xref: /reactos/dll/win32/windowscodecs/icoformat.c (revision 0623a6f8)
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 
21 #include <stdarg.h>
22 
23 #define COBJMACROS
24 
25 #include "windef.h"
26 #include "winbase.h"
27 #include "wingdi.h"
28 #include "objbase.h"
29 
30 #include "wincodecs_private.h"
31 
32 #include "wine/debug.h"
33 
34 WINE_DEFAULT_DEBUG_CHANNEL(wincodecs);
35 
36 #include "pshpack1.h"
37 
38 typedef struct {
39     BYTE bWidth;
40     BYTE bHeight;
41     BYTE bColorCount;
42     BYTE bReserved;
43     WORD wPlanes;
44     WORD wBitCount;
45     DWORD dwDIBSize;
46     DWORD dwDIBOffset;
47 } ICONDIRENTRY;
48 
49 typedef struct
50 {
51     WORD idReserved;
52     WORD idType;
53     WORD idCount;
54 } ICONHEADER;
55 
56 #include "poppack.h"
57 
58 typedef struct {
59     IWICBitmapDecoder IWICBitmapDecoder_iface;
60     LONG ref;
61     BOOL initialized;
62     IStream *stream;
63     ICONHEADER header;
64     CRITICAL_SECTION lock; /* must be held when accessing stream */
65 } IcoDecoder;
66 
67 typedef struct {
68     IWICBitmapFrameDecode IWICBitmapFrameDecode_iface;
69     LONG ref;
70     UINT width, height;
71     double dpiX, dpiY;
72     BYTE *bits;
73 } IcoFrameDecode;
74 
75 static inline IcoDecoder *impl_from_IWICBitmapDecoder(IWICBitmapDecoder *iface)
76 {
77     return CONTAINING_RECORD(iface, IcoDecoder, IWICBitmapDecoder_iface);
78 }
79 
80 static inline IcoFrameDecode *impl_from_IWICBitmapFrameDecode(IWICBitmapFrameDecode *iface)
81 {
82     return CONTAINING_RECORD(iface, IcoFrameDecode, IWICBitmapFrameDecode_iface);
83 }
84 
85 static HRESULT WINAPI IcoFrameDecode_QueryInterface(IWICBitmapFrameDecode *iface, REFIID iid,
86     void **ppv)
87 {
88     IcoFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
89     TRACE("(%p,%s,%p)\n", iface, debugstr_guid(iid), ppv);
90 
91     if (!ppv) return E_INVALIDARG;
92 
93     if (IsEqualIID(&IID_IUnknown, iid) ||
94         IsEqualIID(&IID_IWICBitmapSource, iid) ||
95         IsEqualIID(&IID_IWICBitmapFrameDecode, iid))
96     {
97         *ppv = &This->IWICBitmapFrameDecode_iface;
98     }
99     else
100     {
101         *ppv = NULL;
102         return E_NOINTERFACE;
103     }
104 
105     IUnknown_AddRef((IUnknown*)*ppv);
106     return S_OK;
107 }
108 
109 static ULONG WINAPI IcoFrameDecode_AddRef(IWICBitmapFrameDecode *iface)
110 {
111     IcoFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
112     ULONG ref = InterlockedIncrement(&This->ref);
113 
114     TRACE("(%p) refcount=%u\n", iface, ref);
115 
116     return ref;
117 }
118 
119 static ULONG WINAPI IcoFrameDecode_Release(IWICBitmapFrameDecode *iface)
120 {
121     IcoFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
122     ULONG ref = InterlockedDecrement(&This->ref);
123 
124     TRACE("(%p) refcount=%u\n", iface, ref);
125 
126     if (ref == 0)
127     {
128         HeapFree(GetProcessHeap(), 0, This->bits);
129         HeapFree(GetProcessHeap(), 0, This);
130     }
131 
132     return ref;
133 }
134 
135 static HRESULT WINAPI IcoFrameDecode_GetSize(IWICBitmapFrameDecode *iface,
136     UINT *puiWidth, UINT *puiHeight)
137 {
138     IcoFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
139 
140     *puiWidth = This->width;
141     *puiHeight = This->height;
142 
143     TRACE("(%p) -> (%i,%i)\n", iface, *puiWidth, *puiHeight);
144 
145     return S_OK;
146 }
147 
148 static HRESULT WINAPI IcoFrameDecode_GetPixelFormat(IWICBitmapFrameDecode *iface,
149     WICPixelFormatGUID *pPixelFormat)
150 {
151     memcpy(pPixelFormat, &GUID_WICPixelFormat32bppBGRA, sizeof(GUID));
152     return S_OK;
153 }
154 
155 static HRESULT WINAPI IcoFrameDecode_GetResolution(IWICBitmapFrameDecode *iface,
156     double *pDpiX, double *pDpiY)
157 {
158     IcoFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
159 
160     *pDpiX = This->dpiX;
161     *pDpiY = This->dpiY;
162 
163     TRACE("(%p) -> (%f,%f)\n", iface, *pDpiX, *pDpiY);
164 
165     return S_OK;
166 }
167 
168 static HRESULT WINAPI IcoFrameDecode_CopyPalette(IWICBitmapFrameDecode *iface,
169     IWICPalette *pIPalette)
170 {
171     TRACE("(%p,%p)\n", iface, pIPalette);
172     return WINCODEC_ERR_PALETTEUNAVAILABLE;
173 }
174 
175 static HRESULT WINAPI IcoFrameDecode_CopyPixels(IWICBitmapFrameDecode *iface,
176     const WICRect *prc, UINT cbStride, UINT cbBufferSize, BYTE *pbBuffer)
177 {
178     IcoFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
179     TRACE("(%p,%p,%u,%u,%p)\n", iface, prc, cbStride, cbBufferSize, pbBuffer);
180 
181     return copy_pixels(32, This->bits, This->width, This->height, This->width * 4,
182         prc, cbStride, cbBufferSize, pbBuffer);
183 }
184 
185 static HRESULT WINAPI IcoFrameDecode_GetMetadataQueryReader(IWICBitmapFrameDecode *iface,
186     IWICMetadataQueryReader **ppIMetadataQueryReader)
187 {
188     TRACE("(%p,%p)\n", iface, ppIMetadataQueryReader);
189     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
190 }
191 
192 static HRESULT WINAPI IcoFrameDecode_GetColorContexts(IWICBitmapFrameDecode *iface,
193     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
194 {
195     TRACE("(%p,%u,%p,%p)\n", iface, cCount, ppIColorContexts, pcActualCount);
196     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
197 }
198 
199 static HRESULT WINAPI IcoFrameDecode_GetThumbnail(IWICBitmapFrameDecode *iface,
200     IWICBitmapSource **ppIThumbnail)
201 {
202     TRACE("(%p,%p)\n", iface, ppIThumbnail);
203     return IWICBitmapFrameDecode_QueryInterface(iface, &IID_IWICBitmapSource, (void **)ppIThumbnail);
204 }
205 
206 static const IWICBitmapFrameDecodeVtbl IcoFrameDecode_Vtbl = {
207     IcoFrameDecode_QueryInterface,
208     IcoFrameDecode_AddRef,
209     IcoFrameDecode_Release,
210     IcoFrameDecode_GetSize,
211     IcoFrameDecode_GetPixelFormat,
212     IcoFrameDecode_GetResolution,
213     IcoFrameDecode_CopyPalette,
214     IcoFrameDecode_CopyPixels,
215     IcoFrameDecode_GetMetadataQueryReader,
216     IcoFrameDecode_GetColorContexts,
217     IcoFrameDecode_GetThumbnail
218 };
219 
220 static inline void pixel_set_trans(DWORD* pixel, BOOL transparent)
221 {
222     if (transparent) *pixel = 0;
223     else *pixel |= 0xff000000;
224 }
225 
226 static HRESULT ReadIcoDib(IStream *stream, IcoFrameDecode *result)
227 {
228     HRESULT hr;
229     BmpDecoder *bmp_decoder;
230     IWICBitmapDecoder *decoder;
231     IWICBitmapFrameDecode *framedecode;
232     WICPixelFormatGUID pixelformat;
233     IWICBitmapSource *source;
234     BOOL has_alpha=FALSE; /* if TRUE, alpha data might be in the image data */
235     WICRect rc;
236 
237     hr = IcoDibDecoder_CreateInstance(&bmp_decoder);
238     if (SUCCEEDED(hr))
239     {
240         BmpDecoder_GetWICDecoder(bmp_decoder, &decoder);
241         hr = IWICBitmapDecoder_Initialize(decoder, stream, WICDecodeMetadataCacheOnLoad);
242 
243         if (SUCCEEDED(hr))
244             hr = IWICBitmapDecoder_GetFrame(decoder, 0, &framedecode);
245 
246         if (SUCCEEDED(hr))
247         {
248             hr = IWICBitmapFrameDecode_GetSize(framedecode, &result->width, &result->height);
249 
250             if (SUCCEEDED(hr))
251             {
252                 result->bits = HeapAlloc(GetProcessHeap(), 0, result->width * result->height * 4);
253                 if (!result->bits) hr = E_OUTOFMEMORY;
254             }
255 
256             if (SUCCEEDED(hr))
257                 hr = IWICBitmapFrameDecode_GetPixelFormat(framedecode, &pixelformat);
258 
259             if (IsEqualGUID(&pixelformat, &GUID_WICPixelFormat32bppBGR) ||
260                 IsEqualGUID(&pixelformat, &GUID_WICPixelFormat32bppBGRA))
261             {
262                 source = (IWICBitmapSource*)framedecode;
263                 IWICBitmapSource_AddRef(source);
264                 has_alpha = TRUE;
265             }
266             else
267             {
268                 hr = WICConvertBitmapSource(&GUID_WICPixelFormat32bppBGRA,
269                     (IWICBitmapSource*)framedecode, &source);
270                 has_alpha = FALSE;
271             }
272 
273             if (SUCCEEDED(hr))
274             {
275                 rc.X = 0;
276                 rc.Y = 0;
277                 rc.Width = result->width;
278                 rc.Height = result->height;
279                 hr = IWICBitmapSource_CopyPixels(source, &rc, result->width * 4,
280                     result->width * result->height * 4, result->bits);
281 
282                 IWICBitmapSource_Release(source);
283             }
284 
285             if (SUCCEEDED(hr))
286                 hr = IWICBitmapFrameDecode_GetResolution(framedecode, &result->dpiX, &result->dpiY);
287 
288             IWICBitmapFrameDecode_Release(framedecode);
289         }
290 
291         if (SUCCEEDED(hr) && has_alpha)
292         {
293             /* If the alpha channel is fully transparent, we should ignore it. */
294             int nonzero_alpha = 0;
295             UINT i;
296 
297             for (i=0; i<(result->height*result->width); i++)
298             {
299                 if (result->bits[i*4+3] != 0)
300                 {
301                     nonzero_alpha = 1;
302                     break;
303                 }
304             }
305 
306             if (!nonzero_alpha)
307             {
308                 for (i=0; i<(result->height*result->width); i++)
309                     result->bits[i*4+3] = 0xff;
310 
311                 has_alpha = FALSE;
312             }
313         }
314 
315         if (SUCCEEDED(hr) && !has_alpha)
316         {
317             /* set alpha data based on the AND mask */
318             UINT andBytesPerRow = (result->width+31)/32*4;
319             UINT andBytes = andBytesPerRow * result->height;
320             INT andStride;
321             BYTE *tempdata=NULL;
322             BYTE *andRow;
323             BYTE *bitsRow;
324             UINT bitsStride = result->width * 4;
325             UINT x, y;
326             ULONG offset;
327             ULONG bytesread;
328             LARGE_INTEGER seek;
329             int topdown;
330 
331             BmpDecoder_FindIconMask(bmp_decoder, &offset, &topdown);
332 
333             if (offset)
334             {
335                 seek.QuadPart = offset;
336 
337                 hr = IStream_Seek(stream, seek, STREAM_SEEK_SET, 0);
338 
339                 if (SUCCEEDED(hr))
340                 {
341                     tempdata = HeapAlloc(GetProcessHeap(), 0, andBytes);
342                     if (!tempdata) hr = E_OUTOFMEMORY;
343                 }
344 
345                 if (SUCCEEDED(hr))
346                     hr = IStream_Read(stream, tempdata, andBytes, &bytesread);
347 
348                 if (SUCCEEDED(hr) && bytesread == andBytes)
349                 {
350                     if (topdown)
351                     {
352                         andStride = andBytesPerRow;
353                         andRow = tempdata;
354                     }
355                     else
356                     {
357                         andStride = -andBytesPerRow;
358                         andRow = tempdata + (result->height-1)*andBytesPerRow;
359                     }
360 
361                     bitsRow = result->bits;
362                     for (y=0; y<result->height; y++) {
363                         BYTE *andByte=andRow;
364                         DWORD *bitsPixel=(DWORD*)bitsRow;
365                         for (x=0; x<result->width; x+=8) {
366                             BYTE andVal=*andByte++;
367                             pixel_set_trans(bitsPixel++, andVal>>7&1);
368                             if (x+1 < result->width) pixel_set_trans(bitsPixel++, andVal>>6&1);
369                             if (x+2 < result->width) pixel_set_trans(bitsPixel++, andVal>>5&1);
370                             if (x+3 < result->width) pixel_set_trans(bitsPixel++, andVal>>4&1);
371                             if (x+4 < result->width) pixel_set_trans(bitsPixel++, andVal>>3&1);
372                             if (x+5 < result->width) pixel_set_trans(bitsPixel++, andVal>>2&1);
373                             if (x+6 < result->width) pixel_set_trans(bitsPixel++, andVal>>1&1);
374                             if (x+7 < result->width) pixel_set_trans(bitsPixel++, andVal&1);
375                         }
376                         andRow += andStride;
377                         bitsRow += bitsStride;
378                     }
379                 }
380 
381                 HeapFree(GetProcessHeap(), 0, tempdata);
382             }
383         }
384 
385         IWICBitmapDecoder_Release(decoder);
386     }
387 
388     return hr;
389 }
390 
391 static HRESULT ReadIcoPng(IStream *stream, IcoFrameDecode *result)
392 {
393     IWICBitmapDecoder *decoder = NULL;
394     IWICBitmapFrameDecode *sourceFrame = NULL;
395     IWICBitmapSource *sourceBitmap = NULL;
396     WICRect rect;
397     HRESULT hr;
398 
399     hr = PngDecoder_CreateInstance(&IID_IWICBitmapDecoder, (void**)&decoder);
400     if (FAILED(hr))
401         goto end;
402     hr = IWICBitmapDecoder_Initialize(decoder, stream, WICDecodeMetadataCacheOnLoad);
403     if (FAILED(hr))
404         goto end;
405     hr = IWICBitmapDecoder_GetFrame(decoder, 0, &sourceFrame);
406     if (FAILED(hr))
407         goto end;
408     hr = WICConvertBitmapSource(&GUID_WICPixelFormat32bppBGRA, (IWICBitmapSource*)sourceFrame, &sourceBitmap);
409     if (FAILED(hr))
410         goto end;
411     hr = IWICBitmapFrameDecode_GetSize(sourceFrame, &result->width, &result->height);
412     if (FAILED(hr))
413         goto end;
414     hr = IWICBitmapFrameDecode_GetResolution(sourceFrame, &result->dpiX, &result->dpiY);
415     if (FAILED(hr))
416         goto end;
417     result->bits = HeapAlloc(GetProcessHeap(), 0, 4 * result->width * result->height);
418     if (result->bits == NULL)
419     {
420         hr = E_OUTOFMEMORY;
421         goto end;
422     }
423     rect.X = 0;
424     rect.Y = 0;
425     rect.Width = result->width;
426     rect.Height = result->height;
427     hr = IWICBitmapSource_CopyPixels(sourceBitmap, &rect, 4*result->width,
428                                      4*result->width*result->height, result->bits);
429 
430 end:
431     if (decoder != NULL)
432         IWICBitmapDecoder_Release(decoder);
433     if (sourceFrame != NULL)
434         IWICBitmapFrameDecode_Release(sourceFrame);
435     if (sourceBitmap != NULL)
436         IWICBitmapSource_Release(sourceBitmap);
437     return hr;
438 }
439 
440 static HRESULT WINAPI IcoDecoder_QueryInterface(IWICBitmapDecoder *iface, REFIID iid,
441     void **ppv)
442 {
443     IcoDecoder *This = impl_from_IWICBitmapDecoder(iface);
444     TRACE("(%p,%s,%p)\n", iface, debugstr_guid(iid), ppv);
445 
446     if (!ppv) return E_INVALIDARG;
447 
448     if (IsEqualIID(&IID_IUnknown, iid) ||
449         IsEqualIID(&IID_IWICBitmapDecoder, iid))
450     {
451         *ppv = &This->IWICBitmapDecoder_iface;
452     }
453     else
454     {
455         *ppv = NULL;
456         return E_NOINTERFACE;
457     }
458 
459     IUnknown_AddRef((IUnknown*)*ppv);
460     return S_OK;
461 }
462 
463 static ULONG WINAPI IcoDecoder_AddRef(IWICBitmapDecoder *iface)
464 {
465     IcoDecoder *This = impl_from_IWICBitmapDecoder(iface);
466     ULONG ref = InterlockedIncrement(&This->ref);
467 
468     TRACE("(%p) refcount=%u\n", iface, ref);
469 
470     return ref;
471 }
472 
473 static ULONG WINAPI IcoDecoder_Release(IWICBitmapDecoder *iface)
474 {
475     IcoDecoder *This = impl_from_IWICBitmapDecoder(iface);
476     ULONG ref = InterlockedDecrement(&This->ref);
477 
478     TRACE("(%p) refcount=%u\n", iface, ref);
479 
480     if (ref == 0)
481     {
482         This->lock.DebugInfo->Spare[0] = 0;
483         DeleteCriticalSection(&This->lock);
484         if (This->stream) IStream_Release(This->stream);
485         HeapFree(GetProcessHeap(), 0, This);
486     }
487 
488     return ref;
489 }
490 
491 static HRESULT WINAPI IcoDecoder_QueryCapability(IWICBitmapDecoder *iface, IStream *stream,
492     DWORD *capability)
493 {
494     HRESULT hr;
495 
496     TRACE("(%p,%p,%p)\n", iface, stream, capability);
497 
498     if (!stream || !capability) return E_INVALIDARG;
499 
500     hr = IWICBitmapDecoder_Initialize(iface, stream, WICDecodeMetadataCacheOnDemand);
501     if (hr != S_OK) return hr;
502 
503     *capability = WICBitmapDecoderCapabilityCanDecodeAllImages;
504     return S_OK;
505 }
506 
507 static HRESULT WINAPI IcoDecoder_Initialize(IWICBitmapDecoder *iface, IStream *pIStream,
508     WICDecodeOptions cacheOptions)
509 {
510     IcoDecoder *This = impl_from_IWICBitmapDecoder(iface);
511     LARGE_INTEGER seek;
512     HRESULT hr;
513     ULONG bytesread;
514     TRACE("(%p,%p,%x)\n", iface, pIStream, cacheOptions);
515 
516     EnterCriticalSection(&This->lock);
517 
518     if (This->initialized)
519     {
520         hr = WINCODEC_ERR_WRONGSTATE;
521         goto end;
522     }
523 
524     seek.QuadPart = 0;
525     hr = IStream_Seek(pIStream, seek, STREAM_SEEK_SET, NULL);
526     if (FAILED(hr)) goto end;
527 
528     hr = IStream_Read(pIStream, &This->header, sizeof(ICONHEADER), &bytesread);
529     if (FAILED(hr)) goto end;
530     if (bytesread != sizeof(ICONHEADER) ||
531         This->header.idReserved != 0 ||
532         This->header.idType != 1)
533     {
534         hr = E_FAIL;
535         goto end;
536     }
537 
538     This->initialized = TRUE;
539     This->stream = pIStream;
540     IStream_AddRef(pIStream);
541 
542 end:
543 
544     LeaveCriticalSection(&This->lock);
545 
546     return hr;
547 }
548 
549 static HRESULT WINAPI IcoDecoder_GetContainerFormat(IWICBitmapDecoder *iface,
550     GUID *pguidContainerFormat)
551 {
552     memcpy(pguidContainerFormat, &GUID_ContainerFormatIco, sizeof(GUID));
553     return S_OK;
554 }
555 
556 static HRESULT WINAPI IcoDecoder_GetDecoderInfo(IWICBitmapDecoder *iface,
557     IWICBitmapDecoderInfo **ppIDecoderInfo)
558 {
559     HRESULT hr;
560     IWICComponentInfo *compinfo;
561 
562     TRACE("(%p,%p)\n", iface, ppIDecoderInfo);
563 
564     hr = CreateComponentInfo(&CLSID_WICIcoDecoder, &compinfo);
565     if (FAILED(hr)) return hr;
566 
567     hr = IWICComponentInfo_QueryInterface(compinfo, &IID_IWICBitmapDecoderInfo,
568         (void**)ppIDecoderInfo);
569 
570     IWICComponentInfo_Release(compinfo);
571 
572     return hr;
573 }
574 
575 static HRESULT WINAPI IcoDecoder_CopyPalette(IWICBitmapDecoder *iface,
576     IWICPalette *pIPalette)
577 {
578     TRACE("(%p,%p)\n", iface, pIPalette);
579     return WINCODEC_ERR_PALETTEUNAVAILABLE;
580 }
581 
582 static HRESULT WINAPI IcoDecoder_GetMetadataQueryReader(IWICBitmapDecoder *iface,
583     IWICMetadataQueryReader **ppIMetadataQueryReader)
584 {
585     TRACE("(%p,%p)\n", iface, ppIMetadataQueryReader);
586     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
587 }
588 
589 static HRESULT WINAPI IcoDecoder_GetPreview(IWICBitmapDecoder *iface,
590     IWICBitmapSource **ppIBitmapSource)
591 {
592     TRACE("(%p,%p)\n", iface, ppIBitmapSource);
593     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
594 }
595 
596 static HRESULT WINAPI IcoDecoder_GetColorContexts(IWICBitmapDecoder *iface,
597     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
598 {
599     TRACE("(%p,%u,%p,%p)\n", iface, cCount, ppIColorContexts, pcActualCount);
600     return WINCODEC_ERR_UNSUPPORTEDOPERATION;
601 }
602 
603 static HRESULT WINAPI IcoDecoder_GetThumbnail(IWICBitmapDecoder *iface,
604     IWICBitmapSource **ppIThumbnail)
605 {
606     TRACE("(%p,%p)\n", iface, ppIThumbnail);
607     return WINCODEC_ERR_CODECNOTHUMBNAIL;
608 }
609 
610 static HRESULT WINAPI IcoDecoder_GetFrameCount(IWICBitmapDecoder *iface,
611     UINT *pCount)
612 {
613     IcoDecoder *This = impl_from_IWICBitmapDecoder(iface);
614 
615     if (!pCount) return E_INVALIDARG;
616 
617     EnterCriticalSection(&This->lock);
618     *pCount = This->initialized ? This->header.idCount : 0;
619     LeaveCriticalSection(&This->lock);
620 
621     TRACE("(%p) <-- %d\n", iface, *pCount);
622 
623     return S_OK;
624 }
625 
626 static HRESULT WINAPI IcoDecoder_GetFrame(IWICBitmapDecoder *iface,
627     UINT index, IWICBitmapFrameDecode **ppIBitmapFrame)
628 {
629     IcoDecoder *This = impl_from_IWICBitmapDecoder(iface);
630     IcoFrameDecode *result=NULL;
631     LARGE_INTEGER seek;
632     ULARGE_INTEGER offset, length;
633     HRESULT hr;
634     ULONG bytesread;
635     ICONDIRENTRY entry;
636     IWICStream *substream=NULL;
637     DWORD magic;
638     TRACE("(%p,%u,%p)\n", iface, index, ppIBitmapFrame);
639 
640     EnterCriticalSection(&This->lock);
641 
642     if (!This->initialized)
643     {
644         hr = WINCODEC_ERR_FRAMEMISSING;
645         goto fail;
646     }
647 
648     if (This->header.idCount < index)
649     {
650         hr = E_INVALIDARG;
651         goto fail;
652     }
653 
654     result = HeapAlloc(GetProcessHeap(), 0, sizeof(IcoFrameDecode));
655     if (!result)
656     {
657         hr = E_OUTOFMEMORY;
658         goto fail;
659     }
660 
661     result->IWICBitmapFrameDecode_iface.lpVtbl = &IcoFrameDecode_Vtbl;
662     result->ref = 1;
663     result->bits = NULL;
664 
665     /* read the icon entry */
666     seek.QuadPart = sizeof(ICONHEADER) + sizeof(ICONDIRENTRY) * index;
667     hr = IStream_Seek(This->stream, seek, STREAM_SEEK_SET, 0);
668     if (FAILED(hr)) goto fail;
669 
670     hr = IStream_Read(This->stream, &entry, sizeof(ICONDIRENTRY), &bytesread);
671     if (FAILED(hr) || bytesread != sizeof(ICONDIRENTRY)) goto fail;
672 
673     /* create a stream object for this icon */
674     hr = StreamImpl_Create(&substream);
675     if (FAILED(hr)) goto fail;
676 
677     offset.QuadPart = entry.dwDIBOffset;
678     length.QuadPart = entry.dwDIBSize;
679     hr = IWICStream_InitializeFromIStreamRegion(substream, This->stream, offset, length);
680     if (FAILED(hr)) goto fail;
681 
682     /* read the bitmapinfo size or magic number */
683     hr = IWICStream_Read(substream, &magic, sizeof(magic), &bytesread);
684     if (FAILED(hr) || bytesread != sizeof(magic)) goto fail;
685 
686     /* forward to the appropriate decoding function based on the magic number */
687     switch (magic)
688     {
689     case sizeof(BITMAPCOREHEADER):
690     case 64: /* sizeof(BITMAPCOREHEADER2) */
691     case sizeof(BITMAPINFOHEADER):
692     case sizeof(BITMAPV4HEADER):
693     case sizeof(BITMAPV5HEADER):
694         hr = ReadIcoDib((IStream*)substream, result);
695         break;
696     case 0x474e5089:
697         hr = ReadIcoPng((IStream*)substream, result);
698         break;
699     default:
700         FIXME("Unrecognized ICO frame magic: %x\n", magic);
701         hr = E_FAIL;
702         break;
703     }
704     if (FAILED(hr)) goto fail;
705 
706     *ppIBitmapFrame = &result->IWICBitmapFrameDecode_iface;
707 
708     LeaveCriticalSection(&This->lock);
709 
710     IWICStream_Release(substream);
711 
712     return S_OK;
713 
714 fail:
715     LeaveCriticalSection(&This->lock);
716     HeapFree(GetProcessHeap(), 0, result);
717     if (substream) IWICStream_Release(substream);
718     if (SUCCEEDED(hr)) hr = E_FAIL;
719     TRACE("<-- %x\n", hr);
720     return hr;
721 }
722 
723 static const IWICBitmapDecoderVtbl IcoDecoder_Vtbl = {
724     IcoDecoder_QueryInterface,
725     IcoDecoder_AddRef,
726     IcoDecoder_Release,
727     IcoDecoder_QueryCapability,
728     IcoDecoder_Initialize,
729     IcoDecoder_GetContainerFormat,
730     IcoDecoder_GetDecoderInfo,
731     IcoDecoder_CopyPalette,
732     IcoDecoder_GetMetadataQueryReader,
733     IcoDecoder_GetPreview,
734     IcoDecoder_GetColorContexts,
735     IcoDecoder_GetThumbnail,
736     IcoDecoder_GetFrameCount,
737     IcoDecoder_GetFrame
738 };
739 
740 HRESULT IcoDecoder_CreateInstance(REFIID iid, void** ppv)
741 {
742     IcoDecoder *This;
743     HRESULT ret;
744 
745     TRACE("(%s,%p)\n", debugstr_guid(iid), ppv);
746 
747     *ppv = NULL;
748 
749     This = HeapAlloc(GetProcessHeap(), 0, sizeof(IcoDecoder));
750     if (!This) return E_OUTOFMEMORY;
751 
752     This->IWICBitmapDecoder_iface.lpVtbl = &IcoDecoder_Vtbl;
753     This->ref = 1;
754     This->stream = NULL;
755     This->initialized = FALSE;
756     InitializeCriticalSection(&This->lock);
757     This->lock.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": IcoDecoder.lock");
758 
759     ret = IWICBitmapDecoder_QueryInterface(&This->IWICBitmapDecoder_iface, iid, ppv);
760     IWICBitmapDecoder_Release(&This->IWICBitmapDecoder_iface);
761 
762     return ret;
763 }
764