[Spice-devel] [vdagent-win PATCH v3 2/5] Initial rewrite of image conversion code

Frediano Ziglio fziglio at redhat.com
Fri Jul 14 15:42:39 UTC 2017


> 
> On Fri, 2017-07-14 at 13:57 +0100, Frediano Ziglio wrote:
> > Remove CxImage linking.
> > Support Windows BMP format.
> > 
> > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> > ---
> >  Makefile.am                 |   4 +-
> >  configure.ac                |   4 +-
> >  mingw-spice-vdagent.spec.in |   2 -
> >  vdagent/image.cpp           | 182
> >  ++++++++++++++++++++++++++++++++++---------
> > -
> >  vdagent/image.h             |  13 ++++
> >  5 files changed, 159 insertions(+), 46 deletions(-)
> > 
> > diff --git a/Makefile.am b/Makefile.am
> > index 868199e..b35dd57 100644
> > --- a/Makefile.am
> > +++ b/Makefile.am
> > @@ -23,8 +23,8 @@ LIBS = -lversion
> >  
> >  bin_PROGRAMS = vdagent vdservice
> >  
> > -vdagent_LDADD = -lwtsapi32 $(CXIMAGE_LIBS) vdagent_rc.$(OBJEXT)
> > -vdagent_CXXFLAGS = $(AM_CXXFLAGS) $(CXIMAGE_CFLAGS)
> > +vdagent_LDADD = -lwtsapi32 -lgdi32 vdagent_rc.$(OBJEXT)
> > +vdagent_CXXFLAGS = $(AM_CXXFLAGS)
> >  vdagent_LDFLAGS = $(AM_LDFLAGS) -Wl,--subsystem,windows
> >  vdagent_SOURCES =			\
> >  	common/vdcommon.cpp             \
> > diff --git a/configure.ac b/configure.ac
> > index ff489cc..4eac4b4 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -42,6 +42,7 @@ AC_DEFINE_UNQUOTED([BUILD_YEAR], "$BUILD_YEAR", [Build
> > year])
> >  # Check for programs
> >  AC_PROG_CC
> >  AC_PROG_CXX
> > +AX_CXX_COMPILE_STDCXX_11
> >  AM_PROG_CC_C_O
> >  AC_PROG_INSTALL
> >  AC_CHECK_TOOL(WINDRES, [windres])
> > @@ -100,9 +101,6 @@ dnl
> > ------------------------------------------------------
> > ---------------------
> >  dnl - Check library dependencies
> >  dnl
> >  -----------------------------------------------------------------------
> > ----
> >  
> > -PKG_CHECK_MODULES(CXIMAGE, [cximage])
> > -CXIMAGE_LIBS=`$PKG_CONFIG --static --libs cximage`
> > -
> >  dnl
> >  -----------------------------------------------------------------------
> > ----
> >  dnl - Makefiles, etc.
> >  dnl
> >  -----------------------------------------------------------------------
> > ----
> > diff --git a/mingw-spice-vdagent.spec.in b/mingw-spice-vdagent.spec.in
> > index 563341d..8cfd01a 100644
> > --- a/mingw-spice-vdagent.spec.in
> > +++ b/mingw-spice-vdagent.spec.in
> > @@ -13,8 +13,6 @@ Source0:        vdagent-win-
> > %{version}%{?_version_suffix}.tar.xz
> >  
> >  BuildRequires:  mingw32-filesystem >= 23
> >  BuildRequires:  mingw64-filesystem >= 23
> > -BuildRequires:  mingw32-cximage-static
> > -BuildRequires:  mingw64-cximage-static
> >  BuildRequires:  mingw32-jasper-static
> >  BuildRequires:  mingw64-jasper-static
> >  BuildRequires:  mingw32-libjpeg-turbo-static
> > diff --git a/vdagent/image.cpp b/vdagent/image.cpp
> > index 598a742..6f7608d 100644
> > --- a/vdagent/image.cpp
> > +++ b/vdagent/image.cpp
> > @@ -16,71 +16,175 @@
> >  */
> >  
> >  #include <spice/macros.h>
> > +#include <memory>
> > +#include <vector>
> >  
> >  #include "vdcommon.h"
> >  #include "image.h"
> >  
> > -#include "ximage.h"
> > +ImageCoder *create_bitmap_coder();
> > +ImageCoder *create_png_coder();
> >  
> > -typedef struct ImageType {
> > -    uint32_t type;
> > -    DWORD cximage_format;
> > -} ImageType;
> > -
> > -static const ImageType image_types[] = {
> > -    {VD_AGENT_CLIPBOARD_IMAGE_PNG, CXIMAGE_FORMAT_PNG},
> > -    {VD_AGENT_CLIPBOARD_IMAGE_BMP, CXIMAGE_FORMAT_BMP},
> > -};
> > -
> > -static DWORD get_cximage_format(uint32_t type)
> > +static ImageCoder *get_coder(uint32_t vdagent_type)
> >  {
> > -    for (unsigned int i = 0; i < SPICE_N_ELEMENTS(image_types); i++) {
> > -        if (image_types[i].type == type) {
> > -            return image_types[i].cximage_format;
> > -        }
> > +    switch (vdagent_type) {
> > +    case VD_AGENT_CLIPBOARD_IMAGE_BMP:
> > +        return create_bitmap_coder();
> > +    case VD_AGENT_CLIPBOARD_IMAGE_PNG:
> > +        return create_png_coder();
> >      }
> > -    return 0;
> > +    return NULL;
> >  }
> >  
> >  HANDLE get_image_handle(const VDAgentClipboard& clipboard, uint32_t size,
> > UINT &format)
> >  {
> > -    HANDLE clip_data;
> > -    DWORD cximage_format = get_cximage_format(clipboard.type);
> > -    ASSERT(cximage_format);
> > -    CxImage image((BYTE*)clipboard.data, size, cximage_format);
> > -    clip_data = image.CopyToHandle();
> > +    std::unique_ptr<ImageCoder> coder(get_coder(clipboard.type));
> > +    if (!coder) {
> > +        return NULL;
> > +    }
> > +
> > +    format = CF_DIB;
> 
> so it is just an output parameter (and always set to CF_DIB)
> 

Currently only CF_DIB is used. But potentially other clipboard types
can be used for images.

> > +    size_t dib_size = coder->get_dib_size(clipboard.data, size);
> > +    if (!dib_size) {
> > +        return NULL;
> > +    }
> > +    HANDLE clip_data = GlobalAlloc(GMEM_MOVEABLE, dib_size);
> > +    if (clip_data) {
> > +        uint8_t* dst = (uint8_t*)GlobalLock(clip_data);
> > +        if (!dst) {
> > +            GlobalFree(clip_data);
> > +            return NULL;
> > +        }
> > +        coder->get_dib_data(dst, clipboard.data, size);
> > +        GlobalUnlock(clip_data);
> > +    }
> >      return clip_data;
> >  }
> >  
> >  uint8_t* get_raw_clipboard_image(const VDAgentClipboardRequest&
> > clipboard_request,
> >                                   HANDLE clip_data, long& new_size)
> >  {
> > -    CxImage image;
> > -    uint8_t *new_data = NULL;
> > -    DWORD cximage_format = get_cximage_format(clipboard_request.type);
> > -    HPALETTE pal = 0;
> > +    if (GetObjectType(clip_data) != OBJ_BITMAP) {
> > +        return NULL;
> > +    }
> > +
> > +    std::unique_ptr<ImageCoder> coder(get_coder(clipboard_request.type));
> > +    if (!coder) {
> > +        return NULL;
> > +    }
> >  
> > -    ASSERT(cximage_format);
> > +    HPALETTE pal = 0;
> >      if (IsClipboardFormatAvailable(CF_PALETTE)) {
> >          pal = (HPALETTE)GetClipboardData(CF_PALETTE);
> >      }
> > -    if (!image.CreateFromHBITMAP((HBITMAP)clip_data, pal)) {
> > -        vd_printf("Image create from handle failed");
> > -        return NULL;
> > +
> > +    // extract DIB
> > +    BITMAP bitmap;
> > +    GetObject(clip_data, sizeof(bitmap), &bitmap);
> > +
> > +    struct {
> > +        BITMAPINFOHEADER head;
> > +        RGBQUAD colors[256];
> > +    } info;
> > +
> > +    BITMAPINFOHEADER& head(info.head);
> > +    memset(&head, 0, sizeof(head));
> > +    head.biSize = sizeof(head);
> > +    head.biWidth = bitmap.bmWidth;
> > +    head.biHeight = bitmap.bmHeight;
> > +    head.biPlanes = bitmap.bmPlanes;
> > +    head.biBitCount = bitmap.bmBitsPixel >= 16 ? 24 : bitmap.bmBitsPixel;
> > +    head.biCompression = BI_RGB;
> > +
> > +    HDC dc = GetDC(NULL);
> > +    HPALETTE old_pal = NULL;
> > +    if (pal) {
> > +        old_pal = (HPALETTE)SelectObject(dc, pal);
> > +        RealizePalette(dc);
> > +    }
> > +    size_t stride = ((head.biWidth * head.biBitCount + 31u) & ~31u) / 8u;
> > +    std::vector<uint8_t> bits(stride * head.biHeight);
> > +    int res = GetDIBits(dc, (HBITMAP) clip_data, 0, head.biHeight,
> > +                        &bits[0], (LPBITMAPINFO)&info, DIB_RGB_COLORS);
> > +    if (pal) {
> > +        SelectObject(dc, old_pal);
> >      }
> > -    if (!image.Encode(new_data, new_size, cximage_format)) {
> > -        vd_printf("Image encode to type %u failed",
> > clipboard_request.type);
> > +    ReleaseDC(NULL, dc);
> > +    if (!res) {
> >          return NULL;
> >      }
> > -    vd_printf("Image encoded to %lu bytes", new_size);
> > -    return new_data;
> > +
> > +    // convert DIB to desired format
> > +    return coder->from_bitmap(*(LPBITMAPINFO)&info, &bits[0], new_size);
> >  }
> >  
> >  void free_raw_clipboard_image(uint8_t *data)
> >  {
> > -    // this is really just a free however is better to make
> > -    // the free from CxImage code as on Windows the free
> > -    // can be different between libraries
> > -    CxImage image;
> > -    image.FreeMemory(data);
> > +    free(data);
> > +}
> > +
> > +class BitmapCoder: public ImageCoder
> > +{
> > +public:
> > +    BitmapCoder() {};
> > +    size_t get_dib_size(const uint8_t *data, size_t size);
> > +    void get_dib_data(uint8_t *dib, const uint8_t *data, size_t size);
> > +    uint8_t *from_bitmap(const BITMAPINFO& info, const void *bits, long
> > &size);
> > +};
> > +
> > +size_t BitmapCoder::get_dib_size(const uint8_t *data, size_t size)
> > +{
> > +    if (*(const WORD*)data == 'B'+'M'*256u)
> 

what about memcmp(data, "BM", 2) == 0 ??

> isn't nicer to compare byte by byte instead of casting and multiplication ?
> (or
> do the shift instead of the multiplication???).
> 
> > +        return size > 14 ? size - 14 : 0;
> > +    return size;
> > +}
> > +
> > +void BitmapCoder::get_dib_data(uint8_t *dib, const uint8_t *data, size_t
> > size)
> > +{
> > +    // just strip the file header if present, images can be either BMP or
> > DIB
> > +    size_t new_size = get_dib_size(data, size);
> > +    memcpy(dib, data + (size - new_size), new_size);
> > +}
> > +
> > +uint8_t *BitmapCoder::from_bitmap(const BITMAPINFO& info, const void
> > *bits,
> > long &size)
> > +{
> > +    const BITMAPINFOHEADER& head(info.bmiHeader);
> > +
> > +    size_t palette_size = 0;
> > +    DWORD max_colors = 0;
> > +    switch (head.biBitCount) {
> > +    case 1:
> > +        max_colors = 2;
> > +        break;
> > +    case 4:
> > +        max_colors = 16;
> > +        break;
> > +    case 8:
> > +        max_colors = 256;
> > +        break;
> 
> what about other values? cannot be reached?
> 

true colors, so no palette and max_colors will be 0. Maybe

    switch (head.biBitCount) {
    case 1:
    case 4:
    case 8:
        max_colors = 1 << head.biBitCount;
        break;
    default:
        max_colors = 0;
        break;
    }

?

> > +    }
> > +    palette_size = sizeof(RGBQUAD) * std::min(head.biClrUsed, max_colors);
> > +
> > +    const size_t stride = ((head.biWidth * head.biBitCount + 31u) & ~31u)
> > /
> > 8u;
> 
> maybe it can be a function to "hide" the math (and avoid repeating it)
> 

make sense. Not clear where I should put such function. Maybe image.h ?

size_t compute_dib_stride(unsigned width, unsigned bit_count) ?

> > +    const size_t image_size = stride * head.biHeight;
> 
> also it is possible to return the image_size. the stride is not used after
> that
> (same in get_raw_clipboard_image())
> 

other code uses stride so a function just computing the stride would
be good.

> > +    size = sizeof(head) + palette_size + image_size;
> > +
> > +    uint8_t *data = (uint8_t *) malloc(size);
> > +    if (!data) {
> > +        return NULL;
> > +    }
> > +    memcpy(data, &info, sizeof(head) + palette_size);
> > +    memcpy(data + sizeof(head) + palette_size, bits, image_size);
> > +    return data;
> > +}
> > +
> > +ImageCoder *create_bitmap_coder()
> > +{
> > +    return new BitmapCoder();
> > +}
> > +
> > +// TODO
> > +ImageCoder *create_png_coder()
> > +{
> > +    return NULL;
> >  }
> > diff --git a/vdagent/image.h b/vdagent/image.h
> > index 379c5cc..75e2268 100644
> > --- a/vdagent/image.h
> > +++ b/vdagent/image.h
> > @@ -18,6 +18,19 @@
> >  #ifndef VDAGENT_IMAGE_H_
> >  #define VDAGENT_IMAGE_H_
> >  
> > +class ImageCoder
> > +{
> > +public:
> > +    ImageCoder() {};
> > +    virtual ~ImageCoder() {}
> > +    virtual size_t get_dib_size(const uint8_t *data, size_t size)=0;
> > +    virtual void get_dib_data(uint8_t *dib, const uint8_t *data, size_t
> > size)=0;
> > +    virtual uint8_t *from_bitmap(const BITMAPINFO& info, const void *bits,
> > long &size)=0;
> > +private:
> > +    ImageCoder(const ImageCoder& rhs);
> > +    void operator=(const ImageCoder &rhs);
> > +};
> > +
> >  /**
> >   * Returns image to put in the clipboard.
> >   *
> 
> It is a nice improvement.
> 
> Thanks,
> Pavel
> 
> 
> 

Frediano


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