mrmBot-Matrix/natives/jpeg.cc

69 lines
2.1 KiB
C++

#include <napi.h>
#include <vips/vips8>
using namespace std;
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>>();
int quality = obj.Has("quality")
? obj.Get("quality").As<Napi::Number>().Int32Value()
: 0;
string type = obj.Get("type").As<Napi::String>().Utf8Value();
Napi::Object result = Napi::Object::New(env);
if (type == "gif") {
VImage in =
VImage::new_from_buffer(
data.Data(), data.Length(), "",
VImage::option()->set("access", "sequential")->set("n", -1))
.colourspace(VIPS_INTERPRETATION_sRGB);
if (!in.has_alpha()) in = in.bandjoin(255);
int page_height = vips_image_get_page_height(in.get_image());
void *jpgBuf;
size_t jpgLength;
in.write_to_buffer(
".jpg", &jpgBuf, &jpgLength,
VImage::option()->set("Q", quality)->set("strip", true));
VImage final = VImage::new_from_buffer(jpgBuf, jpgLength, "");
final.set(VIPS_META_PAGE_HEIGHT, page_height);
final.set("delay", in.get_array_int("delay"));
void *buf;
size_t length;
final.write_to_buffer(("." + type).c_str(), &buf, &length,
VImage::option()->set("dither", 0));
vips_thread_shutdown();
result.Set("data", Napi::Buffer<char>::Copy(env, (char *)buf, length));
result.Set("type", type);
} else {
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();
result.Set("data", Napi::Buffer<char>::Copy(env, (char *)buf, length));
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");
}
}