How can I view movie subtitles on a new AppleTV?

I have an .avi and an .srt for a Mandarin movie. I used HandBrakeCLI to generate a M4V file that I could import into iTunes. In iTunes there is an option to turn the subtitles on and off, which works beautifully.

But when I move over to my AppleTV and select the movie from my computer's library, the subtitles do not show when played. I don't see any option in the AppleTV UI to turn subtitles on/off during movie playback.

All I could find was a setting in the Settings menu to set subtitles to "English" - would this be a global setting? Regardless it had no effect on my movie.

How can I view the subtitles when I watch on my AppleTV?

FYI here is the HandBrakeCLI command I used:

HandBrakeCLI -i /Volumes/Drobo/Movies/Ip\ Man\ The\ Legend\ is\ Born.avi -o /Users/emh/Desktop/movie.m4v --preset="AppleTV" --srt-file /Volumes/Drobo/Movies/Ip\ Man\ The\ Legend\ is\ Born.srt --srt-lang English --srt-default

I'm not sure if this will work in your case, but someone on this forum seems to have had some success in a similar situation by simply changing the file extention from .mp4 to .m4v.

They were also using handbrake.

Use Subler.

Open file, click plus sign at top right to add srt file, and then save.

This process is both very fast and easy.

I'm not sure whether you have a problem with the subtitle track for that specific rip you made however, generally, using the AppleTV 2nd Gen, when the movie is playing, you can hold down the 'Select' button on the remote for a few seconds and it will show you a menu where you can choose whether to display any subtitles for this movie and also which audio track to use (useful if you have two language tracks or have also ripped the commentary track to your file).

Hold down the select button during playback.

Doing so will pause video playback and present menus for subtitle track, audio track, and speaker selection.

This may be an old question, but Apple's unintuitive UI clearly hasn't changed.