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fix #2024 (TODO - avoid image copy for lossy encoding of views)

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This commit is contained in:
Dane Springmeyer 2013-09-26 20:07:04 -07:00
parent 3531276864
commit 0ca2edb206
1 changed files with 79 additions and 12 deletions
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91
include/mapnik/webp_io.hpp
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@ -68,6 +68,58 @@ std::string webp_encoding_error(WebPEncodingError error)
return os;
}
template <typename T2>
inline int import_image_data(T2 const& image,
WebPPicture & pic,
bool alpha)
{
// Reason for copy: https://github.com/mapnik/mapnik/issues/2024
// TODO - figure out way to pass view pixels directly to webp importer
image_data_32 im(image.width(),image.height());
for (unsigned y = 0; y < image.height(); ++y)
{
typename T2::pixel_type const * row_from = image.getRow(y);
image_data_32::pixel_type * row_to = im.getRow(y);
for (unsigned x = 0; x < image.width(); ++x)
{
row_to[x] = row_from[x];
}
}
int stride = sizeof(typename T2::pixel_type) * im.width();
if (alpha)
{
return WebPPictureImportRGBA(&pic, im.getBytes(), stride);
}
else
{
#if (WEBP_ENCODER_ABI_VERSION >> 8) >= 1
return WebPPictureImportRGBX(&pic, im.getBytes(), stride);
#else
return WebPPictureImportRGBA(&pic, im.getBytes(), stride);
#endif
}
}
template <>
inline int import_image_data(image_data_32 const& im,
WebPPicture & pic,
bool alpha)
{
int stride = sizeof(image_data_32::pixel_type) * im.width();
if (alpha)
{
return WebPPictureImportRGBA(&pic, im.getBytes(), stride);
}
else
{
#if (WEBP_ENCODER_ABI_VERSION >> 8) >= 1
return WebPPictureImportRGBX(&pic, im.getBytes(), stride);
#else
return WebPPictureImportRGBA(&pic, im.getBytes(), stride);
#endif
}
}
template <typename T1, typename T2>
void save_as_webp(T1& file,
float quality,
@ -109,25 +161,40 @@ void save_as_webp(T1& file,
}
pic.width = image.width();
pic.height = image.height();
int ok = 0;
#if (WEBP_ENCODER_ABI_VERSION >> 8) >= 1
pic.use_argb = !!lossless;
#endif
int ok = 0;
if (alpha)
// lossless fast track
if (pic.use_argb)
{
int stride = sizeof(typename T2::pixel_type) * image.width();
ok = WebPPictureImportRGBA(&pic, image.getBytes(), stride);
pic.colorspace = static_cast<WebPEncCSP>(pic.colorspace | WEBP_CSP_ALPHA_BIT);
if (WebPPictureAlloc(&pic)) {
ok = 1;
const int width = pic.width;
const int height = pic.height;
for (int y = 0; y < height; ++y) {
typename T2::pixel_type const * row = image.getRow(y);
for (int x = 0; x < width; ++x) {
const unsigned rgba = row[x];
unsigned a = (rgba >> 24) & 0xff;
unsigned r = rgba & 0xff;
unsigned g = (rgba >> 8 ) & 0xff;
unsigned b = (rgba >> 16) & 0xff;
const uint32_t argb = (a << 24) | (r << 16) | (g << 8) | (b);
pic.argb[x + y * pic.argb_stride] = argb;
}
}
}
}
else
{
int stride = sizeof(typename T2::pixel_type) * image.width();
#if (WEBP_ENCODER_ABI_VERSION >> 8) >= 1
ok = WebPPictureImportRGBX(&pic, image.getBytes(), stride);
#else
ok = WebPPictureImportRGBA(&pic, image.getBytes(), stride);
#endif
// different approach for lossy since ImportYUVAFromRGBA is needed
// to prepare WebPPicture and working with view pixels is not viable
ok = import_image_data(image,pic,alpha);
}
#else
ok = import_image_data(image,pic,alpha);
#endif
if (!ok)
{
throw std::runtime_error(webp_encoding_error(pic.error_code));