Outdated guide

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Magnusb1
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Outdated guide

Post by Magnusb1 » Tue Aug 28, 2012 2:41 pm

I love your detailed guides, but I think the Surround sound guide is a little outdated. https://trac.handbrake.fr/wiki/SurroundSoundGuide
Please take a little time to look over it and verify that all the information in it still counts today. :D

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JohnAStebbins
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Re: Outdated guide

Post by JohnAStebbins » Tue Aug 28, 2012 3:38 pm

It's all still accurate. There are just a few more options available now for passthru and other multi-channel encodes.

Magnusb1
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Re: Outdated guide

Post by Magnusb1 » Tue Aug 28, 2012 4:52 pm

Be aware that, due to technical concerns, Dolby Pro Logic II is currently created as 5.0 sound.
Still counts?

Sadly, it is very difficult to hear all those discrete channels of sound. It cannot be sent over an optical cable to a home theater amp. If you try, whether on a Mac or an AppleTV, you will only hear "downmixed" surround sound, similar to Dolby Pro Logic.
Similar to Dolby Pro Logic II with or without the subwoofer channel?
My setup is Apple TV - HDMI - TV - Optical - Logitech Z906 Sorround Speakers, do I achive the full quality or the "downmixed"?

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JohnAStebbins
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Re: Outdated guide

Post by JohnAStebbins » Tue Aug 28, 2012 7:13 pm

Magnusb1 wrote:Be aware that, due to technical concerns, Dolby Pro Logic II is currently created as 5.0 sound.
Still counts?
Yes. The spec for dpl2 allows mixing subwoffer channel as an option into front left/right. But it is not required and HandBrake does not do it. It can cause serious distortion in speaker systems that were not designed for these frequencies.
Sadly, it is very difficult to hear all those discrete channels of sound. It cannot be sent over an optical cable to a home theater amp. If you try, whether on a Mac or an AppleTV, you will only hear "downmixed" surround sound, similar to Dolby Pro Logic.
Similar to Dolby Pro Logic II with or without the subwoofer channel?
My setup is Apple TV - HDMI - TV - Optical - Logitech Z906 Sorround Speakers, do I achive the full quality or the "downmixed"?
This refers to playback of audio encoded to 6ch AAC and the what AppleTV and QT do with such a track. I'm pretty certain it still applies. If you want all tracks, you need to encode to something like ac3 that can be sent digitally to your receiver or you need the additional hardware mentioned.

Magnusb1
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Joined: Tue Aug 28, 2012 2:38 pm

Re: Outdated guide

Post by Magnusb1 » Wed Aug 29, 2012 2:33 pm

JohnAStebbins wrote:
Magnusb1 wrote: Sadly, it is very difficult to hear all those discrete channels of sound. It cannot be sent over an optical cable to a home theater amp. If you try, whether on a Mac or an AppleTV, you will only hear "downmixed" surround sound, similar to Dolby Pro Logic.
Similar to Dolby Pro Logic II with or without the subwoofer channel?
My setup is Apple TV - HDMI - TV - Optical - Logitech Z906 Sorround Speakers, do I achive the full quality or the "downmixed"?
This refers to playback of audio encoded to 6ch AAC and the what AppleTV and QT do with such a track. I'm pretty certain it still applies. If you want all tracks, you need to encode to something like ac3 that can be sent digitally to your receiver or you need the additional hardware mentioned.
I tried the auto-passthru, the apple TV wouldn't play off the audio nicely with the audio. If I crate an AC3 6-channel discrete audio track with 640bitrate, will it still also be "downmixed" sorround sound? Thank you very much for your proffesional support.

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Rodeo
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Re: Outdated guide

Post by Rodeo » Wed Aug 29, 2012 2:46 pm

The AppleTV expects the following:

1) 2-channel AAC track (Stereo or Lt/Rt*)

2) AC3 track (preferably 48 kHz, which is already the case for DVD and BD sources)

When an AC3 track is available in the source, use AC3 Passthru, else use the AC3 encoder.

AC3 5.1 ("6-channel discrete") is proper surround sound (not matrix-encoded into 2 channels like Lt/Rt).


* In HandBrake, that would be either Dolby Surround or Dolby Pro Logic II

dynaflash
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Re: Outdated guide

Post by dynaflash » Thu Aug 30, 2012 3:17 pm

JohnAStebbins wrote:This refers to playback of audio encoded to 6ch AAC and the what AppleTV and QT do with such a track. I'm pretty certain it still applies. If you want all tracks, you need to encode to something like ac3 that can be sent digitally to your receiver or you need the additional hardware mentioned.
This is certainly still the case with the atv (all three gens). Before the atv 1 had AC3 Passthru (originally it only supported aac 2 channel) the rumors started coming down the pipe that software version 2.0 for the appletv would support true 5.1 surround. So we presumed it was going to be 5.1 AAC discrete (six discreet channels). At the time the appletv was largely the reason we added 6 channel aac. However, when the software shipped we immediatly tested it. Much surprised that is was passing thru AC3 5.1 DD . Nice. but then we tested how it handled our six channel aac. Frankly you get a strange aac 3.0 mixdown. So, there you have it.

Oh, and Rodeo is right, the first aac two channel track is required for the atv to recognize the second AC3 track, provided you have you optical to a AC3 5.1 capable sound setup. Just a single AC3 track will not work correctly and if it does ( it did during one atv 1 software revision) it will likely be broken in the next software update. That happened as I said and many people suddenly had to re encode a bunch of stuff that only had the one track.

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