mrmBot-Matrix/natives/jpeg.cc

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#include <napi.h>
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#include <vips/vips8>
using namespace std;
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using namespace vips;
Napi::Value Jpeg(const Napi::CallbackInfo &info) {
Napi::Env env = info.Env();
try {
Napi::Object obj = info[0].As<Napi::Object>();
Napi::Buffer<char> data = obj.Get("data").As<Napi::Buffer<char>>();
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int quality = obj.Has("quality")
? obj.Get("quality").As<Napi::Number>().Int32Value()
: 0;
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string type = obj.Get("type").As<Napi::String>().Utf8Value();
Napi::Object result = Napi::Object::New(env);
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if (type == "gif") {
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VImage in =
VImage::new_from_buffer(
data.Data(), data.Length(), "",
VImage::option()->set("access", "sequential")->set("n", -1))
.colourspace(VIPS_INTERPRETATION_sRGB);
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if (!in.has_alpha())
in = in.bandjoin(255);
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int width = in.width();
int pageHeight = vips_image_get_page_height(in.get_image());
int totalHeight = in.height();
int nPages = vips_image_get_n_pages(in.get_image());
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VImage final;
if (totalHeight > 65500) {
vector<VImage> img;
for (int i = 0; i < nPages; i++) {
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VImage img_frame = in.crop(0, i * pageHeight, width, pageHeight);
void *jpgBuf;
size_t jpgLength;
img_frame.write_to_buffer(
".jpg", &jpgBuf, &jpgLength,
VImage::option()->set("Q", quality)->set("strip", true));
VImage jpeged = VImage::new_from_buffer(jpgBuf, jpgLength, "");
jpeged.set(VIPS_META_PAGE_HEIGHT, pageHeight);
jpeged.set("delay", in.get_array_int("delay"));
img.push_back(jpeged);
}
final = VImage::arrayjoin(img, VImage::option()->set("across", 1));
final.set(VIPS_META_PAGE_HEIGHT, pageHeight);
} else {
void *jpgBuf;
size_t jpgLength;
in.write_to_buffer(
".jpg", &jpgBuf, &jpgLength,
VImage::option()->set("Q", quality)->set("strip", true));
final = VImage::new_from_buffer(jpgBuf, jpgLength, "");
final.set(VIPS_META_PAGE_HEIGHT, pageHeight);
final.set("delay", in.get_array_int("delay"));
}
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void *buf;
size_t length;
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final.write_to_buffer(("." + type).c_str(), &buf, &length,
type == "gif" ? VImage::option()->set("dither", 0)
: 0);
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vips_thread_shutdown();
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result.Set("data", Napi::Buffer<char>::Copy(env, (char *)buf, length));
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result.Set("type", type);
} else {
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VImage in = VImage::new_from_buffer(data.Data(), data.Length(), "");
void *buf;
size_t length;
in.write_to_buffer(
".jpg", &buf, &length,
VImage::option()->set("Q", quality)->set("strip", true));
vips_thread_shutdown();
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result.Set("data", Napi::Buffer<char>::Copy(env, (char *)buf, length));
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result.Set("type", "jpg");
}
return result;
} catch (std::exception const &err) {
throw Napi::Error::New(env, err.what());
} catch (...) {
throw Napi::Error::New(env, "Unknown error");
}
}