granicus.if.org Git - imagemagick/blob - coders/webp.c

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %                                                                             %
   6 %                         W   W  EEEEE  BBBB   PPPP                           %
   7 %                         W   W  E      B   B  P   P                          %
   8 %                         W W W  EEE    BBBB   PPPP                           %
   9 %                         WW WW  E      B   B  P                              %
  10 %                         W   W  EEEEE  BBBB   P                              %
  11 %                                                                             %
  12 %                                                                             %
  13 %                         Read/Write WebP Image Format                        %
  14 %                                                                             %
  15 %                              Software Design                                %
  16 %                                John Cristy                                  %
  17 %                                 March 2011                                  %
  18 %                                                                             %
  19 %                                                                             %
  20 %  Copyright 1999-2013 ImageMagick Studio LLC, a non-profit organization      %
  21 %  dedicated to making software imaging solutions freely available.           %
  22 %                                                                             %
  23 %  You may not use this file except in compliance with the License.  You may  %
  24 %  obtain a copy of the License at                                            %
  25 %                                                                             %
  26 %    http://www.imagemagick.org/script/license.php                            %
  27 %                                                                             %
  28 %  Unless required by applicable law or agreed to in writing, software        %
  29 %  distributed under the License is distributed on an "AS IS" BASIS,          %
  30 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
  31 %  See the License for the specific language governing permissions and        %
  32 %  limitations under the License.                                             %
  33 %                                                                             %
  34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  35 %
  36 %
  37 */
  38 \f
  39 /*
  40   Include declarations.
  41 */
  42 #include "MagickCore/studio.h"
  43 #include "MagickCore/artifact.h"
  44 #include "MagickCore/blob.h"
  45 #include "MagickCore/blob-private.h"
  46 #include "MagickCore/client.h"
  47 #include "MagickCore/colorspace-private.h"
  48 #include "MagickCore/display.h"
  49 #include "MagickCore/exception.h"
  50 #include "MagickCore/exception-private.h"
  51 #include "MagickCore/image.h"
  52 #include "MagickCore/image-private.h"
  53 #include "MagickCore/list.h"
  54 #include "MagickCore/magick.h"
  55 #include "MagickCore/monitor.h"
  56 #include "MagickCore/monitor-private.h"
  57 #include "MagickCore/memory_.h"
  58 #include "MagickCore/option.h"
  59 #include "MagickCore/pixel-accessor.h"
  60 #include "MagickCore/quantum-private.h"
  61 #include "MagickCore/static.h"
  62 #include "MagickCore/string_.h"
  63 #include "MagickCore/string-private.h"
  64 #include "MagickCore/module.h"
  65 #include "MagickCore/utility.h"
  66 #include "MagickCore/xwindow.h"
  67 #include "MagickCore/xwindow-private.h"
  68 #if defined(MAGICKCORE_WEBP_DELEGATE)
  69 #include <webp/decode.h>
  70 #include <webp/encode.h>
  71 #endif
  72 \f
  73 /*
  74   Forward declarations.
  75 */
  76 #if defined(MAGICKCORE_WEBP_DELEGATE)
  77 static MagickBooleanType
  78   WriteWEBPImage(const ImageInfo *,Image *,ExceptionInfo *);
  79 #endif
  80 \f
  81 /*
  82 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  83 %                                                                             %
  84 %                                                                             %
  85 %                                                                             %
  86 %   I s W E B P                                                               %
  87 %                                                                             %
  88 %                                                                             %
  89 %                                                                             %
  90 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  91 %
  92 %  IsWEBP() returns MagickTrue if the image format type, identified by the
  93 %  magick string, is WebP.
  94 %
  95 %  The format of the IsWEBP method is:
  96 %
  97 %      MagickBooleanType IsWEBP(const unsigned char *magick,const size_t length)
  98 %
  99 %  A description of each parameter follows:
 100 %
 101 %    o magick: compare image format pattern against these bytes.
 102 %
 103 %    o length: Specifies the length of the magick string.
 104 %
 105 */
 106 static MagickBooleanType IsWEBP(const unsigned char *magick,const size_t length)
 107 {
 108   if (length < 12)
 109     return(MagickFalse);
 110   if (LocaleNCompare((const char *) magick+8,"WEBP",4) == 0)
 111     return(MagickTrue);
 112   return(MagickFalse);
 113 }
 114 \f
 115 #if defined(MAGICKCORE_WEBP_DELEGATE)
 116 /*
 117 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 118 %                                                                             %
 119 %                                                                             %
 120 %                                                                             %
 121 %   R e a d W E B P I m a g e                                                 %
 122 %                                                                             %
 123 %                                                                             %
 124 %                                                                             %
 125 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 126 %
 127 %  ReadWEBPImage() reads an image in the WebP image format.
 128 %
 129 %  The format of the ReadWEBPImage method is:
 130 %
 131 %      Image *ReadWEBPImage(const ImageInfo *image_info,
 132 %        ExceptionInfo *exception)
 133 %
 134 %  A description of each parameter follows:
 135 %
 136 %    o image_info: the image info.
 137 %
 138 %    o exception: return any errors or warnings in this structure.
 139 %
 140 */
 141
 142 static inline uint32_t ReadWebPLSBWord(const unsigned char *restrict data)
 143 {
 144   register const unsigned char
 145     *p;
 146
 147   register uint32_t
 148     value;
 149
 150   p=data;
 151   value=(uint32_t) (*p++);
 152   value|=((uint32_t) (*p++)) << 8;
 153   value|=((uint32_t) (*p++)) << 16;
 154   value|=((uint32_t) (*p++)) << 24;
 155   return(value);
 156 }
 157
 158 static MagickBooleanType IsWEBPImageLossless(const unsigned char *stream,
 159   const size_t length)
 160 {
 161 #define VP8_CHUNK_INDEX  15
 162 #define LOSSLESS_FLAG  'L'
 163 #define EXTENDED_HEADER  'X'
 164 #define VP8_CHUNK_HEADER  "VP8"
 165 #define VP8_CHUNK_HEADER_SIZE  3
 166 #define RIFF_HEADER_SIZE  12
 167 #define VP8X_CHUNK_SIZE  10
 168 #define TAG_SIZE  4
 169 #define CHUNK_SIZE_BYTES  4
 170 #define CHUNK_HEADER_SIZE  8
 171 #define MAX_CHUNK_PAYLOAD  (~0U-CHUNK_HEADER_SIZE-1)
 172
 173   ssize_t
 174     offset;
 175
 176   /*
 177     Read simple header.
 178   */
 179   if (stream[VP8_CHUNK_INDEX] != EXTENDED_HEADER)
 180     return(stream[VP8_CHUNK_INDEX] == LOSSLESS_FLAG ? MagickTrue : MagickFalse);
 181   /*
 182     Read extended header.
 183   */
 184   offset=RIFF_HEADER_SIZE+TAG_SIZE+CHUNK_SIZE_BYTES+VP8X_CHUNK_SIZE;
 185   while (offset <= (ssize_t) length)
 186   {
 187     uint32_t
 188       chunk_size,
 189       chunk_size_pad;
 190
 191     chunk_size=ReadWebPLSBWord(stream+offset+TAG_SIZE);
 192     if (chunk_size > MAX_CHUNK_PAYLOAD)
 193       break;
 194     chunk_size_pad=(CHUNK_HEADER_SIZE+chunk_size+1) & ~1;
 195     if (memcmp(stream+offset,VP8_CHUNK_HEADER,VP8_CHUNK_HEADER_SIZE) == 0)
 196       return(*(stream+offset+VP8_CHUNK_HEADER_SIZE) == LOSSLESS_FLAG ?
 197         MagickTrue : MagickFalse);
 198     offset+=chunk_size_pad;
 199   }
 200   return(MagickFalse);
 201 }
 202
 203 static Image *ReadWEBPImage(const ImageInfo *image_info,
 204   ExceptionInfo *exception)
 205 {
 206   Image
 207     *image;
 208
 209   int
 210     webp_status;
 211
 212   MagickBooleanType
 213     status;
 214
 215   register unsigned char
 216     *p;
 217
 218   size_t
 219     length;
 220
 221   ssize_t
 222     count,
 223     y;
 224
 225   unsigned char
 226     *stream;
 227
 228   WebPDecoderConfig
 229     configure;
 230
 231   WebPDecBuffer
 232     *restrict webp_image = &configure.output;
 233
 234   WebPBitstreamFeatures
 235     *restrict features = &configure.input;
 236
 237   /*
 238     Open image file.
 239   */
 240   assert(image_info != (const ImageInfo *) NULL);
 241   assert(image_info->signature == MagickSignature);
 242   if (image_info->debug != MagickFalse)
 243     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 244       image_info->filename);
 245   assert(exception != (ExceptionInfo *) NULL);
 246   assert(exception->signature == MagickSignature);
 247   image=AcquireImage(image_info,exception);
 248   status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
 249   if (status == MagickFalse)
 250     {
 251       image=DestroyImageList(image);
 252       return((Image *) NULL);
 253     }
 254   if (WebPInitDecoderConfig(&configure) == 0)
 255     ThrowReaderException(ResourceLimitError,"UnableToDecodeImageFile");
 256   webp_image->colorspace=MODE_RGBA;
 257   length=(size_t) GetBlobSize(image);
 258   stream=(unsigned char *) AcquireQuantumMemory(length,sizeof(*stream));
 259   if (stream == (unsigned char *) NULL)
 260     ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 261   count=ReadBlob(image,length,stream);
 262   if (count != (ssize_t) length)
 263     ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
 264   webp_status=WebPGetFeatures(stream,length,features);
 265   if (webp_status == VP8_STATUS_OK)
 266     {
 267       image->columns=(size_t) features->width;
 268       image->rows=(size_t) features->height;
 269       image->depth=8;
 270       image->alpha_trait=features->has_alpha != 0 ? BlendPixelTrait :
 271         UndefinedPixelTrait;
 272       if (image_info->ping != MagickFalse)
 273         {
 274           stream=(unsigned char*) RelinquishMagickMemory(stream);
 275           (void) CloseBlob(image);
 276           return(GetFirstImageInList(image));
 277         }
 278       webp_status=WebPDecode(stream,length,&configure);
 279     }
 280   if (webp_status != VP8_STATUS_OK)
 281     {
 282       stream=(unsigned char*) RelinquishMagickMemory(stream);
 283       switch (webp_status)
 284       {
 285         case VP8_STATUS_OUT_OF_MEMORY:
 286         {
 287           ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
 288           break;
 289         }
 290         case VP8_STATUS_BITSTREAM_ERROR:
 291         {
 292           ThrowReaderException(CorruptImageError,"CorruptImage");
 293           break;
 294         }
 295         case VP8_STATUS_UNSUPPORTED_FEATURE:
 296         {
 297           ThrowReaderException(CoderError,"DataEncodingSchemeIsNotSupported");
 298           break;
 299         }
 300         case VP8_STATUS_NOT_ENOUGH_DATA:
 301         {
 302           ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
 303           break;
 304         }
 305         default:
 306           ThrowReaderException(CorruptImageError,"CorruptImage");
 307       }
 308     }
 309   if (IsWEBPImageLossless(stream,length) != MagickFalse)
 310     image->quality=100;
 311   p=webp_image->u.RGBA.rgba;
 312   for (y=0; y < (ssize_t) image->rows; y++)
 313   {
 314     register Quantum
 315       *q;
 316
 317     register ssize_t
 318       x;
 319
 320     q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
 321     if (q == (Quantum *) NULL)
 322       break;
 323     for (x=0; x < (ssize_t) image->columns; x++)
 324     {
 325       SetPixelRed(image,ScaleCharToQuantum(*p++),q);
 326       SetPixelGreen(image,ScaleCharToQuantum(*p++),q);
 327       SetPixelBlue(image,ScaleCharToQuantum(*p++),q);
 328       SetPixelAlpha(image,ScaleCharToQuantum(*p++),q);
 329       q+=GetPixelChannels(image);
 330     }
 331     if (SyncAuthenticPixels(image,exception) == MagickFalse)
 332       break;
 333     status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
 334       image->rows);
 335     if (status == MagickFalse)
 336       break;
 337   }
 338   WebPFreeDecBuffer(webp_image);
 339   stream=(unsigned char*) RelinquishMagickMemory(stream);
 340   return(image);
 341 }
 342 #endif
 343 \f
 344 /*
 345 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 346 %                                                                             %
 347 %                                                                             %
 348 %                                                                             %
 349 %   R e g i s t e r W E B P I m a g e                                         %
 350 %                                                                             %
 351 %                                                                             %
 352 %                                                                             %
 353 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 354 %
 355 %  RegisterWEBPImage() adds attributes for the WebP image format to
 356 %  the list of supported formats.  The attributes include the image format
 357 %  tag, a method to read and/or write the format, whether the format
 358 %  supports the saving of more than one frame to the same file or blob,
 359 %  whether the format supports native in-memory I/O, and a brief
 360 %  description of the format.
 361 %
 362 %  The format of the RegisterWEBPImage method is:
 363 %
 364 %      size_t RegisterWEBPImage(void)
 365 %
 366 */
 367 ModuleExport size_t RegisterWEBPImage(void)
 368 {
 369   char
 370     version[MaxTextExtent];
 371
 372   MagickInfo
 373     *entry;
 374
 375   *version='\0';
 376   entry=SetMagickInfo("WEBP");
 377 #if defined(MAGICKCORE_WEBP_DELEGATE)
 378   entry->decoder=(DecodeImageHandler *) ReadWEBPImage;
 379   entry->encoder=(EncodeImageHandler *) WriteWEBPImage;
 380   (void) FormatLocaleString(version,MaxTextExtent,"libwebp %d.%d.%d",
 381     (WebPGetDecoderVersion() >> 16) & 0xff,
 382     (WebPGetDecoderVersion() >> 8) & 0xff,
 383     (WebPGetDecoderVersion() >> 0) & 0xff);
 384 #endif
 385   entry->description=ConstantString("WebP Image Format");
 386   entry->mime_type=ConstantString("image/x-webp");
 387   entry->adjoin=MagickFalse;
 388   entry->module=ConstantString("WEBP");
 389   entry->magick=(IsImageFormatHandler *) IsWEBP;
 390   if (*version != '\0')
 391     entry->version=ConstantString(version);
 392   (void) RegisterMagickInfo(entry);
 393   return(MagickImageCoderSignature);
 394 }
 395 \f
 396 /*
 397 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 398 %                                                                             %
 399 %                                                                             %
 400 %                                                                             %
 401 %   U n r e g i s t e r W E B P I m a g e                                     %
 402 %                                                                             %
 403 %                                                                             %
 404 %                                                                             %
 405 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 406 %
 407 %  UnregisterWEBPImage() removes format registrations made by the WebP module
 408 %  from the list of supported formats.
 409 %
 410 %  The format of the UnregisterWEBPImage method is:
 411 %
 412 %      UnregisterWEBPImage(void)
 413 %
 414 */
 415 ModuleExport void UnregisterWEBPImage(void)
 416 {
 417   (void) UnregisterMagickInfo("WEBP");
 418 }
 419 #if defined(MAGICKCORE_WEBP_DELEGATE)
 420 \f
 421 /*
 422 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 423 %                                                                             %
 424 %                                                                             %
 425 %                                                                             %
 426 %   W r i t e W E B P I m a g e                                               %
 427 %                                                                             %
 428 %                                                                             %
 429 %                                                                             %
 430 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 431 %
 432 %  WriteWEBPImage() writes an image in the WebP image format.
 433 %
 434 %  The format of the WriteWEBPImage method is:
 435 %
 436 %      MagickBooleanType WriteWEBPImage(const ImageInfo *image_info,
 437 %        Image *image)
 438 %
 439 %  A description of each parameter follows.
 440 %
 441 %    o image_info: the image info.
 442 %
 443 %    o image:  The image.
 444 %
 445 */
 446
 447 static int WebPWriter(const unsigned char *stream,size_t length,
 448   const WebPPicture *const picture)
 449 {
 450   Image
 451     *image;
 452
 453   image=(Image *) picture->custom_ptr;
 454   return(length != 0 ? (int) WriteBlob(image,length,stream) : 1);
 455 }
 456
 457 static MagickBooleanType WriteWEBPImage(const ImageInfo *image_info,
 458   Image *image,ExceptionInfo *exception)
 459 {
 460   const char
 461     *value;
 462
 463   int
 464     webp_status;
 465
 466   MagickBooleanType
 467     status;
 468
 469   MemoryInfo
 470     *pixel_info;
 471
 472   register uint32_t
 473     *restrict q;
 474
 475   ssize_t
 476     y;
 477
 478   WebPConfig
 479     configure;
 480
 481   WebPPicture
 482     picture;
 483
 484   WebPAuxStats
 485     statistics;
 486
 487   /*
 488     Open output image file.
 489   */
 490   assert(image_info != (const ImageInfo *) NULL);
 491   assert(image_info->signature == MagickSignature);
 492   assert(image != (Image *) NULL);
 493   assert(image->signature == MagickSignature);
 494   if (image->debug != MagickFalse)
 495     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 496   if ((image->columns > 16383UL) || (image->rows > 16383UL))
 497     ThrowWriterException(ImageError,"WidthOrHeightExceedsLimit");
 498   status=OpenBlob(image_info,image,WriteBinaryBlobMode,exception);
 499   if (status == MagickFalse)
 500     return(status);
 501   if ((WebPPictureInit(&picture) == 0) || (WebPConfigInit(&configure) == 0))
 502     ThrowWriterException(ResourceLimitError,"UnableToEncodeImageFile");
 503   picture.writer=WebPWriter;
 504   picture.custom_ptr=(void *) image;
 505   picture.stats=(&statistics);
 506   picture.width=(int) image->columns;
 507   picture.height=(int) image->rows;
 508   picture.argb_stride=(int) image->columns;
 509   picture.use_argb=1;
 510   if (image->quality != UndefinedCompressionQuality)
 511     configure.quality=(float) image->quality;
 512   else
 513     if (image->quality >= 100)
 514       configure.lossless=1;
 515   value=GetImageOption(image_info,"webp:lossless");
 516   if (value != (char *) NULL)
 517     configure.lossless=ParseCommandOption(MagickBooleanOptions,MagickFalse,
 518       value);
 519   value=GetImageOption(image_info,"webp:method");
 520   if (value != (char *) NULL)
 521     configure.method=StringToInteger(value);
 522   value=GetImageOption(image_info,"webp:image-hint");
 523   if (value != (char *) NULL)
 524     {
 525       if (LocaleCompare(value,"graph") == 0)
 526         configure.image_hint=WEBP_HINT_GRAPH;
 527       if (LocaleCompare(value,"photo") == 0)
 528         configure.image_hint=WEBP_HINT_PHOTO;
 529       if (LocaleCompare(value,"picture") == 0)
 530         configure.image_hint=WEBP_HINT_PICTURE;
 531     }
 532   value=GetImageOption(image_info,"webp:target-size");
 533   if (value != (char *) NULL)
 534     configure.target_size=StringToInteger(value);
 535   value=GetImageOption(image_info,"webp:target-psnr");
 536   if (value != (char *) NULL)
 537     configure.target_PSNR=(float) StringToDouble(value,(char **) NULL);
 538   value=GetImageOption(image_info,"webp:segments");
 539   if (value != (char *) NULL)
 540     configure.segments=StringToInteger(value);
 541   value=GetImageOption(image_info,"webp:sns-strength");
 542   if (value != (char *) NULL)
 543     configure.sns_strength=StringToInteger(value);
 544   value=GetImageOption(image_info,"webp:filter-strength");
 545   if (value != (char *) NULL)
 546     configure.filter_strength=StringToInteger(value);
 547   value=GetImageOption(image_info,"webp:filter-sharpness");
 548   if (value != (char *) NULL)
 549     configure.filter_sharpness=StringToInteger(value);
 550   value=GetImageOption(image_info,"webp:filter-type");
 551   if (value != (char *) NULL)
 552     configure.filter_type=StringToInteger(value);
 553   value=GetImageOption(image_info,"webp:auto-filter");
 554   if (value != (char *) NULL)
 555     configure.autofilter=ParseCommandOption(MagickBooleanOptions,MagickFalse,
 556       value);
 557   value=GetImageOption(image_info,"webp:alpha-compression");
 558   if (value != (char *) NULL)
 559     configure.alpha_compression=StringToInteger(value);
 560   value=GetImageOption(image_info,"webp:alpha-filtering");
 561   if (value != (char *) NULL)
 562     configure.alpha_filtering=StringToInteger(value);
 563   value=GetImageOption(image_info,"webp:alpha-quality");
 564   if (value != (char *) NULL)
 565     configure.alpha_quality=StringToInteger(value);
 566   value=GetImageOption(image_info,"webp:pass");
 567   if (value != (char *) NULL)
 568     configure.pass=StringToInteger(value);
 569   value=GetImageOption(image_info,"webp:show-compressed");
 570   if (value != (char *) NULL)
 571     configure.show_compressed=StringToInteger(value);
 572   value=GetImageOption(image_info,"webp:preprocessing");
 573   if (value != (char *) NULL)
 574     configure.preprocessing=StringToInteger(value);
 575   value=GetImageOption(image_info,"webp:partitions");
 576   if (value != (char *) NULL)
 577     configure.partitions=StringToInteger(value);
 578   value=GetImageOption(image_info,"webp:partition-limit");
 579   if (value != (char *) NULL)
 580     configure.partition_limit=StringToInteger(value);
 581   if (WebPValidateConfig(&configure) == 0)
 582     ThrowWriterException(ResourceLimitError,"UnableToEncodeImageFile");
 583   /*
 584     Allocate memory for pixels.
 585   */
 586   (void) TransformImageColorspace(image,sRGBColorspace,exception);
 587   pixel_info=AcquireVirtualMemory(image->columns,image->rows*
 588     sizeof(*picture.argb));
 589   if (pixel_info == (MemoryInfo *) NULL)
 590     ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
 591   picture.argb=(uint32_t *) GetVirtualMemoryBlob(pixel_info);
 592   /*
 593     Convert image to WebP raster pixels.
 594   */
 595   q=picture.argb;
 596   for (y=0; y < (ssize_t) image->rows; y++)
 597   {
 598     register const Quantum
 599       *restrict p;
 600
 601     register ssize_t
 602       x;
 603
 604     p=GetVirtualPixels(image,0,y,image->columns,1,exception);
 605     if (p == (const Quantum *) NULL)
 606       break;
 607     for (x=0; x < (ssize_t) image->columns; x++)
 608     {
 609       *q++=(uint32_t) (image->alpha_trait == BlendPixelTrait ?
 610         ScaleQuantumToChar(GetPixelAlpha(image,p)) << 24 : 0xff000000) |
 611         (ScaleQuantumToChar(GetPixelRed(image,p)) << 16) |
 612         (ScaleQuantumToChar(GetPixelGreen(image,p)) << 8) |
 613         (ScaleQuantumToChar(GetPixelBlue(image,p)));
 614       p+=GetPixelChannels(image);
 615     }
 616     status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
 617       image->rows);
 618     if (status == MagickFalse)
 619       break;
 620   }
 621   webp_status=WebPEncode(&configure,&picture);
 622   WebPPictureFree(&picture);
 623   pixel_info=RelinquishVirtualMemory(pixel_info);
 624   (void) CloseBlob(image);
 625   return(webp_status == 0 ? MagickFalse : MagickTrue);
 626 }
 627 #endif