* * metadatamux_png_lazy_update: * @png_data: [in] png data handle * * This function wrap metadata chunk with proper PNG bytes. * @see_also: #metadata_lazy_update * * Returns: nothing */ void metadatamux_png_lazy_update (PngMuxData * png_data) { gsize i; MetadataChunkArray *chunks = png_data->inject_chunks; GST_INFO ("checking %d chunks", chunks->len); for (i = 0; i < chunks->len; ++i) { GST_INFO ("checking chunk[%" G_GSIZE_FORMAT "], type=%d, len=%u", i, chunks->chunk[i].type, chunks->chunk[i].size); if (chunks->chunk[i].size > 0 && chunks->chunk[i].data) { switch (chunks->chunk[i].type) { case MD_CHUNK_XMP: metadatamux_wrap_xmp_chunk (&chunks->chunk[i]); break; default: GST_ERROR ("Unexpected chunk for PNG muxer."); break; } } } } /* * static helper functions implementation */ /* * metadatamux_png_reading: * @png_data: [in] png data handle * @buf: [in] data to be parsed. @buf will increment during the parsing step. * So it will hold the next byte to be read inside a parsing function or on * the next nested parsing function. And so, @bufsize will decrement. * @bufsize: [in] size of @buf in bytes. This value will decrement during the * parsing for the same reason that @buf will advance. * @offset: is the offset where @step_buf starts from the beginnig of the * stream * @step_buf: holds the pointer to the buffer passed to * #metadatamux_png_parse. It means that any point inside this function * the offset (related to the beginning of the whole stream) after the last * byte read so far is "(*buf - step_buf) + offset" * @next_start: is a pointer after @step_buf which indicates where the next * call to #metadatamux_png_parse should start on the next call to this * function. It means, that after return, this function has * consumed *@next_start - @buf bytes. Which also means that @offset should * also be incremanted by (*@next_start - @buf) for the next time. * @next_size: [out] number of minimal bytes in @buf for the next call to this * function * * This function is used to parse a PNG stream step-by-step incrementally. * If this function quickly finds the place (offset) in which EXIF, IPTC and * XMP chunk should be written to. * The found places are written to @png_data->inject_chunks * @see_also: #metadatamux_png_init * * Returns: * * %META_PARSING_ERROR * * %META_PARSING_DONE if parse has finished. Now strip and * inject chunks has been found. Or some chunk has been found and should be * held or jumped. * * %META_PARSING_NEED_MORE_DATA if this function should be * called again (look @next_start and @next_size) * * */ static MetadataParsingReturn metadatamux_png_reading (PngMuxData * png_data, guint8 ** buf, guint32 * bufsize, const guint32 offset, const guint8 * step_buf, guint8 ** next_start, guint32 * next_size) { int ret = META_PARSING_ERROR; guint8 mark[4]; guint32 chunk_size = 0; MetadataChunk chunk; *next_start = *buf; if (*bufsize < 8) { *next_size = (*buf - *next_start) + 8; ret = META_PARSING_NEED_MORE_DATA; goto done; } chunk_size = READ (*buf, *bufsize) << 24; chunk_size += READ (*buf, *bufsize) << 16; chunk_size += READ (*buf, *bufsize) << 8; chunk_size += READ (*buf, *bufsize); mark[0] = READ (*buf, *bufsize); mark[1] = READ (*buf, *bufsize); mark[2] = READ (*buf, *bufsize); mark[3] = READ (*buf, *bufsize); if (!(mark[0] == 'I' && mark[1] == 'H' && mark[2] == 'D' && mark[3] == 'R')) { ret = META_PARSING_ERROR; png_data->state = PNG_MUX_NULL; goto done; } /* always inject after first chunk (IHDR) */ memset (&chunk, 0x00, sizeof (MetadataChunk)); /* 8(header) + 4(size) +4(id) + chunksize + 4(crc) */ chunk.offset_orig = chunk_size + 20; chunk.type = MD_CHUNK_XMP; metadata_chunk_array_append_sorted (png_data->inject_chunks, &chunk); png_data->state = PNG_MUX_DONE; ret = META_PARSING_DONE; done: return ret; } /* * metadatamux_update_crc: * @crc: seed to calculate the CRC * @buf: data to calculate the CRC for * @len: size in bytes of @buf * * Calculates the CRC of a data buffer for a seed @crc. * @see_also: #metadatamux_calc_crc * * Returns: the CRC of the bytes buf[0..len-1]. */ static guint32 metadatamux_update_crc (guint32 crc, guint8 * buf, guint32 len) { guint32 c = crc; guint32 n; for (n = 0; n < len; n++) { c = metadatamux_crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8); } return c; } /* * metadatamux_calc_crc: * @buf: data to calculate the CRC for * @len: size in bytes of @buf * * Calculates the CRC of a data buffer. * * Returns: the CRC of the bytes buf[0..len-1]. */ static guint32 metadatamux_calc_crc (guint8 * buf, guint32 len) { return metadatamux_update_crc (0xffffffffL, buf, len) ^ 0xffffffffL; } /* * metadatamux_wrap_xmp_chunk: * @chunk: chunk to be wrapped * * Wraps a XMP chunk with proper PNG bytes (mark, size and crc in the end) * * Returns: nothing */ static void metadatamux_wrap_xmp_chunk (MetadataChunk * chunk) { static const char XmpHeader[] = "XML:com.adobe.xmp"; guint8 *data = NULL; guint32 crc; data = g_new (guint8, 12 + 18 + 4 + chunk->size); memcpy (data + 8, XmpHeader, 18); memset (data + 8 + 18, 0x00, 4); memcpy (data + 8 + 18 + 4, chunk->data, chunk->size); g_free (chunk->data); chunk->data = data; chunk->size += 18 + 4; data[0] = (chunk->size >> 24) & 0xFF; data[1] = (chunk->size >> 16) & 0xFF; data[2] = (chunk->size >> 8) & 0xFF; data[3] = chunk->size & 0xFF; data[4] = 'i'; data[5] = 'T'; data[6] = 'X'; data[7] = 't'; crc = metadatamux_calc_crc (data + 4, chunk->size + 4); data[chunk->size + 8] = (crc >> 24) & 0xFF; data[chunk->size + 9] = (crc >> 16) & 0xFF; data[chunk->size + 10] = (crc >> 8) & 0xFF; data[chunk->size + 11] = crc & 0xFF; chunk->size += 12; }