Add converter from RGF to PNG

.gitignore

@@ -31,5 +31,4 @@ videos/**
 lib/
 .vscode/
 bin
-out.wav
+scripts/out.*
-

scripts/rgf2png.js

@@ -0,0 +1,157 @@
+#!/usr/bin/env node
+
+const fs = require("fs")
+const zlib = require("zlib")
+
+function compressImg(fn) {
+    const rgf = fs.readFileSync(fn)
+
+    const width = rgf[0]
+    const height = rgf[1]
+
+    const expSz = ((width + 7) >> 3) * height + 2
+
+    console.log(`w=${width} h=${height} sz=${rgf.length} exp=${expSz}`)
+
+    let crcTable
+
+    function crc32(buf) {
+        if (!crcTable) {
+            crcTable = []
+            for (let i = 0; i < 256; i++) {
+                let curr = i;
+                for (let j = 0; j < 8; j++) {
+                    if (curr & 1) {
+                        curr = 0xedb88320 ^ (curr >>> 1);
+                    } else {
+                        curr = curr >>> 1;
+                    }
+                }
+                crcTable[i] = curr
+            }
+        }
+
+        let crc = -1;
+        for (var i = 0; i < buf.length; i++) {
+            crc = crcTable[(crc ^ buf[i]) & 0xff] ^ (crc >>> 8);
+        }
+        return (crc ^ -1) >>> 0;
+    }
+
+
+    /*
+    Width	4 bytes
+    Height	4 bytes
+    Bit depth	1 byte
+    Colour type	1 byte
+    Compression method	1 byte
+    Filter method	1 byte
+    Interlace method	1 byte
+    */
+
+    const chunks = []
+
+    function addChunk(mark, addsize) {
+        const buf = Buffer.alloc(mark.length + addsize)
+        for (let i = 0; i < mark.length; ++i) {
+            buf[i] = mark.charCodeAt(i)
+        }
+        chunks.push(buf)
+        return buf
+    }
+
+    const hd = addChunk("IHDR", 4 + 4 + 5)
+    hd.writeInt32BE(width, 4)
+    hd.writeInt32BE(height, 8)
+    hd[12] = 1 // bit depth
+    hd[13] = 0 // color type - grayscale
+    hd[14] = 0 // compression - deflate
+    hd[15] = 0 // filter method
+    hd[16] = 0 // interlace method - no interlace
+
+    const scanlines = []
+    const scanlen = (width + 7) >> 3
+
+    let srcptr = 2
+    let srcmask = 0x01
+    for (let y = 0; y < height; ++y) {
+        const scan = Buffer.alloc(1 + scanlen)
+        scanlines.push(scan)
+        let dstptr = 1
+        let dstmask = 0x80
+        for (let x = 0; x < width; ++x) {
+            if (!(rgf[srcptr] & srcmask)) {
+                scan[dstptr] |= dstmask
+            }
+            dstmask >>= 1;
+            if (dstmask == 0) {
+                dstmask = 0x80
+                dstptr++
+            }
+            srcmask <<= 1;
+            if (srcmask > 0x80) {
+                srcmask = 0x01
+                srcptr++
+            }
+        }
+        if (srcmask != 0x01) {
+            srcmask = 0x01
+            srcptr++
+        }
+
+        if (false) {
+            // seems to increase file size
+            scan[0] = 1 // sub
+            let prev = 0
+            for (let i = 1; i < scan.length; ++i) {
+                let p = scan[i]
+                scan[i] = (p - prev) & 0xff
+                prev = p
+            }
+        }
+    }
+
+    const dat = zlib.deflateSync(Buffer.concat(scanlines), {
+        level: 9
+    })
+    const idat = addChunk("IDAT", dat.length)
+    dat.copy(idat, 4)
+    addChunk("IEND", 0)
+
+    const output = [new Buffer([137, 80, 78, 71, 13, 10, 26, 10])]
+
+    function intBuf(v) {
+        let b = new Buffer(4)
+        b.writeUInt32BE(v, 0)
+        return b
+    }
+    for (let ch of chunks) {
+        output.push(intBuf(ch.length - 4))
+        output.push(ch)
+        output.push(intBuf(crc32(ch)))
+    }
+
+    let outp = Buffer.concat(output)
+    return outp
+}
+
+let sz = 0
+let bf
+let out = {}
+for (let i = 2; i < process.argv.length; ++i) {
+    let fn = process.argv[i]
+    let m = /([^\/]+\/[^/]+)\.rgf$/.exec(fn)
+    let bn = m[1]
+    bf = compressImg(fn)
+    out[bn] = "data:image/png;base64," + bf.toString("base64")
+    sz += bf.length
+}
+
+console.log("total " + sz)
+fs.writeFileSync("out.json", JSON.stringify(out, null, 4))
+fs.writeFileSync("out.png", bf)
+
+//if (require("os").platform() == "darwin")
+//    require('child_process').execSync("afplay out.wav")
+
+// TODO also play on Windows

scripts/rsf2wav.js

@@ -37,7 +37,7 @@ wavHd.writeInt32LE(datasize, 40)
 
 const wav = Buffer.concat([wavHd, rsf.slice(8)])
 
-console.log("writing out.wav")
+console.log("writing out.wav; " + samplerate + "Hz")
 fs.writeFileSync("out.wav", wav)
 
 if (require("os").platform() == "darwin")