audio-buffer-list - npm Package Compare versions

Comparing version 1.3.4 to 1.4.0

index.js

@@ -16,3 +16,2 @@ /**
 var extend = require('object-assign')
-var context = require('audio-context')
 var nidx = require('negative-index')
@@ -62,3 +61,3 @@
 AudioBufferList.prototype.numberOfChannels = 0
-AudioBufferList.prototype.sampleRate = context.sampleRate || 44100
+AudioBufferList.prototype.sampleRate = null
 
@@ -98,19 +97,31 @@ //copy from channel into destination array
 //return float array with channel data
-AudioBufferList.prototype.getChannelData = function (channel) {
-  if (!this._bufs.length) return new Float32Array()
+AudioBufferList.prototype.getChannelData = function (channel, from, to) {
+  if (from == null) from = 0
+  if (to == null) to = this.length
+  from = nidx(from, this.length)
+  to = nidx(to, this.length)
 
+  if (!this._bufs.length || from === to) return new Float32Array()
+
   //shortcut single buffer preserving subarraying
-  if (this._bufs.length === 1) return this._bufs[0].getChannelData(channel)
+  if (this._bufs.length === 1) {
+    return this._bufs[0].getChannelData(channel).subarray(from, to)
+  }
 
   var floatArray = this._bufs[0].getChannelData(0).constructor
-  var data = new floatArray(this.length)
+  var data = new floatArray(to - from)
+  var fromOffset = this._offset(from)
+  var toOffset = this._offset(to)
 
-  var offset = 0
-  for (var i = 0, l = this._bufs.length; i < l; i++) {
+  var firstBuf = this._bufs[fromOffset[0]]
+  data.set(firstBuf.getChannelData(channel).subarray(fromOffset[1]))
+
+  var offset = -fromOffset[1] + firstBuf.length
+  for (var i = fromOffset[0] + 1, l = toOffset[0]; i < l; i++) {
     var buf = this._bufs[i]
-    if (channel < buf.numberOfChannels) {
-      data.set(buf.getChannelData(channel), offset);
-    }
+    data.set(buf.getChannelData(channel), offset);
     offset += buf.length
   }
+  var lastBuf = this._bufs[toOffset[0]]
+  data.set(lastBuf.getChannelData(channel).subarray(0, toOffset[1]), offset)
 
@@ -152,3 +163,3 @@ return data
 AudioBufferList.prototype._appendBuffer = function (buf) {
-  if (buf.sampleRate != this.sampleRate) throw Error('Required sample rate is ' + this.sampleRate + ', passed ' + buf.sampleRate)
+  // if (buf.sampleRate != this.sampleRate) throw Error('Required sample rate is ' + this.sampleRate + ', passed ' + buf.sampleRate)
 
@@ -162,2 +173,5 @@ BufferList.prototype._appendBuffer.call(this, buf)
 
+  //init sampleRate
+  if (!this.sampleRate) this.sampleRate = buf.sampleRate
+
   return this
@@ -247,3 +261,3 @@ }
   if (start == end) {
-    let res = new AudioBufferList([], {context: this.context})
+    let res = new AudioBufferList([])
     return res
@@ -284,5 +298,5 @@ }
 
+//clone with preserving data
 AudioBufferList.prototype.duplicate = function duplicate () {
-  var i = 0
-    , copy = new AudioBufferList()
+  var i = 0, copy = new AudioBufferList()
 
@@ -296,2 +310,3 @@ for (; i < this._bufs.length; i++)
 
+
 ;(function () {
@@ -410,29 +425,58 @@ var methods = {
 
-//return new buffer by mapping it
+//return new list via applying fn to each buffer from the indicated range
 AudioBufferList.prototype.map = function map (fn, from, to) {
-  let before, after, middle
-  if (from != null) {
-    before = this.shallowSlice(0, from)
-  }
-  if (to != null) {
-    after = this.shallowSlice(to)
-  }
-  if (before || after) middle = this.shallowSlice(from, to)
-  else middle = this
+  if (from == null) from = 0
+  if (to == null) to = this.length
+  from = nidx(from, this.length)
+  to = nidx(to, this.length)
 
-  let maxChannels = 0
-  middle._bufs = middle._bufs.map((buf, idx) => {
-    buf = fn.call(this, buf, idx, this._bufs, this)
-    if (buf.numberOfChannels > maxChannels) maxChannels = buf.numberOfChannels
-    return buf
+  let fromOffset = this._offset(from)
+  let toOffset = this._offset(to)
+
+  let offset = from - fromOffset[1]
+  let before = this._bufs.slice(0, fromOffset[0])
+  let after = this._bufs.slice(toOffset[0] + 1)
+  let middle = this._bufs.slice(fromOffset[0], toOffset[1] + 1)
+
+  middle = middle.map((buf, idx) => {
+    let result = fn.call(this, buf, idx, offset, this._bufs, this)
+    if (result === undefined || result === true) result = buf
+    //ignore removed buffers
+    if (!result) {
+      return null;
+    }
+
+    //track offset
+    offset += result.length
+
+    return result
   })
-  if (before) middle = before.append(middle)
-  if (after) middle = middle.append(after)
+  .filter((buf) => {
+    return buf ? !!buf.length : false
+  })
 
-  if (!before && !after) {
-    this.numberOfChannels = maxChannels
+  return new AudioBufferList(before.concat(middle).concat(after))
+}
+
+//apply fn to every buffer for the indicated range
+AudioBufferList.prototype.each = function each (fn, from, to) {
+  if (from == null) from = 0
+  if (to == null) to = this.length
+  from = nidx(from, this.length)
+  to = nidx(to, this.length)
+
+  let fromOffset = this._offset(from)
+  let toOffset = this._offset(to)
+
+  let offset = from - fromOffset[1]
+
+  let middle = this._bufs.slice(fromOffset[0], toOffset[1] + 1)
+
+  for (let i = fromOffset[0], l = toOffset[0]+1; i < l; i++) {
+    let buf = this._bufs[i]
+    fn.call(this, buf, i, offset, this._bufs, this)
+    offset += buf.length
   }
 
-  return middle
+  return this;
 }
-

package.json

 {
   "name": "audio-buffer-list",
-  "version": "1.3.4",
+  "version": "1.4.0",
   "description": "Data structure for sequence of AudioBuffers",
@@ -5,0 +5,0 @@ "main": "index.js",

readme.md

 # audio-buffer-list [![Build Status](https://travis-ci.org/audiojs/audio-buffer-list.svg?branch=master)](https://travis-ci.org/audiojs/audio-buffer-list) [![experimental](http://badges.github.io/stability-badges/dist/experimental.svg)](http://github.com/badges/stability-badges)
 
-Extension of [BufferList](https://npmjs.org/package/bl) for [AudioBuffers](https://npmjs.org/package/audio-buffer). Handy and performant to deal with sequence of audio buffers − accumulate, read, stream, modify, delete etc. It provides interfaces both of _AudioBuffer_ and _BufferList_, as well as bunch of other useful methods.
+Extension of [BufferList](https://npmjs.org/package/bl) for [AudioBuffers](https://npmjs.org/package/audio-buffer). Handy and performant to deal with (possibly long) sequence of audio buffers − accumulate, read, stream, modify, delete etc. It provides interfaces of both _AudioBuffer_ and _BufferList_, as well as bunch of other useful methods.
 
@@ -43,7 +43,27 @@ ## Usage
 
-### `list.map((buffer, index) => buffer, from=0, to=-0)`
+### `list.map((buffer, index, offset) => buffer|bool?, from=0, to=-0)`
 
-Create new list by mapping every buffer. Optionally pass offsets `from` and `to` to map only subset.
+Create new list by mapping every buffer. Optionally pass offsets `from` and `to` to map only buffers covering the subset, keeping the rest unchanged. If no buffer returned from the mapper function then the old buffer will be preserved. If `null` returned then the buffer will be discarded. `offset` tracks `buffer` offset in new list, `index` reflects buffer count.
 
+```js
+list = list.map((buf, idx, offset) => {
+	for (let c = 0; c < channels; c++) {
+		let data = buf.getChannelData(channel)
 
+		//start buffer from the subset may start earlier than the subset
+		//end buffer from the subset may end later than the subset
+		for (let i = Math.max(from - offset, 0),
+					l = Math.min(to - offset, buf.length);
+					i < l; i++) {
+			data[i] = process(data[i])
+		}
+	}
+}, from, to)
+```
+
+### `list.each((buffer, index, offset) => {}, from=0, to=-0)`
+
+Iterate over buffers from the indicated range. Buffers can be modified in-place during the iterating.
+
+
 ## [AudioBuffer](https://github.com/audiojs/audio-buffer) properties & methods
@@ -50,0 +70,0 @@

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Improved metrics

Total package byte prevSize

20998

increased by12.22%

Lines of code

420

increased by8.25%

Number of lines in readme file

139

increased by16.81%

No dependency changes