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Apple TV and Surround Sound
- Thread starter Cave Man
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Sorta off topic of the OP, but also related to my basement Home Cinema, since I might use AppleTV in the future and I'd really like full lossless surround sound and 1080p.
My equipment:
Frt Proj: Sony VPL-VW60 (I just picked that up tonight, still in the box!)
Screen: I am going CinemaWide, was in Nashville all week and had a chance to experience that at HiFiBuys, http://www.avsforum.com/avs-vb/showthread.php?t=977638
A/V: Denon 4308CI
Speakers: Paradigm Monitor 9's, CC390 center, 4 ADP390
Check out my IB subwoofer I'm gonna build:http://ibsubwoofers.proboards51.com/index.cgi?board=projects&action=display&thread=1198261510&page=1
For Home Theatre/Audio, I've surfed a few of the boards, such as; S&V, Home Theatre Shack, etc, seems the one I like most is AVS Fourm.
(I'm "mtbdudex" at all of them)
They have a specific section on 2.35:1 screens, I'm going with the Constant Height set-up, my Sony VW60 is capable with an external Anamorphic lens.
My room is 14.5 feet wide , 18.5 feet long, 8.75 feet tall, if you look at the IB post you can see I tried to minimize sound intrusion into my home via some soundproofing measures. Of course once my room is all finished/etc I'll work on some acoustic treatments to handle some of the basic issues, 1st order harmonics, etc. The Audessy in the Denon should help, I'm a newbie in acoustic treatments and am willing to learn/apply some stuff, but I'm not gonna go totally wild and have these tilted panels everywhere either.
I'm mounting the frt proj with 16 foot throw distance (lens to screen), proj of course is "upside down", mounted from ceiling.
Actually, IP is very important to the 360. Xbox Live is free (Silver). When you first boot the console it has you create a profile. If the console has net access it autocreates a XBL account.
If AppleTV was intergrated with iChat where you can see when friends come on. You can see what movies friends are watching. You can chat (text, audio, or video). That would be a pretty close to the experience of XBL outside of playing games together. The 360 is very friend centric which requires net access.
Actually I think iChat interface for AppleTV would be the coolest thing they could do. Add the ability to see what others are watching (meaning you can't watch what they are watching but can see the title). Or just updates on what activities they are up to. Right now the AppleTV is a one way experience. You only download to the box. Data doesn't leave the box. Make it two way. That would open up tons of possibilities.
Topic: DD+ is more likely as a passthrough means. It wouldn't add too much in the way of download size or even bit-rate (IMHO). THD or DTSMA start out too big to make it worthwhile. Can DPLII output sound only from the rear speakers? Some folks here make it sound like there is no difference in having matrix sound versus having discreet sound. You know the scene in the Matrix where Neo dodged bullets like he was an agent, can DPLII have the bullet fire sound just like it does when using DD?
mtbdudex and diamond.g, and others, something I'd overlooked which should have been rather obvious to me as to why AppleTV cannot support "HD" Surround sound at this point...
The simple explanation is this: Neither Dolby TrueHD nor full-bandwidth Dolby Digital Plus would be feasible because the bitstream requirements are astronomical relative to Dolby Digital AC-3.
Let me illustrate...
H.264 Main Profile 3.0 has a cap of 10Mbps. Currently the AppleTV operates at a maximum around 5Mbps for the total bitstream, audio and video.
Now, this is not a problem with AC-3 pass through because the standard AC-3 5.1-channel bitstream is 448 Kbps. Dolby Laboratories states that at 448 Kbps their format is acoustically transparent... that is, it's indiscernible from an uncompressed source. I'm not going to get in an argument here... I've done professional mastering, and I agree with Dolby Labs engineers. I've heard it all and no anecdotal argument from an audiophile (especially those who have never read Ken Pohlmann's Principles of Digital Audio) is going to change that.
The fact is, if uncompressed 24-bit uncompressed (Linear PCM) multichannel audio is what you want, then there's no mathematical way around this:
24-bit amplitude resolution X 48 kHz sampling frequency X 8 channels=
9.216 Mbps bitstream (audio only)
Clearly, you should see several problems, including the tremendous file size, the ridiculous amount of time it would take to download, the hardware and software limitations, and so on.
At some point in the future this might not be a problem, but currently it's just not feasible.
But, I wouldn't worry about it for a while... Most film soundtrack masters have been mastered to 16-bit, 48KHz, resolution. This means that there's a significant gap between the amplitude resolution of the source, and the amplitude resolution possible with HD audio. You will gain no added benefit from the tremendous number of soundtracks that are not going to be remastered entirely from the 24-bit multitrack master.
But I would like to see such a system in the future. 24-bit amplitude resolution is noticeably more dynamic than 16-bit. For now, we'll have to live with AC-3. I've done professional soundtrack mastering and I can live with that just fine and frankly, so can you.
The simple explanation is this: Neither Dolby TrueHD nor full-bandwidth Dolby Digital Plus would be feasible because the bitstream requirements are astronomical relative to Dolby Digital AC-3.
Let me illustrate...
H.264 Main Profile 3.0 has a cap of 10Mbps. Currently the AppleTV operates at a maximum around 5Mbps for the total bitstream, audio and video.
Now, this is not a problem with AC-3 pass through because the standard AC-3 5.1-channel bitstream is 448 Kbps. Dolby Laboratories states that at 448 Kbps their format is acoustically transparent... that is, it's indiscernible from an uncompressed source. I'm not going to get in an argument here... I've done professional mastering, and I agree with Dolby Labs engineers. I've heard it all and no anecdotal argument from an audiophile (especially those who have never read Ken Pohlmann's Principles of Digital Audio) is going to change that.
The fact is, if uncompressed 24-bit uncompressed (Linear PCM) multichannel audio is what you want, then there's no mathematical way around this:
24-bit amplitude resolution X 48 kHz sampling frequency X 8 channels=
9.216 Mbps bitstream (audio only)
Clearly, you should see several problems, including the tremendous file size, the ridiculous amount of time it would take to download, the hardware and software limitations, and so on.
At some point in the future this might not be a problem, but currently it's just not feasible.
But, I wouldn't worry about it for a while... Most film soundtrack masters have been mastered to 16-bit, 48KHz, resolution. This means that there's a significant gap between the amplitude resolution of the source, and the amplitude resolution possible with HD audio. You will gain no added benefit from the tremendous number of soundtracks that are not going to be remastered entirely from the 24-bit multitrack master.
But I would like to see such a system in the future. 24-bit amplitude resolution is noticeably more dynamic than 16-bit. For now, we'll have to live with AC-3. I've done professional soundtrack mastering and I can live with that just fine and frankly, so can you.
Successful streaming of MP4 with AC3 (but chatter only)
I have a few seconds of a movie that can stream to the ATV and it has the chatter that you hear from an AC3 soundtrack that's going through a non-DD receiver. Here's what I did:
1. Transcoded the movie from a VIDEO_TS folder of a ripped DVD to and AVI with AC3 passthrough using Handbrake.
2. Opened the AVI file and did a "Save As" to convert it to a MOV container. (This file plays on my Mac Mini with Perian to produce 5.1 surround with Quicktime, Front Row or iTunes.)
3. Dropped this MOV file onto VisualHub and started the conversion to MP4.
4. Aborted the conversion after a few minutes just to see if it would work.
5. Dropped it into iTunes and it was accepted.
6. Looked for it from the ATV and it was there!!
7. Played it from the ATV and my non-DD Sony receiver (Dolby Pro Logic) played the chatter from the movie.
So, is it possible that this file could provide DD 5.1 on an ATV? Would the ATV need the Perian codec installed for the passthrough? Ideas? Suggestions? I'm sure there's something that would preclude this, but my excitement is because it's the first time I've been able to get a movie file with AC3 5.1 surround to show up on the ATV. If anyone has an ATV connected to a DD receiver, I'd be happy to share this snipped of movie if they want to test it out.
I have a few seconds of a movie that can stream to the ATV and it has the chatter that you hear from an AC3 soundtrack that's going through a non-DD receiver. Here's what I did:
1. Transcoded the movie from a VIDEO_TS folder of a ripped DVD to and AVI with AC3 passthrough using Handbrake.
2. Opened the AVI file and did a "Save As" to convert it to a MOV container. (This file plays on my Mac Mini with Perian to produce 5.1 surround with Quicktime, Front Row or iTunes.)
3. Dropped this MOV file onto VisualHub and started the conversion to MP4.
4. Aborted the conversion after a few minutes just to see if it would work.
5. Dropped it into iTunes and it was accepted.
6. Looked for it from the ATV and it was there!!
7. Played it from the ATV and my non-DD Sony receiver (Dolby Pro Logic) played the chatter from the movie.
So, is it possible that this file could provide DD 5.1 on an ATV? Would the ATV need the Perian codec installed for the passthrough? Ideas? Suggestions? I'm sure there's something that would preclude this, but my excitement is because it's the first time I've been able to get a movie file with AC3 5.1 surround to show up on the ATV. If anyone has an ATV connected to a DD receiver, I'd be happy to share this snipped of movie if they want to test it out.
I can't answer whether or not it will for sure work because the update is not out yet... anyone would be speculating as to the method used by Apple for packing and unpacking the AC-3 bistream.
What do you mean by "chatter"? I don't want a copy of the file as that would constitute piracy. I have Dolby Digital encoding tools myself... I'll take one of the Dolby Digital trailers and encode it as H.264 with AC-3 pass through to assess the results when the AppleTV update is out. I use those for system calibration on my home theater since they're designed more dynamically than the average soundtrack mix so one can quickly assess operation of all six channels and adjust accordingly where there are dropouts/level mismatches, etc.
hmm - how do i subscribe to this thread??
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hey ... completely new ... but want to track this thread, how do i subscribe to it?
sorry, i know i shouldn't post here ... but don't know how to subscribe?
On the top of the thread you have an icon called "thread tools". In the drop-down menu is the subscribe function.
No dice
Caveman, I could not replicate the same results no matter how I tried. Here's what I did.
1. I ripped a short section of Star Wars Ep 1 as AVI using AC-3 passthru in Handbrake. I tested this on my Windows box with processes my surround. It worked perfectly.
2. I saved as a MOV using Quicktime Pro.
3. I converted 1st in VisualHub using "for AppleTV settings" in the iTunes tab with the h.264 codec, and then using the "mp4" tab with h.264 checked. Neither worked. I got stereo out of both. This could possibly be because of my setup, but I used VLC to playback every video and when the surround worked, I knew it and I had the option for 5.1 in the right-click menu.
*4. I tried converting straight from avi to mp4 using ffmpegx with passthru audio, but got no sound at all.
**Other things I tried - converting to mp4 with DPLII, Dolby Surround, and 6-channel discrete in handbrake and none of them gave me proper sound in quicktime or VLC. The best option I got was "2 front 2 rear" which left my center channel high and dry. Using DPLII and Dolby Surround the only options I had were "stereo, reverse stereo, left, and right." These were also the only options I had available for the DPLII.mp4 file you provided.
I want to get an appleTV soon, but I need to convert my library 1st, so here are my questions. you said
proagg
Caveman, I could not replicate the same results no matter how I tried. Here's what I did.
1. I ripped a short section of Star Wars Ep 1 as AVI using AC-3 passthru in Handbrake. I tested this on my Windows box with processes my surround. It worked perfectly.
2. I saved as a MOV using Quicktime Pro.
3. I converted 1st in VisualHub using "for AppleTV settings" in the iTunes tab with the h.264 codec, and then using the "mp4" tab with h.264 checked. Neither worked. I got stereo out of both. This could possibly be because of my setup, but I used VLC to playback every video and when the surround worked, I knew it and I had the option for 5.1 in the right-click menu.
*4. I tried converting straight from avi to mp4 using ffmpegx with passthru audio, but got no sound at all.
**Other things I tried - converting to mp4 with DPLII, Dolby Surround, and 6-channel discrete in handbrake and none of them gave me proper sound in quicktime or VLC. The best option I got was "2 front 2 rear" which left my center channel high and dry. Using DPLII and Dolby Surround the only options I had were "stereo, reverse stereo, left, and right." These were also the only options I had available for the DPLII.mp4 file you provided.
I want to get an appleTV soon, but I need to convert my library 1st, so here are my questions. you said
but then you said
So did it show up or not? Secondly, since I will continue (for now) to have the windows box process my audio which can handle optical input from the apple tv, I would assume that processing surround aac is possible or am I confusing some terms? Can anyone confirm this? And finally, can anyone with a hacked apple tv give me some input on their surround sound experience? Thoroughly confused,
proagg
Encoding DVDs for ATV2 with DD 5.1?
I just noticed this on the ATV web page:
MPEG-4: Up to 3 Mbps, Simple Profile with AAC-LC audio up to 160 Kbps (maximum resolution: 720 by 432 pixels at 30 fps) in .m4v, .mp4, and .mov file formats
I don't think .mov was listed before - can someone else recall? If not, then that suggests the way I encode for my Mac Mini HTPC may work with the ATV2 as described here:
1. Transcode the movie from a VIDEO_TS folder of a ripped DVD to an AVI with AC3 passthrough using Handbrake.
2. Open the AVI file in QuickTime Pro and do a "Save As" to convert it to a MOV container.
3. Drop it into iTunes. (should show up as a movie)
4. Looked for it from the ATV.
5. Does it illuminate your Dolby Digital indicator on your receiver (via optical connection)???
Does anyone have 30 minutes to give it a try? Please report back here if you do.
TIA.
I just noticed this on the ATV web page:
MPEG-4: Up to 3 Mbps, Simple Profile with AAC-LC audio up to 160 Kbps (maximum resolution: 720 by 432 pixels at 30 fps) in .m4v, .mp4, and .mov file formats
I don't think .mov was listed before - can someone else recall? If not, then that suggests the way I encode for my Mac Mini HTPC may work with the ATV2 as described here:
1. Transcode the movie from a VIDEO_TS folder of a ripped DVD to an AVI with AC3 passthrough using Handbrake.
2. Open the AVI file in QuickTime Pro and do a "Save As" to convert it to a MOV container.
3. Drop it into iTunes. (should show up as a movie)
4. Looked for it from the ATV.
5. Does it illuminate your Dolby Digital indicator on your receiver (via optical connection)???
Does anyone have 30 minutes to give it a try? Please report back here if you do.
TIA.
Is that an HD download from the Apple TV that you hacked into to get out or - how was that one encoded Handbrake ? - Please share ! 
That's straight from the ATV Take 2 upgrade disk image. I dl'd it from Apple and pulled it out of the finder. What's important, I think, is that it appears to be just a plain ol' AC3 file. That's very encouraging.
Small step forward...
OK, I followed the following steps I found on apple's forums and I got 5.1 working, but the video was (using Xvid) unbearable. After switching to the FFMPEG encoder, the video looks great and surround sound works great. The only thing is, the sound wasn't synced up. Hopefully with a full Movie it will match properly. I also don't know how this will work with all my AVI's, but I'm pretty excited to get this far.
OK, I followed the following steps I found on apple's forums and I got 5.1 working, but the video was (using Xvid) unbearable. After switching to the FFMPEG encoder, the video looks great and surround sound works great. The only thing is, the sound wasn't synced up. Hopefully with a full Movie it will match properly. I also don't know how this will work with all my AVI's, but I'm pretty excited to get this far.
I feel like I'm talking to myself here, but maybe my findings will save someone else the trouble...anyways here's what I've learned so far (in no special order):
Although not all MOVs will go straight to the AppleTV, using the above method gets the MOV into iTunes and AppleTV every time.
IMHO...The Xvid and FFMPEG encoders suck! Go with x264 and the h.264 codec, it produces excellent video in comparison.
Although the author of the above directions did not explain this, I find it necessary to choose "no audio" in handbrake or else Quicktime slaps the two audio tracks together, creating a crappy echo sound.
When I did a full movie encode, Mac The Ripper added a few seconds of silence at the end of the audio, so check your lengths when adding the video and audio.
The author doesn't explain the quicktime process in detail, so there's a couple things I figured out: 1. Select the whole clip of audio via "select all", and then copy. 2. If you try and paste it with the video, quicktime puts them side-by-side, so instead select the whole clip of video and then choose "Add to selection and scale" (you might be able to choose "add to movie", but I haven't tried).
Although not all MOVs will go straight to the AppleTV, using the above method gets the MOV into iTunes and AppleTV every time.
IMHO...The Xvid and FFMPEG encoders suck! Go with x264 and the h.264 codec, it produces excellent video in comparison.
Although the author of the above directions did not explain this, I find it necessary to choose "no audio" in handbrake or else Quicktime slaps the two audio tracks together, creating a crappy echo sound.
When I did a full movie encode, Mac The Ripper added a few seconds of silence at the end of the audio, so check your lengths when adding the video and audio.
The author doesn't explain the quicktime process in detail, so there's a couple things I figured out: 1. Select the whole clip of audio via "select all", and then copy. 2. If you try and paste it with the video, quicktime puts them side-by-side, so instead select the whole clip of video and then choose "Add to selection and scale" (you might be able to choose "add to movie", but I haven't tried).
No, please keep up the posting. It does help folks (like me) who are curious to see how this works. I've held off buying AppleTV until this update mainly for the 5.1 audio. Any information found is appreciated
Re:
Haha, I'm still trying to figure that part out. I have tried cutting off the end in QT, because it seems to stay synced from the beginning, but I cant get it exact, so it doesn't sync properly. I thought I had gotten the audio out incorrectly in MTR, because I chose specific chapters, but when I switched to "title only," MTR claimed that the output would be exactly 2:16:05, but it actually added even more time than thru chapter selection (it came out 2:18:00). So this is frustrating.
On the AVI side FFMPEGX, a shareware app, seems like it will work for the AVIs I own. I successfully stripped out the AC3, and the MP4 is on its way. If it works I might post instructions.
Edit: I don't know why, but FFMPEGX added over an hour worth of empty space to both the audio and video...searching for a better solution.
Update: VisualHub has been updated today to support AppleTV in 5.1! I don't own this software yet, but I am definitely going to purchase it next paycheck. User reports seem good so far, and my thinking is that the easiest way to get content from DVD to AppleTV will be thru Handbrake as an AVI, and then thru VisualHub. But I can't confirm anything yet. You can check out the thread on the VisualHub forums here. Also, you can see the changelog here.
Haha, I'm still trying to figure that part out. I have tried cutting off the end in QT, because it seems to stay synced from the beginning, but I cant get it exact, so it doesn't sync properly. I thought I had gotten the audio out incorrectly in MTR, because I chose specific chapters, but when I switched to "title only," MTR claimed that the output would be exactly 2:16:05, but it actually added even more time than thru chapter selection (it came out 2:18:00). So this is frustrating.
On the AVI side FFMPEGX, a shareware app, seems like it will work for the AVIs I own. I successfully stripped out the AC3, and the MP4 is on its way. If it works I might post instructions.
Edit: I don't know why, but FFMPEGX added over an hour worth of empty space to both the audio and video...searching for a better solution.
Update: VisualHub has been updated today to support AppleTV in 5.1! I don't own this software yet, but I am definitely going to purchase it next paycheck. User reports seem good so far, and my thinking is that the easiest way to get content from DVD to AppleTV will be thru Handbrake as an AVI, and then thru VisualHub. But I can't confirm anything yet. You can check out the thread on the VisualHub forums here. Also, you can see the changelog here.
I didn't want to hijack the VisualHub thread...
I think this will mean more to many of you than me since you're more familiar with a lot of the terms and what means what on a technical level.
Anyway, it seems like the Handbreak crowd is going a different route (at least for the time being) than VH and making some progress.
http://forum.handbrake.fr/viewtopic.php?f=4&t=195
I think this will mean more to many of you than me since you're more familiar with a lot of the terms and what means what on a technical level.
Anyway, it seems like the Handbreak crowd is going a different route (at least for the time being) than VH and making some progress.
http://forum.handbrake.fr/viewtopic.php?f=4&t=195
er thats an old thread from back when we originally put dpl, dpl2 and 6 channel discrete aac into HB.
That does not provide 5.1 dd for the atv2 unfortunately.
Our solution would involve .mp4 and not .mov for the record.
Sorry for the mistake. I think I even looked at the 2007 date, but it didn't register vice 2008.
Very tired today.
Same problem here. I could not get it to see my 5.1 DD MOV files that work just fine on my Mini home theater system. I've updated Visual Hub and am currently encoding Revenge of the Sith. I'll give it a look-over, but others are reporting VH only puts in one audio track - either AC3 or 2-channel. The intro movie of Take 2 has two audio tracks; AC3 and 2-channel. But on inspection, the AC3 was deslected. There must be a way to encode 2-channel and AC3 in the same file. I suspect it's only a matter of time until this is resolved; perhaps days or weeks (fingers crossed).