diff --git a/badger-am.js b/badger-am.js
index 0bdc984..e94a93e 100755
--- a/badger-am.js
+++ b/badger-am.js
@@ -9,20 +9,21 @@ const recursive = require('recursive-readdir');
 const app = require('./package.json');
 const audio = require('./lib/audio');
 const util = require('./lib/util');
+const cli = require('./lib/cli');
 
 // generate timestamp
 const start = process.hrtime();
 
-main();
+badger();
 
 // "main"
-function main() {
-    util.printLogo();
-    parseCLI();
+function badger() {
+    cli.printLogo();
+    run();
 }
 
-// process command line arguments
-function parseCLI() {
+// start from command lines
+function run() {
     // general options
     commander
         .version(app.version)
@@ -38,70 +39,33 @@ function parseCLI() {
     commander
         .command('sort <input> <output>')
         .description('sort audio files by tags')
-        .option('-f, --format <type>', 'specify audio format (\'flac\', \'mp3\')', 'flac')
+        .option('-f, --format <type>', 'specify audio format (\'flac\', \'mp3\')', '.flac')
         .action(sort);
     // artwork
     commander
         .command('artwork <input>')
         .description('extract cover artwork')
-        .option('-f, --format <type>', 'specify audio format (\'flac\', \'mp3\')', 'flac')
+        .option('-f, --format <type>', 'specify audio format (\'flac\', \'mp3\')', '.flac')
         .action(artwork);
     // parse command line arguments
     commander.parse(process.argv);
 }
 
-// convert files
-function convert(input, output, options) {
-    async.waterfall([
-        function (asyncCallback) {
-            recursive(input, [ignoreFilter], asyncCallback);
-        },
-        function (files, asyncCallback) {
-            console.log(files.length + ' \'flac\' files found');
-            // display progressbar
-            const bar = util.createProgressBar(files.length);
-            // handle each file
-            async.eachLimit(files, commander.concurrency, function (file, eachCallback) {
-                processFileConvert(output, file, options, function (err) {
-                    bar.tick();
-                    if (err) {
-                        return eachCallback(err);
-                    }
-                    eachCallback();
-                });
-            }, function (err) {
-                if (err) {
-                    return asyncCallback(err);
-                }
-                asyncCallback();
-            });
-        }
-    ], function (err, result) {
-        util.exit(err, start);
-    });
-
-    function ignoreFilter(file, stats) {
-        return !stats.isDirectory() && path.extname(file).indexOf('flac') == -1;
+// create config object
+function getConfig(input, output, options, commander) {
+    return {
+        input: path.normalize(input),
+        output: path.normalize(output),
+        concurrency: commander.concurrency || os.cpus().length,
+        bitrate: options.bitrate || 320,
+        format: options.format || '.flac'
     }
 }
 
-// move file to location defined by its metadata
-function processFileConvert(output, sourceFile, options, callback) {
-    async.waterfall([
-        function (asyncCallback) {
-            audio.extractMetadata(sourceFile, asyncCallback)
-        },
-        function (metadata, asyncCallback) {
-            util.pathFromMetadata(sourceFile, output, metadata, asyncCallback);
-        },
-        function (targetFile, asyncCallback) {
-            audio.convert(sourceFile, targetFile, options.bitrate, asyncCallback);
-        }
-    ], function (err, results) {
-        if (err) {
-            return callback(err);
-        }
-        callback(null, results);
+// convert files
+function convert(input, output, options) {
+    audio.batchConvert(getConfig(input, output, options, commander), function (err) {
+        cli.exit(err);
     });
 }
 
diff --git a/lib/audio.js b/lib/audio.js
index a59f229..9ee125f 100644
--- a/lib/audio.js
+++ b/lib/audio.js
@@ -6,29 +6,71 @@ const metadata = require('musicmetadata');
 const ffmpeg = require('fluent-ffmpeg');
 const fse = require('fs-extra');
 const util = require('./util');
+const cli = require('./cli');
+
+// convert all files in input directory
+function batchConvert(config, callback) {
+    async.waterfall([
+        // get files
+        function (waterfallCallback) {
+            util.readDirRecursive(config.input, config.format, waterfallCallback);
+        },
+        // display info, prompt user and create progressbar
+        function (files, waterfallCallback) {
+            cli.askForConfirmation(files.length + ' files found.\nstart conversion now?', ['yes', 'y'], function (err) {
+                if (err) {
+                    return waterfallCallback(err);
+                }
+                waterfallCallback(null, files, cli.createProgressBar(files.length));
+            });
+        },
+        // process each file
+        function (files, bar, waterfallCallback) {
+            async.eachLimit(files, config.concurrency, function (file, eachCallback) {
+                convert(file, config, function (err) {
+                    bar.tick();
+                    if (err) {
+                        return eachCallback(err);
+                    }
+                    eachCallback();
+                });
+            }, waterfallCallback);
+        }
+    ], callback);
+}
 
 // convert file to mp3 at specified bitrate
-function convert(input, output, bitrate, callback) {
-    output = path.join(path.dirname(output), path.basename(output, path.extname(output)) + '.mp3');
-    async.series([
-        function (asyncCallback) {
-            fse.mkdirs(path.dirname(output), asyncCallback);
+function convert(source, config, callback) {
+    async.waterfall([
+        // get metadata
+        function (waterfallCallback) {
+            extractMetadata(source, waterfallCallback);
         },
-        function (asyncCallback) {
-            ffmpeg(path.normalize(input)).audioCodec('libmp3lame').audioBitrate(bitrate).save(output)
+        // create path from metadata
+        function (metadata, waterfallCallback) {
+            util.getPathByMetadata(source, config.output, metadata, waterfallCallback);
+        },
+        // create target directory
+        function (target, waterfallCallback) {
+            target = path.join(path.dirname(target), path.basename(target, path.extname(target)) + '.mp3');
+            fse.mkdirs(path.dirname(target), function (err) {
+                if (err) {
+                    return waterfallCallback(err);
+                }
+                waterfallCallback(null, target, config);
+            });
+        },
+        // convert file to mp3
+        function (target, config, waterfallCallback) {
+            ffmpeg(path.normalize(source)).audioCodec('libmp3lame').audioBitrate(config.bitrate).save(target)
                 .on('error', function (err) {
-                    return asyncCallback(err);
+                    return waterfallCallback(err);
                 })
                 .on('end', function () {
-                    asyncCallback();
+                    waterfallCallback();
                 });
         }
-    ], function (err, results) {
-        if (err) {
-            return callback(err);
-        }
-        callback();
-    });
+    ], callback);
 }
 
 // extract cover artwork
@@ -68,5 +110,6 @@ function extractMetadata(sourceFile, callback) {
 
 // api
 exports.convert = convert;
+exports.batchConvert = batchConvert;
 exports.extractArtwork = extractArtwork;
 exports.extractMetadata = extractMetadata;
\ No newline at end of file
diff --git a/package.json b/package.json
index eccf262..eed97ac 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "badger-am",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "license": "MIT",
   "description": "audio manager",
   "author": "Daniel Sommer <daniel.sommer@velvettear.de>",