MP4 & Dolby Atmos

HandBrake for Windows support
Forum rules
An Activity Log is required for support requests. Please read How-to get an activity log? for details on how and why this should be provided.
Post Reply
Salem874
Posts: 7
Joined: Sun Jun 19, 2016 9:32 pm

MP4 & Dolby Atmos

Post by Salem874 » Tue Feb 19, 2019 6:08 pm

Description of problem or question:
Encoding HEVC with Atmos to an MP4 container results in the Atmos being stripped to a base AC3 audio track at 640kbps



Steps to reproduce the problem (If Applicable):
Use a source file with Dolby Atmos track, encode it in Handbrake with all audio tracks passed through. Dolby Digital, Dolby Digital+, DTS-HD passes through fine but the Dolby Atmos seems to be stripped/downconverted to a 640kbps track. Is Atmos not supported in the MP4 container? I'd read that neither was DTS/DTS-HD MA but Handbrake has no problem muxing it in (and outpuit file seems to be playable). I'd love to rip to MP4 and keep the Atmos track! is this something that is possible?

rollin_eng
Veteran User
Posts: 3025
Joined: Wed May 04, 2011 11:06 pm

Re: MP4 & Dolby Atmos

Post by rollin_eng » Tue Feb 19, 2019 6:18 pm

Could you please post your HB logs, instructions can be found here:

https://handbrake.fr/docs/en/latest/hel ... y-log.html

Woodstock
Veteran User
Posts: 2972
Joined: Tue Aug 27, 2013 6:39 am

Re: MP4 & Dolby Atmos

Post by Woodstock » Tue Feb 19, 2019 11:28 pm

If we had the log, we could determine what settings you used, what handbrake saw in the source, and how it dealt with it.

User avatar
Rodeo
HandBrake Team
Posts: 12046
Joined: Tue Mar 03, 2009 8:55 pm

Re: MP4 & Dolby Atmos

Post by Rodeo » Wed Feb 20, 2019 5:07 pm

HandBrake cannot mux TrueHD/TrueHD+Atmos to the MP4 container (no publicly-available software can, as far as I know). Not really an issue since nothing would be able to play it back anyway…

Salem874
Posts: 7
Joined: Sun Jun 19, 2016 9:32 pm

Re: MP4 & Dolby Atmos

Post by Salem874 » Mon Feb 25, 2019 10:49 pm

Rodeo wrote:
Wed Feb 20, 2019 5:07 pm
HandBrake cannot mux TrueHD/TrueHD+Atmos to the MP4 container (no publicly-available software can, as far as I know). Not really an issue since nothing would be able to play it back anyway…
Thanks for the reply, i was just about to post the log now...

That's interesting, seeing as DTS is (apparently) also not supported in the MP4 container, yet Handbrake does right these.

Maybe one day...

User avatar
Rodeo
HandBrake Team
Posts: 12046
Joined: Tue Mar 03, 2009 8:55 pm

Re: MP4 & Dolby Atmos

Post by Rodeo » Tue Feb 26, 2019 3:39 pm

Nah, DTS in MP4 is supported… either via the officially-registered sample entry codes (like Dolby MLP/TrueHD)* which no publicly-available software I know of support, but also in an unofficial way (used by HandBrake) supported by a lot of open-source playback software (VLC and many others).

*the specifications for how to mux using the official sample entry codes aren't public (that I know of) and probably require official licensing, non-disclosure agreements, etc.

Post Reply