Image losing transparency

What is your operating system?
Windows 10

What is your Shotcut version (see Help > About Shotcut)? Is it 32-bit?

Can you repeat the problem? If so, what are the steps?
(Please be specific and use the names as seen in Shotcut, preferably English. Include a screenshot or screen recording if you can. Also, you can attach logs from either View > Application Log or right-click a job and choose View Log.)

Working on a project that has multiple video tracks, with an track for images on top for some text overlays - which were PNG’s with transparent backgrounds. I watched it over and over while editing and the transparency worked perfectly.

I added my music audio track (below the video tracks) and transparency on my images still worked fine. Then I added my voiceover audio track (and all the video and the image tracks were locked at this point) and suddenly the transparent background on my images track is broken - they are completely black except for their text portion and so cover the video entirely. Basically they were working fine and the track was locked and then suddenly, they were not working…

I started Shotcut v22.03 and opened an existing project I have with 4 video tracks and 1 audio track. I added some PNGs with transparent backgrounds to V4. Then, I added two audio tracks. The PNGs still have a transparent background for me. So, I did not reproduce it trying to follow the steps you provided.
Did you use the new Record Audio feature to add the voiceover audio track?
Did you restart Shotcut and reopen the project to see if the project is broken or this was a run time only event?
Did you reorder tracks at any time?
Please upload the project file if you can.

Hi - I recorded the voiceover audio outside of Shotcut and added the mp3 file to my project playlist.

I did close and restart Shotcut and the transparency issue persisted.

When I had my finished music audio track on the very bottom (while transparency was still working) I added a new audio track for the voiceover, which became the new bottom track - I moved it up one level, and then added the mp3 file to the track. That’s when I noticed the transparency was lost.

first cut.mlt (225.1 KB)

Yeah, that caused the problem related to moving audio tracks. I reproduced it now:

  1. open existing timeline project
  2. add audio track
  3. add video track
  4. add something with transparency to upper most video track
  5. add audio track
  6. move bottom audio track to be top audio track

Please see if this modified version of the project fixes your problem:

first cut - fixed1.mlt (225.5 KB)

Hey - that process wasn’t exactly the same order I did, more like:

  1. New project with audio track pre-existing on bottom level but sat empty while I worked on video first.
  2. Multiple video tracks added with media, with transparent images on the top level.
  3. Added media on the pre-existing audio track.
  4. Added another audio track which became the bottom track, moved it up one level, added media to that.

It seems like the transparency issue is fixed in your version (thank you!) but I tried playing it three times and Shotcut always crashes after about 1.5 seconds. Can you tell me what you did to correct this so I can try to reproduce the fix on my end too?

It is effectively the same process that triggers the same bug.

It requires editing the XML in the .mlt file, which I do not recommend you do. I see another piece of this not quite correct that might be the cause of the crash. Here is a new version:

first cut - fix2.mlt (225.1 KB)

Thank you! I’m still getting a lot of crashes when previewing the video but it seems to be at different points every time I try? Not sure if it’s the file or my computer. I’m going to try exporting it too and seeing if that turns out ok, if not I’ll be back! :slight_smile:

For preventing this issue next time then, would you say it might be best for me to leave adding transparent PNG images for the very last step? Since it seemed to be subsequent steps that messed them up?

This is fixed for the next version.