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Maintaining aspect ratio/Keeping black bars when viewing video in fullscreen mode

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  • Last reply by zeroknight

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A video I am watching is in 4:3 aspect ratio and comes with black bars in the embedded player; however, when i enter fullscreen (on a 16:9 display) the video stretches horizontally, getting rid of the black bars, resulting in a bottom portion of the video being cut off. This happens on my macbook pro running firefox 116.0.1 that is connected to a television monitor. This issue does not happen on my desktop monitor of 16:9 resolution. For about one second or so when the video first enters into fullscreen, the video is played how I want it to be played (non stretched, 4:3 aspect ratio, with vertical black bars on the sides), but then it auto adjusts itself and switches to a stretched resolution, which is what I DO NOT want. In case this info is important: When I exit the video, the entire screen is in a stretched resolution for only about a second until it then adjusts itself again to return to a normal display view. I am in dire need of help, it's driving me crazy.


(similar to this thread: https://support.mozilla.org/en-US/questions/1401072 , except my problem occurs on a non youtube site, so im not sure how the tags solution would work)

A video I am watching is in 4:3 aspect ratio and comes with black bars in the embedded player; however, when i enter fullscreen (on a 16:9 display) the video stretches horizontally, getting rid of the black bars, resulting in a bottom portion of the video being cut off. This happens on my macbook pro running firefox 116.0.1 that is connected to a television monitor. This issue does not happen on my desktop monitor of 16:9 resolution. For about one second or so when the video first enters into fullscreen, the video is played how I want it to be played (non stretched, 4:3 aspect ratio, with vertical black bars on the sides), but then it auto adjusts itself and switches to a stretched resolution, which is what I DO NOT want. In case this info is important: When I exit the video, the entire screen is in a stretched resolution for only about a second until it then adjusts itself again to return to a normal display view. I am in dire need of help, it's driving me crazy. (similar to this thread: https://support.mozilla.org/en-US/questions/1401072 , except my problem occurs on a non youtube site, so im not sure how the tags solution would work)

All Replies (2)

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Hi there! It sounds like you're experiencing a frustrating issue with video playback on Firefox. This problem might be related to how Firefox is handling the aspect ratio when you go into fullscreen mode. To fix this, try adjusting your browser settings. You can go to the Firefox menu, then choose Options or Preferences (depending on your operating system). From there, head to the General tab and find the "Performance" section. Check the box that says "Use recommended performance settings" and restart Firefox. This should help maintain the aspect ratio and keep those black bars when you watch videos in fullscreen. If the issue persists, you can also try disabling hardware acceleration under the "General" section in Options/Preferences. Hope this helps and makes your video-watching experience more enjoyable! If the problem continues, don't hesitate to reach out for assistance.

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Is the TV scaled correctly for other apps showing 4:3 videos or is it just Firefox? Have you tried adjusting the TV zoom/scale settings?

See if it makes any difference if you go to about:config in the address bar and change full-screen-api.macos-native-full-screen to true.