How to watch a .ts video file on an iPad

Handbrake should do everything you need:

HandBrake is a tool for converting video from nearly any format to a selection of modern, widely supported codecs.

It will re-encode the video but it does it relatively quickly, and re-encoding audio formats/selecting audio tracks and subtitles is all possible. Great software, free too.

After some fiddling, I've found one way to watch the video on the iPad.

Changing the container and the audio encoding

This can be done in one step using ffmpeg (installed through Homebrew), loop it for all .ts files in the directory.

The target format is mp4, and only the second audio channel is converted to AAC. The video is simply copied without any additional re-encoding. This takes about 2 minutes per 3.5 GB file, it's pretty fast.

for i in *.ts ; do 
    ffmpeg -i $i -c:v copy -c:a aac -b:a 384k -strict -2 -map 0:v:0 -map 0:a:1 $(basename -s .ts $i).mp4
done

iPad App

The resulting file can be previewed in QuickTime or in Finder, but it can't be imported into iTunes for some reason. I've got a question open for this here: Is there a way to show import errors in iTunes?

I've found that the files can be played fine in a third-party app. The app is called nPlayer free: https://itunes.apple.com/us/app/nplayer-free-best-player-movies/id945304853?mt=8

Confusingly enough, there's another app called nPlayer, which is not free, uses an almost identical icon, but seems to be a completely different app with a different look and feel, and from a different developer.

Anyway, nPlayer free plays the video perfectly fine after uploading the video via iTunes File Sharing.

Conclusion

While this is not exactly what I was looking for (importing the video to iTunes and watching using the iPad's native player app), it works for me. The re-encoding of the audio using ffmpeg is fast and painless, and it can be automated through a script, and transferring the file through iTunes File Sharing is not a big deal either.

I'll still keep this question open to see whether there are any other options.

The best video player on iOS is Infuse.

http://firecore.com/infuse

It processes the video on the device and doesn't need any server or previous conversion. It will play your file with the least amount of effort, there is a free version but unfortunately you will need to pay for the Pro because your file contains AC3 audio.