Blu-ray audio settings for handbrake

[edd1234]

When I load a blu-ray in handbrake, and select "High Profile", it gives me two audio tracks.
The first is "AAC (avcodec)" with "Dolby Pro Logic II" - From what I understand this a stereo stream, yet is an "intelligent" one, and some playback devices can kind of transform it into some form of half-decent surround sound. I also understand that this one is included for compatibility with iPhones and the like.
The second is always "AC3 Passthru", even though the source is usually "DTS 5.1" or "DTS-HD MA 5.1". How does this work - I swear it can't passthrough one from one codec to another?

My second question is what is the best combination of audio output codecs so that the surround sound is preserved while also having general compatibility.
I'm not too worried about passthrough or anything lossless, so would there be anything wrong or stupid with the following:

1) DTS-HD ---> AAC (avcodec), Dolby Pro Logic II, 160bitrate, Auto Samplerate
2) DTS-HD ---> AAC (avcodec), 5.1 Channels, 320bitrate, Auto Samplerate

or:

1) DTS-HD ---> AAC (avcodec), Dolby Pro Logic II, 160bitrate, Auto Samplerate
2) DTS-HD ---> Auto-Passthru

If I take the first suggestion - is this a waste/pointless. Is there anything the second track wouldn't play on?
Also for the first suggestion, how would the media player (e.g. sony blu-ray player playing MP4 off USB stick) choose the better audio track? I've never seen an option to choose.

And for the second suggestion, can DTS-HD just be passed-through to an MP4?


Thank you!!!!

Note: I'm converting using the "av_mp4" container that's appeared in the recent nightlies, but from what I understand this is just a better version of the normal "Mp4" one.

[hogger129]

For AC3 passthrough, I think all it's doing is on-the-fly decoding into Dolby Digital.

My second question is what is the best combination of audio output codecs so that the surround sound is preserved while also having general compatibility.

Definitely AC3 5.1. I would use either 448k or 640k bit rate.



I also am wondering why MP4? I guess it depends on what you're using for playback, but I would recommend MKV instead.

[hello_hello]

The second is always "AC3 Passthru", even though the source is usually "DTS 5.1" or "DTS-HD MA 5.1". How does this work - I swear it can't passthrough one from one codec to another?

There's an option in Handbrake's settings to enable advanced passthru options, but I couldn't get them to work anyway. Logically for DTS it should default to DTS passthru and for AC3 it'd be AC3 passthru, but it seems pretty intent on sticking with AC3, and if the source isn't AC3, it re-encodes it. Unless you manually change the output setting.

My second question is what is the best combination of audio output codecs so that the surround sound is preserved while also having general compatibility.

AC3 is probably the most compatible. I usually keep existing AC3 or re-encode DTS as multi-channel AAC. I only use one audio stream. I don't see the point in wasting space with two unless you know for sure you'll be playing the encode on a device with limited audio support. And even then.... if it's for a portable device etc you can easily use the audio stream in Handbrake's output file and re-encode it later on if need be. Swap the newly encoded audio for the old and create a new output file (copying the video) and you'll have a one containing audio the device can play.

DTS requires a licence so not all devices support it. Bluray players will, but media players in TVs etc mightn't. The Samsung TV in the house does. The Sharp TV doesn't. For media players which are DivX HD certified, DTS is optional (unless they're a Bluray player). Almost everything will play AC3 and AAC.[/QUOTE]

MP4 is horrible to work with. MKV is much easier thanks to MKVMergeGUI and it's widely supported. Every device in this house newer than a DVD player plays MKVs.