First release

node_modules/mux.js/es/codecs/adts.js

@@ -0,0 +1,128 @@
+/**
+ * mux.js
+ *
+ * Copyright (c) Brightcove
+ * Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
+ */
+'use strict';
+
+var Stream = require('../utils/stream.js');
+
+var ONE_SECOND_IN_TS = require('../utils/clock').ONE_SECOND_IN_TS;
+
+var _AdtsStream;
+
+var ADTS_SAMPLING_FREQUENCIES = [96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 7350];
+/*
+ * Accepts a ElementaryStream and emits data events with parsed
+ * AAC Audio Frames of the individual packets. Input audio in ADTS
+ * format is unpacked and re-emitted as AAC frames.
+ *
+ * @see http://wiki.multimedia.cx/index.php?title=ADTS
+ * @see http://wiki.multimedia.cx/?title=Understanding_AAC
+ */
+
+_AdtsStream = function AdtsStream(handlePartialSegments) {
+  var buffer,
+      frameNum = 0;
+
+  _AdtsStream.prototype.init.call(this);
+
+  this.push = function (packet) {
+    var i = 0,
+        frameLength,
+        protectionSkipBytes,
+        frameEnd,
+        oldBuffer,
+        sampleCount,
+        adtsFrameDuration;
+
+    if (!handlePartialSegments) {
+      frameNum = 0;
+    }
+
+    if (packet.type !== 'audio') {
+      // ignore non-audio data
+      return;
+    } // Prepend any data in the buffer to the input data so that we can parse
+    // aac frames the cross a PES packet boundary
+
+
+    if (buffer) {
+      oldBuffer = buffer;
+      buffer = new Uint8Array(oldBuffer.byteLength + packet.data.byteLength);
+      buffer.set(oldBuffer);
+      buffer.set(packet.data, oldBuffer.byteLength);
+    } else {
+      buffer = packet.data;
+    } // unpack any ADTS frames which have been fully received
+    // for details on the ADTS header, see http://wiki.multimedia.cx/index.php?title=ADTS
+
+
+    while (i + 5 < buffer.length) {
+      // Look for the start of an ADTS header..
+      if (buffer[i] !== 0xFF || (buffer[i + 1] & 0xF6) !== 0xF0) {
+        // If a valid header was not found,  jump one forward and attempt to
+        // find a valid ADTS header starting at the next byte
+        i++;
+        continue;
+      } // The protection skip bit tells us if we have 2 bytes of CRC data at the
+      // end of the ADTS header
+
+
+      protectionSkipBytes = (~buffer[i + 1] & 0x01) * 2; // Frame length is a 13 bit integer starting 16 bits from the
+      // end of the sync sequence
+
+      frameLength = (buffer[i + 3] & 0x03) << 11 | buffer[i + 4] << 3 | (buffer[i + 5] & 0xe0) >> 5;
+      sampleCount = ((buffer[i + 6] & 0x03) + 1) * 1024;
+      adtsFrameDuration = sampleCount * ONE_SECOND_IN_TS / ADTS_SAMPLING_FREQUENCIES[(buffer[i + 2] & 0x3c) >>> 2];
+      frameEnd = i + frameLength; // If we don't have enough data to actually finish this ADTS frame, return
+      // and wait for more data
+
+      if (buffer.byteLength < frameEnd) {
+        return;
+      } // Otherwise, deliver the complete AAC frame
+
+
+      this.trigger('data', {
+        pts: packet.pts + frameNum * adtsFrameDuration,
+        dts: packet.dts + frameNum * adtsFrameDuration,
+        sampleCount: sampleCount,
+        audioobjecttype: (buffer[i + 2] >>> 6 & 0x03) + 1,
+        channelcount: (buffer[i + 2] & 1) << 2 | (buffer[i + 3] & 0xc0) >>> 6,
+        samplerate: ADTS_SAMPLING_FREQUENCIES[(buffer[i + 2] & 0x3c) >>> 2],
+        samplingfrequencyindex: (buffer[i + 2] & 0x3c) >>> 2,
+        // assume ISO/IEC 14496-12 AudioSampleEntry default of 16
+        samplesize: 16,
+        data: buffer.subarray(i + 7 + protectionSkipBytes, frameEnd)
+      });
+      frameNum++; // If the buffer is empty, clear it and return
+
+      if (buffer.byteLength === frameEnd) {
+        buffer = undefined;
+        return;
+      } // Remove the finished frame from the buffer and start the process again
+
+
+      buffer = buffer.subarray(frameEnd);
+    }
+  };
+
+  this.flush = function () {
+    frameNum = 0;
+    this.trigger('done');
+  };
+
+  this.reset = function () {
+    buffer = void 0;
+    this.trigger('reset');
+  };
+
+  this.endTimeline = function () {
+    buffer = void 0;
+    this.trigger('endedtimeline');
+  };
+};
+
+_AdtsStream.prototype = new Stream();
+module.exports = _AdtsStream;