Merge branch 'dev' of github.com:mrtianjin829/wavtobin into dev

argp.js

@@ -2,19 +2,25 @@ function gen(args) {
   let cf = {
      file: "",
      sampleRate: 32000,
-     output: "out.bin"
+     output: "out.bin",
+     useFFmpeg: false,
+     help: false
   };
   args.forEach((v,i)=>{
-     if(v == "-r"){
+     if(i <= 1) return
+
+     if(v == "--sampleRate" || v == "-r"){
         cf.sampleRate = parseInt(args[i+1]);
-     } else if(v == "-o"){
+     }  else if(v == "--help" || v == "-h") {
+	cf.help = true
+     }  else if(v == "--output" || v == "-o"){
         cf.output = args[i+1]
-     } else if(v.endsWith(".wav")){
+     } else if(v == "--ffmpeg"){
+        cf.useFFmpeg = true
+     } else {
         cf.file = v
      }
   })
-  console.log("Received arguments as: ")
-  console.log(cf)
   return cf;
 }
 

ffmpeg.js

@@ -0,0 +1,30 @@
+let cp = require("child_process") // sussy variable name o_O
+const pth = require("path")
+const os = require("os")
+function makeid(length) {
+    let result = '';
+    const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
+    const charactersLength = characters.length;
+    let counter = 0;
+    while (counter < length) {
+      result += characters.charAt(Math.floor(Math.random() * charactersLength));
+      counter += 1;
+    }
+    return result;
+}
+async function ffmpeg(input){
+   let ret = {
+       path: "",
+       exitcode: 0
+   };
+   let path = pth.resolve(os.tmpdir(),makeid(16)+".wav")
+   let proc = cp.spawn("ffmpeg",["-i",input,path])
+   proc.stdout.pipe(process.stdout)
+   let get_code = ()=>new Promise(res=>proc.on("close",res))
+   ret.exitcode = await get_code();
+   ret.path = path
+   console.log("[wtb.ffmpeg] exit code is "+ret.exitcode)
+   return ret
+}
+
+module.exports = ffmpeg

help.txt

@@ -0,0 +1,10 @@
+USAGE: (command) [OPTIONS] FILE
+Options:
+
+   -o / --output : Specify output file (default is out.bin)
+   -r / --sampleRate : Sample rate of output file (default is 32000)
+   --ffmpeg : Use ffmpeg to enable wavtobin to process other audio types
+
+Example:
+    (command) -r 32000 -o out.bin file.wav
+    (command) -r 48000 -o /home/myfile.bin --ffmpeg file.mp3

index.js

@@ -1,27 +1,51 @@
 #!/usr/bin/node
-console.log("WaveBin");
+console.log("[wtb] WaveToBin");
+const ffmpeg = require("./ffmpeg");
+(async function(){
 try {
+  // Import library for handling wav files.
   const { WaveFile } = require("wavefile");
+  // Load filesystem API
   const fs = require("fs");
+  // Initialize output file as an wave file
   const wf = new WaveFile();
+  // Procure argyments
   const cf = require("./argp")(process.argv)
-  const fd = fs.readFileSync(cf.file);
+  // Read the file.
+  if(cf.help){
+     console.log(fs.readFileSync("help.txt").toString("utf8"))
+     return
+  }
+  let inputFilePath = cf.file
+  if(cf.useFFmpeg){
+      console.log("[wtb] Waiting for FFmpeg")
+      inputFilePath = (await ffmpeg(inputFilePath)).path
+  }
+  const fd = fs.readFileSync(inputFilePath);
+  // Load input file into wf.
   wf.fromBuffer(fd);
-  wf.toSampleRate(cf.sampleRate);
-  wf.toBitDepth("8");
+  /*do important conversions
+   *this will convert the sample-type into PCM u8
+   *changes the sample rate to the desired rate otherwise 32 Khz (good for html5bytebeat)
+   * */
+  if(wf.fmt.sampleRate != cf.sampleRate) wf.toSampleRate(cf.sampleRate);
+  if(wf.bitDepth !== "8") wf.toBitDepth("8");
+  // Obtain "samples" from audio
   let smp = wf.getSamples();
-  let n;
+  let n; // contains the PCM buffer for output file
   // properly interleave the channels
   if (wf.fmt.numChannels == 2) {
     let [a, b] = smp;
+    // Use average to mix stereo channels.
     n = a.map((v, i) => (v + b[i]) / 2);
   } else {
     n = smp;
   }
   n = new Uint8Array(n);
-  fs.writeFileSync(cf.output, Buffer.from(n));
+  fs.writeFileSync(cf.output, Buffer.from(n)); // Write output.
 } catch (err) {
+  // Definitely helpful error handling.
   console.log("[wtb] an error occurred:");
   throw err
   process.exit(1);
-}
+}})()