FYI, in order to play the 5.1 AC3 audio track on your Apple TV, go to settings -> Audio & Video -> Dolby Digital -> set to "ON" (NOT AUTO).
This will play your 5.1 audio by default. If the video does not have a 5.1 track, it will default to the primary audio track.
i tried this but half my files stopped playing with sound.
So, to summarize, your mkv has a surround sound track (3/2+1). When you run a chapter through HB, using the aTV3 preset, you end up with only the AAC Dolby Prologic track and no AC3 track. Correct?
Try running the chapter again, and when you select the preset, go to the HB audio tab and verify that you see the 1st track as AAC Dolby Prologic II and the next track as AC3 passthrough. If that is the the way the audio tab is set, run the chapter and post back the output m4v results.
i just did this again, and the MKV has the 3 tracks i mentioned
the 2 surround tracks, Lossless and 3/2+1 are both DTS, 6ch tracks.
the 2/0 track is AC-3, 2ch.
i have a question:
for the videos missing surround tracks, can i readd them from the original mkv's using subtler? im new to this really but i do realise that subler can remove and add tracks to a file? i really would like to avoid reencoding the 10 or so files missing surround tracks. im hoping i can recreate the original MKV's for them and just add the missing surround tracks manually with subler.
im gonna edit this post after i run a test as you instructed.
edit**
okay i noticed something unusual, when i went to the audio tab, two audio tracks were automatically selected - both are repeating the same track, track 2. (english) it avoided putting track 0 or track 1 (non english language) into the list. on the track tab it says ac3 dolby surround in brackets, under the codec track, the first one is AAC and the second one is AC3 Passthru.
i'm certain when i did the original encode of this mkv, i selected all 3 tracks, in fact i know i did because the resulting file included all 3 tracks but did not keep the DTS ones in surround format. and theres no way i made this mistake 10 or so times on other files, including some personal favourites.
im going to run a couple encoding tests see if i get the same result again.
just to make sure i didnt make a mistake 1st time, i did the same way i usually do, and again, same result:
all 3 tracks become stereo, listed as 2ch.
test 2: gonna not mess with any settings, just standard at3 preset.
okay, test 2, didnt touch quality, aspect ratio settings (loose/strict etc) or frame rate, i didnt even touch audio. so it defaulted with repeating track 2 twice. the track 2 which is supposed to be commentary in stereo. this time i put the resulting encode in subler, and what do you know? it includes 2 tracks, one stereo as default , AAC 2 ch, and a surround track, AC-3 but says '2ch'! i dont know how to make sense of that.
okay, my last test for now atleast - i tried the same thing as test 2 but only selecting the dts hd surround track, in subler, it only shows a stereo track AAC 2ch.
so subler or hb is having an issue here?
im hoping to just take out the original tracks from the original mkv and put them in my m4v file if thats possible?