Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * jdatadst.c |
| 3 | * |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 4 | * Copyright (C) 1994-1996, Thomas G. Lane. |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 5 | * Modified 2009 by Guido Vollbeding. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 6 | * This file is part of the Independent JPEG Group's software. |
| 7 | * For conditions of distribution and use, see the accompanying README file. |
| 8 | * |
| 9 | * This file contains compression data destination routines for the case of |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 10 | * emitting JPEG data to memory or to a file (or any stdio stream). |
| 11 | * While these routines are sufficient for most applications, |
| 12 | * some will want to use a different destination manager. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 13 | * IMPORTANT: we assume that fwrite() will correctly transcribe an array of |
| 14 | * JOCTETs into 8-bit-wide elements on external storage. If char is wider |
| 15 | * than 8 bits on your machine, you may need to do some tweaking. |
| 16 | */ |
| 17 | |
| 18 | /* this is not a core library module, so it doesn't define JPEG_INTERNALS */ |
| 19 | #include "jinclude.h" |
| 20 | #include "jpeglib.h" |
| 21 | #include "jerror.h" |
| 22 | |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 23 | #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */ |
| 24 | extern void * malloc JPP((size_t size)); |
| 25 | extern void free JPP((void *ptr)); |
| 26 | #endif |
| 27 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 28 | |
| 29 | /* Expanded data destination object for stdio output */ |
| 30 | |
| 31 | typedef struct { |
| 32 | struct jpeg_destination_mgr pub; /* public fields */ |
| 33 | |
| 34 | FILE * outfile; /* target stream */ |
| 35 | JOCTET * buffer; /* start of buffer */ |
| 36 | } my_destination_mgr; |
| 37 | |
| 38 | typedef my_destination_mgr * my_dest_ptr; |
| 39 | |
| 40 | #define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */ |
| 41 | |
| 42 | |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 43 | #if JPEG_LIB_VERSION >= 80 |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 44 | /* Expanded data destination object for memory output */ |
| 45 | |
| 46 | typedef struct { |
| 47 | struct jpeg_destination_mgr pub; /* public fields */ |
| 48 | |
| 49 | unsigned char ** outbuffer; /* target buffer */ |
| 50 | unsigned long * outsize; |
| 51 | unsigned char * newbuffer; /* newly allocated buffer */ |
| 52 | JOCTET * buffer; /* start of buffer */ |
| 53 | size_t bufsize; |
| 54 | } my_mem_destination_mgr; |
| 55 | |
| 56 | typedef my_mem_destination_mgr * my_mem_dest_ptr; |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 57 | #endif |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 58 | |
| 59 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 60 | /* |
| 61 | * Initialize destination --- called by jpeg_start_compress |
| 62 | * before any data is actually written. |
| 63 | */ |
| 64 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 65 | METHODDEF(void) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 66 | init_destination (j_compress_ptr cinfo) |
| 67 | { |
| 68 | my_dest_ptr dest = (my_dest_ptr) cinfo->dest; |
| 69 | |
| 70 | /* Allocate the output buffer --- it will be released when done with image */ |
| 71 | dest->buffer = (JOCTET *) |
| 72 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| 73 | OUTPUT_BUF_SIZE * SIZEOF(JOCTET)); |
| 74 | |
| 75 | dest->pub.next_output_byte = dest->buffer; |
| 76 | dest->pub.free_in_buffer = OUTPUT_BUF_SIZE; |
| 77 | } |
| 78 | |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 79 | #if JPEG_LIB_VERSION >= 80 |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 80 | METHODDEF(void) |
| 81 | init_mem_destination (j_compress_ptr cinfo) |
| 82 | { |
| 83 | /* no work necessary here */ |
| 84 | } |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 85 | #endif |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 86 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 87 | |
| 88 | /* |
| 89 | * Empty the output buffer --- called whenever buffer fills up. |
| 90 | * |
| 91 | * In typical applications, this should write the entire output buffer |
| 92 | * (ignoring the current state of next_output_byte & free_in_buffer), |
| 93 | * reset the pointer & count to the start of the buffer, and return TRUE |
| 94 | * indicating that the buffer has been dumped. |
| 95 | * |
| 96 | * In applications that need to be able to suspend compression due to output |
| 97 | * overrun, a FALSE return indicates that the buffer cannot be emptied now. |
| 98 | * In this situation, the compressor will return to its caller (possibly with |
| 99 | * an indication that it has not accepted all the supplied scanlines). The |
| 100 | * application should resume compression after it has made more room in the |
| 101 | * output buffer. Note that there are substantial restrictions on the use of |
| 102 | * suspension --- see the documentation. |
| 103 | * |
| 104 | * When suspending, the compressor will back up to a convenient restart point |
| 105 | * (typically the start of the current MCU). next_output_byte & free_in_buffer |
| 106 | * indicate where the restart point will be if the current call returns FALSE. |
| 107 | * Data beyond this point will be regenerated after resumption, so do not |
| 108 | * write it out when emptying the buffer externally. |
| 109 | */ |
| 110 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 111 | METHODDEF(boolean) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 112 | empty_output_buffer (j_compress_ptr cinfo) |
| 113 | { |
| 114 | my_dest_ptr dest = (my_dest_ptr) cinfo->dest; |
| 115 | |
| 116 | if (JFWRITE(dest->outfile, dest->buffer, OUTPUT_BUF_SIZE) != |
| 117 | (size_t) OUTPUT_BUF_SIZE) |
| 118 | ERREXIT(cinfo, JERR_FILE_WRITE); |
| 119 | |
| 120 | dest->pub.next_output_byte = dest->buffer; |
| 121 | dest->pub.free_in_buffer = OUTPUT_BUF_SIZE; |
| 122 | |
| 123 | return TRUE; |
| 124 | } |
| 125 | |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 126 | #if JPEG_LIB_VERSION >= 80 |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 127 | METHODDEF(boolean) |
| 128 | empty_mem_output_buffer (j_compress_ptr cinfo) |
| 129 | { |
| 130 | size_t nextsize; |
| 131 | JOCTET * nextbuffer; |
| 132 | my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest; |
| 133 | |
| 134 | /* Try to allocate new buffer with double size */ |
| 135 | nextsize = dest->bufsize * 2; |
| 136 | nextbuffer = malloc(nextsize); |
| 137 | |
| 138 | if (nextbuffer == NULL) |
| 139 | ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10); |
| 140 | |
| 141 | MEMCOPY(nextbuffer, dest->buffer, dest->bufsize); |
| 142 | |
| 143 | if (dest->newbuffer != NULL) |
| 144 | free(dest->newbuffer); |
| 145 | |
| 146 | dest->newbuffer = nextbuffer; |
| 147 | |
| 148 | dest->pub.next_output_byte = nextbuffer + dest->bufsize; |
| 149 | dest->pub.free_in_buffer = dest->bufsize; |
| 150 | |
| 151 | dest->buffer = nextbuffer; |
| 152 | dest->bufsize = nextsize; |
| 153 | |
| 154 | return TRUE; |
| 155 | } |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 156 | #endif |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 157 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 158 | |
| 159 | /* |
| 160 | * Terminate destination --- called by jpeg_finish_compress |
| 161 | * after all data has been written. Usually needs to flush buffer. |
| 162 | * |
| 163 | * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding |
| 164 | * application must deal with any cleanup that should happen even |
| 165 | * for error exit. |
| 166 | */ |
| 167 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 168 | METHODDEF(void) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 169 | term_destination (j_compress_ptr cinfo) |
| 170 | { |
| 171 | my_dest_ptr dest = (my_dest_ptr) cinfo->dest; |
| 172 | size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer; |
| 173 | |
| 174 | /* Write any data remaining in the buffer */ |
| 175 | if (datacount > 0) { |
| 176 | if (JFWRITE(dest->outfile, dest->buffer, datacount) != datacount) |
| 177 | ERREXIT(cinfo, JERR_FILE_WRITE); |
| 178 | } |
| 179 | fflush(dest->outfile); |
| 180 | /* Make sure we wrote the output file OK */ |
| 181 | if (ferror(dest->outfile)) |
| 182 | ERREXIT(cinfo, JERR_FILE_WRITE); |
| 183 | } |
| 184 | |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 185 | #if JPEG_LIB_VERSION >= 80 |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 186 | METHODDEF(void) |
| 187 | term_mem_destination (j_compress_ptr cinfo) |
| 188 | { |
| 189 | my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest; |
| 190 | |
| 191 | *dest->outbuffer = dest->buffer; |
| 192 | *dest->outsize = dest->bufsize - dest->pub.free_in_buffer; |
| 193 | } |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 194 | #endif |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 195 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 196 | |
| 197 | /* |
| 198 | * Prepare for output to a stdio stream. |
| 199 | * The caller must have already opened the stream, and is responsible |
| 200 | * for closing it after finishing compression. |
| 201 | */ |
| 202 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 203 | GLOBAL(void) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 204 | jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile) |
| 205 | { |
| 206 | my_dest_ptr dest; |
| 207 | |
| 208 | /* The destination object is made permanent so that multiple JPEG images |
| 209 | * can be written to the same file without re-executing jpeg_stdio_dest. |
| 210 | * This makes it dangerous to use this manager and a different destination |
| 211 | * manager serially with the same JPEG object, because their private object |
| 212 | * sizes may be different. Caveat programmer. |
| 213 | */ |
| 214 | if (cinfo->dest == NULL) { /* first time for this JPEG object? */ |
| 215 | cinfo->dest = (struct jpeg_destination_mgr *) |
| 216 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, |
| 217 | SIZEOF(my_destination_mgr)); |
| 218 | } |
| 219 | |
| 220 | dest = (my_dest_ptr) cinfo->dest; |
| 221 | dest->pub.init_destination = init_destination; |
| 222 | dest->pub.empty_output_buffer = empty_output_buffer; |
| 223 | dest->pub.term_destination = term_destination; |
| 224 | dest->outfile = outfile; |
| 225 | } |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 226 | |
| 227 | |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 228 | #if JPEG_LIB_VERSION >= 80 |
Guido Vollbeding | 989630f | 2010-01-10 00:00:00 +0000 | [diff] [blame] | 229 | /* |
| 230 | * Prepare for output to a memory buffer. |
| 231 | * The caller may supply an own initial buffer with appropriate size. |
| 232 | * Otherwise, or when the actual data output exceeds the given size, |
| 233 | * the library adapts the buffer size as necessary. |
| 234 | * The standard library functions malloc/free are used for allocating |
| 235 | * larger memory, so the buffer is available to the application after |
| 236 | * finishing compression, and then the application is responsible for |
| 237 | * freeing the requested memory. |
| 238 | */ |
| 239 | |
| 240 | GLOBAL(void) |
| 241 | jpeg_mem_dest (j_compress_ptr cinfo, |
| 242 | unsigned char ** outbuffer, unsigned long * outsize) |
| 243 | { |
| 244 | my_mem_dest_ptr dest; |
| 245 | |
| 246 | if (outbuffer == NULL || outsize == NULL) /* sanity check */ |
| 247 | ERREXIT(cinfo, JERR_BUFFER_SIZE); |
| 248 | |
| 249 | /* The destination object is made permanent so that multiple JPEG images |
| 250 | * can be written to the same buffer without re-executing jpeg_mem_dest. |
| 251 | */ |
| 252 | if (cinfo->dest == NULL) { /* first time for this JPEG object? */ |
| 253 | cinfo->dest = (struct jpeg_destination_mgr *) |
| 254 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, |
| 255 | SIZEOF(my_mem_destination_mgr)); |
| 256 | } |
| 257 | |
| 258 | dest = (my_mem_dest_ptr) cinfo->dest; |
| 259 | dest->pub.init_destination = init_mem_destination; |
| 260 | dest->pub.empty_output_buffer = empty_mem_output_buffer; |
| 261 | dest->pub.term_destination = term_mem_destination; |
| 262 | dest->outbuffer = outbuffer; |
| 263 | dest->outsize = outsize; |
| 264 | dest->newbuffer = NULL; |
| 265 | |
| 266 | if (*outbuffer == NULL || *outsize == 0) { |
| 267 | /* Allocate initial buffer */ |
| 268 | dest->newbuffer = *outbuffer = malloc(OUTPUT_BUF_SIZE); |
| 269 | if (dest->newbuffer == NULL) |
| 270 | ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10); |
| 271 | *outsize = OUTPUT_BUF_SIZE; |
| 272 | } |
| 273 | |
| 274 | dest->pub.next_output_byte = dest->buffer = *outbuffer; |
| 275 | dest->pub.free_in_buffer = dest->bufsize = *outsize; |
| 276 | } |
DRC | 36a6eec | 2010-10-08 08:05:44 +0000 | [diff] [blame] | 277 | #endif |