antosdk-apps/libwvnc/build/debug/decoder.js

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JavaScript
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2020-12-29 20:36:35 +01:00
let resolution;
decode_jpeg = (raw, msg) =>
{
if(!JpegImage)
{
console.error("The JPEG library is not available");
return 0;
}
let jpeg = new JpegImage()
jpeg.parse(raw)
if(jpeg.width != msg.w || jpeg.height != msg.h)
{
console.error("Incorrect data size: expect " + msg.w*msg.h*4 + " got " + jpeg.width*jpeg.height*4);
return 0;
}
msg.pixels = new Uint8Array(msg.w*msg.h*4);
let data = jpeg.getData(msg.w, msg.h);
for(let j = 0; j < msg.h; j++)
{
for(let i = 0; i < msg.w; i++)
{
let index = j*msg.w*4 + i*4;
msg.pixels[index] = data[j*msg.w*3 + i*3];
msg.pixels[index+1] = data[j*msg.w*3 + i*3 + 1];
msg.pixels[index+2] = data[j*msg.w*3 + i*3 + 2];
msg.pixels[index+3] = 255;
}
}
return msg.pixels.length;
}
decode_raw = (raw, msg) =>
{
let size =raw.length;
if(resolution.depth == 32)
{
msg.pixels = new Uint8Array(raw);
return size;
}
if(resolution.depth != 16)
{
console.error("Unsupported depth" + resolution.depth);
return 0;
}
let bytes = resolution.depth/8;
let npixels = size / bytes;
let outsize = npixels*4;
if(outsize != msg.w*msg.h*4)
{
console.error("Incorrect data size: expect " + msg.w*msg.h*4 + " got " + outsize);
return 0;
}
msg.pixels = new Uint8Array(outsize);
let value = 0;
let px = {};
for(let i = 0; i < npixels; i++)
{
value = 0;
for(let j=0; j < bytes; j++ )
value = (raw[i * bytes + j] << (j*8)) | value ;
// lookup for pixel
msg.pixels[i*4] = (value & 0x1F) * (255 / 31);
msg.pixels[i*4+1] = ((value >> 5) & 0x3F) * (255 / 63);
msg.pixels[i*4+2] = ((value >> 11) & 0x1F) * (255 / 31);
msg.pixels[i*4+3] = 255;
}
return outsize;
}
decode = (arr) =>
{
let datain = new Uint8Array(arr);
let msg = {
x: datain[1] | (datain[2] << 8),
y: datain[3] | (datain[4] << 8),
w: datain[5] | (datain[6] << 8),
h: datain[7] | (datain[8] << 8),
flag: datain[9],
pixels: undefined
}
switch (msg.flag) {
case 0x0:
decode_raw(datain.subarray(10), msg);
break;
case 0x1:
decode_jpeg(datain.subarray(10), msg);
break;
default:
console.error("Unknow flag: " + msg.flag);
}
if(msg.pixels)
{
msg.pixels = msg.pixels.buffer;
postMessage(msg, [msg.pixels]);
}
}
onmessage = (e) => {
if(e.data.depth)
{
resolution = e.data;
}
else if(e.data.libjpeg)
{
importScripts(e.data.libjpeg);
}
else
{
decode(e.data);
}
}