mirror of
https://github.com/KubaPro010/fm-dx-webserver.git
synced 2026-07-30 00:39:16 +02:00
oh how much did i MISS 3las, i surely LOVE firefox and its compatiblity (might as well switch to fucking ie)
This commit is contained in:
@@ -0,0 +1,319 @@
|
||||
/*
|
||||
MPEG audio format reader is part of 3LAS (Low Latency Live Audio Streaming)
|
||||
https://github.com/JoJoBond/3LAS
|
||||
*/
|
||||
window.startTimeConnectionWatchdog = performance.now();
|
||||
var __extends = (this && this.__extends) || (function () {
|
||||
var extendStatics = function (d, b) {
|
||||
extendStatics = Object.setPrototypeOf ||
|
||||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
|
||||
function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; };
|
||||
return extendStatics(d, b);
|
||||
};
|
||||
return function (d, b) {
|
||||
if (typeof b !== "function" && b !== null)
|
||||
throw new TypeError("Class extends value " + String(b) + " is not a constructor or null");
|
||||
extendStatics(d, b);
|
||||
function __() { this.constructor = d; }
|
||||
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
|
||||
};
|
||||
})();
|
||||
var MPEGFrameInfo = /** @class */ (function () {
|
||||
function MPEGFrameInfo(data, sampleCount, sampleRate) {
|
||||
this.Data = data;
|
||||
this.SampleCount = sampleCount;
|
||||
this.SampleRate = sampleRate;
|
||||
}
|
||||
return MPEGFrameInfo;
|
||||
}());
|
||||
var AudioFormatReader_MPEG = /** @class */ (function (_super) {
|
||||
__extends(AudioFormatReader_MPEG, _super);
|
||||
function AudioFormatReader_MPEG(audio, logger, errorCallback, beforeDecodeCheck, dataReadyCallback, addId3Tag, minDecodeFrames) {
|
||||
var _this = _super.call(this, audio, logger, errorCallback, beforeDecodeCheck, dataReadyCallback) || this;
|
||||
_this._OnDecodeSuccess = _this.OnDecodeSuccess.bind(_this);
|
||||
_this._OnDecodeError = _this.OnDecodeError.bind(_this);
|
||||
_this.AddId3Tag = addId3Tag;
|
||||
_this.MinDecodeFrames = minDecodeFrames;
|
||||
_this.Frames = new Array();
|
||||
_this.FrameStartIdx = -1;
|
||||
_this.FrameEndIdx = -1;
|
||||
_this.FrameSamples = 0;
|
||||
_this.FrameSampleRate = 0;
|
||||
_this.TimeBudget = 0;
|
||||
return _this;
|
||||
}
|
||||
// Deletes all frames from the databuffer and framearray and all samples from the samplearray
|
||||
AudioFormatReader_MPEG.prototype.PurgeData = function () {
|
||||
_super.prototype.PurgeData.call(this);
|
||||
this.Frames = new Array();
|
||||
this.FrameStartIdx = -1;
|
||||
this.FrameEndIdx = -1;
|
||||
this.FrameSamples = 0;
|
||||
this.FrameSampleRate = 0;
|
||||
this.TimeBudget = 0;
|
||||
};
|
||||
// Extracts all currently possible frames
|
||||
AudioFormatReader_MPEG.prototype.ExtractAll = function () {
|
||||
// Look for frames
|
||||
this.FindFrame();
|
||||
// Repeat as long as we can extract frames
|
||||
while (this.CanExtractFrame()) {
|
||||
// Extract frame and push into array
|
||||
this.Frames.push(this.ExtractFrame());
|
||||
// Look for frames
|
||||
this.FindFrame();
|
||||
}
|
||||
// Check if we have enough frames to decode
|
||||
if (this.Frames.length >= this.MinDecodeFrames) {
|
||||
// Note:
|
||||
// =====
|
||||
// mp3 frames have an overlap of [granule size] so we can't use the first or last [granule size] samples.
|
||||
// [granule size] is equal to half of a [frame size] in samples (using the mp3's sample rate).
|
||||
// Sum up the playback time of each decoded frame and data buffer lengths
|
||||
// Note: Since mp3-Frames overlap by half of their sample-length we expect the
|
||||
// first and last frame to be only half as long. Some decoders will still output
|
||||
// the full frame length by adding zeros.
|
||||
var bufferLength = 0;
|
||||
var expectedTotalPlayTime_1 = 0;
|
||||
var firstGranulePlayTime_1 = 0;
|
||||
var lastGranulePlayTime_1 = 0;
|
||||
firstGranulePlayTime_1 = this.Frames[0].SampleCount / this.Frames[0].SampleRate / 2.0; // Only half of data is usable due to overlap
|
||||
expectedTotalPlayTime_1 += firstGranulePlayTime_1;
|
||||
bufferLength += this.Frames[0].Data.length;
|
||||
for (var i = 1; i < this.Frames.length - 1; i++) {
|
||||
expectedTotalPlayTime_1 += this.Frames[i].SampleCount / this.Frames[i].SampleRate;
|
||||
bufferLength += this.Frames[i].Data.length;
|
||||
}
|
||||
lastGranulePlayTime_1 = this.Frames[this.Frames.length - 1].SampleCount / this.Frames[this.Frames.length - 1].SampleRate / 2.0; // Only half of data is usable due to overlap
|
||||
expectedTotalPlayTime_1 += lastGranulePlayTime_1;
|
||||
bufferLength += this.Frames[this.Frames.length - 1].Data.length;
|
||||
// If needed, add some space for the ID3v2 tag
|
||||
if (this.AddId3Tag) {
|
||||
bufferLength += AudioFormatReader_MPEG.Id3v2Tag.length;
|
||||
}
|
||||
// Create a buffer long enough to hold everything
|
||||
var decodeBuffer = new Uint8Array(bufferLength);
|
||||
var offset = 0;
|
||||
// If needed, add ID3v2 tag to beginning of buffer
|
||||
if (this.AddId3Tag) {
|
||||
decodeBuffer.set(AudioFormatReader_MPEG.Id3v2Tag, offset);
|
||||
offset += AudioFormatReader_MPEG.Id3v2Tag.length;
|
||||
}
|
||||
// Add the frames to the window
|
||||
for (var i = 0; i < this.Frames.length; i++) {
|
||||
decodeBuffer.set(this.Frames[i].Data, offset);
|
||||
offset += this.Frames[i].Data.length;
|
||||
}
|
||||
// Remove the used frames from the array
|
||||
this.Frames.splice(0, this.Frames.length - 1);
|
||||
// Increment Id
|
||||
var id_1 = this.Id++;
|
||||
// Check if decoded frames might be too far back in the past
|
||||
if (!this.OnBeforeDecode(id_1, expectedTotalPlayTime_1))
|
||||
return;
|
||||
// Push window to the decoder
|
||||
this.Audio.decodeAudioData(decodeBuffer.buffer, (function (decodedData) {
|
||||
var _id = id_1;
|
||||
var _expectedTotalPlayTime = expectedTotalPlayTime_1;
|
||||
var _firstGranulePlayTime = firstGranulePlayTime_1;
|
||||
var _lastGranulePlayTime = lastGranulePlayTime_1;
|
||||
this._OnDecodeSuccess(decodedData, _id, _expectedTotalPlayTime, _firstGranulePlayTime, _lastGranulePlayTime);
|
||||
}).bind(this), this._OnDecodeError.bind(this));
|
||||
}
|
||||
};
|
||||
// Finds frame boundries within the data buffer
|
||||
AudioFormatReader_MPEG.prototype.FindFrame = function () {
|
||||
// Find frame start
|
||||
if (this.FrameStartIdx < 0) {
|
||||
var i = 0;
|
||||
// Make sure we don't exceed array bounds
|
||||
while ((i + 1) < this.DataBuffer.length) {
|
||||
// Look for MPEG sync word
|
||||
if (this.DataBuffer[i] == 0xFF && (this.DataBuffer[i + 1] & 0xE0) == 0xE0) {
|
||||
// Sync found, set frame start
|
||||
this.FrameStartIdx = i;
|
||||
break;
|
||||
}
|
||||
i++;
|
||||
}
|
||||
}
|
||||
// Find frame end
|
||||
if (this.FrameStartIdx >= 0 && this.FrameEndIdx < 0) {
|
||||
// Check if we have enough data to process the header
|
||||
if ((this.FrameStartIdx + 2) < this.DataBuffer.length) {
|
||||
// Get header data
|
||||
// Version index
|
||||
var ver = (this.DataBuffer[this.FrameStartIdx + 1] & 0x18) >>> 3;
|
||||
// Layer index
|
||||
var lyr = (this.DataBuffer[this.FrameStartIdx + 1] & 0x06) >>> 1;
|
||||
// Padding? 0/1
|
||||
var pad = (this.DataBuffer[this.FrameStartIdx + 2] & 0x02) >>> 1;
|
||||
// Bitrate index
|
||||
var brx = (this.DataBuffer[this.FrameStartIdx + 2] & 0xF0) >>> 4;
|
||||
// SampRate index
|
||||
var srx = (this.DataBuffer[this.FrameStartIdx + 2] & 0x0C) >>> 2;
|
||||
// Resolve flags to real values
|
||||
var bitrate = AudioFormatReader_MPEG.MPEG_bitrates[ver][lyr][brx] * 1000;
|
||||
var samprate = AudioFormatReader_MPEG.MPEG_srates[ver][srx];
|
||||
var samples = AudioFormatReader_MPEG.MPEG_frame_samples[ver][lyr];
|
||||
var slot_size = AudioFormatReader_MPEG.MPEG_slot_size[lyr];
|
||||
// In-between calculations
|
||||
var bps = samples / 8.0;
|
||||
var fsize = ((bps * bitrate) / samprate) + ((pad == 1) ? slot_size : 0);
|
||||
// Truncate to integer
|
||||
var frameSize = Math.floor(fsize);
|
||||
// Store number of samples and samplerate for frame
|
||||
this.FrameSamples = samples;
|
||||
this.FrameSampleRate = samprate;
|
||||
// Set end frame boundry
|
||||
this.FrameEndIdx = this.FrameStartIdx + frameSize;
|
||||
}
|
||||
}
|
||||
};
|
||||
// Checks if there is a frame ready to be extracted
|
||||
AudioFormatReader_MPEG.prototype.CanExtractFrame = function () {
|
||||
if (this.FrameStartIdx < 0 || this.FrameEndIdx < 0)
|
||||
return false;
|
||||
else if (this.FrameEndIdx <= this.DataBuffer.length)
|
||||
return true;
|
||||
else
|
||||
return false;
|
||||
};
|
||||
// Extract a single frame from the buffer
|
||||
AudioFormatReader_MPEG.prototype.ExtractFrame = function () {
|
||||
// Extract frame data from buffer
|
||||
var frameArray = this.DataBuffer.buffer.slice(this.FrameStartIdx, this.FrameEndIdx);
|
||||
// Remove frame from buffer
|
||||
if ((this.FrameEndIdx + 1) < this.DataBuffer.length)
|
||||
this.DataBuffer = new Uint8Array(this.DataBuffer.buffer.slice(this.FrameEndIdx));
|
||||
else
|
||||
this.DataBuffer = new Uint8Array(0);
|
||||
// Reset Start/End indices
|
||||
this.FrameStartIdx = 0;
|
||||
this.FrameEndIdx = -1;
|
||||
return new MPEGFrameInfo(new Uint8Array(frameArray), this.FrameSamples, this.FrameSampleRate);
|
||||
};
|
||||
// Is called if the decoding of the window succeeded
|
||||
AudioFormatReader_MPEG.prototype.OnDecodeSuccess = function (decodedData, id, expectedTotalPlayTime, firstGranulePlayTime, lastGranulePlayTime) {
|
||||
window.startTimeConnectionWatchdog = performance.now();
|
||||
var extractSampleCount;
|
||||
var extractSampleOffset;
|
||||
var delta = 0.001;
|
||||
// Check if we got the expected number of samples
|
||||
if (expectedTotalPlayTime > decodedData.duration) {
|
||||
// We got less samples than expect, we suspect that they were truncated equally at start and end.
|
||||
// This can happen in case of sample rate conversions.
|
||||
extractSampleCount = decodedData.length;
|
||||
extractSampleOffset = 0;
|
||||
this.TimeBudget += (expectedTotalPlayTime - decodedData.duration);
|
||||
}
|
||||
else if (expectedTotalPlayTime < decodedData.duration) {
|
||||
// We got more samples than expect, we suspect that zeros were added equally at start and end.
|
||||
// This can happen in case of sample rate conversions or edge frame handling.
|
||||
extractSampleCount = Math.ceil(expectedTotalPlayTime * decodedData.sampleRate);
|
||||
var budgetSamples = this.TimeBudget * decodedData.sampleRate;
|
||||
if (budgetSamples > 1.0) {
|
||||
if (budgetSamples > decodedData.length - extractSampleCount) {
|
||||
budgetSamples = decodedData.length - extractSampleCount;
|
||||
}
|
||||
extractSampleCount += budgetSamples;
|
||||
this.TimeBudget -= (budgetSamples / decodedData.sampleRate);
|
||||
}
|
||||
var diff = decodedData.duration - expectedTotalPlayTime;
|
||||
if ((diff - firstGranulePlayTime - lastGranulePlayTime) >= -delta) {
|
||||
// Both first and last granule are present. Cut out middle section.
|
||||
extractSampleOffset = Math.floor((decodedData.length - extractSampleCount) / 2);
|
||||
}
|
||||
if (Math.abs(firstGranulePlayTime - lastGranulePlayTime) <= delta) {
|
||||
// First and last granule are equal. We need to make an educated guess which one is present.
|
||||
if (isIOS || isIPadOS || isMacOSX) {
|
||||
// I don't know why, but Apple does things differently.
|
||||
extractSampleOffset = Math.floor((decodedData.length - extractSampleCount) / 2);
|
||||
}
|
||||
else {
|
||||
// Assume last granule is present.
|
||||
extractSampleOffset = decodedData.length - extractSampleCount;
|
||||
}
|
||||
}
|
||||
else if (Math.abs(diff - firstGranulePlayTime) <= delta) {
|
||||
// Last granule is present.
|
||||
extractSampleOffset = decodedData.length - extractSampleCount;
|
||||
}
|
||||
else if (Math.abs(diff - lastGranulePlayTime) <= delta) {
|
||||
// First granule is present.
|
||||
extractSampleOffset = 0;
|
||||
}
|
||||
else {
|
||||
// The difference is not equal to neither the first, the last nor the sum of both granule. So we just use the middle.
|
||||
extractSampleOffset = Math.floor((decodedData.length - extractSampleCount) / 2);
|
||||
}
|
||||
}
|
||||
else {
|
||||
// We got the expected number of samples, no adaption needed
|
||||
extractSampleCount = decodedData.length;
|
||||
extractSampleOffset = 0;
|
||||
}
|
||||
// Create a buffer that can hold the frame to extract
|
||||
var audioBuffer = this.Audio.createBuffer(decodedData.numberOfChannels, extractSampleCount, decodedData.sampleRate);
|
||||
// Fill buffer with the last part of the decoded frame leave out last granule
|
||||
for (var i = 0; i < decodedData.numberOfChannels; i++)
|
||||
audioBuffer.getChannelData(i).set(decodedData.getChannelData(i).subarray(extractSampleOffset, extractSampleOffset + extractSampleCount));
|
||||
this.OnDataReady(id, audioBuffer);
|
||||
};
|
||||
// Is called in case the decoding of the window fails
|
||||
AudioFormatReader_MPEG.prototype.OnDecodeError = function (_error) {
|
||||
this.ErrorCallback();
|
||||
};
|
||||
// MPEG versions - use [version]
|
||||
AudioFormatReader_MPEG.MPEG_versions = new Array(25, 0, 2, 1);
|
||||
// Layers - use [layer]
|
||||
AudioFormatReader_MPEG.MPEG_layers = new Array(0, 3, 2, 1);
|
||||
// Bitrates - use [version][layer][bitrate]
|
||||
AudioFormatReader_MPEG.MPEG_bitrates = new Array(new Array(// Version 2.5
|
||||
new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), // Reserved
|
||||
new Array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0), // Layer 3
|
||||
new Array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0), // Layer 2
|
||||
new Array(0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0) // Layer 1
|
||||
), new Array(// Reserved
|
||||
new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), // Invalid
|
||||
new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), // Invalid
|
||||
new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), // Invalid
|
||||
new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) // Invalid
|
||||
), new Array(// Version 2
|
||||
new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), // Reserved
|
||||
new Array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0), // Layer 3
|
||||
new Array(0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0), // Layer 2
|
||||
new Array(0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0) // Layer 1
|
||||
), new Array(// Version 1
|
||||
new Array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), // Reserved
|
||||
new Array(0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0), // Layer 3
|
||||
new Array(0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0), // Layer 2
|
||||
new Array(0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0) // Layer 1
|
||||
));
|
||||
// Sample rates - use [version][srate]
|
||||
AudioFormatReader_MPEG.MPEG_srates = new Array(new Array(11025, 12000, 8000, 0), // MPEG 2.5
|
||||
new Array(0, 0, 0, 0), // Reserved
|
||||
new Array(22050, 24000, 16000, 0), // MPEG 2
|
||||
new Array(44100, 48000, 32000, 0) // MPEG 1
|
||||
);
|
||||
// Samples per frame - use [version][layer]
|
||||
AudioFormatReader_MPEG.MPEG_frame_samples = new Array(
|
||||
// Rsvd 3 2 1 < Layer v Version
|
||||
new Array(0, 576, 1152, 384), // 2.5
|
||||
new Array(0, 0, 0, 0), // Reserved
|
||||
new Array(0, 576, 1152, 384), // 2
|
||||
new Array(0, 1152, 1152, 384) // 1
|
||||
);
|
||||
AudioFormatReader_MPEG.Id3v2Tag = new Uint8Array(new Array(0x49, 0x44, 0x33, // File identifier: "ID3"
|
||||
0x03, 0x00, // Version 2.3
|
||||
0x00, // Flags: no unsynchronisation, no extended header, no experimental indicator
|
||||
0x00, 0x00, 0x00, 0x0D, // Size of the (tag-)frames, extended header and padding
|
||||
0x54, 0x49, 0x54, 0x32, // Title frame: "TIT2"
|
||||
0x00, 0x00, 0x00, 0x02, // Size of the frame data
|
||||
0x00, 0x00, // Frame Flags
|
||||
0x00, 0x20, 0x00 // Frame data (space character) and padding
|
||||
));
|
||||
// Slot size (MPEG unit of measurement) - use [layer]
|
||||
AudioFormatReader_MPEG.MPEG_slot_size = new Array(0, 1, 1, 4); // Rsvd, 3, 2, 1
|
||||
return AudioFormatReader_MPEG;
|
||||
}(AudioFormatReader));
|
||||
Reference in New Issue
Block a user