SE 5.3.0 beta 1: Remux ideas (continuation of #14248)

Nik asked me to open a new issue showing my suggested improvements. Since I have not tested this since beta 1, that's the title I've put on this issue. I do have beta 4 at the moment, so any retests you would want me to try would be on at least that beta. I would probably be on at least beta 5 if you make any changes. Since there have been no further changes to this feature since beta 1, I don't think any retesting on beta 4 is worth the bother. So here's what I posted back in #14248 so it doesn't get lost.

I have SE 5.3.0 beta 1 now & this seems to be addressed quite well by #14764. I've just given this a cursory first pass at using it. I have not sat & watched the result while editing the subtitles. But I expect that to go smoothly whenever I get around to that. It's curious that there were 2 sort of duplicate predecessor Pull Requests (#14728 & #14748) that look like they were just closed & abandoned. #14764 appears to be the one that got merged & made it into SE.

I do have some fit & finish ideas here. In the remux dialog, it might be nice to quote a duration in the video & audio sections. You quote file sizes but durations would be nice. After you do mux together an audio with a video, the completion notification reports a duration. So you've easily got the number at hand. I doubt it would be much trouble to include it in the muxing dialog itself before you do mux something.

During the muxing there is a nice progress bar. But it might be nice to report ongoing elapsed time of the operation. This would be in 2 places. The first is on the dialog box while the remuxing is in progress. The second would be in the notification box that pops up when the operation completes. I should note that my test opera is over 3 hours long, so the remuxing does not complete in "a few seconds." It doesn't take an unreasonable time. But the documentation should note that the length of time to remux something does depend on the duration of what you're remuxing.

There are a couple of Play buttons that I saw at a couple of stages of the operation. I clicked them & they didn't appear to do anything. I'm thinking about it now & I'm not so sure those buttons should be there. My expected work flow would be to do the muxing, then close the dialog & do any playback in the main SE window itself.

My naming convention is this:

<opera> Video <date>.mp4 <opera> Audio <date>.mp4 <opera> Video <date>.vtt

So I start by opening the VTT in SE. This automatically loads the video (a silent video) from the same directory. When I do the remuxing, I tell the audio section of the dialog to use the audio MP4 from that directory. Since I want to keep the video & audio as separate files for the long term, I told the remux operation to place the remuxed file in a different directory with the name <opera> Video <date>.mp4. That would be a name collision in the original directory, hence the use of a working directory, my intention being to discard the muxed file when I'm done. When I exited from the remux dialog, SE still had my VTT loaded up as well as the original silent MP4. I had to use the Video -> Open video menu selection to keep the VTT but load up the muxed output file that has both video & audio. It might be nice to get the process to do that automatically, so the silent video would be replaced by the audible video in SE when you close the remuxing dialog. In other words, when you close the remuxing dialog, replace the original silent MP4 with the audible MP4 in the SE window. You just remuxed something. It would make sense to automatically load that remuxed file into SE instead of making the user do that manually.

This point is probably not strictly related to the remuxing feature. The name of the subtitle in the main SE window title bar shows only the file name without the directory. I'm pretty sure SE used to show the directory in the title bar. This is on Windows 11 Pro 64-bit version 25H2 build 26200.9445. I have now scanned through all the Settings twice & I don't see one that requests the directory name in the title bar. I was able to determine via a quick experiment that the VTT was still the one I had opened from the original directory, not something that had appeared in the working directory to which I had targeted the remuxing. That's good. I would not have wanted the VTT to also go into the working directory. And I certainly would not have wanted some operation to happen automatically without my knowledge.

Overall, this is an excellent addition to SE & I will be using it. My original thought was to use the feature of MPV that allows you to load an external audio file, as I'm showing in the original post in #14248. That is a function that is available in MPV.NET, which just shows that MPV is capable of doing it. In fact, once I've tweaked the subtitles, I will be using MPV.NET in the future any time I want to watch one of these operas I've remuxed. Like I say, I intend to discard the remuxed file. My only wish was to allow me to play back the video & audio from separate files while I edit the subtitles. This new feature does more than I really wanted, but it certainly does provide me a way to do what I want. I would have thought that what I originally asked for would have been simpler, but I'm not complaining.