dlls/windowscodecs/jpegformat.c

   1 /*
   2  * Copyright 2009 Vincent Povirk for CodeWeavers
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include "config.h"
  20 #include "wine/port.h"
  21
  22 #ifdef HAVE_UNISTD_H
  23 # include <unistd.h>
  24 #endif
  25 #include <stdarg.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28
  29 #ifdef SONAME_LIBJPEG
  30 /* This is a hack, so jpeglib.h does not redefine INT32 and the like*/
  31 #define XMD_H
  32 #define UINT8 JPEG_UINT8
  33 #define UINT16 JPEG_UINT16
  34 #define boolean jpeg_boolean
  35 #undef HAVE_STDLIB_H
  36 # include <jpeglib.h>
  37 #undef HAVE_STDLIB_H
  38 #define HAVE_STDLIB_H 1
  39 #undef UINT8
  40 #undef UINT16
  41 #undef boolean
  42 #endif
  43
  44 #define COBJMACROS
  45
  46 #include "windef.h"
  47 #include "winbase.h"
  48 #include "objbase.h"
  49 #include "wincodec.h"
  50
  51 #include "wincodecs_private.h"
  52
  53 #include "wine/debug.h"
  54 #include "wine/library.h"
  55
  56 WINE_DEFAULT_DEBUG_CHANNEL(wincodecs);
  57
  58 #ifdef SONAME_LIBJPEG
  59
  60 static void *libjpeg_handle;
  61
  62 #define MAKE_FUNCPTR(f) static typeof(f) * p##f
  63 MAKE_FUNCPTR(jpeg_CreateDecompress);
  64 MAKE_FUNCPTR(jpeg_destroy_decompress);
  65 MAKE_FUNCPTR(jpeg_read_header);
  66 MAKE_FUNCPTR(jpeg_read_scanlines);
  67 MAKE_FUNCPTR(jpeg_resync_to_restart);
  68 MAKE_FUNCPTR(jpeg_start_decompress);
  69 MAKE_FUNCPTR(jpeg_std_error);
  70 #undef MAKE_FUNCPTR
  71
  72 static void *load_libjpeg(void)
  73 {
  74     if((libjpeg_handle = wine_dlopen(SONAME_LIBJPEG, RTLD_NOW, NULL, 0)) != NULL) {
  75
  76 #define LOAD_FUNCPTR(f) \
  77     if((p##f = wine_dlsym(libjpeg_handle, #f, NULL, 0)) == NULL) { \
  78         libjpeg_handle = NULL; \
  79         return NULL; \
  80     }
  81
  82         LOAD_FUNCPTR(jpeg_CreateDecompress);
  83         LOAD_FUNCPTR(jpeg_destroy_decompress);
  84         LOAD_FUNCPTR(jpeg_read_header);
  85         LOAD_FUNCPTR(jpeg_read_scanlines);
  86         LOAD_FUNCPTR(jpeg_resync_to_restart);
  87         LOAD_FUNCPTR(jpeg_start_decompress);
  88         LOAD_FUNCPTR(jpeg_std_error);
  89 #undef LOAD_FUNCPTR
  90     }
  91     return libjpeg_handle;
  92 }
  93
  94 typedef struct {
  95     const IWICBitmapDecoderVtbl *lpVtbl;
  96     const IWICBitmapFrameDecodeVtbl *lpFrameVtbl;
  97     LONG ref;
  98     BOOL initialized;
  99     BOOL cinfo_initialized;
 100     IStream *stream;
 101     struct jpeg_decompress_struct cinfo;
 102     struct jpeg_error_mgr jerr;
 103     struct jpeg_source_mgr source_mgr;
 104     BYTE source_buffer[1024];
 105     BYTE *image_data;
 106     CRITICAL_SECTION lock;
 107 } JpegDecoder;
 108
 109 static inline JpegDecoder *decoder_from_decompress(j_decompress_ptr decompress)
 110 {
 111     return CONTAINING_RECORD(decompress, JpegDecoder, cinfo);
 112 }
 113
 114 static inline JpegDecoder *decoder_from_frame(IWICBitmapFrameDecode *iface)
 115 {
 116     return CONTAINING_RECORD(iface, JpegDecoder, lpFrameVtbl);
 117 }
 118
 119 static HRESULT WINAPI JpegDecoder_QueryInterface(IWICBitmapDecoder *iface, REFIID iid,
 120     void **ppv)
 121 {
 122     JpegDecoder *This = (JpegDecoder*)iface;
 123     TRACE("(%p,%s,%p)\n", iface, debugstr_guid(iid), ppv);
 124
 125     if (!ppv) return E_INVALIDARG;
 126
 127     if (IsEqualIID(&IID_IUnknown, iid) || IsEqualIID(&IID_IWICBitmapDecoder, iid))
 128     {
 129         *ppv = This;
 130     }
 131     else
 132     {
 133         *ppv = NULL;
 134         return E_NOINTERFACE;
 135     }
 136
 137     IUnknown_AddRef((IUnknown*)*ppv);
 138     return S_OK;
 139 }
 140
 141 static ULONG WINAPI JpegDecoder_AddRef(IWICBitmapDecoder *iface)
 142 {
 143     JpegDecoder *This = (JpegDecoder*)iface;
 144     ULONG ref = InterlockedIncrement(&This->ref);
 145
 146     TRACE("(%p) refcount=%u\n", iface, ref);
 147
 148     return ref;
 149 }
 150
 151 static ULONG WINAPI JpegDecoder_Release(IWICBitmapDecoder *iface)
 152 {
 153     JpegDecoder *This = (JpegDecoder*)iface;
 154     ULONG ref = InterlockedDecrement(&This->ref);
 155
 156     TRACE("(%p) refcount=%u\n", iface, ref);
 157
 158     if (ref == 0)
 159     {
 160         This->lock.DebugInfo->Spare[0] = 0;
 161         DeleteCriticalSection(&This->lock);
 162         if (This->cinfo_initialized) pjpeg_destroy_decompress(&This->cinfo);
 163         if (This->stream) IStream_Release(This->stream);
 164         HeapFree(GetProcessHeap(), 0, This->image_data);
 165         HeapFree(GetProcessHeap(), 0, This);
 166     }
 167
 168     return ref;
 169 }
 170
 171 static HRESULT WINAPI JpegDecoder_QueryCapability(IWICBitmapDecoder *iface, IStream *pIStream,
 172     DWORD *pdwCapability)
 173 {
 174     FIXME("(%p,%p,%p): stub\n", iface, pIStream, pdwCapability);
 175     return E_NOTIMPL;
 176 }
 177
 178 static void source_mgr_init_source(j_decompress_ptr cinfo)
 179 {
 180 }
 181
 182 static jpeg_boolean source_mgr_fill_input_buffer(j_decompress_ptr cinfo)
 183 {
 184     JpegDecoder *This = decoder_from_decompress(cinfo);
 185     HRESULT hr;
 186     ULONG bytesread;
 187
 188     hr = IStream_Read(This->stream, This->source_buffer, 1024, &bytesread);
 189
 190     if (hr != S_OK || bytesread == 0)
 191     {
 192         return FALSE;
 193     }
 194     else
 195     {
 196         This->source_mgr.next_input_byte = This->source_buffer;
 197         This->source_mgr.bytes_in_buffer = bytesread;
 198         return TRUE;
 199     }
 200 }
 201
 202 static void source_mgr_skip_input_data(j_decompress_ptr cinfo, long num_bytes)
 203 {
 204     JpegDecoder *This = decoder_from_decompress(cinfo);
 205     LARGE_INTEGER seek;
 206
 207     if (num_bytes > This->source_mgr.bytes_in_buffer)
 208     {
 209         seek.QuadPart = num_bytes - This->source_mgr.bytes_in_buffer;
 210         IStream_Seek(This->stream, seek, STREAM_SEEK_CUR, NULL);
 211         This->source_mgr.bytes_in_buffer = 0;
 212     }
 213     else if (num_bytes > 0)
 214     {
 215         This->source_mgr.next_input_byte += num_bytes;
 216         This->source_mgr.bytes_in_buffer -= num_bytes;
 217     }
 218 }
 219
 220 static void source_mgr_term_source(j_decompress_ptr cinfo)
 221 {
 222 }
 223
 224 static HRESULT WINAPI JpegDecoder_Initialize(IWICBitmapDecoder *iface, IStream *pIStream,
 225     WICDecodeOptions cacheOptions)
 226 {
 227     JpegDecoder *This = (JpegDecoder*)iface;
 228     int ret;
 229     LARGE_INTEGER seek;
 230     TRACE("(%p,%p,%u)\n", iface, pIStream, cacheOptions);
 231
 232     EnterCriticalSection(&This->lock);
 233
 234     if (This->cinfo_initialized)
 235     {
 236         LeaveCriticalSection(&This->lock);
 237         return WINCODEC_ERR_WRONGSTATE;
 238     }
 239
 240     This->cinfo.err = pjpeg_std_error(&This->jerr);
 241
 242     pjpeg_CreateDecompress(&This->cinfo, JPEG_LIB_VERSION, sizeof(struct jpeg_decompress_struct));
 243
 244     This->cinfo_initialized = TRUE;
 245
 246     This->stream = pIStream;
 247     IStream_AddRef(pIStream);
 248
 249     seek.QuadPart = 0;
 250     IStream_Seek(This->stream, seek, STREAM_SEEK_SET, NULL);
 251
 252     This->source_mgr.bytes_in_buffer = 0;
 253     This->source_mgr.init_source = source_mgr_init_source;
 254     This->source_mgr.fill_input_buffer = source_mgr_fill_input_buffer;
 255     This->source_mgr.skip_input_data = source_mgr_skip_input_data;
 256     This->source_mgr.resync_to_restart = pjpeg_resync_to_restart;
 257     This->source_mgr.term_source = source_mgr_term_source;
 258
 259     This->cinfo.src = &This->source_mgr;
 260
 261     ret = pjpeg_read_header(&This->cinfo, TRUE);
 262
 263     if (ret != JPEG_HEADER_OK) {
 264         WARN("Jpeg image in stream has bad format, read header returned %d.\n",ret);
 265         LeaveCriticalSection(&This->lock);
 266         return E_FAIL;
 267     }
 268
 269     if (This->cinfo.jpeg_color_space == JCS_GRAYSCALE)
 270         This->cinfo.out_color_space = JCS_GRAYSCALE;
 271     else
 272         This->cinfo.out_color_space = JCS_RGB;
 273
 274     if (!pjpeg_start_decompress(&This->cinfo))
 275     {
 276         ERR("jpeg_start_decompress failed\n");
 277         LeaveCriticalSection(&This->lock);
 278         return E_FAIL;
 279     }
 280
 281     This->initialized = TRUE;
 282
 283     LeaveCriticalSection(&This->lock);
 284
 285     return S_OK;
 286 }
 287
 288 static HRESULT WINAPI JpegDecoder_GetContainerFormat(IWICBitmapDecoder *iface,
 289     GUID *pguidContainerFormat)
 290 {
 291     memcpy(pguidContainerFormat, &GUID_ContainerFormatJpeg, sizeof(GUID));
 292     return S_OK;
 293 }
 294
 295 static HRESULT WINAPI JpegDecoder_GetDecoderInfo(IWICBitmapDecoder *iface,
 296     IWICBitmapDecoderInfo **ppIDecoderInfo)
 297 {
 298     FIXME("(%p,%p): stub\n", iface, ppIDecoderInfo);
 299     return E_NOTIMPL;
 300 }
 301
 302 static HRESULT WINAPI JpegDecoder_CopyPalette(IWICBitmapDecoder *iface,
 303     IWICPalette *pIPalette)
 304 {
 305     TRACE("(%p,%p)\n", iface, pIPalette);
 306
 307     return WINCODEC_ERR_PALETTEUNAVAILABLE;
 308 }
 309
 310 static HRESULT WINAPI JpegDecoder_GetMetadataQueryReader(IWICBitmapDecoder *iface,
 311     IWICMetadataQueryReader **ppIMetadataQueryReader)
 312 {
 313     FIXME("(%p,%p): stub\n", iface, ppIMetadataQueryReader);
 314     return E_NOTIMPL;
 315 }
 316
 317 static HRESULT WINAPI JpegDecoder_GetPreview(IWICBitmapDecoder *iface,
 318     IWICBitmapSource **ppIBitmapSource)
 319 {
 320     FIXME("(%p,%p): stub\n", iface, ppIBitmapSource);
 321     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 322 }
 323
 324 static HRESULT WINAPI JpegDecoder_GetColorContexts(IWICBitmapDecoder *iface,
 325     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
 326 {
 327     FIXME("(%p,%u,%p,%p): stub\n", iface, cCount, ppIColorContexts, pcActualCount);
 328     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 329 }
 330
 331 static HRESULT WINAPI JpegDecoder_GetThumbnail(IWICBitmapDecoder *iface,
 332     IWICBitmapSource **ppIThumbnail)
 333 {
 334     FIXME("(%p,%p): stub\n", iface, ppIThumbnail);
 335     return WINCODEC_ERR_CODECNOTHUMBNAIL;
 336 }
 337
 338 static HRESULT WINAPI JpegDecoder_GetFrameCount(IWICBitmapDecoder *iface,
 339     UINT *pCount)
 340 {
 341     *pCount = 1;
 342     return S_OK;
 343 }
 344
 345 static HRESULT WINAPI JpegDecoder_GetFrame(IWICBitmapDecoder *iface,
 346     UINT index, IWICBitmapFrameDecode **ppIBitmapFrame)
 347 {
 348     JpegDecoder *This = (JpegDecoder*)iface;
 349     TRACE("(%p,%u,%p)\n", iface, index, ppIBitmapFrame);
 350
 351     if (!This->initialized) return WINCODEC_ERR_NOTINITIALIZED;
 352
 353     if (index != 0) return E_INVALIDARG;
 354
 355     IWICBitmapDecoder_AddRef(iface);
 356     *ppIBitmapFrame = (IWICBitmapFrameDecode*)&This->lpFrameVtbl;
 357
 358     return S_OK;
 359 }
 360
 361 static const IWICBitmapDecoderVtbl JpegDecoder_Vtbl = {
 362     JpegDecoder_QueryInterface,
 363     JpegDecoder_AddRef,
 364     JpegDecoder_Release,
 365     JpegDecoder_QueryCapability,
 366     JpegDecoder_Initialize,
 367     JpegDecoder_GetContainerFormat,
 368     JpegDecoder_GetDecoderInfo,
 369     JpegDecoder_CopyPalette,
 370     JpegDecoder_GetMetadataQueryReader,
 371     JpegDecoder_GetPreview,
 372     JpegDecoder_GetColorContexts,
 373     JpegDecoder_GetThumbnail,
 374     JpegDecoder_GetFrameCount,
 375     JpegDecoder_GetFrame
 376 };
 377
 378 static HRESULT WINAPI JpegDecoder_Frame_QueryInterface(IWICBitmapFrameDecode *iface, REFIID iid,
 379     void **ppv)
 380 {
 381     TRACE("(%p,%s,%p)\n", iface, debugstr_guid(iid), ppv);
 382
 383     if (!ppv) return E_INVALIDARG;
 384
 385     if (IsEqualIID(&IID_IUnknown, iid) ||
 386         IsEqualIID(&IID_IWICBitmapSource, iid) ||
 387         IsEqualIID(&IID_IWICBitmapFrameDecode, iid))
 388     {
 389         *ppv = iface;
 390     }
 391     else
 392     {
 393         *ppv = NULL;
 394         return E_NOINTERFACE;
 395     }
 396
 397     IUnknown_AddRef((IUnknown*)*ppv);
 398     return S_OK;
 399 }
 400
 401 static ULONG WINAPI JpegDecoder_Frame_AddRef(IWICBitmapFrameDecode *iface)
 402 {
 403     JpegDecoder *This = decoder_from_frame(iface);
 404     return IUnknown_AddRef((IUnknown*)This);
 405 }
 406
 407 static ULONG WINAPI JpegDecoder_Frame_Release(IWICBitmapFrameDecode *iface)
 408 {
 409     JpegDecoder *This = decoder_from_frame(iface);
 410     return IUnknown_Release((IUnknown*)This);
 411 }
 412
 413 static HRESULT WINAPI JpegDecoder_Frame_GetSize(IWICBitmapFrameDecode *iface,
 414     UINT *puiWidth, UINT *puiHeight)
 415 {
 416     JpegDecoder *This = decoder_from_frame(iface);
 417     *puiWidth = This->cinfo.output_width;
 418     *puiHeight = This->cinfo.output_height;
 419     TRACE("(%p)->(%u,%u)\n", iface, *puiWidth, *puiHeight);
 420     return S_OK;
 421 }
 422
 423 static HRESULT WINAPI JpegDecoder_Frame_GetPixelFormat(IWICBitmapFrameDecode *iface,
 424     WICPixelFormatGUID *pPixelFormat)
 425 {
 426     JpegDecoder *This = decoder_from_frame(iface);
 427     TRACE("(%p,%p)\n", iface, pPixelFormat);
 428     if (This->cinfo.out_color_space == JCS_RGB)
 429         memcpy(pPixelFormat, &GUID_WICPixelFormat24bppBGR, sizeof(GUID));
 430     else /* This->cinfo.out_color_space == JCS_GRAYSCALE */
 431         memcpy(pPixelFormat, &GUID_WICPixelFormat8bppGray, sizeof(GUID));
 432     return S_OK;
 433 }
 434
 435 static HRESULT WINAPI JpegDecoder_Frame_GetResolution(IWICBitmapFrameDecode *iface,
 436     double *pDpiX, double *pDpiY)
 437 {
 438     FIXME("(%p,%p,%p): stub\n", iface, pDpiX, pDpiY);
 439     return E_NOTIMPL;
 440 }
 441
 442 static HRESULT WINAPI JpegDecoder_Frame_CopyPalette(IWICBitmapFrameDecode *iface,
 443     IWICPalette *pIPalette)
 444 {
 445     FIXME("(%p,%p): stub\n", iface, pIPalette);
 446     return E_NOTIMPL;
 447 }
 448
 449 static HRESULT WINAPI JpegDecoder_Frame_CopyPixels(IWICBitmapFrameDecode *iface,
 450     const WICRect *prc, UINT cbStride, UINT cbBufferSize, BYTE *pbBuffer)
 451 {
 452     JpegDecoder *This = decoder_from_frame(iface);
 453     UINT bpp;
 454     UINT stride;
 455     UINT data_size;
 456     UINT max_row_needed;
 457     TRACE("(%p,%p,%u,%u,%p)\n", iface, prc, cbStride, cbBufferSize, pbBuffer);
 458
 459     if (This->cinfo.out_color_space == JCS_GRAYSCALE) bpp = 8;
 460     else bpp = 24;
 461
 462     stride = bpp * This->cinfo.output_width;
 463     data_size = stride * This->cinfo.output_height;
 464
 465     max_row_needed = prc->Y + prc->Height;
 466     if (max_row_needed > This->cinfo.output_height) return E_INVALIDARG;
 467
 468     EnterCriticalSection(&This->lock);
 469
 470     if (!This->image_data)
 471     {
 472         This->image_data = HeapAlloc(GetProcessHeap(), 0, data_size);
 473         if (!This->image_data)
 474         {
 475             LeaveCriticalSection(&This->lock);
 476             return E_OUTOFMEMORY;
 477         }
 478     }
 479
 480     while (max_row_needed > This->cinfo.output_scanline)
 481     {
 482         UINT first_scanline = This->cinfo.output_scanline;
 483         UINT max_rows;
 484         JSAMPROW out_rows[4];
 485         UINT i, j;
 486         JDIMENSION ret;
 487
 488         max_rows = min(This->cinfo.output_height-first_scanline, 4);
 489         for (i=0; i<max_rows; i++)
 490             out_rows[i] = This->image_data + stride * (first_scanline+i);
 491
 492         ret = pjpeg_read_scanlines(&This->cinfo, out_rows, max_rows);
 493
 494         if (ret == 0)
 495         {
 496             ERR("read_scanlines failed\n");
 497             LeaveCriticalSection(&This->lock);
 498             return E_FAIL;
 499         }
 500
 501         if (bpp == 24)
 502         {
 503             /* libjpeg gives us RGB data and we want BGR, so byteswap the data */
 504             for (i=first_scanline; i<This->cinfo.output_scanline; i++)
 505             {
 506                 BYTE *pixel = This->image_data + stride * i;
 507                 for (j=0; j<This->cinfo.output_width; j++)
 508                 {
 509                     BYTE red=pixel[0];
 510                     BYTE blue=pixel[2];
 511                     pixel[0]=blue;
 512                     pixel[2]=red;
 513                     pixel+=3;
 514                 }
 515             }
 516         }
 517     }
 518
 519     LeaveCriticalSection(&This->lock);
 520
 521     return copy_pixels(bpp, This->image_data,
 522         This->cinfo.output_width, This->cinfo.output_height, stride,
 523         prc, cbStride, cbBufferSize, pbBuffer);
 524 }
 525
 526 static HRESULT WINAPI JpegDecoder_Frame_GetMetadataQueryReader(IWICBitmapFrameDecode *iface,
 527     IWICMetadataQueryReader **ppIMetadataQueryReader)
 528 {
 529     FIXME("(%p,%p): stub\n", iface, ppIMetadataQueryReader);
 530     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 531 }
 532
 533 static HRESULT WINAPI JpegDecoder_Frame_GetColorContexts(IWICBitmapFrameDecode *iface,
 534     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
 535 {
 536     FIXME("(%p,%u,%p,%p): stub\n", iface, cCount, ppIColorContexts, pcActualCount);
 537     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 538 }
 539
 540 static HRESULT WINAPI JpegDecoder_Frame_GetThumbnail(IWICBitmapFrameDecode *iface,
 541     IWICBitmapSource **ppIThumbnail)
 542 {
 543     FIXME("(%p,%p): stub\n", iface, ppIThumbnail);
 544     return WINCODEC_ERR_CODECNOTHUMBNAIL;
 545 }
 546
 547 static const IWICBitmapFrameDecodeVtbl JpegDecoder_Frame_Vtbl = {
 548     JpegDecoder_Frame_QueryInterface,
 549     JpegDecoder_Frame_AddRef,
 550     JpegDecoder_Frame_Release,
 551     JpegDecoder_Frame_GetSize,
 552     JpegDecoder_Frame_GetPixelFormat,
 553     JpegDecoder_Frame_GetResolution,
 554     JpegDecoder_Frame_CopyPalette,
 555     JpegDecoder_Frame_CopyPixels,
 556     JpegDecoder_Frame_GetMetadataQueryReader,
 557     JpegDecoder_Frame_GetColorContexts,
 558     JpegDecoder_Frame_GetThumbnail
 559 };
 560
 561 HRESULT JpegDecoder_CreateInstance(IUnknown *pUnkOuter, REFIID iid, void** ppv)
 562 {
 563     JpegDecoder *This;
 564     HRESULT ret;
 565
 566     TRACE("(%p,%s,%p)\n", pUnkOuter, debugstr_guid(iid), ppv);
 567
 568     if (!libjpeg_handle && !load_libjpeg())
 569     {
 570         ERR("Failed reading JPEG because unable to find %s\n", SONAME_LIBJPEG);
 571         return E_FAIL;
 572     }
 573
 574     *ppv = NULL;
 575
 576     if (pUnkOuter) return CLASS_E_NOAGGREGATION;
 577
 578     This = HeapAlloc(GetProcessHeap(), 0, sizeof(JpegDecoder));
 579     if (!This) return E_OUTOFMEMORY;
 580
 581     This->lpVtbl = &JpegDecoder_Vtbl;
 582     This->lpFrameVtbl = &JpegDecoder_Frame_Vtbl;
 583     This->ref = 1;
 584     This->initialized = FALSE;
 585     This->cinfo_initialized = FALSE;
 586     This->stream = NULL;
 587     This->image_data = NULL;
 588     InitializeCriticalSection(&This->lock);
 589     This->lock.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": JpegDecoder.lock");
 590
 591     ret = IUnknown_QueryInterface((IUnknown*)This, iid, ppv);
 592     IUnknown_Release((IUnknown*)This);
 593
 594     return ret;
 595 }
 596
 597 #else /* !defined(SONAME_LIBJPEG) */
 598
 599 HRESULT JpegDecoder_CreateInstance(IUnknown *pUnkOuter, REFIID iid, void** ppv)
 600 {
 601     ERR("Trying to load JPEG picture, but JPEG support is not compiled in.\n");
 602     return E_FAIL;
 603 }
 604
 605 #endif