# Firefox is having issues with screen sharing

**URL:** <https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724>\
**Category:** Web\
**Tags:** video-sdk\
**Created:** [August 1, 2023, 11:06am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724 "2023-08-01T11:06:43Z")\
**Posts on this page:** 12\
**Page:** 1

<div class="post-metadata">

**Author:** ![takeshi.odaka](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/takeshi.odaka/32/50689_2.png) [@takeshi.odaka](https://devforum.zoom.us/u/takeshi.odaka)\
**Post date:** [August 1, 2023, 11:06am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/1 "2023-08-01T11:06:44Z")

</div>

**Description**  
When I share my screen with Firefox, part of the screen is enlarged and I cannot see the whole screen.

**Browser Console Error**  
no error

**Which Web Video SDK version?**  
1.8.2

**To Reproduce(If applicable)**  
Steps to reproduce the behavior:

1. start video
2. Click on Start screen sharing

**Device (please complete the following information):**

- Device: MacBook Air M1 2020
- OS: macOS 13.4.1
- Browser: Firefox
- Browser Version: 115.0.2

---

<div class="post-metadata">

**Author:** ![vic.yang](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/vic.yang/32/24656_2.png) [@vic.yang](https://devforum.zoom.us/u/vic.yang)\
**Post date:** [August 2, 2023, 2:30am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/2 "2023-08-02T02:30:53Z")

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Hey @takeshi.odaka

Thanks for your feedback.

Is `SharedArrayBuffer` enabled on Firefox?

Could you try to use `stream.updateSharingCanvasDimension` to update the size of the canvas?

Thanks  
Vic

---

<div class="post-metadata">

**Author:** ![takeshi.odaka](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/takeshi.odaka/32/50689_2.png) [@takeshi.odaka](https://devforum.zoom.us/u/takeshi.odaka)\
**Post date:** [August 7, 2023, 12:57pm UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/3 "2023-08-07T12:57:58Z")

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Hey @vic.yang

thank you for the advice.

SharedArrayBuffer is disabled in Firefox.

I tried stream.updateSharingCanvasDimension but no improvement.

I will describe the specific process flow, so please check if there are any problems.

```auto
stream.startShareScreen(targetElement)

stream.updateVideoCanvasDimension(canvasElement, width, height)
.then(() => {
  stream.adjustRenderedVideoPosition(
    canvasElement,
    zoomSessionId,
    width,
    height,
    0,
    0
  ).then(() => {      
stream.value?.updateSharingCanvasDimension(width, height)
})

```

Thanks  
Takeshi

---

<div class="post-metadata">

**Author:** ![vic.yang](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/vic.yang/32/24656_2.png) [@vic.yang](https://devforum.zoom.us/u/vic.yang)\
**Post date:** [August 8, 2023, 1:39am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/4 "2023-08-08T01:39:04Z")

</div>

Hey @takeshi.odaka

What’s the difference between `stream` and `stream.value`?

Could you confirm that `targetElement` and `canvasElement` are different elements and the `targetElement` matches the condition of `stream.isStartShareScreenWithVideoElement` ?

`stream. updateSharingCanvasDimension` is used on the receiving side, it’s aimed to solve the issue of partial display or unclear sharing content.

Thanks  
Vic

---

<div class="post-metadata">

**Author:** ![takeshi.odaka](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/takeshi.odaka/32/50689_2.png) [@takeshi.odaka](https://devforum.zoom.us/u/takeshi.odaka)\
**Post date:** [August 9, 2023, 3:37am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/5 "2023-08-09T03:37:02Z")

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Hey @vic.yang

thank you for making sure

There was an error in the description of targetElement and canvasElement.  
Because stream.value was not written correctly  
We will send you the correct code.

I’m sorry again, but please check

```auto
stream.startShareScreen(canvasElement)

stream.updateVideoCanvasDimension(canvasElement, width, height)
.then(() => {
  stream.adjustRenderedVideoPosition(
    canvasElement,
    zoomSessionId,
    width,
    height,
    0,
    0
  ).then(() => {      
stream.updateSharingCanvasDimension(width, height)
})

```

Thanks  
Takeshi

---

<div class="post-metadata">

**Author:** ![vic.yang](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/vic.yang/32/24656_2.png) [@vic.yang](https://devforum.zoom.us/u/vic.yang)\
**Post date:** [August 9, 2023, 7:11am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/6 "2023-08-09T07:11:27Z")

</div>

Hey @takeshi.odaka

Does this code run on Firefox side?

> `stream.startShareScreen(canvasElement)`

Does the following code run on another device?

> `stream.updateVideoCanvasDimension(canvasElement, width, height) `  
> `.then(() => {`  
> `stream.adjustRenderedVideoPosition( `  
> `canvasElement,`  
> `zoomSessionId, `  
> ` width,`  
> ` height,`  
> `0,`  
> `0`  
> `).then(() => { `  
> `stream.updateSharingCanvasDimension(width, height)`  
> `})`

There is one limitation that video and sharing cannot use the same canvas to render.

Thanks  
Vic

---

<div class="post-metadata">

**Author:** ![takeshi.odaka](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/takeshi.odaka/32/50689_2.png) [@takeshi.odaka](https://devforum.zoom.us/u/takeshi.odaka)\
**Post date:** [August 17, 2023, 12:10pm UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/7 "2023-08-17T12:10:14Z")

</div>

Hey @vic.yang

Thank you for confirming.

We will reply to your inquiry.

> Does this code run on Firefox side?

```auto
stream.startShareScreen(canvasElement)

```

The following code is executed when screen sharing is started in Firefox.

> Does the following code run on another device?

```auto
stream.updateVideoCanvasDimension(canvasElement, width, height)
.then(() => {
stream.adjustRenderedVideoPosition(
canvasElement,
zoomSessionId,
width,
height,
0,
0
).then(() => {
stream.updateSharingCanvasDimension(width, height)
})

```

We have confirmed that it works on Chrome and Firefox.

> There is one limitation that video and sharing cannot use the same canvas to render.

We are aware of this.  
Video and Share don’t use the same canvas.

I have learned two things about the behavior of screen sharing in Firefox, so I will tell you.

- It was confirmed that the screen sharing status becomes normal when the display size of the enlarged application is changed after screen sharing the application.

- We were able to confirm that the screen can be displayed correctly when sharing the screen of the application displayed on the external monitor when Firefox is displayed on the external monitor.

Do you have any idea how to improve something from this phenomenon?

Please check

Thanks

Takeshi

---

<div class="post-metadata">

**Author:** ![vic.yang](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/vic.yang/32/24656_2.png) [@vic.yang](https://devforum.zoom.us/u/vic.yang)\
**Post date:** [August 17, 2023, 1:03pm UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/8 "2023-08-17T13:03:18Z")

</div>

Hey @takeshi.odaka

Thanks for sharing the info with us.

Did you have screen scaling set on either of the two monitors?

I found a similar issue in Bugzilla, maybe it’s the issue with Firefox itself.

> **[1767019 - Firefox screensharing a window only shares the top-left quarter...](https://bugzilla.mozilla.org/show_bug.cgi?id=1767019)**
>
> UNCONFIRMED (nobody) in Core - Widget: Gtk. Last updated 2023-08-16.

Thanks  
Vic

---

<div class="post-metadata">

**Author:** ![takeshi.odaka](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/takeshi.odaka/32/50689_2.png) [@takeshi.odaka](https://devforum.zoom.us/u/takeshi.odaka)\
**Post date:** [August 24, 2023, 12:21pm UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/9 "2023-08-24T12:21:50Z")

</div>

Hey @vic.yang

Thank you for confirming.  
Thank you for reporting the bug in Firefox.

There was a description in the URL you sent that the screen sharing screen will be enlarged on Google Meet, so  
We have confirmed, but we could not confirm the occurrence on Google Meet.

Screen sharing can be performed normally with version 1.5.5 of the Web Video SDK,  
It started happening after upgrading to version 1.8.2.  
Is this issue caused by the web video SDK version?

Thanks  
Takeshi

---

<div class="post-metadata">

**Author:** ![takeshi.odaka](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/takeshi.odaka/32/50689_2.png) [@takeshi.odaka](https://devforum.zoom.us/u/takeshi.odaka)\
**Post date:** [September 5, 2023, 1:12am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/10 "2023-09-05T01:12:14Z")

</div>

Hey @vic.yang

It looks like you haven’t responded to my last post yet.  
I would appreciate it if you could provide me with some advice or information regarding my question.  
Thank you

Thanks  
Takeshi

---

<div class="post-metadata">

**Author:** ![vic.yang](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/vic.yang/32/24656_2.png) [@vic.yang](https://devforum.zoom.us/u/vic.yang)\
**Post date:** [September 5, 2023, 1:20am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/11 "2023-09-05T01:20:29Z")

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Hey @takeshi.odaka

Sorry for the late reply.

Would you mind reporting the logs to us when the issue occurs?

Starting from Video SDK Web 1.8.5, we provide the client-side telemetry feature, here is the usage:

> **[Video SDK - web - Service quality](https://developers.zoom.us/docs/video-sdk/web/quality/#client-side-telemetry)**
>
> The Zoom Developer Platform is an open platform that allows third-party developers to build applications and integrations upon Zoom’s video-first unified communications platform.

Thanks  
Vic

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/6/1/614bdd549b610bbaa46ff934617683a02bdaa03c.png) [@system](https://devforum.zoom.us/u/system)\
**Post date:** [October 5, 2023, 11:21am UTC](https://devforum.zoom.us/t/firefox-is-having-issues-with-screen-sharing/92724/12 "2023-10-05T11:21:20Z")

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