Use boost.gil for overlaying images from libass

This commit is contained in:
Thomas Goyne 2013-01-24 08:16:23 -08:00
parent 6bd6ed5e5b
commit 2113ed9580
2 changed files with 20 additions and 37 deletions

View file

@ -80,7 +80,7 @@ endif
# SUBTITLES
###########
ifeq (yes, $(HAVE_LIBASS))
subtitles_provider_libass.o: CXXFLAGS += $(CFLAGS_LIBASS)
subtitles_provider_libass.o: CXXFLAGS += $(CFLAGS_LIBASS) -Wno-c++11-narrowing
subtitles_provider.o: CXXFLAGS += $(CFLAGS_LIBASS)
LIBS += $(LIBS_LIBASS)
SRC += subtitles_provider_libass.cpp

View file

@ -137,49 +137,32 @@ void LibassSubtitlesProvider::DrawSubtitles(AegiVideoFrame &frame,double time) {
// libass actually returns several alpha-masked monochrome images.
// Here, we loop through their linked list, get the colour of the current, and blend into the frame.
// This is repeated for all of them.
while (img) {
using namespace boost::gil;
auto dst = interleaved_view(frame.w, frame.h, (bgra8_pixel_t*)frame.data, frame.pitch);
if (frame.flipped)
dst = flipped_up_down_view(dst);
for (; img; img = img->next) {
unsigned int opacity = 255 - ((unsigned int)_a(img->color));
unsigned int r = (unsigned int)_r(img->color);
unsigned int g = (unsigned int)_g(img->color);
unsigned int b = (unsigned int)_b(img->color);
// Prepare copy
int src_stride = img->stride;
int dst_stride = frame.pitch;
const unsigned char *src = img->bitmap;
auto srcview = interleaved_view(img->w, img->h, (gray8_pixel_t*)img->bitmap, img->stride);
auto dstview = subimage_view(dst, img->dst_x, img->dst_y, img->w, img->h);
unsigned char *dst = frame.data;
if (frame.flipped) {
dst += dst_stride * (frame.h - 1);
dst_stride *= -1;
}
dst += (img->dst_y * dst_stride + img->dst_x * 4);
transform_pixels(dstview, srcview, dstview, [=](const bgra8_pixel_t frame, const gray8_pixel_t src) -> bgra8_pixel_t {
unsigned int k = ((unsigned)src) * opacity / 255;
unsigned int ck = 255 - k;
// Copy image to destination frame
for (int y = 0; y < img->h; y++) {
unsigned char *dstp = dst;
for (int x = 0; x < img->w; ++x) {
unsigned int k = ((unsigned)src[x]) * opacity / 255;
unsigned int ck = 255 - k;
*dstp = (k * b + ck * *dstp) / 255;
++dstp;
*dstp = (k * g + ck * *dstp) / 255;
++dstp;
*dstp = (k * r + ck * *dstp) / 255;
++dstp;
++dstp;
}
dst += dst_stride;
src += src_stride;
}
img = img->next;
bgra8_pixel_t ret;
ret[0] = (k * b + ck * frame[0]) / 255;
ret[1] = (k * g + ck * frame[1]) / 255;
ret[2] = (k * r + ck * frame[2]) / 255;
ret[3] = 0;
return ret;
});
}
}