recursal/MDN huggingface dataset:
RTCInboundRtpStreamStats: fecPacketsReceived property
=====================================================

 The **`fecPacketsReceived`** property
 of the `RTCInboundRtpStreamStats` dictionary indicates how many
 Forward Error Correction (FEC) packets have been received by this RTP receiver
 from the remote peer.

 An FEC packet provides parity information which can
 be used to attempt to reconstruct RTP data packets which have been corrupted in
 transit.

Syntax
------


```js
const fecPacketsReceived = rtcInboundRtpStreamStats.fecPacketsReceived
```

### Value

 An unsigned integer value which indicates the total number of FEC packets which have
 been received from the remote peer during this RTP session. Forward Error Correction
 uses an exclusive-or method to perform parity checks on the received data.

 By using the FEC parity information to attempt to reconstruct damaged packets, it is
 possible to avoid the need to retransmit damaged packets, which in turn helps to
 reduce lag, or the need to skip damaged frames entirely.


**Note:** This counter may also be incremented when FEC packets arrive
 in-band along with media content; this can happen with Opus, for example.


Usage notes
-----------

 It's possible that a subset of the FEC packets which have been received were discarded
 instead of being used. This can happen if the packets covered by the FEC packets have
 already been received successfully or have already been reconstructed using a
 previously-received FEC packet. This may also happen if the FEC packet arrives outside
 the window of time in which the client will attempt to use it.

 If you wish to know how many of the received packets were discarded, you can examine
 the value of `fecPacketsDiscarded`.

Specifications
--------------

| Specification |
| --- |
| Identifiers for WebRTC's Statistics API # dom-rtcinboundrtpstreamstats-fecpacketsreceived |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* RFC 5109 (RTP Payload Format for Generic Forward Error Correction)
RTCInboundRtpStreamStats: id property
=====================================

The **`id`** property of the `RTCInboundRtpStreamStats` dictionary is a string that uniquely identifies the object for which this object provides statistics.

Using the `id`, you can correlate this statistics object with others, in order to monitor statistics over time for a given WebRTC object, such as an `RTCPeerConnection`, or an `RTCDataChannel`.

Value
-----

A string that uniquely identifies the object for which this `RTCInboundRtpStreamStats` object provides statistics.

The format of the ID string is not defined by the specification, so you cannot reliably make any assumptions about the contents of the string, or assume that the format of the string will remain unchanged for a given object type.

Specifications
--------------

| Specification |
| --- |
| Identifiers for WebRTC's Statistics API # dom-rtcstats-id |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
RTCInboundRtpStreamStats: nackCount property
============================================

 The **`nackCount`** property of the
 `RTCInboundRtpStreamStats` dictionary is a numeric value indicating the
 number of times the receiver sent a **NACK** packet to the sender.

 A NACK (Negative ACKnowledgement, also called "Generic NACK") packet tells the sender
 that one or more of the RTP packets it sent were lost in transport.

Value
-----

 An integer value indicating how many times the receiver sent a NACK packet to the
 sender after detecting that one or more packets were lost during transport.

Specifications
--------------

| Specification |
| --- |
| Identifiers for WebRTC's Statistics API # dom-rtcinboundrtpstreamstats-nackcount |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
RTCInboundRtpStreamStats: lastPacketReceivedTimestamp property
==============================================================

The **`lastPacketReceivedTimestamp`** property of the `RTCInboundRtpStreamStats` dictionary indicates the time at which the most recently received packet arrived from this source.

Value
-----

A `DOMHighResTimeStamp` which specifies the time at which the most recently received packet arrived on this RTP stream.

**Note:** This value differs from the `timestamp`,
 which represents the time at which the statistics object was created.


Specifications
--------------

| Specification |
| --- |
| Identifiers for WebRTC's Statistics API # dom-rtcinboundrtpstreamstats-lastpacketreceivedtimestamp |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
RTCInboundRtpStreamStats: trackId property
==========================================

**Deprecated:** This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The **`trackId`** property of the `RTCInboundRtpStreamStats` dictionary indicates the `id` of the `RTCReceiverAudioTrackAttachmentStats` or `RTCReceiverVideoTrackAttachmentStats` object representing the `MediaStreamTrack` which is receiving the incoming media.

Value
-----

A string containing the ID of the `RTCReceiverAudioTrackAttachmentStats` or `RTCReceiverVideoTrackAttachmentStats` object representing the track which is receiving the media from this RTP session.

Specifications
--------------

#### No specification found

No specification data found for `api.RTCInboundRtpStreamStats.trackId`.  
Check for problems with this page or contribute a missing `spec_url` to mdn/browser-compat-data. Also make sure the specification is included in w3c/browser-specs.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
RTCInboundRtpStreamStats: sliCount property
===========================================

 The **`sliCount`** property of the
 `RTCInboundRtpStreamStats` dictionary indicates how many **Slice
Loss Indication** (**SLI**) packets the
 `RTCRtpReceiver` for which this object provides statistics sent to the
 remote `RTCRtpSender`.

 An SLI packet is used by a decoder to let
 the encoder know that it's detected corruption of one or more consecutive macroblocks
 (in scan order) in the received media.

 In general, what's usually of interest is that the higher this number is, the more the
 stream data is becoming corrupted between the sender and the receiver, requiring resends
 or dropping frames.

Value
-----

 An unsigned integer indicating the number of SLI packets this receiver sent to the
 remote sender due to lost runs of macroblocks. A high value of `sliCount` may
 be an indication of an unreliable network.

This is a very technical part of how video codecs work. For details, see RFC 4585: 6.3.2.

**Note:** This value is only present for video media.

Specifications
--------------

#### No specification found

No specification data found for `api.RTCInboundRtpStreamStats.sliCount`.  
Check for problems with this page or contribute a missing `spec_url` to mdn/browser-compat-data. Also make sure the specification is included in w3c/browser-specs.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* RFC 4585, section 6.3.2: Definition of "Slice Loss Indication" in the document
 *Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based
Feedback (RTP/AVPF)*.
RTCInboundRtpStreamStats: perDscpPacketsReceived property
=========================================================

 The **`perDscpPacketsReceived`**
 property of the `RTCInboundRtpStreamStats` dictionary is a record
 comprised of key/value pairs in which each key is a string representation of a
 Differentiated Services Code Point and the value is the number of packets received for
 that DCSP.


**Note:** Not all operating systems make data available on a per-DSCP
 basis, so this property shouldn't be relied upon on those systems.


Value
-----

 A record comprised of string/value pairs. Each key is the string representation of a
 single Differentiated Services Code Point (DSCP)'s ID number.


**Note:** Due to network bleaching and remapping, the numbers seen on
 this record are not necessarily going to match the values as they were when the data
 was sent.


Specifications
--------------

#### No specification found

No specification data found for `api.RTCInboundRtpStreamStats.perDscpPacketsReceived`.  
Check for problems with this page or contribute a missing `spec_url` to mdn/browser-compat-data. Also make sure the specification is included in w3c/browser-specs.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* RFC 2474: The Differentiated Service field in IPv4 and IPv6 headers
RTCInboundRtpStreamStats: packetsFailedDecryption property
==========================================================

 The **`packetsFailedDecryption`**
 property of the `RTCInboundRtpStreamStats` dictionary indicates the total
 number of RTP packets which failed to be decrypted successfully after
 being received by the local end of the connection during this session.

Value
-----

 An integer value which indicates how many packets the local end of the RTP connection
 could not be successfully decrypted.

Specifications
--------------

#### No specification found

No specification data found for `api.RTCInboundRtpStreamStats.packetsFailedDecryption`.  
Check for problems with this page or contribute a missing `spec_url` to mdn/browser-compat-data. Also make sure the specification is included in w3c/browser-specs.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.

See also
--------

* RFC 3711, section 3.3: Description of the decryption process for secure RTP packets
RTCInboundRtpStreamStats: receiverId property
=============================================

The **`receiverId`** property of the `RTCInboundRtpStreamStats` dictionary specifies the `id` of the `RTCAudioReceiverStats` or `RTCVideoReceiverStats` object representing the `RTCRtpReceiver` receiving the stream.

Value
-----

A string which contains the ID of the `RTCAudioReceiverStats` or `RTCVideoReceiverStats` object which provides information about the `RTCRtpReceiver` which is receiving the streamed media.

Specifications
--------------

#### No specification found

No specification data found for `api.RTCInboundRtpStreamStats.receiverId`.  
Check for problems with this page or contribute a missing `spec_url` to mdn/browser-compat-data. Also make sure the specification is included in w3c/browser-specs.

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: removeItem() method
=================================

The **`removeItem()`** method of the `SVGPointList` interface removes a `point` from the list.

Syntax
------


```js
removeItem(index)
```

### Parameters

`index`

The index of the item to remove.

### Return value

The removed `SVGPoint` object.

### Exceptions

`NoModificationAllowedError` `DOMException`

Thrown if the list is read-only.

`IndexSizeError` `DOMException`

Thrown if the index passed in is greater than the number of items in the list.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. The item at index `2` is removed.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
console.log(example.points.removeItem(2));
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_removeItem |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: clear() method
============================

The **`clear()`** method of the `SVGPointList` interface removes all items from the list.

Syntax
------


```js
clear()
```

### Parameters

None.

### Return value

None (`undefined`).

### Exceptions

`NoModificationAllowedError` `DOMException`

Thrown if the list is read-only.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. Calling `clear()` empties the list. Therefore the polyline no longer displays in the SVG.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
example.points.clear();
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_clear |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: insertItemBefore() method
=======================================

The **`insertItemBefore()`** method of the `SVGPointList` interface inserts a `point` before another item in the list.

Syntax
------


```js
insertItemBefore(obj, index)
```

### Parameters

`obj`

An `SVGPoint` object containing the coordinates of the point to be inserted.

`index`

The index of the item the object should be inserted before. If the index passed in is greater than the length of the list, then index will be set to the list length and the item inserted before the last item in the list.

### Return value

The `SVGPoint` object that was inserted.

### Exceptions

`NoModificationAllowedError` `DOMException`

Thrown if the list is read-only.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. A new `SVGPoint` is created, and inserted before the point at index `2`.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
let svgpoint = document.getElementById("svg").createSVGPoint();
svgpoint.y = 10;
svgpoint.x = 10;
console.log(example.points.insertItemBefore(svgpoint, 2));
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_insertItemBefore |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: numberOfItems property
====================================

The **`numberOfItems`** read-only property of the `SVGPointList` interface returns the number of items in the list.

Value
-----

The number of items in the list.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. The `numberOfItems` property returns `5`.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
console.log(example.points.numberOfItems); // 5
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_numberOfItems |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: appendItem() method
=================================

The **`appendItem()`** method of the `SVGPointList` interface adds a `point` to the end of the list.

Syntax
------


```js
appendItem(obj)
```

### Parameters

`obj`

An `SVGPoint` object containing the coordinates of the point to be appended.

### Return value

The `SVGPoint` object that was appended.

### Exceptions

`NoModificationAllowedError` `DOMException`

Thrown if the list is read-only.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. A new `SVGPoint` is created, and appended to the list.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
let svgpoint = document.getElementById("svg").createSVGPoint();
svgpoint.y = 10;
svgpoint.x = 10;
console.log(example.points.appendItem(svgpoint));
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_appendItem |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: replaceItem() method
==================================

The **`replaceItem()`** method of the `SVGPointList` interface replaces a `point` in the list.

Syntax
------


```js
replaceItem(obj, index)
```

### Parameters

`obj`

An `point` object containing the coordinates of the point to be inserted.

`index`

The index of the item to replace.

### Return value

The new `SVGPoint` object.

### Exceptions

`NoModificationAllowedError` `DOMException`

Thrown if the list is read-only.

`IndexSizeError` `DOMException`

Thrown if the index passed in is greater than the number of items in the list.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. A new `SVGPoint` is created, then replaces the point at index `1` (the second item in the list).


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
let svgpoint = document.getElementById("svg").createSVGPoint();
svgpoint.y = 10;
svgpoint.x = 10;
console.log(example.points.replaceItem(svgpoint, 1));
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_replaceItem |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: length property
=============================

The **`length`** read-only property of the `SVGPointList` interface returns the number of items in the list.

Value
-----

The number of items in the list.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. The `length` property returns `5`.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
console.log(example.points.length); // 5
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_length |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: initialize() method
=================================

The **`initialize()`** method of the `SVGPointList` interface clears the list then adds a single new `SVGPoint` object to the list.

Syntax
------


```js
initialize(obj)
```

### Parameters

`obj`

An `SVGPoint` object containing the coordinates of the point to be added when the list is initialized.

### Return value

The added `SVGPoint` object.

### Exceptions

`NoModificationAllowedError` `DOMException`

Thrown if the list is read-only.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. Returning `SVGPointList.length` gives the value `5`. After calling `initialize()`, returning `SVGPointList.length` gives the value `1`.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
console.log(example.points.length); //5;
let svgpoint = document.getElementById("svg").createSVGPoint();
example.points.initialize(svgpoint);
console.log(example.points.length); //1
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_initialize |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
SVGPointList: getItem() method
==============================

The **`getItem()`** method of the `SVGPointList` interface gets one item from the list at the specified index.

Syntax
------


```js
getItem(index)
```

### Parameters

`index`

The index of the item to return.

### Return value

An `SVGPoint` object.

### Exceptions

`IndexSizeError` `DOMException`

Thrown if the index passed in is greater than the number of items in the list.

Examples
--------

The following example shows an SVG which contains a `<polyline>` with five coordinate pairs. The `SVGPoint` at index `0`.


```html
<svg id="svg" viewBox="-10 -10 120 120" xmlns="http://www.w3.org/2000/svg">
  <polyline
 id="example"
 stroke="black"
 fill="none"
 points="50,0 21,90 98,35 2,35 79,90" />
</svg>
```



```js
let example = document.getElementById("example");
console.log(example.points.getItem(0));
```

Specifications
--------------

| Specification |
| --- |
| Scalable Vector Graphics (SVG) 2 # \_\_svg\_\_SVGNameList\_\_getItem |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
MediaKeySystemAccess: createMediaKeys() method
==============================================

 The `MediaKeySystemAccess.createMediaKeys()` method returns a
 `Promise` that resolves to a new `MediaKeys` object.

Syntax
------


```js
createMediaKeys()
```

### Parameters

None.

### Return value

A `Promise`.

Specifications
--------------

| Specification |
| --- |
| Encrypted Media Extensions # dom-mediakeysystemaccess-createmediakeys |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.
MediaKeySystemAccess: keySystem property
========================================

 The `MediaKeySystemAccess.keySystem` read-only property returns a
 string identifying the key system being used.

Value
-----

A string.

Specifications
--------------

| Specification |
| --- |
| Encrypted Media Extensions # dom-mediakeysystemaccess-keysystem |

Browser compatibility
---------------------

BCD tables only load in the browser with JavaScript enabled. Enable JavaScript to view data.