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Update WebRTC media source stats (#32538)
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* RTCAudioSourceStats - make consistent, improve docs on kind property, mark optional audio source stats

* RTCVideoSourceStats - draft

* Add remainder of Video source updates

* Add spec-urls for audiosource and videosource

* Make kind consistent

* Fix missing frames case

* Update files/en-us/web/api/rtcvideosourcestats/framespersecond/index.md

Co-authored-by: Hamish Willee <[email protected]>

* Update files/en-us/web/api/rtcvideosourcestats/framespersecond/index.md

Co-authored-by: Hamish Willee <[email protected]>

* Update files/en-us/web/api/rtcvideosourcestats/index.md

Co-authored-by: wbamberg <[email protected]>

* Apply suggestions from code review

* Update files/en-us/web/api/rtcvideosourcestats/index.md

* Improve conditional comment a'la wbamberg suggestion

* Update files/en-us/web/api/rtcvideosourcestats/index.md

Co-authored-by: wbamberg <[email protected]>

---------

Co-authored-by: wbamberg <[email protected]>
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hamishwillee and wbamberg authored Mar 22, 2024
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Expand Up @@ -10,7 +10,7 @@ browser-compat: api.RTCStatsReport.type_media-source.audioLevel

{{APIRef("WebRTC")}}{{SeeCompatTable}}

The {{domxref("RTCAudioSourceStats")}} dictionary's **`audioLevel`** property represents the audio level of the media source.
The **`audioLevel`** property of the {{domxref("RTCAudioSourceStats")}} dictionary represents the audio level of the media source.

The level is averaged over some small implementation-dependent interval.
Users can alternatively calculate the average audio level over some arbitrary duration using the algorithm described in the [`RTCAudioSourceStats` description](/en-US/docs/Web/API/RTCAudioSourceStats#description).
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11 changes: 7 additions & 4 deletions files/en-us/web/api/rtcaudiosourcestats/index.md
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Expand Up @@ -3,25 +3,28 @@ title: RTCAudioSourceStats
slug: Web/API/RTCAudioSourceStats
page-type: web-api-interface
browser-compat: api.RTCStatsReport.type_media-source
spec-urls: https://w3c.github.io/webrtc-stats/#dom-rtcaudiosourcestats
---

{{APIRef("WebRTC")}}

The [WebRTC API](/en-US/docs/Web/API/WebRTC_API)'s **`RTCAudioSourceStats`** dictionary provides information about an audio track that is attached to one or more senders.
The **`RTCAudioSourceStats`** dictionary of the [WebRTC API](/en-US/docs/Web/API/WebRTC_API) provides statistics information about an audio track ({{domxref("MediaStreamTrack")}}) that is attached to one or more senders ({{domxref("RTCRtpSender")}}).

These statistics can be obtained by iterating the {{domxref("RTCStatsReport")}} returned by {{domxref("RTCRtpSender.getStats()")}} or {{domxref("RTCPeerConnection.getStats()")}} until you find a report with the [`type`](#type) of `media-source` and a [`kind`](#kind) of `audio`.

> **Note:** For audio information about remotely sourced tracks (that are being received), see {{domxref("RTCInboundRtpStreamStats")}}.
## Instance properties

- {{domxref("RTCAudioSourceStats.audioLevel", "audioLevel")}} {{Experimental_Inline}}
- {{domxref("RTCAudioSourceStats.audioLevel", "audioLevel")}} {{Experimental_Inline}}{{optional_inline}}
- : A number that represents the audio level of the media source.
- {{domxref("RTCAudioSourceStats.totalAudioEnergy", "totalAudioEnergy")}} {{Experimental_Inline}}
- {{domxref("RTCAudioSourceStats.totalAudioEnergy", "totalAudioEnergy")}} {{Experimental_Inline}}{{optional_inline}}
- : A number that represents the total audio energy of the media source over the lifetime of the stats object.
- {{domxref("RTCAudioSourceStats.totalSamplesDuration", "totalSamplesDuration")}} {{Experimental_Inline}}
- {{domxref("RTCAudioSourceStats.totalSamplesDuration", "totalSamplesDuration")}} {{Experimental_Inline}}{{optional_inline}}
- : A number that represents the total duration of all samples produced by the media source over the lifetime of the stats object.

### Common media-source properties

The following properties are present in both `RTCAudioSourceStats` and {{domxref("RTCVideoSourceStats")}}: <!-- RTCMediaSourceStats -->

- {{domxref("RTCAudioSourceStats.trackIdentifier", "trackIdentifier")}}
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4 changes: 2 additions & 2 deletions files/en-us/web/api/rtcaudiosourcestats/kind/index.md
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Expand Up @@ -8,9 +8,9 @@ browser-compat: api.RTCStatsReport.type_media-source.kind

{{APIRef("WebRTC")}}

The {{domxref("RTCAudioSourceStats")}} dictionary's **`kind`** property is a string value that is used to differentiate `audio` and `video` media sources.
The **`kind`** property of the {{domxref("RTCAudioSourceStats")}} dictionary is a string with the value `audio`.

Along with the {{domxref("RTCAudioSourceStats.type", "type")}}, this identifies the object as an {{domxref("RTCAudioSourceStats")}} object when iterating the {{domxref("RTCStatsReport")}} returned by {{domxref("RTCRtpSender.getStats()")}} or {{domxref("RTCPeerConnection.getStats()")}}.
The `kind` is used to differentiate between audio and video media sources when iterating an {{domxref("RTCStatsReport")}}, which both have a {{domxref("RTCAudioSourceStats.type", "type")}} of `media-source` (a `kind` of `video` indicates an {{domxref("RTCVideoSourceStats")}} object).

## Value

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Expand Up @@ -10,7 +10,7 @@ browser-compat: api.RTCStatsReport.type_media-source.totalAudioEnergy

{{APIRef("WebRTC")}}{{SeeCompatTable}}

The {{domxref("RTCAudioSourceStats")}} dictionary's **`totalAudioEnergy`** property represents the total audio energy of the media source over the lifetime of this stats object.
The **`totalAudioEnergy`** property of the {{domxref("RTCAudioSourceStats")}} dictionary represents the total audio energy of the media source over the lifetime of this stats object.

The total energy across a particular duration can be determined by subtracting the value of this property returned by two different `getStats()` calls.

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Expand Up @@ -10,7 +10,7 @@ browser-compat: api.RTCStatsReport.type_media-source.totalSamplesDuration

{{APIRef("WebRTC")}}{{SeeCompatTable}}

The {{domxref("RTCAudioSourceStats")}} dictionary's **`totalSamplesDuration`** property represents the combined duration of all samples produced by the media source over the lifetime of this stats object, in seconds.
The **`totalSamplesDuration`** property of the {{domxref("RTCAudioSourceStats")}} dictionary represents the combined duration of all samples produced by the media source over the lifetime of this stats object, in seconds.
It does not include samples dropped before reaching this media source. <!-- Dropped samples in `droppedSamplesDuration`; not implemented -->

This can be used with {{domxref("RTCAudioSourceStats.totalAudioEnergy", "totalAudioEnergy")}} to compute an [average audio level over different intervals](/en-US/docs/Web/API/RTCAudioSourceStats#description).
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Expand Up @@ -8,7 +8,7 @@ browser-compat: api.RTCStatsReport.type_media-source.trackIdentifier

{{APIRef("WebRTC")}}

The {{domxref("RTCAudioSourceStats")}} dictionary's property **`trackIdentifier`** contains the `id` attribute of the associated [`MediaStreamTrack`](/en-US/docs/Web/API/MediaStreamTrack).
The **`trackIdentifier`** property of the {{domxref("RTCAudioSourceStats")}} dictionary contains the `id` attribute of the associated [`MediaStreamTrack`](/en-US/docs/Web/API/MediaStreamTrack).

## Value

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2 changes: 1 addition & 1 deletion files/en-us/web/api/rtcaudiosourcestats/type/index.md
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Expand Up @@ -8,7 +8,7 @@ browser-compat: api.RTCStatsReport.type_media-source.type

{{APIRef("WebRTC")}}

The {{domxref("RTCAudioSourceStats")}} dictionary's property **`type`** is a string with value `media-source`.
The **`type`** property of the {{domxref("RTCAudioSourceStats")}} dictionary is a string with value `media-source`.

The type of `media-source` identifies the type of statistics as either {{domxref("RTCAudioSourceStats")}} or {{domxref("RTCVideoSourceStats")}} when iterating the {{domxref("RTCStatsReport")}} returned by {{domxref("RTCRtpSender.getStats()")}} or {{domxref("RTCPeerConnection.getStats()")}}.
The type of stats can further be differentiated using the {{domxref("RTCAudioSourceStats.kind", "kind")}}, which will be `audio` for `RTCAudioSourceStats`.
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42 changes: 42 additions & 0 deletions files/en-us/web/api/rtcvideosourcestats/frames/index.md
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---
title: "RTCVideoSourceStats: frames property"
short-title: frames
slug: Web/API/RTCVideoSourceStats/frames
page-type: web-api-instance-property
browser-compat: api.RTCStatsReport.type_media-source.frames
---

{{APIRef("WebRTC")}}

The **`frames`** property of the {{domxref("RTCVideoSourceStats")}} dictionary indicates the total number of frames originating from this video source over its lifetime.

## Value

A number indicating the total number of frames originating from this source.

## Examples

This example shows how you might iterate the stats object returned from `RTCRtpSender.getStats()` to get the video source stats, and then extract the `frames`.

```js
// where sender is an RTCRtpSender
const stats = await sender.getStats();
let videoSourceStats = null;

stats.forEach((report) => {
if (report.type === "media-source" && report.kind==="video") {
videoSourceStats = report;
break;
}
});

const frames = videoSourceStats?.frames;
```
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}
46 changes: 46 additions & 0 deletions files/en-us/web/api/rtcvideosourcestats/framespersecond/index.md
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---
title: "RTCVideoSourceStats: framesPerSecond property"
short-title: framesPerSecond
slug: Web/API/RTCVideoSourceStats/framesPerSecond
page-type: web-api-instance-property
browser-compat: api.RTCStatsReport.type_media-source.framesPerSecond
---

{{APIRef("WebRTC")}}

The **`framesPerSecond`** property of the {{domxref("RTCVideoSourceStats")}} dictionary indicates the number of frames originating from this video source in the last second.

The property is not defined on the stats object for the first second of its lifetime.

## Value

A number indicating the frames originating from this source in the last second.

## Examples

This example shows how you might iterate the stats object returned from `RTCRtpSender.getStats()` to get the video source stats, and then extract the `framesPerSecond`.

```js
// where sender is an RTCRtpSender
const stats = await sender.getStats();
let videoSourceStats = null;

stats.forEach((report) => {
if (report.type === "media-source" && report.kind==="video") {
videoSourceStats = report;
break;
}
});

// Note, test is conditional in case the stats object
// does not include video source stats
const fps = videoSourceStats?.framesPerSecond;
```
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}
46 changes: 46 additions & 0 deletions files/en-us/web/api/rtcvideosourcestats/height/index.md
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---
title: "RTCVideoSourceStats: height property"
short-title: height
slug: Web/API/RTCVideoSourceStats/height
page-type: web-api-instance-property
browser-compat: api.RTCStatsReport.type_media-source.height
---

{{APIRef("WebRTC")}}

The **`height`** property of the {{domxref("RTCVideoSourceStats")}} dictionary indicates the height, in pixels, of the last frame originating from this source.

This property is not defined on the stats object until after the first frame has been produced.

## Value

A positive number indicating the height, in pixels.

## Examples

This example shows how you might iterate the stats object returned from `RTCRtpSender.getStats()` to get the video source stats, and then extract the `height`.

```js
// where sender is an RTCRtpSender
const stats = await sender.getStats();
let videoSourceStats = null;

stats.forEach((report) => {
if (report.type === "media-source" && report.kind==="video") {
videoSourceStats = report;
break;
}
});

// Note, test is conditional in case the stats object
// does not include video source stats
const height = videoSourceStats?.height;
```
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}
27 changes: 27 additions & 0 deletions files/en-us/web/api/rtcvideosourcestats/id/index.md
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---
title: "RTCVideoSourceStats: id property"
short-title: id
slug: Web/API/RTCVideoSourceStats/id
page-type: web-api-instance-property
browser-compat: api.RTCStatsReport.type_media-source.id
---

{{APIRef("WebRTC")}}

The **`id`** property of the {{domxref("RTCVideoSourceStats")}} dictionary is a string which 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 {{domxref("RTCPeerConnection")}}, or an {{domxref("RTCDataChannel")}}.

## Value

A string that uniquely identifies the object for which this `RTCVideoSourceStats` 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

{{Specifications}}

## Browser compatibility

{{Compat}}
85 changes: 85 additions & 0 deletions files/en-us/web/api/rtcvideosourcestats/index.md
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---
title: RTCVideoSourceStats
slug: Web/API/RTCVideoSourceStats
page-type: web-api-interface
browser-compat: api.RTCStatsReport.type_media-source
spec-urls: https://w3c.github.io/webrtc-stats/#dom-rtcvideosourcestats
---

{{APIRef("WebRTC")}}

The **`RTCVideoSourceStats`** dictionary of the [WebRTC API](/en-US/docs/Web/API/WebRTC_API) provides statistics information about a video track ({{domxref("MediaStreamTrack")}}) that is attached to one or more senders ({{domxref("RTCRtpSender")}}).

These statistics can be obtained by iterating the {{domxref("RTCStatsReport")}} returned by {{domxref("RTCRtpSender.getStats()")}} or {{domxref("RTCPeerConnection.getStats()")}} until you find a report with the [`type`](#type) of `media-source` and a [`kind`](#kind) of `video`.

> **Note:** For video information about remotely sourced tracks (that are being received), see {{domxref("RTCInboundRtpStreamStats")}}.
## Instance properties

- {{domxref("RTCVideoSourceStats.frames", "frames")}} {{optional_inline}}
- : A positive number that indicates the total number of frames originating from this video source.
- {{domxref("RTCVideoSourceStats.framesPerSecond", "framesPerSecond")}} {{optional_inline}}
- : A positive number that represents the number of frames originating from this video source in the last second.
This property is not defined on this stats object for the first second of its existence.
- {{domxref("RTCVideoSourceStats.height", "height")}} {{optional_inline}}
- : A number that represents the height, in pixels, of the last frame originating from this source.
This property is not defined on this stats object until after the first frame has been produced.
- {{domxref("RTCVideoSourceStats.width", "width")}} {{optional_inline}}
- : A number that represents the width, in pixels, of the most recent frame originating from this source.
This property is not defined on this stats object until after the first frame has been produced.

### Common media-source properties

The following properties are present in both `RTCVideoSourceStats` and {{domxref("RTCAudioSourceStats")}}: <!-- RTCMediaSourceStats -->

- {{domxref("RTCVideoSourceStats.trackIdentifier", "trackIdentifier")}}
- : A string that contains the [`id`](/en-US/docs/Web/API/MediaStreamTrack/id) value of the [`MediaStreamTrack`](/en-US/docs/Web/API/MediaStreamTrack) associated with the video source.
- {{domxref("RTCVideoSourceStats.kind", "kind")}}
- : A string indicating whether this object represents stats for a video source or a media source. For an `RTCVideoSourceStats` this will always be `video`.

### Common instance properties

The following properties are common to all statistics objects. <!-- RTCStats -->

- {{domxref("RTCVideoSourceStats.id", "id")}}
- : A string that uniquely identifies the object that is being monitored to produce this set of statistics.
- {{domxref("RTCVideoSourceStats.timestamp", "timestamp")}}
- : A {{domxref("DOMHighResTimeStamp")}} object indicating the time at which the sample was taken for this statistics object.
- {{domxref("RTCVideoSourceStats.type", "type")}}
- : A string with the value `"media-source"`, indicating that the object is an instance of either {{domxref("RTCVideoSourceStats")}} or {{domxref("RTCVideoSourceStats")}}.

## Description

The interface provides statistics about a video media source attached to one or more senders.
The information includes a identifier for the associated `MediaStreamTrack`, along with the height and width of the last frame sent from the source, the number of frames sent from the source, and the frame rate.

## Examples

This example shows how you might iterate the stats object returned from `RTCRtpSender.getStats()` to get the video-specific media-source stats.

```js
// where sender is an RTCRtpSender
const stats = await sender.getStats();
let videoSourceStats = null;

stats.forEach((report) => {
if (report.type === "media-source" && report.kind==="video") {
videoSourceStats = report;
break;
}
});

// videoSourceStats will be null if the report did not include video source stats
const frames = videoSourceStats?.frames;
const fps = videoSourceStats?.framesPerSecond;
const width = videoSourceStats?.width;
const height = videoSourceStats?.height;
```
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}
25 changes: 25 additions & 0 deletions files/en-us/web/api/rtcvideosourcestats/kind/index.md
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---
title: "RTCVideoSourceStats: kind property"
short-title: kind
slug: Web/API/RTCVideoSourceStats/kind
page-type: web-api-instance-property
browser-compat: api.RTCStatsReport.type_media-source.kind
---

{{APIRef("WebRTC")}}

The **`kind`** property of the {{domxref("RTCVideoSourceStats")}} dictionary is a string with the value `video`.

The `kind` is used to differentiate between audio and video media sources when iterating an {{domxref("RTCStatsReport")}}, which both have a {{domxref("RTCVideoSourceStats.type", "type")}} of `media-source` (a `kind` of `audio` indicates an {{domxref("RTCAudioSourceStats")}} object).

## Value

A string with the value `video`.

## Specifications

{{Specifications}}

## Browser compatibility

{{Compat}}
27 changes: 27 additions & 0 deletions files/en-us/web/api/rtcvideosourcestats/timestamp/index.md
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---
title: "RTCVideoSourceStats: timestamp property"
short-title: timestamp
slug: Web/API/RTCVideoSourceStats/timestamp
page-type: web-api-instance-property
browser-compat: api.RTCStatsReport.type_media-source.timestamp
---

{{APIRef("WebRTC")}}

The **`timestamp`** property of the {{domxref("RTCVideoSourceStats")}} dictionary is a {{domxref("DOMHighResTimeStamp")}} object specifying the time at which the data in the object was sampled.

The time is given in milliseconds elapsed since the first moment of January 1, 1970, UTC (also known as [Unix time](/en-US/docs/Glossary/Unix_time)).

## Value

A {{domxref("DOMHighResTimeStamp")}} value indicating the time at which the activity described by the statistics in this object was recorded, in milliseconds elapsed since the beginning of January 1, 1970, UTC.

The value should be accurate to within a few milliseconds but may not be entirely precise, either because of hardware or operating system limitations or because of [fingerprinting](/en-US/docs/Glossary/Fingerprinting) protection in the form of reduced clock precision or accuracy.

## Specifications

{{Specifications}}

## Browser compatibility

{{Compat}}
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