Infuse not automatically adjusting the Aspect Ratio when playing SD TV recordings

Infuse does not automatically adjust the Aspect Ratio when watching SD recordings.

I use Jellyfin to record TV programs from HD & SD TV channels, and watch those recordings via an Apple 4KTV.

If the recording is in SD and it starts in the 4:3 Aspect Ratio (eg. the recording catches the tail end of an old movie), then when the format changes to 16:9 Infuse keeps playing the recording in 4:3. The only way to fix the Aspect Ratio is to mess around with the Video/Zoom Mode options and set it to Stretch (*). The VLC & MrMC apps don’t seem to have the same problem and automatically adjust the Aspect Ratio.

Even more annoying is if the recording starts in 16:9 before switching to 4:3. In this situation I have not found any Zoom Mode / Aspect Ratio combination that converts the 16:9 playback to 4:3. With these recordings I have no option but to use VLC or MrMC to watch them.

(*) This option doesn’t work at all in the Mac version of Infuse.

Incidentally, MrMC has a brilliant Pixel Ratio feature that allows for micro adjustments in Aspect Ratio. Any chance of this being added to Infuse?

So you have a single file that has multiple aspect ratios? What happens in the file itself? Are there black bars that are changing sizes as aspect ratio changes or are they separate cropped files merged together? I don’t think Infuse analyzes images the videos to determine aspect ratio, especially if it is changing mid video. What happens if you play this file in vlc?

<So you have a single file that has multiple aspect ratios?>
Correct. It’s a recording made by Jellyfin from an SD TV channel. The first 2 minutes of the file contains the end of a film (broadcast in 4:3). The film ends and commercials are broadcast (in 16:9) followed by the TV program I intended to record.

<What happens in the file itself? Are there black bars that are changing sizes as aspect ratio changes or are they separate cropped files merged together?>
I don’t know the answer to that - it was recorded as a single 63 minute file.

<What happens if you play this file in vlc?>
The aspect ratio changes at the appropriate points in the recording - with black bars at the side for the 4:3 section and full 16:9 widescreen (with no black bars) for the remainder of the file.
With Infuse, the black bars remain and the 16:9 image is squashed in the 4:3 ratio.

This is an old bug that dates back several years. It only seems to affect SD recordings, not HD. I’ve raised it because it’s happened twice so far this week on 2 separate recordings.