MicroDVD/Sub format (no text formatting)

captions.js

@@ -15,9 +15,11 @@ module.exports = {
     scc: require('./lib/scc.js'),
     srt: require('./lib/srt.js'),
     smi: require('./lib/smi.js'),
+    sub: require('./lib/sub.js'),
     vtt: require('./lib/vtt.js'),
     smpte_tt: require('./lib/smpte_tt.js'),
     ttml: require('./lib/ttml.js'),
     time: require('./lib/time.js'),
-    macros: require('./lib/macros.js')
+    macros: require('./lib/macros.js'),
+    errors: require('./errors')
 };

errors/index.js

@@ -0,0 +1,6 @@
+/**
+ * Created by ufuk on 30.1.2015.
+ */
+var InvalidFormatError = require('./invalid-format-error');
+
+module.exports.InvalidFormatError = InvalidFormatError;

errors/invalid-format-error.js

@@ -0,0 +1,13 @@
+/**
+ * Created by ufuk on 30.1.2015.
+ */
+function InvalidFormatError(message) {
+    this.message = message;
+    this.stack = new Error().stack;
+    this.type = this.name;
+}
+
+InvalidFormatError.prototype = Object.create(Error.prototype);
+InvalidFormatError.prototype.name = 'InvalidFormatError';
+
+module.exports = InvalidFormatError;

lib/sub.js

@@ -0,0 +1,91 @@
+/** @module scc
+ * @memberOf node-captions
+ */
+/*jslint node: true, nomen: true, plusplus: true, unparam: true, todo: true, regexp: true */
+'use strict';
+
+var errors = require('../errors');
+var SUB_REGEX_STRING = /^\{(\d+)\}\{(\d+)\}(.*?)$/;
+
+
+module.exports = {
+
+    /**
+     * Parses sub captions, errors if format is invalid
+     * @function
+     * @param {string} filedata - String of caption data
+     * @param {callback} callback - function to call when complete
+     * @public
+     */
+    parse: function (filedata, callback) {
+        var lines;
+        lines = filedata.toString().split(/(?:\r\n|\r|\n)/gm);
+        if (module.exports.verify(lines)) {
+            return callback(null, lines);
+        }
+        return callback(new errors.InvalidFormatError('Invalid Sub Format'));
+    },
+
+    /**
+     * verifies sub data
+     * @function
+     * @param {array} data - JSON array of captions
+     * @public
+     */
+    verify: function (data) {
+        //has to be an array of lines.
+        return (SUB_REGEX_STRING.test(data[0]));
+    },
+
+    /**
+     * Converts the SUB file to a proprietary JSON format
+     * @function
+     * @param {string} data - Entire SUB file content
+     * @param {Number} fps - Fps of the movie file
+     * @public
+     */
+    toJSON: function (fps, data) {
+        var json = {},
+            parsed,
+            index,
+            textStart,
+            startTimeMicro,
+            endTimeMicro,
+            captionText,
+            counter = 1;
+        json.captions = [];
+        for (index = 0; index < data.length; index++) {
+            if (data[index].trim() !== '' && data[index].trim().length > 0) {
+                parsed = data[index].trim().match(SUB_REGEX_STRING);
+                textStart = parsed[3].lastIndexOf('}') > 0 || 0;
+                captionText = parsed[3].substr(textStart).replace('|','{break}');
+                startTimeMicro = module.exports.translateTime(Number(parsed[1]), fps);
+                endTimeMicro = module.exports.translateTime(Number(parsed[2]), fps);
+
+                if (captionText !== '')
+                {
+                    json.captions.push({
+                        id: counter,
+                        text: captionText,
+                        startTimeMicro: startTimeMicro,
+                        endTimeMicro: endTimeMicro
+                    });
+                    counter++;
+                }
+            }
+        }
+        return json.captions;
+    },
+
+    /**
+     * Converts SUB timestamps to microseconds
+     * @function
+     * @public
+     * @param {string} timeStamp - Timestamp of SUB line
+     * @param {Number} fps - Fps of the movie file
+     */
+    translateTime: function (timeStamp, fps) {
+        return timeStamp/fps*1000*1000;
+    }
+};
+