gifformat.c 41.9 KB
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/*
 * Copyright 2009 Vincent Povirk for CodeWeavers
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 * Copyright 2012 Dmitry Timoshkov
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 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "config.h"

#include <stdarg.h>

#define COBJMACROS
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#define NONAMELESSUNION
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#include "windef.h"
#include "winbase.h"
#include "objbase.h"
#include "wincodec.h"
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#include "wincodecsdk.h"
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#include "ungif.h"

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#include "wincodecs_private.h"

#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(wincodecs);

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static LPWSTR strdupAtoW(const char *src)
{
    int len = MultiByteToWideChar(CP_ACP, 0, src, -1, NULL, 0);
    LPWSTR dst = HeapAlloc(GetProcessHeap(), 0, len * sizeof(WCHAR));
    if (dst) MultiByteToWideChar(CP_ACP, 0, src, -1, dst, len);
    return dst;
}

static HRESULT load_LSD_metadata(IStream *stream, const GUID *vendor, DWORD options,
                                 MetadataItem **items, DWORD *count)
{
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#include "pshpack1.h"
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    struct logical_screen_descriptor
    {
        char signature[6];
        USHORT width;
        USHORT height;
        BYTE packed;
        /* global_color_table_flag : 1;
         * color_resolution : 3;
         * sort_flag : 1;
         * global_color_table_size : 3;
         */
        BYTE background_color_index;
        BYTE pixel_aspect_ratio;
    } lsd_data;
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#include "poppack.h"
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    HRESULT hr;
    ULONG bytesread, i;
    MetadataItem *result;

    *items = NULL;
    *count = 0;

    hr = IStream_Read(stream, &lsd_data, sizeof(lsd_data), &bytesread);
    if (FAILED(hr) || bytesread != sizeof(lsd_data)) return S_OK;

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    result = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(MetadataItem) * 9);
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    if (!result) return E_OUTOFMEMORY;

    for (i = 0; i < 9; i++)
    {
        PropVariantInit(&result[i].schema);
        PropVariantInit(&result[i].id);
        PropVariantInit(&result[i].value);
    }

    result[0].id.vt = VT_LPWSTR;
    result[0].id.u.pwszVal = strdupAtoW("Signature");
    result[0].value.vt = VT_UI1|VT_VECTOR;
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    result[0].value.u.caub.cElems = sizeof(lsd_data.signature);
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    result[0].value.u.caub.pElems = HeapAlloc(GetProcessHeap(), 0, sizeof(lsd_data.signature));
    memcpy(result[0].value.u.caub.pElems, lsd_data.signature, sizeof(lsd_data.signature));

    result[1].id.vt = VT_LPWSTR;
    result[1].id.u.pwszVal = strdupAtoW("Width");
    result[1].value.vt = VT_UI2;
    result[1].value.u.uiVal = lsd_data.width;

    result[2].id.vt = VT_LPWSTR;
    result[2].id.u.pwszVal = strdupAtoW("Height");
    result[2].value.vt = VT_UI2;
    result[2].value.u.uiVal = lsd_data.height;

    result[3].id.vt = VT_LPWSTR;
    result[3].id.u.pwszVal = strdupAtoW("GlobalColorTableFlag");
    result[3].value.vt = VT_BOOL;
    result[3].value.u.boolVal = (lsd_data.packed >> 7) & 1;

    result[4].id.vt = VT_LPWSTR;
    result[4].id.u.pwszVal = strdupAtoW("ColorResolution");
    result[4].value.vt = VT_UI1;
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    result[4].value.u.bVal = (lsd_data.packed >> 4) & 7;
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    result[5].id.vt = VT_LPWSTR;
    result[5].id.u.pwszVal = strdupAtoW("SortFlag");
    result[5].value.vt = VT_BOOL;
    result[5].value.u.boolVal = (lsd_data.packed >> 3) & 1;

    result[6].id.vt = VT_LPWSTR;
    result[6].id.u.pwszVal = strdupAtoW("GlobalColorTableSize");
    result[6].value.vt = VT_UI1;
    result[6].value.u.bVal = lsd_data.packed & 7;

    result[7].id.vt = VT_LPWSTR;
    result[7].id.u.pwszVal = strdupAtoW("BackgroundColorIndex");
    result[7].value.vt = VT_UI1;
    result[7].value.u.bVal = lsd_data.background_color_index;

    result[8].id.vt = VT_LPWSTR;
    result[8].id.u.pwszVal = strdupAtoW("PixelAspectRatio");
    result[8].value.vt = VT_UI1;
    result[8].value.u.bVal = lsd_data.pixel_aspect_ratio;

    *items = result;
    *count = 9;

    return S_OK;
}

static const MetadataHandlerVtbl LSDReader_Vtbl = {
    0,
    &CLSID_WICLSDMetadataReader,
    load_LSD_metadata
};

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HRESULT LSDReader_CreateInstance(REFIID iid, void **ppv)
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{
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    return MetadataReader_Create(&LSDReader_Vtbl, iid, ppv);
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}

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#include "pshpack1.h"
struct image_descriptor
{
    USHORT left;
    USHORT top;
    USHORT width;
    USHORT height;
    BYTE packed;
    /* local_color_table_flag : 1;
     * interlace_flag : 1;
     * sort_flag : 1;
     * reserved : 2;
     * local_color_table_size : 3;
     */
};
#include "poppack.h"

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static HRESULT load_IMD_metadata(IStream *stream, const GUID *vendor, DWORD options,
                                 MetadataItem **items, DWORD *count)
{
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    struct image_descriptor imd_data;
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    HRESULT hr;
    ULONG bytesread, i;
    MetadataItem *result;

    *items = NULL;
    *count = 0;

    hr = IStream_Read(stream, &imd_data, sizeof(imd_data), &bytesread);
    if (FAILED(hr) || bytesread != sizeof(imd_data)) return S_OK;

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    result = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(MetadataItem) * 8);
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    if (!result) return E_OUTOFMEMORY;

    for (i = 0; i < 8; i++)
    {
        PropVariantInit(&result[i].schema);
        PropVariantInit(&result[i].id);
        PropVariantInit(&result[i].value);
    }

    result[0].id.vt = VT_LPWSTR;
    result[0].id.u.pwszVal = strdupAtoW("Left");
    result[0].value.vt = VT_UI2;
    result[0].value.u.uiVal = imd_data.left;

    result[1].id.vt = VT_LPWSTR;
    result[1].id.u.pwszVal = strdupAtoW("Top");
    result[1].value.vt = VT_UI2;
    result[1].value.u.uiVal = imd_data.top;

    result[2].id.vt = VT_LPWSTR;
    result[2].id.u.pwszVal = strdupAtoW("Width");
    result[2].value.vt = VT_UI2;
    result[2].value.u.uiVal = imd_data.width;

    result[3].id.vt = VT_LPWSTR;
    result[3].id.u.pwszVal = strdupAtoW("Height");
    result[3].value.vt = VT_UI2;
    result[3].value.u.uiVal = imd_data.height;

    result[4].id.vt = VT_LPWSTR;
    result[4].id.u.pwszVal = strdupAtoW("LocalColorTableFlag");
    result[4].value.vt = VT_BOOL;
    result[4].value.u.boolVal = (imd_data.packed >> 7) & 1;

    result[5].id.vt = VT_LPWSTR;
    result[5].id.u.pwszVal = strdupAtoW("InterlaceFlag");
    result[5].value.vt = VT_BOOL;
    result[5].value.u.boolVal = (imd_data.packed >> 6) & 1;

    result[6].id.vt = VT_LPWSTR;
    result[6].id.u.pwszVal = strdupAtoW("SortFlag");
    result[6].value.vt = VT_BOOL;
    result[6].value.u.boolVal = (imd_data.packed >> 5) & 1;

    result[7].id.vt = VT_LPWSTR;
    result[7].id.u.pwszVal = strdupAtoW("LocalColorTableSize");
    result[7].value.vt = VT_UI1;
    result[7].value.u.bVal = imd_data.packed & 7;

    *items = result;
    *count = 8;

    return S_OK;
}

static const MetadataHandlerVtbl IMDReader_Vtbl = {
    0,
    &CLSID_WICIMDMetadataReader,
    load_IMD_metadata
};

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HRESULT IMDReader_CreateInstance(REFIID iid, void **ppv)
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{
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    return MetadataReader_Create(&IMDReader_Vtbl, iid, ppv);
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}

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static HRESULT load_GCE_metadata(IStream *stream, const GUID *vendor, DWORD options,
                                 MetadataItem **items, DWORD *count)
{
#include "pshpack1.h"
    struct graphic_control_extenstion
    {
        BYTE packed;
        /* reservred: 3;
         * disposal : 3;
         * user_input_flag : 1;
         * transparency_flag : 1;
         */
         USHORT delay;
         BYTE transparent_color_index;
    } gce_data;
#include "poppack.h"
    HRESULT hr;
    ULONG bytesread, i;
    MetadataItem *result;

    *items = NULL;
    *count = 0;

    hr = IStream_Read(stream, &gce_data, sizeof(gce_data), &bytesread);
    if (FAILED(hr) || bytesread != sizeof(gce_data)) return S_OK;

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    result = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(MetadataItem) * 5);
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    if (!result) return E_OUTOFMEMORY;

    for (i = 0; i < 5; i++)
    {
        PropVariantInit(&result[i].schema);
        PropVariantInit(&result[i].id);
        PropVariantInit(&result[i].value);
    }

    result[0].id.vt = VT_LPWSTR;
    result[0].id.u.pwszVal = strdupAtoW("Disposal");
    result[0].value.vt = VT_UI1;
    result[0].value.u.bVal = (gce_data.packed >> 2) & 7;

    result[1].id.vt = VT_LPWSTR;
    result[1].id.u.pwszVal = strdupAtoW("UserInputFlag");
    result[1].value.vt = VT_BOOL;
    result[1].value.u.boolVal = (gce_data.packed >> 1) & 1;

    result[2].id.vt = VT_LPWSTR;
    result[2].id.u.pwszVal = strdupAtoW("TransparencyFlag");
    result[2].value.vt = VT_BOOL;
    result[2].value.u.boolVal = gce_data.packed & 1;

    result[3].id.vt = VT_LPWSTR;
    result[3].id.u.pwszVal = strdupAtoW("Delay");
    result[3].value.vt = VT_UI2;
    result[3].value.u.uiVal = gce_data.delay;

    result[4].id.vt = VT_LPWSTR;
    result[4].id.u.pwszVal = strdupAtoW("TransparentColorIndex");
    result[4].value.vt = VT_UI1;
    result[4].value.u.bVal = gce_data.transparent_color_index;

    *items = result;
    *count = 5;

    return S_OK;
}

static const MetadataHandlerVtbl GCEReader_Vtbl = {
    0,
    &CLSID_WICGCEMetadataReader,
    load_GCE_metadata
};

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HRESULT GCEReader_CreateInstance(REFIID iid, void **ppv)
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{
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    return MetadataReader_Create(&GCEReader_Vtbl, iid, ppv);
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}

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static HRESULT load_APE_metadata(IStream *stream, const GUID *vendor, DWORD options,
                                 MetadataItem **items, DWORD *count)
{
#include "pshpack1.h"
    struct application_extenstion
    {
        BYTE extension_introducer;
        BYTE extension_label;
        BYTE block_size;
        BYTE application[11];
    } ape_data;
#include "poppack.h"
    HRESULT hr;
    ULONG bytesread, data_size, i;
    MetadataItem *result;
    BYTE subblock_size;
    BYTE *data;

    *items = NULL;
    *count = 0;

    hr = IStream_Read(stream, &ape_data, sizeof(ape_data), &bytesread);
    if (FAILED(hr) || bytesread != sizeof(ape_data)) return S_OK;
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    if (ape_data.extension_introducer != 0x21 ||
        ape_data.extension_label != APPLICATION_EXT_FUNC_CODE ||
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        ape_data.block_size != 11)
        return S_OK;

    data = NULL;
    data_size = 0;

    for (;;)
    {
        hr = IStream_Read(stream, &subblock_size, sizeof(subblock_size), &bytesread);
        if (FAILED(hr) || bytesread != sizeof(subblock_size))
        {
            HeapFree(GetProcessHeap(), 0, data);
            return S_OK;
        }
        if (!subblock_size) break;

        if (!data)
            data = HeapAlloc(GetProcessHeap(), 0, subblock_size + 1);
        else
        {
            BYTE *new_data = HeapReAlloc(GetProcessHeap(), 0, data, data_size + subblock_size + 1);
            if (!new_data)
            {
                HeapFree(GetProcessHeap(), 0, data);
                return S_OK;
            }
            data = new_data;
        }
        data[data_size] = subblock_size;
        hr = IStream_Read(stream, data + data_size + 1, subblock_size, &bytesread);
        if (FAILED(hr) || bytesread != subblock_size)
        {
            HeapFree(GetProcessHeap(), 0, data);
            return S_OK;
        }
        data_size += subblock_size + 1;
    }

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    result = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(MetadataItem) * 2);
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    if (!result)
    {
        HeapFree(GetProcessHeap(), 0, data);
        return E_OUTOFMEMORY;
    }

    for (i = 0; i < 2; i++)
    {
        PropVariantInit(&result[i].schema);
        PropVariantInit(&result[i].id);
        PropVariantInit(&result[i].value);
    }

    result[0].id.vt = VT_LPWSTR;
    result[0].id.u.pwszVal = strdupAtoW("Application");
    result[0].value.vt = VT_UI1|VT_VECTOR;
    result[0].value.u.caub.cElems = sizeof(ape_data.application);
    result[0].value.u.caub.pElems = HeapAlloc(GetProcessHeap(), 0, sizeof(ape_data.application));
    memcpy(result[0].value.u.caub.pElems, ape_data.application, sizeof(ape_data.application));

    result[1].id.vt = VT_LPWSTR;
    result[1].id.u.pwszVal = strdupAtoW("Data");
    result[1].value.vt = VT_UI1|VT_VECTOR;
    result[1].value.u.caub.cElems = data_size;
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    result[1].value.u.caub.pElems = data;
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    *items = result;
    *count = 2;

    return S_OK;
}

static const MetadataHandlerVtbl APEReader_Vtbl = {
    0,
    &CLSID_WICAPEMetadataReader,
    load_APE_metadata
};

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HRESULT APEReader_CreateInstance(REFIID iid, void **ppv)
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{
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    return MetadataReader_Create(&APEReader_Vtbl, iid, ppv);
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}

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static HRESULT load_GifComment_metadata(IStream *stream, const GUID *vendor, DWORD options,
                                        MetadataItem **items, DWORD *count)
{
#include "pshpack1.h"
    struct gif_extenstion
    {
        BYTE extension_introducer;
        BYTE extension_label;
    } ext_data;
#include "poppack.h"
    HRESULT hr;
    ULONG bytesread, data_size;
    MetadataItem *result;
    BYTE subblock_size;
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    char *data;
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    *items = NULL;
    *count = 0;

    hr = IStream_Read(stream, &ext_data, sizeof(ext_data), &bytesread);
    if (FAILED(hr) || bytesread != sizeof(ext_data)) return S_OK;
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    if (ext_data.extension_introducer != 0x21 ||
        ext_data.extension_label != COMMENT_EXT_FUNC_CODE)
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        return S_OK;

    data = NULL;
    data_size = 0;

    for (;;)
    {
        hr = IStream_Read(stream, &subblock_size, sizeof(subblock_size), &bytesread);
        if (FAILED(hr) || bytesread != sizeof(subblock_size))
        {
            HeapFree(GetProcessHeap(), 0, data);
            return S_OK;
        }
        if (!subblock_size) break;

        if (!data)
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            data = HeapAlloc(GetProcessHeap(), 0, subblock_size + 1);
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        else
        {
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            char *new_data = HeapReAlloc(GetProcessHeap(), 0, data, data_size + subblock_size + 1);
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            if (!new_data)
            {
                HeapFree(GetProcessHeap(), 0, data);
                return S_OK;
            }
            data = new_data;
        }
        hr = IStream_Read(stream, data + data_size, subblock_size, &bytesread);
        if (FAILED(hr) || bytesread != subblock_size)
        {
            HeapFree(GetProcessHeap(), 0, data);
            return S_OK;
        }
        data_size += subblock_size;
    }

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    data[data_size] = 0;

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    result = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(MetadataItem));
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    if (!result)
    {
        HeapFree(GetProcessHeap(), 0, data);
        return E_OUTOFMEMORY;
    }

    PropVariantInit(&result->schema);
    PropVariantInit(&result->id);
    PropVariantInit(&result->value);

    result->id.vt = VT_LPWSTR;
    result->id.u.pwszVal = strdupAtoW("TextEntry");
    result->value.vt = VT_LPSTR;
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    result->value.u.pszVal = data;
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    *items = result;
    *count = 1;

    return S_OK;
}

static const MetadataHandlerVtbl GifCommentReader_Vtbl = {
    0,
    &CLSID_WICGifCommentMetadataReader,
    load_GifComment_metadata
};

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HRESULT GifCommentReader_CreateInstance(REFIID iid, void **ppv)
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{
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    return MetadataReader_Create(&GifCommentReader_Vtbl, iid, ppv);
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}

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static IStream *create_stream(const void *data, int data_size)
{
    HRESULT hr;
    IStream *stream;
    HGLOBAL hdata;
    void *locked_data;

    hdata = GlobalAlloc(GMEM_MOVEABLE, data_size);
    if (!hdata) return NULL;

    locked_data = GlobalLock(hdata);
    memcpy(locked_data, data, data_size);
    GlobalUnlock(hdata);

    hr = CreateStreamOnHGlobal(hdata, TRUE, &stream);
    return FAILED(hr) ? NULL : stream;
}

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static HRESULT create_metadata_reader(const void *data, int data_size,
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                                      class_constructor constructor,
                                      IWICMetadataReader **reader)
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{
    HRESULT hr;
    IWICMetadataReader *metadata_reader;
    IWICPersistStream *persist;
    IStream *stream;

    /* FIXME: Use IWICComponentFactory_CreateMetadataReader once it's implemented */

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    hr = constructor(&IID_IWICMetadataReader, (void**)&metadata_reader);
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    if (FAILED(hr)) return hr;

    hr = IWICMetadataReader_QueryInterface(metadata_reader, &IID_IWICPersistStream, (void **)&persist);
    if (FAILED(hr))
    {
        IWICMetadataReader_Release(metadata_reader);
        return hr;
    }

    stream = create_stream(data, data_size);
    IWICPersistStream_LoadEx(persist, stream, NULL, WICPersistOptionsDefault);
    IStream_Release(stream);

    IWICPersistStream_Release(persist);

    *reader = metadata_reader;
    return S_OK;
}

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typedef struct {
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    IWICBitmapDecoder IWICBitmapDecoder_iface;
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    IWICMetadataBlockReader IWICMetadataBlockReader_iface;
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    IStream *stream;
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    BYTE LSD_data[13]; /* Logical Screen Descriptor */
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    LONG ref;
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    BOOL initialized;
    GifFileType *gif;
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    UINT current_frame;
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    CRITICAL_SECTION lock;
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} GifDecoder;

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typedef struct {
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    IWICBitmapFrameDecode IWICBitmapFrameDecode_iface;
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    IWICMetadataBlockReader IWICMetadataBlockReader_iface;
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    LONG ref;
    SavedImage *frame;
    GifDecoder *parent;
} GifFrameDecode;

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static inline GifDecoder *impl_from_IWICBitmapDecoder(IWICBitmapDecoder *iface)
{
    return CONTAINING_RECORD(iface, GifDecoder, IWICBitmapDecoder_iface);
}

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static inline GifDecoder *impl_from_IWICMetadataBlockReader(IWICMetadataBlockReader *iface)
{
    return CONTAINING_RECORD(iface, GifDecoder, IWICMetadataBlockReader_iface);
}

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static inline GifFrameDecode *impl_from_IWICBitmapFrameDecode(IWICBitmapFrameDecode *iface)
{
    return CONTAINING_RECORD(iface, GifFrameDecode, IWICBitmapFrameDecode_iface);
}

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static inline GifFrameDecode *frame_from_IWICMetadataBlockReader(IWICMetadataBlockReader *iface)
{
    return CONTAINING_RECORD(iface, GifFrameDecode, IWICMetadataBlockReader_iface);
}

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static HRESULT WINAPI GifFrameDecode_QueryInterface(IWICBitmapFrameDecode *iface, REFIID iid,
    void **ppv)
{
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    GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
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    TRACE("(%p,%s,%p)\n", iface, debugstr_guid(iid), ppv);

    if (!ppv) return E_INVALIDARG;

    if (IsEqualIID(&IID_IUnknown, iid) ||
        IsEqualIID(&IID_IWICBitmapSource, iid) ||
        IsEqualIID(&IID_IWICBitmapFrameDecode, iid))
    {
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        *ppv = &This->IWICBitmapFrameDecode_iface;
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    }
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    else if (IsEqualIID(&IID_IWICMetadataBlockReader, iid))
    {
        *ppv = &This->IWICMetadataBlockReader_iface;
    }
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    else
    {
        *ppv = NULL;
        return E_NOINTERFACE;
    }

    IUnknown_AddRef((IUnknown*)*ppv);
    return S_OK;
}

static ULONG WINAPI GifFrameDecode_AddRef(IWICBitmapFrameDecode *iface)
{
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    GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
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    ULONG ref = InterlockedIncrement(&This->ref);

    TRACE("(%p) refcount=%u\n", iface, ref);

    return ref;
}

static ULONG WINAPI GifFrameDecode_Release(IWICBitmapFrameDecode *iface)
{
658
    GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
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    ULONG ref = InterlockedDecrement(&This->ref);

    TRACE("(%p) refcount=%u\n", iface, ref);

    if (ref == 0)
    {
665
        IWICBitmapDecoder_Release(&This->parent->IWICBitmapDecoder_iface);
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        HeapFree(GetProcessHeap(), 0, This);
    }

    return ref;
}

static HRESULT WINAPI GifFrameDecode_GetSize(IWICBitmapFrameDecode *iface,
    UINT *puiWidth, UINT *puiHeight)
{
675
    GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
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    TRACE("(%p,%p,%p)\n", iface, puiWidth, puiHeight);

    *puiWidth = This->frame->ImageDesc.Width;
    *puiHeight = This->frame->ImageDesc.Height;

    return S_OK;
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}

static HRESULT WINAPI GifFrameDecode_GetPixelFormat(IWICBitmapFrameDecode *iface,
    WICPixelFormatGUID *pPixelFormat)
{
    memcpy(pPixelFormat, &GUID_WICPixelFormat8bppIndexed, sizeof(GUID));

    return S_OK;
}

static HRESULT WINAPI GifFrameDecode_GetResolution(IWICBitmapFrameDecode *iface,
    double *pDpiX, double *pDpiY)
{
695
    GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
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    const GifWord aspect_word = This->parent->gif->SAspectRatio;
    const double aspect = (aspect_word > 0) ? ((aspect_word + 15.0) / 64.0) : 1.0;
    TRACE("(%p,%p,%p)\n", iface, pDpiX, pDpiY);

    *pDpiX = 96.0 / aspect;
    *pDpiY = 96.0;

    return S_OK;
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}

static HRESULT WINAPI GifFrameDecode_CopyPalette(IWICBitmapFrameDecode *iface,
    IWICPalette *pIPalette)
{
709
    GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
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    WICColor colors[256];
    ColorMapObject *cm = This->frame->ImageDesc.ColorMap;
    int i, trans;
    ExtensionBlock *eb;
    TRACE("(%p,%p)\n", iface, pIPalette);

    if (!cm) cm = This->parent->gif->SColorMap;

    if (cm->ColorCount > 256)
    {
        ERR("GIF contains %i colors???\n", cm->ColorCount);
        return E_FAIL;
    }

    for (i = 0; i < cm->ColorCount; i++) {
        colors[i] = 0xff000000| /* alpha */
                    cm->Colors[i].Red << 16|
                    cm->Colors[i].Green << 8|
                    cm->Colors[i].Blue;
    }

    /* look for the transparent color extension */
732 733
    for (i = 0; i < This->frame->Extensions.ExtensionBlockCount; ++i) {
	eb = This->frame->Extensions.ExtensionBlocks + i;
734 735 736
	if (eb->Function == GRAPHICS_EXT_FUNC_CODE && eb->ByteCount == 8) {
	    if (eb->Bytes[3] & 1) {
	        trans = (unsigned char)eb->Bytes[6];
737 738 739 740 741 742
	        colors[trans] &= 0xffffff; /* set alpha to 0 */
	        break;
	    }
	}
    }

743
    return IWICPalette_InitializeCustom(pIPalette, colors, cm->ColorCount);
744 745
}

746 747 748 749 750 751 752 753
static HRESULT copy_interlaced_pixels(const BYTE *srcbuffer,
    UINT srcwidth, UINT srcheight, INT srcstride, const WICRect *rc,
    UINT dststride, UINT dstbuffersize, BYTE *dstbuffer)
{
    UINT row_offset; /* number of bytes into the source rows where the data starts */
    const BYTE *src;
    BYTE *dst;
    UINT y;
754
    WICRect rect;
755

756 757 758 759 760 761 762 763 764 765 766 767 768
    if (!rc)
    {
        rect.X = 0;
        rect.Y = 0;
        rect.Width = srcwidth;
        rect.Height = srcheight;
        rc = &rect;
    }
    else
    {
        if (rc->X < 0 || rc->Y < 0 || rc->X+rc->Width > srcwidth || rc->Y+rc->Height > srcheight)
            return E_INVALIDARG;
    }
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    if (dststride < rc->Width)
        return E_INVALIDARG;

    if ((dststride * rc->Height) > dstbuffersize)
        return E_INVALIDARG;

    row_offset = rc->X;

    dst = dstbuffer;
    for (y=rc->Y; y-rc->Y < rc->Height; y++)
    {
        if (y%8 == 0)
            src = srcbuffer + srcstride * (y/8);
        else if (y%4 == 0)
            src = srcbuffer + srcstride * ((srcheight+7)/8 + y/8);
        else if (y%2 == 0)
            src = srcbuffer + srcstride * ((srcheight+3)/4 + y/4);
        else /* y%2 == 1 */
            src = srcbuffer + srcstride * ((srcheight+1)/2 + y/2);
        src += row_offset;
        memcpy(dst, src, rc->Width);
        dst += dststride;
    }
    return S_OK;
}

796 797 798
static HRESULT WINAPI GifFrameDecode_CopyPixels(IWICBitmapFrameDecode *iface,
    const WICRect *prc, UINT cbStride, UINT cbBufferSize, BYTE *pbBuffer)
{
799
    GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
800 801 802 803 804 805 806 807 808 809 810 811 812 813
    TRACE("(%p,%p,%u,%u,%p)\n", iface, prc, cbStride, cbBufferSize, pbBuffer);

    if (This->frame->ImageDesc.Interlace)
    {
        return copy_interlaced_pixels(This->frame->RasterBits, This->frame->ImageDesc.Width,
            This->frame->ImageDesc.Height, This->frame->ImageDesc.Width,
            prc, cbStride, cbBufferSize, pbBuffer);
    }
    else
    {
        return copy_pixels(8, This->frame->RasterBits, This->frame->ImageDesc.Width,
            This->frame->ImageDesc.Height, This->frame->ImageDesc.Width,
            prc, cbStride, cbBufferSize, pbBuffer);
    }
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}

static HRESULT WINAPI GifFrameDecode_GetMetadataQueryReader(IWICBitmapFrameDecode *iface,
    IWICMetadataQueryReader **ppIMetadataQueryReader)
{
    TRACE("(%p,%p)\n", iface, ppIMetadataQueryReader);
    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
}

static HRESULT WINAPI GifFrameDecode_GetColorContexts(IWICBitmapFrameDecode *iface,
    UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
{
    TRACE("(%p,%u,%p,%p)\n", iface, cCount, ppIColorContexts, pcActualCount);
    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
}

static HRESULT WINAPI GifFrameDecode_GetThumbnail(IWICBitmapFrameDecode *iface,
    IWICBitmapSource **ppIThumbnail)
{
    TRACE("(%p,%p)\n", iface, ppIThumbnail);
    return WINCODEC_ERR_CODECNOTHUMBNAIL;
}

static const IWICBitmapFrameDecodeVtbl GifFrameDecode_Vtbl = {
    GifFrameDecode_QueryInterface,
    GifFrameDecode_AddRef,
    GifFrameDecode_Release,
    GifFrameDecode_GetSize,
    GifFrameDecode_GetPixelFormat,
    GifFrameDecode_GetResolution,
    GifFrameDecode_CopyPalette,
    GifFrameDecode_CopyPixels,
    GifFrameDecode_GetMetadataQueryReader,
    GifFrameDecode_GetColorContexts,
    GifFrameDecode_GetThumbnail
};

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static HRESULT WINAPI GifFrameDecode_Block_QueryInterface(IWICMetadataBlockReader *iface,
    REFIID iid, void **ppv)
{
    GifFrameDecode *This = frame_from_IWICMetadataBlockReader(iface);
    return IWICBitmapFrameDecode_QueryInterface(&This->IWICBitmapFrameDecode_iface, iid, ppv);
}

static ULONG WINAPI GifFrameDecode_Block_AddRef(IWICMetadataBlockReader *iface)
{
    GifFrameDecode *This = frame_from_IWICMetadataBlockReader(iface);
    return IWICBitmapFrameDecode_AddRef(&This->IWICBitmapFrameDecode_iface);
}

static ULONG WINAPI GifFrameDecode_Block_Release(IWICMetadataBlockReader *iface)
{
    GifFrameDecode *This = frame_from_IWICMetadataBlockReader(iface);
    return IWICBitmapFrameDecode_Release(&This->IWICBitmapFrameDecode_iface);
}

static HRESULT WINAPI GifFrameDecode_Block_GetContainerFormat(IWICMetadataBlockReader *iface,
    GUID *guid)
{
    TRACE("(%p,%p)\n", iface, guid);

    if (!guid) return E_INVALIDARG;

    *guid = GUID_ContainerFormatGif;
    return S_OK;
}

static HRESULT WINAPI GifFrameDecode_Block_GetCount(IWICMetadataBlockReader *iface,
    UINT *count)
{
884 885
    GifFrameDecode *This = frame_from_IWICMetadataBlockReader(iface);

886 887 888 889
    TRACE("%p,%p\n", iface, count);

    if (!count) return E_INVALIDARG;

890
    *count = This->frame->Extensions.ExtensionBlockCount + 1;
891 892 893 894 895 896 897 898 899 900 901 902 903
    return S_OK;
}

static HRESULT create_IMD_metadata_reader(GifFrameDecode *This, IWICMetadataReader **reader)
{
    HRESULT hr;
    IWICMetadataReader *metadata_reader;
    IWICPersistStream *persist;
    IStream *stream;
    struct image_descriptor IMD_data;

    /* FIXME: Use IWICComponentFactory_CreateMetadataReader once it's implemented */

904
    hr = IMDReader_CreateInstance(&IID_IWICMetadataReader, (void **)&metadata_reader);
905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926
    if (FAILED(hr)) return hr;

    hr = IWICMetadataReader_QueryInterface(metadata_reader, &IID_IWICPersistStream, (void **)&persist);
    if (FAILED(hr))
    {
        IWICMetadataReader_Release(metadata_reader);
        return hr;
    }

    /* recreate IMD structure from GIF decoder data */
    IMD_data.left = This->frame->ImageDesc.Left;
    IMD_data.top = This->frame->ImageDesc.Top;
    IMD_data.width = This->frame->ImageDesc.Width;
    IMD_data.height = This->frame->ImageDesc.Height;
    IMD_data.packed = 0;
    /* interlace_flag */
    IMD_data.packed |= This->frame->ImageDesc.Interlace ? (1 << 6) : 0;
    if (This->frame->ImageDesc.ColorMap)
    {
        /* local_color_table_flag */
        IMD_data.packed |= 1 << 7;
        /* local_color_table_size */
927
        IMD_data.packed |= This->frame->ImageDesc.ColorMap->BitsPerPixel - 1;
928 929
        /* sort_flag */
        IMD_data.packed |= This->frame->ImageDesc.ColorMap->SortFlag ? 0x20 : 0;
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    }

    stream = create_stream(&IMD_data, sizeof(IMD_data));
    IWICPersistStream_LoadEx(persist, stream, NULL, WICPersistOptionsDefault);
    IStream_Release(stream);

    IWICPersistStream_Release(persist);

    *reader = metadata_reader;
    return S_OK;
}

static HRESULT WINAPI GifFrameDecode_Block_GetReaderByIndex(IWICMetadataBlockReader *iface,
    UINT index, IWICMetadataReader **reader)
{
    GifFrameDecode *This = frame_from_IWICMetadataBlockReader(iface);
946
    int i, gce_index = -1, gce_skipped = 0;
947 948 949

    TRACE("(%p,%u,%p)\n", iface, index, reader);

950
    if (!reader) return E_INVALIDARG;
951 952 953 954

    if (index == 0)
        return create_IMD_metadata_reader(This, reader);

955 956 957 958 959
    if (index >= This->frame->Extensions.ExtensionBlockCount + 1)
        return E_INVALIDARG;

    for (i = 0; i < This->frame->Extensions.ExtensionBlockCount; i++)
    {
960
        class_constructor constructor;
961 962
        const void *data;
        int data_size;
963

964 965 966 967 968 969 970 971 972 973
        if (index != i + 1 - gce_skipped) continue;

        if (This->frame->Extensions.ExtensionBlocks[i].Function == GRAPHICS_EXT_FUNC_CODE)
        {
            gce_index = i;
            gce_skipped = 1;
            continue;
        }
        else if (This->frame->Extensions.ExtensionBlocks[i].Function == COMMENT_EXT_FUNC_CODE)
        {
974
            constructor = GifCommentReader_CreateInstance;
975 976 977 978 979
            data = This->frame->Extensions.ExtensionBlocks[i].Bytes;
            data_size = This->frame->Extensions.ExtensionBlocks[i].ByteCount;
        }
        else
        {
980
            constructor = UnknownMetadataReader_CreateInstance;
981 982 983
            data = This->frame->Extensions.ExtensionBlocks[i].Bytes;
            data_size = This->frame->Extensions.ExtensionBlocks[i].ByteCount;
        }
984
        return create_metadata_reader(data, data_size, constructor, reader);
985 986 987 988 989 990
    }

    if (gce_index == -1) return E_INVALIDARG;

    return create_metadata_reader(This->frame->Extensions.ExtensionBlocks[gce_index].Bytes + 3,
                                  This->frame->Extensions.ExtensionBlocks[gce_index].ByteCount - 4,
991
                                  GCEReader_CreateInstance, reader);
992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011
}

static HRESULT WINAPI GifFrameDecode_Block_GetEnumerator(IWICMetadataBlockReader *iface,
    IEnumUnknown **enumerator)
{
    FIXME("(%p,%p): stub\n", iface, enumerator);
    return E_NOTIMPL;
}

static const IWICMetadataBlockReaderVtbl GifFrameDecode_BlockVtbl =
{
    GifFrameDecode_Block_QueryInterface,
    GifFrameDecode_Block_AddRef,
    GifFrameDecode_Block_Release,
    GifFrameDecode_Block_GetContainerFormat,
    GifFrameDecode_Block_GetCount,
    GifFrameDecode_Block_GetReaderByIndex,
    GifFrameDecode_Block_GetEnumerator
};

1012 1013 1014
static HRESULT WINAPI GifDecoder_QueryInterface(IWICBitmapDecoder *iface, REFIID iid,
    void **ppv)
{
1015
    GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
1016 1017 1018 1019
    TRACE("(%p,%s,%p)\n", iface, debugstr_guid(iid), ppv);

    if (!ppv) return E_INVALIDARG;

1020 1021
    if (IsEqualIID(&IID_IUnknown, iid) ||
        IsEqualIID(&IID_IWICBitmapDecoder, iid))
1022
    {
1023
        *ppv = &This->IWICBitmapDecoder_iface;
1024
    }
1025 1026 1027 1028
    else if (IsEqualIID(&IID_IWICMetadataBlockReader, iid))
    {
        *ppv = &This->IWICMetadataBlockReader_iface;
    }
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040
    else
    {
        *ppv = NULL;
        return E_NOINTERFACE;
    }

    IUnknown_AddRef((IUnknown*)*ppv);
    return S_OK;
}

static ULONG WINAPI GifDecoder_AddRef(IWICBitmapDecoder *iface)
{
1041
    GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
1042 1043 1044 1045 1046 1047 1048 1049 1050
    ULONG ref = InterlockedIncrement(&This->ref);

    TRACE("(%p) refcount=%u\n", iface, ref);

    return ref;
}

static ULONG WINAPI GifDecoder_Release(IWICBitmapDecoder *iface)
{
1051
    GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
1052 1053 1054 1055 1056 1057
    ULONG ref = InterlockedDecrement(&This->ref);

    TRACE("(%p) refcount=%u\n", iface, ref);

    if (ref == 0)
    {
1058 1059 1060 1061 1062
        if (This->stream)
        {
            IStream_Release(This->stream);
            DGifCloseFile(This->gif);
        }
1063 1064
        This->lock.DebugInfo->Spare[0] = 0;
        DeleteCriticalSection(&This->lock);
1065 1066 1067 1068 1069 1070
        HeapFree(GetProcessHeap(), 0, This);
    }

    return ref;
}

1071 1072
static HRESULT WINAPI GifDecoder_QueryCapability(IWICBitmapDecoder *iface, IStream *stream,
    DWORD *capability)
1073
{
1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
    HRESULT hr;

    TRACE("(%p,%p,%p)\n", iface, stream, capability);

    if (!stream || !capability) return E_INVALIDARG;

    hr = IWICBitmapDecoder_Initialize(iface, stream, WICDecodeMetadataCacheOnDemand);
    if (hr != S_OK) return hr;

    *capability = WICBitmapDecoderCapabilityCanDecodeAllImages |
                  WICBitmapDecoderCapabilityCanDecodeSomeImages |
                  WICBitmapDecoderCapabilityCanEnumerateMetadata;
    return S_OK;
1087 1088
}

1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100
static int _gif_inputfunc(GifFileType *gif, GifByteType *data, int len) {
    IStream *stream = gif->UserData;
    ULONG bytesread;
    HRESULT hr;

    if (!stream)
    {
        ERR("attempting to read file after initialization\n");
        return 0;
    }

    hr = IStream_Read(stream, data, len, &bytesread);
1101
    if (FAILED(hr)) bytesread = 0;
1102 1103 1104
    return bytesread;
}

1105 1106 1107
static HRESULT WINAPI GifDecoder_Initialize(IWICBitmapDecoder *iface, IStream *pIStream,
    WICDecodeOptions cacheOptions)
{
1108
    GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
1109 1110 1111 1112 1113
    LARGE_INTEGER seek;
    int ret;

    TRACE("(%p,%p,%x)\n", iface, pIStream, cacheOptions);

1114 1115
    EnterCriticalSection(&This->lock);

1116 1117 1118
    if (This->initialized || This->gif)
    {
        WARN("already initialized\n");
1119
        LeaveCriticalSection(&This->lock);
1120 1121 1122 1123 1124 1125 1126 1127 1128
        return WINCODEC_ERR_WRONGSTATE;
    }

    /* seek to start of stream */
    seek.QuadPart = 0;
    IStream_Seek(pIStream, seek, STREAM_SEEK_SET, NULL);

    /* read all data from the stream */
    This->gif = DGifOpen((void*)pIStream, _gif_inputfunc);
1129 1130 1131 1132 1133
    if (!This->gif)
    {
        LeaveCriticalSection(&This->lock);
        return E_FAIL;
    }
1134 1135

    ret = DGifSlurp(This->gif);
1136 1137 1138 1139 1140
    if (ret == GIF_ERROR)
    {
        LeaveCriticalSection(&This->lock);
        return E_FAIL;
    }
1141 1142 1143 1144

    /* make sure we don't use the stream after this method returns */
    This->gif->UserData = NULL;

1145 1146
    seek.QuadPart = 0;
    IStream_Seek(pIStream, seek, STREAM_SEEK_SET, NULL);
1147
    IStream_Read(pIStream, This->LSD_data, sizeof(This->LSD_data), NULL);
1148

1149 1150 1151
    This->stream = pIStream;
    IStream_AddRef(This->stream);

1152 1153
    This->initialized = TRUE;

1154 1155
    LeaveCriticalSection(&This->lock);

1156
    return S_OK;
1157 1158 1159 1160 1161
}

static HRESULT WINAPI GifDecoder_GetContainerFormat(IWICBitmapDecoder *iface,
    GUID *pguidContainerFormat)
{
1162 1163
    memcpy(pguidContainerFormat, &GUID_ContainerFormatGif, sizeof(GUID));
    return S_OK;
1164 1165 1166 1167 1168
}

static HRESULT WINAPI GifDecoder_GetDecoderInfo(IWICBitmapDecoder *iface,
    IWICBitmapDecoderInfo **ppIDecoderInfo)
{
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
    HRESULT hr;
    IWICComponentInfo *compinfo;

    TRACE("(%p,%p)\n", iface, ppIDecoderInfo);

    hr = CreateComponentInfo(&CLSID_WICGifDecoder, &compinfo);
    if (FAILED(hr)) return hr;

    hr = IWICComponentInfo_QueryInterface(compinfo, &IID_IWICBitmapDecoderInfo,
        (void**)ppIDecoderInfo);

    IWICComponentInfo_Release(compinfo);

    return hr;
1183 1184
}

1185
static HRESULT WINAPI GifDecoder_CopyPalette(IWICBitmapDecoder *iface, IWICPalette *palette)
1186
{
1187 1188 1189
    GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
    WICColor colors[256];
    ColorMapObject *cm;
1190
    int i, trans, count;
1191
    ExtensionBlock *eb;
1192 1193 1194 1195

    TRACE("(%p,%p)\n", iface, palette);

    cm = This->gif->SColorMap;
1196
    if (cm)
1197
    {
1198 1199 1200 1201 1202
        if (cm->ColorCount > 256)
        {
            ERR("GIF contains invalid number of colors: %d\n", cm->ColorCount);
            return E_FAIL;
        }
1203

1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
        for (i = 0; i < cm->ColorCount; i++)
        {
            colors[i] = 0xff000000 | /* alpha */
                        cm->Colors[i].Red << 16 |
                        cm->Colors[i].Green << 8 |
                        cm->Colors[i].Blue;
        }

        count = cm->ColorCount;
    }
    else
1215
    {
1216 1217 1218 1219 1220 1221 1222
        colors[0] = 0xff000000;
        colors[1] = 0xffffffff;

        for (i = 2; i < 256; i++)
            colors[i] = 0xff000000;

        count = 256;
1223 1224
    }

1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239
    /* look for the transparent color extension */
    for (i = 0; i < This->gif->SavedImages[This->current_frame].Extensions.ExtensionBlockCount; i++)
    {
        eb = This->gif->SavedImages[This->current_frame].Extensions.ExtensionBlocks + i;
        if (eb->Function == GRAPHICS_EXT_FUNC_CODE && eb->ByteCount == 8)
        {
            if (eb->Bytes[3] & 1)
            {
                trans = (unsigned char)eb->Bytes[6];
                colors[trans] &= 0xffffff; /* set alpha to 0 */
                break;
            }
        }
    }

1240
    return IWICPalette_InitializeCustom(palette, colors, count);
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}

static HRESULT WINAPI GifDecoder_GetMetadataQueryReader(IWICBitmapDecoder *iface,
    IWICMetadataQueryReader **ppIMetadataQueryReader)
{
    TRACE("(%p,%p)\n", iface, ppIMetadataQueryReader);
    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
}

static HRESULT WINAPI GifDecoder_GetPreview(IWICBitmapDecoder *iface,
    IWICBitmapSource **ppIBitmapSource)
{
    TRACE("(%p,%p)\n", iface, ppIBitmapSource);
    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
}

static HRESULT WINAPI GifDecoder_GetColorContexts(IWICBitmapDecoder *iface,
    UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
{
    TRACE("(%p,%u,%p,%p)\n", iface, cCount, ppIColorContexts, pcActualCount);
    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
}

static HRESULT WINAPI GifDecoder_GetThumbnail(IWICBitmapDecoder *iface,
    IWICBitmapSource **ppIThumbnail)
{
    TRACE("(%p,%p)\n", iface, ppIThumbnail);
    return WINCODEC_ERR_CODECNOTHUMBNAIL;
}

static HRESULT WINAPI GifDecoder_GetFrameCount(IWICBitmapDecoder *iface,
    UINT *pCount)
{
1274
    GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
1275

1276
    if (!pCount) return E_INVALIDARG;
1277

1278 1279 1280
    EnterCriticalSection(&This->lock);
    *pCount = This->gif ? This->gif->ImageCount : 0;
    LeaveCriticalSection(&This->lock);
1281

1282
    TRACE("(%p) <-- %d\n", iface, *pCount);
1283 1284

    return S_OK;
1285 1286 1287 1288 1289
}

static HRESULT WINAPI GifDecoder_GetFrame(IWICBitmapDecoder *iface,
    UINT index, IWICBitmapFrameDecode **ppIBitmapFrame)
{
1290
    GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
1291 1292 1293
    GifFrameDecode *result;
    TRACE("(%p,%u,%p)\n", iface, index, ppIBitmapFrame);

1294
    if (!This->initialized) return WINCODEC_ERR_FRAMEMISSING;
1295 1296 1297 1298 1299 1300

    if (index >= This->gif->ImageCount) return E_INVALIDARG;

    result = HeapAlloc(GetProcessHeap(), 0, sizeof(GifFrameDecode));
    if (!result) return E_OUTOFMEMORY;

1301
    result->IWICBitmapFrameDecode_iface.lpVtbl = &GifFrameDecode_Vtbl;
1302
    result->IWICMetadataBlockReader_iface.lpVtbl = &GifFrameDecode_BlockVtbl;
1303 1304 1305 1306
    result->ref = 1;
    result->frame = &This->gif->SavedImages[index];
    IWICBitmapDecoder_AddRef(iface);
    result->parent = This;
1307
    This->current_frame = index;
1308

1309
    *ppIBitmapFrame = &result->IWICBitmapFrameDecode_iface;
1310 1311

    return S_OK;
1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330
}

static const IWICBitmapDecoderVtbl GifDecoder_Vtbl = {
    GifDecoder_QueryInterface,
    GifDecoder_AddRef,
    GifDecoder_Release,
    GifDecoder_QueryCapability,
    GifDecoder_Initialize,
    GifDecoder_GetContainerFormat,
    GifDecoder_GetDecoderInfo,
    GifDecoder_CopyPalette,
    GifDecoder_GetMetadataQueryReader,
    GifDecoder_GetPreview,
    GifDecoder_GetColorContexts,
    GifDecoder_GetThumbnail,
    GifDecoder_GetFrameCount,
    GifDecoder_GetFrame
};

1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363
static HRESULT WINAPI GifDecoder_Block_QueryInterface(IWICMetadataBlockReader *iface,
    REFIID iid, void **ppv)
{
    GifDecoder *This = impl_from_IWICMetadataBlockReader(iface);
    return IWICBitmapDecoder_QueryInterface(&This->IWICBitmapDecoder_iface, iid, ppv);
}

static ULONG WINAPI GifDecoder_Block_AddRef(IWICMetadataBlockReader *iface)
{
    GifDecoder *This = impl_from_IWICMetadataBlockReader(iface);
    return IWICBitmapDecoder_AddRef(&This->IWICBitmapDecoder_iface);
}

static ULONG WINAPI GifDecoder_Block_Release(IWICMetadataBlockReader *iface)
{
    GifDecoder *This = impl_from_IWICMetadataBlockReader(iface);
    return IWICBitmapDecoder_Release(&This->IWICBitmapDecoder_iface);
}

static HRESULT WINAPI GifDecoder_Block_GetContainerFormat(IWICMetadataBlockReader *iface,
    GUID *guid)
{
    TRACE("(%p,%p)\n", iface, guid);

    if (!guid) return E_INVALIDARG;

    *guid = GUID_ContainerFormatGif;
    return S_OK;
}

static HRESULT WINAPI GifDecoder_Block_GetCount(IWICMetadataBlockReader *iface,
    UINT *count)
{
1364 1365
    GifDecoder *This = impl_from_IWICMetadataBlockReader(iface);

1366 1367 1368 1369
    TRACE("%p,%p\n", iface, count);

    if (!count) return E_INVALIDARG;

1370
    *count = This->gif->Extensions.ExtensionBlockCount + 1;
1371 1372 1373 1374 1375 1376 1377
    return S_OK;
}

static HRESULT WINAPI GifDecoder_Block_GetReaderByIndex(IWICMetadataBlockReader *iface,
    UINT index, IWICMetadataReader **reader)
{
    GifDecoder *This = impl_from_IWICMetadataBlockReader(iface);
1378
    int i;
1379 1380 1381

    TRACE("(%p,%u,%p)\n", iface, index, reader);

1382 1383 1384
    if (!reader) return E_INVALIDARG;

    if (index == 0)
1385
        return create_metadata_reader(This->LSD_data, sizeof(This->LSD_data),
1386
                                      LSDReader_CreateInstance, reader);
1387 1388 1389

    for (i = 0; i < This->gif->Extensions.ExtensionBlockCount; i++)
    {
1390
        class_constructor constructor;
1391 1392 1393 1394

        if (index != i + 1) continue;

        if (This->gif->Extensions.ExtensionBlocks[i].Function == APPLICATION_EXT_FUNC_CODE)
1395
            constructor = APEReader_CreateInstance;
1396
        else if (This->gif->Extensions.ExtensionBlocks[i].Function == COMMENT_EXT_FUNC_CODE)
1397
            constructor = GifCommentReader_CreateInstance;
1398
        else
1399
            constructor = UnknownMetadataReader_CreateInstance;
1400

1401 1402
        return create_metadata_reader(This->gif->Extensions.ExtensionBlocks[i].Bytes,
                                      This->gif->Extensions.ExtensionBlocks[i].ByteCount,
1403
                                      constructor, reader);
1404 1405 1406
    }

    return E_INVALIDARG;
1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426
}

static HRESULT WINAPI GifDecoder_Block_GetEnumerator(IWICMetadataBlockReader *iface,
    IEnumUnknown **enumerator)
{
    FIXME("(%p,%p): stub\n", iface, enumerator);
    return E_NOTIMPL;
}

static const IWICMetadataBlockReaderVtbl GifDecoder_BlockVtbl =
{
    GifDecoder_Block_QueryInterface,
    GifDecoder_Block_AddRef,
    GifDecoder_Block_Release,
    GifDecoder_Block_GetContainerFormat,
    GifDecoder_Block_GetCount,
    GifDecoder_Block_GetReaderByIndex,
    GifDecoder_Block_GetEnumerator
};

1427
HRESULT GifDecoder_CreateInstance(REFIID iid, void** ppv)
1428 1429 1430 1431
{
    GifDecoder *This;
    HRESULT ret;

1432
    TRACE("(%s,%p)\n", debugstr_guid(iid), ppv);
1433 1434 1435 1436 1437 1438

    *ppv = NULL;

    This = HeapAlloc(GetProcessHeap(), 0, sizeof(GifDecoder));
    if (!This) return E_OUTOFMEMORY;

1439
    This->IWICBitmapDecoder_iface.lpVtbl = &GifDecoder_Vtbl;
1440
    This->IWICMetadataBlockReader_iface.lpVtbl = &GifDecoder_BlockVtbl;
1441
    This->stream = NULL;
1442
    This->ref = 1;
1443 1444
    This->initialized = FALSE;
    This->gif = NULL;
1445
    This->current_frame = 0;
1446 1447
    InitializeCriticalSection(&This->lock);
    This->lock.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": GifDecoder.lock");
1448

1449 1450
    ret = IWICBitmapDecoder_QueryInterface(&This->IWICBitmapDecoder_iface, iid, ppv);
    IWICBitmapDecoder_Release(&This->IWICBitmapDecoder_iface);
1451 1452 1453

    return ret;
}