Can anyone identify what has happened to basic text track rendering in QuickTime 7?

Any ideas how to correct for this text rendering issue?

Did you leave the Chapter Text track enabled? If so, then re-sizing the display may create conflicts between the defined text display area and the dimensions of the player display window. If the Chapter Text track is disabled, then the chapter info should only display in the respective QT X/7 Chapter menus as long as the video track is properly linked to the Chapter Text track in the QT 7 Pro properties window.

Graphic Examples:

Here's what I'm seeing when you first import text with or without descriptors. You see the text track offset in a strange way, actually jumping out of the movie frame. All the other rendering junk is caused when resizing the movie, starting and stopping the movie, etc.. This screenshot is from a movie that only contains a single text track.

What is the defined display area for your text? If you haven't defined such an area, then try defining one using the default descriptors. Have never used "null" settings so I don't know if that is what might be causing the problem.

FOLLOW-UP:

Just tried creating a new file from scratch. File opened, played, saved as MOV, re-opened, and re-played normally in QT 7 Pro under Yosemite v10.10.3 on an iMac. Do you have a secondary system on which to run a corruption-conflict cross check?

After comparing the QTScript, I discovered that any text tracks with {anti-alias:on} or {keyedText:on} would display correctly. I don't believe either of these properties are enabled by default so I should not have to add these descriptors just to fix the rendering problem.

Very interesting. Thanks for posting this info. And, as you indicated, those properties were not enable by default in my tests. I may want to look into this further when/if I have the time, so please post back if you learn anything new.

By the way, the default size of the movie frame was 160 X 48. You had mentioned seeing "Null" in a previous post. Was that pertaining to the frame size or text box? What tool do you use to see this setting?

That fits, player display window matches the default text display area. Have not seen "null" or zero values for height and width but was musing as to what might happen if I tried to use them. Ran additional tests later and entered zero values for both—not something I'd ever considered trying previously. It turns out QT 7 doesn't complain about either "null" (empty) or "zero" values here. Instead it simply instates the default 160x48 minimum values in both cases. And, while it does accept and save any non-zero values less than 160 and 48 respectively, the minimum display area opened in a player window has been 160x1 when 1 was the defined height. As to the software tool, I used TextEdit to provide "null", "zero", and "non-zero" values for the descriptors.

If I had more time I could see if other changes or additions to QT Text Descriptors would have any impact on the text rendering correctly.

Again, please post back if you learn anything of further interest.

Do you think I need to reinstall QuickTime Player 7 or just zap some preference files?

I would normally try the files under an alternate user account. If he files play correctly, I would then delete the preference file(s) for the non-working primary user account. If the files still play incorrectly under the secondary user account, I would normally uninstall the QT 7 app and associated files installed by the installer package and then re-install QT 7.