lib/bitio.c

   1 /*  bitio.c
   2     part of swftools
   3     implementation of bitio.h.
   4
   5     Copyright (C) 2003 Matthias Kramm <kramm@quiss.org>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #ifdef HAVE_UNISTD_H
  24 #include <unistd.h>
  25 #endif
  26 #ifdef HAVE_IO_H
  27 #include <io.h>
  28 #endif
  29 #include <string.h>
  30 #include <memory.h>
  31 #include <fcntl.h>
  32
  33 #include "../config.h"
  34
  35 #ifdef HAVE_ZLIB
  36 #include <zlib.h>
  37 #define ZLIB_BUFFER_SIZE 16384
  38 #endif
  39 #include "./bitio.h"
  40
  41 /* ---------------------------- null reader ------------------------------- */
  42
  43 static int reader_nullread(reader_t*r, void* data, int len)
  44 {
  45     memset(data, 0, len);
  46     return len;
  47 }
  48 static void reader_nullread_dealloc(reader_t*r)
  49 {
  50     memset(r, 0, sizeof(reader_t));
  51 }
  52 void reader_init_nullreader(reader_t*r)
  53 {
  54     r->read = reader_nullread;
  55     r->dealloc = reader_nullread_dealloc;
  56     r->internal = 0;
  57     r->type = READER_TYPE_NULL;
  58     r->mybyte = 0;
  59     r->bitpos = 8;
  60     r->pos = 0;
  61 }
  62 /* ---------------------------- file reader ------------------------------- */
  63
  64 static int reader_fileread(reader_t*reader, void* data, int len)
  65 {
  66     int ret = read((int)reader->internal, data, len);
  67     if(ret>=0)
  68         reader->pos += ret;
  69     return ret;
  70 }
  71 void reader_init_filereader(reader_t*r, int handle)
  72 {
  73     r->read = reader_fileread;
  74     r->internal = (void*)handle;
  75     r->type = READER_TYPE_FILE;
  76     r->mybyte = 0;
  77     r->bitpos = 8;
  78     r->pos = 0;
  79 }
  80
  81 /* ---------------------------- mem reader ------------------------------- */
  82
  83 struct memread_t
  84 {
  85     unsigned char*data;
  86     int length;
  87 };
  88 static int reader_memread(reader_t*reader, void* data, int len)
  89 {
  90     struct memread_t*mr = (struct memread_t*)reader->internal;
  91
  92     if(mr->length - reader->pos < len) {
  93         len = mr->length - reader->pos;
  94     }
  95     memcpy(data, &mr->data[reader->pos], len);
  96     reader->pos += len;
  97     return len;
  98 }
  99 static void reader_memread_dealloc(reader_t*reader)
 100 {
 101     if(reader->internal)
 102         free(reader->internal);
 103     memset(reader, 0, sizeof(reader_t));
 104 }
 105 void reader_init_memreader(reader_t*r, void*newdata, int newlength)
 106 {
 107     struct memread_t*mr = (struct memread_t*)malloc(sizeof(struct memread_t));
 108     mr->data = (unsigned char*)newdata;
 109     mr->length = newlength;
 110     r->read = reader_memread;
 111     r->dealloc = reader_memread_dealloc;
 112     r->internal = (void*)mr;
 113     r->type = READER_TYPE_MEM;
 114     r->mybyte = 0;
 115     r->bitpos = 8;
 116     r->pos = 0;
 117 }
 118
 119 /* ---------------------------- mem writer ------------------------------- */
 120
 121 struct memwrite_t
 122 {
 123     unsigned char*data;
 124     int length;
 125 };
 126
 127 static int writer_memwrite_write(writer_t*w, void* data, int len)
 128 {
 129     struct memwrite_t*mw = (struct memwrite_t*)w->internal;
 130     if(mw->length - w->pos > len) {
 131         memcpy(&mw->data[w->pos], data, len);
 132         w->pos += len;
 133         return len;
 134     } else {
 135         memcpy(&mw->data[w->pos], data, mw->length - w->pos);
 136         w->pos = mw->length;
 137         return mw->length - w->pos;
 138     }
 139 }
 140 static void writer_memwrite_finish(writer_t*w)
 141 {
 142     if(w->internal)
 143         free(w->internal);
 144     w->internal = 0;
 145 }
 146 void writer_init_memwriter(writer_t*w, void*data, int len)
 147 {
 148     struct memwrite_t *mr;
 149     mr = (struct memwrite_t*)malloc(sizeof(struct memwrite_t));
 150     mr->data = (unsigned char *)data;
 151     mr->length = len;
 152     memset(w, 0, sizeof(writer_t));
 153     w->write = writer_memwrite_write;
 154     w->finish = writer_memwrite_finish;
 155     w->internal = (void*)mr;
 156     w->type = WRITER_TYPE_MEM;
 157     w->bitpos = 0;
 158     w->mybyte = 0;
 159     w->pos = 0;
 160 }
 161
 162 /* ------------------------- growing mem writer ------------------------------- */
 163
 164 struct growmemwrite_t
 165 {
 166     unsigned char*data;
 167     int length;
 168     U32 grow;
 169 };
 170 static int writer_growmemwrite_write(writer_t*w, void* data, int len)
 171 {
 172     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 173     if(!mw->data) {
 174         fprintf(stderr, "Illegal write operation: data already given away");
 175         exit(1);
 176     }
 177     if(mw->length - w->pos < len) {
 178         int newlength = mw->length;
 179         while(newlength - w->pos < len) {
 180             newlength += mw->grow;
 181         }
 182 #ifdef NO_REALLOC
 183         unsigned char*newmem = (unsigned char*)malloc(newlength);
 184         memcpy(newmem, mw->data, mw->length);
 185         free(mw->data);
 186         mw->data = newmem;
 187 #else
 188         mw->data = (unsigned char*)realloc(mw->data, newlength);
 189 #endif
 190         mw->length = newlength;
 191     }
 192     memcpy(&mw->data[w->pos], data, len);
 193     w->pos += len;
 194     return len;
 195 }
 196 static void writer_growmemwrite_finish(writer_t*w)
 197 {
 198     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 199     if(mw->data) {
 200         free(mw->data);mw->data = 0;
 201     }
 202     mw->length = 0;
 203     free(w->internal);mw=0;
 204     memset(w, 0, sizeof(writer_t));
 205 }
 206 void* writer_growmemwrite_memptr(writer_t*w, int*len)
 207 {
 208     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 209     if(len) {
 210         *len = w->pos;
 211     }
 212     return mw->data;
 213 }
 214 void* writer_growmemwrite_getmem(writer_t*w)
 215 {
 216     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 217     void*ret = mw->data;
 218     /* remove own reference so that neither write() nor finish() can free it.
 219        It's property of the caller now.
 220     */
 221     mw->data = 0;
 222     return ret;
 223 }
 224 void writer_growmemwrite_reset(writer_t*w)
 225 {
 226     struct growmemwrite_t*mw = (struct growmemwrite_t*)w->internal;
 227     w->pos = 0;
 228     w->bitpos = 0;
 229     w->mybyte = 0;
 230 }
 231 void writer_init_growingmemwriter(writer_t*w, U32 grow)
 232 {
 233     struct growmemwrite_t *mw;
 234     mw = (struct growmemwrite_t *)malloc(sizeof(struct growmemwrite_t));
 235     mw->length = 4096;
 236     mw->data = (unsigned char *)malloc(mw->length);
 237     mw->grow = grow;
 238     memset(w, 0, sizeof(writer_t));
 239     w->write = writer_growmemwrite_write;
 240     w->finish = writer_growmemwrite_finish;
 241     w->internal = (void*)mw;
 242     w->type = WRITER_TYPE_GROWING_MEM;
 243     w->bitpos = 0;
 244     w->mybyte = 0;
 245     w->pos = 0;
 246 }
 247
 248 /* ---------------------------- file writer ------------------------------- */
 249
 250 struct filewrite_t
 251 {
 252     int handle;
 253     char free_handle;
 254 };
 255
 256 static int writer_filewrite_write(writer_t*w, void* data, int len)
 257 {
 258     struct filewrite_t * fw= (struct filewrite_t*)w->internal;
 259     return write(fw->handle, data, len);
 260 }
 261 static void writer_filewrite_finish(writer_t*w)
 262 {
 263     struct filewrite_t *mr = (struct filewrite_t*)w->internal;
 264     if(mr->free_handle)
 265         close(mr->handle);
 266     free(w->internal);
 267     memset(w, 0, sizeof(writer_t));
 268 }
 269 void writer_init_filewriter(writer_t*w, int handle)
 270 {
 271     struct filewrite_t *mr = (struct filewrite_t *)malloc(sizeof(struct filewrite_t));
 272     mr->handle = handle;
 273     mr->free_handle = 0;
 274     memset(w, 0, sizeof(writer_t));
 275     w->write = writer_filewrite_write;
 276     w->finish = writer_filewrite_finish;
 277     w->internal = mr;
 278     w->type = WRITER_TYPE_FILE;
 279     w->bitpos = 0;
 280     w->mybyte = 0;
 281     w->pos = 0;
 282 }
 283 void writer_init_filewriter2(writer_t*w, char*filename)
 284 {
 285     int fi = open("movie.swf",
 286 #ifdef O_BINARY
 287             O_BINARY|
 288 #endif
 289             O_WRONLY|O_CREAT|O_TRUNC, 0644);
 290     writer_init_filewriter(w, fi);
 291     ((struct filewrite_t*)w->internal)->free_handle = 1;
 292 }
 293
 294 /* ---------------------------- null writer ------------------------------- */
 295
 296 static int writer_nullwrite_write(writer_t*w, void* data, int len)
 297 {
 298     w->pos += len;
 299     return len;
 300 }
 301 static void writer_nullwrite_finish(writer_t*w)
 302 {
 303     memset(w, 0, sizeof(writer_t));
 304 }
 305 void writer_init_nullwriter(writer_t*w)
 306 {
 307     memset(w, 0, sizeof(writer_t));
 308     w->write = writer_nullwrite_write;
 309     w->finish = writer_nullwrite_finish;
 310     w->internal = 0;
 311     w->type = WRITER_TYPE_NULL;
 312     w->bitpos = 0;
 313     w->mybyte = 0;
 314     w->pos = 0;
 315 }
 316 /* ---------------------------- zlibinflate reader -------------------------- */
 317
 318 struct zlibinflate_t
 319 {
 320 #ifdef HAVE_ZLIB
 321     z_stream zs;
 322     reader_t*input;
 323     unsigned char readbuffer[ZLIB_BUFFER_SIZE];
 324 #endif
 325 };
 326
 327 #ifdef HAVE_ZLIB
 328 static void zlib_error(int ret, char* msg, z_stream*zs)
 329 {
 330     fprintf(stderr, "%s: zlib error (%d): last zlib error: %s\n",
 331           msg,
 332           ret,
 333           zs->msg?zs->msg:"unknown");
 334     perror("errno:");
 335     exit(1);
 336 }
 337 #endif
 338
 339 static int reader_zlibinflate(reader_t*reader, void* data, int len)
 340 {
 341 #ifdef HAVE_ZLIB
 342     struct zlibinflate_t*z = (struct zlibinflate_t*)reader->internal;
 343     int ret;
 344     if(!z) {
 345         return 0;
 346     }
 347     if(!len)
 348         return 0;
 349
 350     z->zs.next_out = (Bytef *)data;
 351     z->zs.avail_out = len;
 352
 353     while(1) {
 354         if(!z->zs.avail_in) {
 355             z->zs.avail_in = z->input->read(z->input, z->readbuffer, ZLIB_BUFFER_SIZE);
 356             z->zs.next_in = z->readbuffer;
 357         }
 358         if(z->zs.avail_in)
 359             ret = inflate(&z->zs, Z_NO_FLUSH);
 360         else
 361             ret = inflate(&z->zs, Z_FINISH);
 362
 363         if (ret != Z_OK &&
 364             ret != Z_STREAM_END) zlib_error(ret, "bitio:inflate_inflate", &z->zs);
 365
 366         if (ret == Z_STREAM_END) {
 367                 int pos = z->zs.next_out - (Bytef*)data;
 368                 ret = inflateEnd(&z->zs);
 369                 if (ret != Z_OK) zlib_error(ret, "bitio:inflate_end", &z->zs);
 370                 free(reader->internal);
 371                 reader->internal = 0;
 372                 reader->pos += pos;
 373                 return pos;
 374         }
 375         if(!z->zs.avail_out) {
 376             break;
 377         }
 378     }
 379     reader->pos += len;
 380     return len;
 381 #else
 382     fprintf(stderr, "Error: swftools was compiled without zlib support");
 383     exit(1);
 384 #endif
 385 }
 386 static void reader_zlibinflate_dealloc(reader_t*reader)
 387 {
 388 #ifdef HAVE_ZLIB
 389     struct zlibinflate_t*z = (struct zlibinflate_t*)reader->internal;
 390     /* test whether read() already did basic deallocation */
 391     if(reader->internal) {
 392         inflateEnd(&z->zs);
 393         free(reader->internal);
 394     }
 395     memset(reader, 0, sizeof(reader_t));
 396 #endif
 397 }
 398 void reader_init_zlibinflate(reader_t*r, reader_t*input)
 399 {
 400 #ifdef HAVE_ZLIB
 401     struct zlibinflate_t*z;
 402     int ret;
 403     memset(r, 0, sizeof(reader_t));
 404     z = (struct zlibinflate_t*)malloc(sizeof(struct zlibinflate_t));
 405     memset(z, 0, sizeof(struct zlibinflate_t));
 406     r->internal = z;
 407     r->read = reader_zlibinflate;
 408     r->dealloc = reader_zlibinflate_dealloc;
 409     r->type = READER_TYPE_ZLIB;
 410     r->pos = 0;
 411     z->input = input;
 412     memset(&z->zs,0,sizeof(z_stream));
 413     z->zs.zalloc = Z_NULL;
 414     z->zs.zfree  = Z_NULL;
 415     z->zs.opaque = Z_NULL;
 416     ret = inflateInit(&z->zs);
 417     if (ret != Z_OK) zlib_error(ret, "bitio:inflate_init", &z->zs);
 418     reader_resetbits(r);
 419 #else
 420     fprintf(stderr, "Error: swftools was compiled without zlib support");
 421     exit(1);
 422 #endif
 423 }
 424
 425 /* ---------------------------- zlibdeflate writer -------------------------- */
 426
 427 struct zlibdeflate_t
 428 {
 429 #ifdef HAVE_ZLIB
 430     z_stream zs;
 431     writer_t*output;
 432     unsigned char writebuffer[ZLIB_BUFFER_SIZE];
 433 #endif
 434 };
 435
 436 static int writer_zlibdeflate_write(writer_t*writer, void* data, int len)
 437 {
 438 #ifdef HAVE_ZLIB
 439     struct zlibdeflate_t*z = (struct zlibdeflate_t*)writer->internal;
 440     int ret;
 441     if(writer->type != WRITER_TYPE_ZLIB) {
 442         fprintf(stderr, "Wrong writer ID (writer not initialized?)\n");
 443         return 0;
 444     }
 445     if(!z) {
 446         fprintf(stderr, "zlib not initialized!\n");
 447         return 0;
 448     }
 449     if(!len)
 450         return 0;
 451
 452     z->zs.next_in = (Bytef *)data;
 453     z->zs.avail_in = len;
 454
 455     while(1) {
 456         ret = deflate(&z->zs, Z_NO_FLUSH);
 457
 458         if (ret != Z_OK) zlib_error(ret, "bitio:deflate_deflate", &z->zs);
 459
 460         if(z->zs.next_out != z->writebuffer) {
 461             z->output->write(z->output, z->writebuffer, z->zs.next_out - (Bytef*)z->writebuffer);
 462             z->zs.next_out = z->writebuffer;
 463             z->zs.avail_out = ZLIB_BUFFER_SIZE;
 464         }
 465
 466         if(!z->zs.avail_in) {
 467             break;
 468         }
 469     }
 470     writer->pos += len;
 471     return len;
 472 #else
 473     fprintf(stderr, "Error: swftools was compiled without zlib support");
 474     exit(1);
 475 #endif
 476 }
 477 static void writer_zlibdeflate_finish(writer_t*writer)
 478 {
 479 #ifdef HAVE_ZLIB
 480     struct zlibdeflate_t*z = (struct zlibdeflate_t*)writer->internal;
 481     writer_t*output;
 482     int ret;
 483     if(writer->type != WRITER_TYPE_ZLIB) {
 484         fprintf(stderr, "Wrong writer ID (writer not initialized?)\n");
 485         return;
 486     }
 487     if(!z)
 488         return;
 489     output= z->output;
 490     while(1) {
 491         ret = deflate(&z->zs, Z_FINISH);
 492         if (ret != Z_OK &&
 493             ret != Z_STREAM_END) zlib_error(ret, "bitio:deflate_finish", &z->zs);
 494
 495         if(z->zs.next_out != z->writebuffer) {
 496             z->output->write(z->output, z->writebuffer, z->zs.next_out - (Bytef*)z->writebuffer);
 497             z->zs.next_out = z->writebuffer;
 498             z->zs.avail_out = ZLIB_BUFFER_SIZE;
 499         }
 500
 501         if (ret == Z_STREAM_END) {
 502             break;
 503
 504         }
 505     }
 506     ret = deflateEnd(&z->zs);
 507     if (ret != Z_OK) zlib_error(ret, "bitio:deflate_end", &z->zs);
 508     free(writer->internal);
 509     memset(writer, 0, sizeof(writer_t));
 510     //output->finish(output);
 511 #else
 512     fprintf(stderr, "Error: swftools was compiled without zlib support");
 513     exit(1);
 514 #endif
 515 }
 516 void writer_init_zlibdeflate(writer_t*w, writer_t*output)
 517 {
 518 #ifdef HAVE_ZLIB
 519     struct zlibdeflate_t*z;
 520     int ret;
 521     memset(w, 0, sizeof(writer_t));
 522     z = (struct zlibdeflate_t*)malloc(sizeof(struct zlibdeflate_t));
 523     memset(z, 0, sizeof(struct zlibdeflate_t));
 524     w->internal = z;
 525     w->write = writer_zlibdeflate_write;
 526     w->finish = writer_zlibdeflate_finish;
 527     w->type = WRITER_TYPE_ZLIB;
 528     w->pos = 0;
 529     z->output = output;
 530     memset(&z->zs,0,sizeof(z_stream));
 531     z->zs.zalloc = Z_NULL;
 532     z->zs.zfree  = Z_NULL;
 533     z->zs.opaque = Z_NULL;
 534     ret = deflateInit(&z->zs, 9);
 535     if (ret != Z_OK) zlib_error(ret, "bitio:deflate_init", &z->zs);
 536     w->bitpos = 0;
 537     w->mybyte = 0;
 538     z->zs.next_out = z->writebuffer;
 539     z->zs.avail_out = ZLIB_BUFFER_SIZE;
 540 #else
 541     fprintf(stderr, "Error: swftools was compiled without zlib support");
 542     exit(1);
 543 #endif
 544 }
 545
 546 /* ----------------------- bit handling routines -------------------------- */
 547
 548 void writer_writebit(writer_t*w, int bit)
 549 {
 550     if(w->bitpos==8)
 551     {
 552         w->write(w, &w->mybyte, 1);
 553         w->bitpos = 0;
 554         w->mybyte = 0;
 555     }
 556     if(bit&1)
 557         w->mybyte |= 1 << (7 - w->bitpos);
 558     w->bitpos ++;
 559 }
 560 void writer_writebits(writer_t*w, unsigned int data, int bits)
 561 {
 562     int t;
 563     for(t=0;t<bits;t++)
 564     {
 565         writer_writebit(w, (data >> (bits-t-1))&1);
 566     }
 567 }
 568 void writer_resetbits(writer_t*w)
 569 {
 570     if(w->bitpos)
 571         w->write(w, &w->mybyte, 1);
 572     w->bitpos = 0;
 573     w->mybyte = 0;
 574 }
 575
 576 unsigned int reader_readbit(reader_t*r)
 577 {
 578     if(r->bitpos==8)
 579     {
 580         r->bitpos=0;
 581         r->read(r, &r->mybyte, 1);
 582     }
 583     return (r->mybyte>>(7-r->bitpos++))&1;
 584 }
 585 unsigned int reader_readbits(reader_t*r, int num)
 586 {
 587     int t;
 588     int val = 0;
 589     for(t=0;t<num;t++)
 590     {
 591         val<<=1;
 592         val|=reader_readbit(r);
 593     }
 594     return val;
 595 }
 596 void reader_resetbits(reader_t*r)
 597 {
 598     r->mybyte = 0;
 599     r->bitpos = 8;
 600
 601 }
 602
 603 U8 reader_readU8(reader_t*r)
 604 {
 605     U8 b = 0;
 606     if(r->read(r, &b, 1)<1) {
 607         fprintf(stderr, "bitio.c:reader_readU8: Read over end of memory region\n");
 608     }
 609     return b;
 610 }
 611 U16 reader_readU16(reader_t*r)
 612 {
 613     U8 b1=0,b2=0;
 614     if(r->read(r, &b1, 1)<1) {
 615         fprintf(stderr, "bitio.c:reader_readU16: Read over end of memory region\n");
 616     }
 617     if(r->read(r, &b2, 1)<1) {
 618         fprintf(stderr, "bitio.c:reader_readU16: Read over end of memory region\n");
 619     }
 620     return b1|b2<<8;
 621 }
 622 U32 reader_readU32(reader_t*r)
 623 {
 624     U8 b1=0,b2=0,b3=0,b4=0;
 625     if(r->read(r, &b1, 1)<1)
 626         fprintf(stderr, "bitio.c:reader_readU32: Read over end of memory region\n");
 627     if(r->read(r, &b2, 1)<1)
 628         fprintf(stderr, "bitio.c:reader_readU32: Read over end of memory region\n");
 629     if(r->read(r, &b3, 1)<1)
 630         fprintf(stderr, "bitio.c:reader_readU32: Read over end of memory region\n");
 631     if(r->read(r, &b4, 1)<1)
 632         fprintf(stderr, "bitio.c:reader_readU32: Read over end of memory region\n");
 633     return b1|b2<<8|b3<<16|b4<<24;
 634 }
 635 float reader_readFloat(reader_t*r)
 636 {
 637     U8 b1=0,b2=0,b3=0,b4=0;
 638     r->read(r, &b1, 1);
 639     r->read(r, &b2, 1);
 640     r->read(r, &b3, 1);
 641     r->read(r, &b4, 1);
 642     U32 w = (b1|b2<<8|b3<<16|b4<<24);
 643     return *(float*)&w;
 644 }
 645 double reader_readDouble(reader_t*r)
 646 {
 647     double f;
 648     r->read(r, &f, 8);
 649     return f;
 650
 651     U8 b[8];
 652     r->read(r, b, 8);
 653     U64 w = ((U64)b[0]|(U64)b[1]<<8|(U64)b[2]<<16|(U64)b[3]<<24|(U64)b[4]<<32|(U64)b[5]<<40|(U64)b[6]<<48|(U64)b[7]<<56);
 654     return *(double*)&w;
 655 }
 656 char*reader_readString(reader_t*r)
 657 {
 658     writer_t g;
 659     writer_init_growingmemwriter(&g, 16);
 660     while(1) {
 661         U8 b = reader_readU8(r);
 662         writer_writeU8(&g, b);
 663         if(!b)
 664             break;
 665     }
 666     char*string = (char*)writer_growmemwrite_getmem(&g);
 667     g.finish(&g);
 668     return string;
 669 }
 670
 671 void writer_writeString(writer_t*w, const char*s)
 672 {
 673     int l = strlen(s);
 674     char zero = 0;
 675     w->write(w, (void*)s, l);
 676     w->write(w, &zero, 1);
 677 }
 678 void writer_writeU8(writer_t*w, unsigned char b)
 679 {
 680     w->write(w, &b, 1);
 681 }
 682 void writer_writeU16(writer_t*w, unsigned short v)
 683 {
 684     unsigned char b1 = v;
 685     unsigned char b2 = v>>8;
 686     w->write(w, &b1, 1);
 687     w->write(w, &b2, 1);
 688 }
 689 void writer_writeU32(writer_t*w, unsigned long v)
 690 {
 691     unsigned char b1 = v;
 692     unsigned char b2 = v>>8;
 693     unsigned char b3 = v>>16;
 694     unsigned char b4 = v>>24;
 695     w->write(w, &b1, 1);
 696     w->write(w, &b2, 1);
 697     w->write(w, &b3, 1);
 698     w->write(w, &b4, 1);
 699 }
 700 void writer_writeFloat(writer_t*w, float f)
 701 {
 702     unsigned long v = *(unsigned long*)&f;
 703     unsigned char b1 = v;
 704     unsigned char b2 = v>>8;
 705     unsigned char b3 = v>>16;
 706     unsigned char b4 = v>>24;
 707     w->write(w, &b1, 1);
 708     w->write(w, &b2, 1);
 709     w->write(w, &b3, 1);
 710     w->write(w, &b4, 1);
 711 }
 712 void writer_writeDouble(writer_t*w, double f)
 713 {
 714     w->write(w, &f, 8);
 715     return;
 716
 717     unsigned long long v = *(unsigned long long*)&f;
 718     unsigned char b1 = v;
 719     unsigned char b2 = v>>8;
 720     unsigned char b3 = v>>16;
 721     unsigned char b4 = v>>24;
 722     unsigned char b5 = v>>32;
 723     unsigned char b6 = v>>40;
 724     unsigned char b7 = v>>48;
 725     unsigned char b8 = v>>56;
 726     w->write(w, &b1, 1);
 727     w->write(w, &b2, 1);
 728     w->write(w, &b3, 1);
 729     w->write(w, &b4, 1);
 730     w->write(w, &b5, 1);
 731     w->write(w, &b6, 1);
 732     w->write(w, &b7, 1);
 733     w->write(w, &b8, 1);
 734 }