Audio encoder settings and presets

General questions or discussion about HandBrake, Video and/or audio transcoding, trends etc.
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Durendal
Posts: 31
Joined: Mon Feb 12, 2007 5:41 pm

Audio encoder settings and presets

Post by Durendal »

I've been tinkering with audio settings for batch encodes. On DVD rips I'm fine leaving it with the 160kbps stereo AAC default, but I'm looking to batch encode some Blu-Rays. I've been tinkering with the presets but find myself wishing that things could be more fine-grained. Sure, I can get it to default to a 5.1 AAC mixdown on each encode. That's simple enough. Does Handbrake have a selection preference when it comes to the default audio track beyond language? A Blu-Ray rip might have multiple audio tracks, maybe 7.1 TrueHD and a 5.1 DTS track, for example. It seems the 7.1 track is usually the first to be selected by Handbrake, but does Handbrake have a precedence for track selection, or is it simply that the 7.1 track is the first listed in the MKV and thus the first used? Is it possible to set up such a precedence, perhaps with encoder settings for each? I might want to encode both tracks as AAC (TrueHD is [Censored]' huge), but I may want to preserve all channels, so a 7.1 AAC with a specified bitrate for the TrueHD track and a 5.1 AAC with a specified bitrate for the DTS track, or just select the best coded/largest number of channels and use that one only with the specified AAC target. It doesn't seem that this is possible, and granted, it's probably further than most users would go. Also, not every Blu-Ray has surround sound. Some may be stereo or even mono tracks, and while it seems Handbrake will only allocate as many tracks as are available (stereo won't mix up to 5.1), it seems to keep the higher bitrate setting, which would be wasted space.
extract
Posts: 10
Joined: Sat Jan 27, 2007 10:45 pm

Re: Audio encoder settings and presets

Post by extract »

In the Audio tab click on Selection Behavior... , here you choose under Mixdown 7.1 Channels. If only 5.1 is available, it will automatically be chosen
Durendal
Posts: 31
Joined: Mon Feb 12, 2007 5:41 pm

Re: Audio encoder settings and presets

Post by Durendal »

True, but what I've noticed is that it doesn't seem to adjust the bitrate. If I choose 7.1 as the default and it's compressing a file that only has stereo then it will still show the 7.1 bitrate, ie, AAC 768kbps, but with stereo audio. Maybe that's just a UI issue, but it would be a real waste of space if it wasn't, even if it's 5.1 with the 7.1 bitrate.
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s55
HandBrake Team
Posts: 10168
Joined: Sun Dec 24, 2006 1:05 pm

Re: Audio encoder settings and presets

Post by s55 »

The UI doesn't support bitrate per channel yet so yes, it will be wasteful. There are encoder limits which will kick in but it can still lead to a slightly bloated audio track.

It's on the todo list to support this.
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