PDA

View Full Version : MP4's & Dolby Digital 5.1 Surround Sound



KDUK
01-03-2015, 06:42 AM
Good morning folks,

I hope you can help me with my query - Iíve been doing quite a lot of work researching and testing, but Iíve reached a point where I canít quite work out what Iím missing, or need to do (or maybe I can but I am hoping thereís a different answer!). Itís a little long, so please bear with meÖget yourself a cup of tea and settle in! :o) If there is somewhere this is already addressed then please point me at it - Iíve not been able to find it thus far but if it already exists fantastic!

Iím in the process of packing out my NAS with all things media. Music is fine, ripping to ALAC to ensure lossless encodes. Iíll figure out moving my iTunes library onto the NAS so I donít rely on the iMac being on 24/7 down the line, Iíve seen a few guides on this and am fairly comfortable. Photos same again, central repository for the billions of photos we take and never look at!

Where Iím trying to get to the best place is around film/TV show media.

Iíve recently purchased MacX DVD which looked to be the best bet from what I read online, and my previous experience using a 2 step system with AN Other DVD Ripper and Handbrake. I donít dislike Handbrake, but it is SÖÖÖLÖÖÖÖÖÖOÖÖ.W! However I might go back to itÖmore on this later! But the intention was to hit a one stop shop where I can rip and then encode DVDs as I want them.

I toyed with keeping a .ISO backup of every disc and then encoding to a suitable file format for viewing on a variety of devices, those being TVís (Samsung Smart TVís currently hooked up to an ATV2 and 3 one of which has a full Sonos 5.1 Surround Sound setup with Playbar, Sub & 2 * Play 1ís), iPhones & iPads.

However I donít think keeping a .ISO of every DVD gives me a whole lot, apart from a bunch of 5-7GB files that will probably never get used again. I am looking at creating the highest quality file as I can and storage space isnít a concern with my 16TB NAS setup, but just donít think keeping a .ISO buys me anything. So I think ripping and encoding to a suitable end file format is probably the way forward so long as it is sufficiently high quality. Thatís where the main thrust of my query begins.

I have looked at the various containers and these days I think itís a straight choice between MKV and MP4. I think the former provides more flexibility, but the latter is probably more widely Ďacceptedí by devices and better suits my needs. From a quality perspective I donít think there is any significant difference, as I will be looking to encode video to the h.264 codec so MP4 will be the container of choice. With h.264 I think I achieve the highest quality video stream for both DVD and Bluray that sufficiently future proofs my digital store.

The audio codec is where I am coming most unstuck. The options that seem to be available / prevalent are AAC and A3C.

Last night I took a new DVD of mine - Drive for what it is worth - and ripped it through MacX DVD. I then converted it to .mp4 with both MacX DVD and Handbrake. The former took perhaps 45 minutes to complete, the latter several hours (I let is run overnight so donít know exactly how long it took, but it was about 10% complete when the MacX DVD encode had completed).

The MacX DVD .mp4 file, encoded with ĎUse High Quality Engine' selected and h.264 video codec bit rates of 2500k, frame rate/resolution & aspect ration Ďkeep originí and audio codec arc, sample rate 44100, bit rate 320 Kbps, channel 6 (not sure if this is 6 channels or channel number 6, whatever that means!) created a file of 1.96GB. However when I loaded this into iTunes and played it through my ATV2 in the lounge with the Sonos Surround Sound, it only came out in Stereo (checked through the Sonos App which tells you the Audio In feed to the PlayBar).

The Handbrake .mp4 file, used the High Profile basis but amended a few settings. It was encoded with h.264 video codec, video quality was Constant Quality RF 19. Audio had Track 0 English (AC3) (2.0 ch) as AAC, Stereo Mixdown at 320 bitrate and Track 1 English (AC3) (5.1 ch) AC3 Passthrough 448 bitrate and created a file of 1.12GB. I loaded this into iTunes and played it as above through the ATV2 & Sonos and it fed the system 5.1 Surround Sound.

So I know that the Samsung TV, ATV & Sonos environment CAN play .mp4 files but encoded through MacX DVD (which would be the preference for speed and the fact it is a one stop shop) I havenít managed to get this working yet.

It may be that MacX DVD cannot do what I need, but everything I read about it beforehand indicated that it could. I have written direct to the MacX DVD support folks too with this query too. But if it canít, aside from being annoyed Iíve just spent £30 on something that doesnít do what I need, at least Iíd know what I need to do around (1) ripping and (2) encoding to .mp4 with Handbrake. If that is the case, are there any other setting / parameter improvements I should be looking at? Or if there is an alternative to MacX DVD that DOES do what I need then I would be happy to look at that too.

Similarly the easiest mechanism may well be to run native Synology DS Video on the TVís and on the iOS devices (there is a Samung TV app and iOS apps) because then Iím not tied to .mp4ís and can use .mkvís which appear on the face of it to have better or at least easier to encode A3C / Surround Sound audio capabilities. The Synology DS415play NAS I have also does transcoding on the fly, but Iíd rather have my files encoded right from the outset than rely on CPU intensive transcoding to get the output I am looking for.

But I wanted to get everything working through the ATVís at this gives me other benefits, is cleaner for me, and, well I am just bought into / tied to the Apple ecosystem (which I appreciate isnít perfect, but it is what it is!).

Iím not sure if Iíve even asked a direct question there (!), but Iíd welcome any thoughts & comments about how I can try and achieve what Iíd like to, especially around getting 5.1 sound cut into my .mp4ís for playback (ideally using MacX DVD).

Thanks!
Kerry

Lifeisabeach
01-03-2015, 01:40 PM
*Whew* That post is one hard read! I'm going to make a couple comments here. First off, regarding Handbrake, it can be as slow or as fast as you need it to be. Slower encodes generally result in higher quality, more accurate results. Faster encodes are going to result in trade-offs on quality. There's no way around this and it holds true for any encoder. The current version of Handbrake is quite excellent and takes a lot of the guesswork out of the settings by providing presets for advanced settings ranging from "ultrafast" to "placebo". It also has "tuned" settings for different media (film, animation, etc). It's a GREAT encoder if you know how to use it properly.

As for your DVD ripper... discussing that much is off-limits here in these forums. I'll just say that MacX is by no means the "best".

You mentioned that you plan to move all your media to an NAS so you don't have to keep your iMac and iTunes running all the time. If you are using an Apple TV (which you mentioned), you won't be able to play anything stored in iTunes, and the ATV will ONLY stream media from iTunes using Home Sharing. At best, you can AirPlay from another device, but I'm not sure if you will be able to stream AC3 tracks that way. You could, of course, still use Netflix and any other 3rd party "channels" provided on the ATV.

My home theater setup is with a Mac Mini running Plex. I first tried this route a few years ago and found the experience lacking for a variety of reasons, but gave it another whirl when the new Mac Minis were released and I have absolutely no reservations in saying that this beats the Apple TV for streaming home media. True 24p output and the option to use lossless audio from my Blu-Rays or even the lossy DTS track (as opposed to down-converting to AC3) just puts this over the top. Setting this all up and managing it isn't easy, but once done, it's done. My wife and in-laws can now operate this as easily as they did the ATV.

As for MKV vs M4V... MKV wins by a huge margin for just how robust and versatile the format is. But it's incompatible with an AppleTV.

I should make a quick recommendation about converting your DVD rips. DVDs are all mastered at 30 fps, in accordance with the refresh rate on analogue TV sets. BUT... almost all content is actually authored at 24 fps in accordance with film standards. So DVDs are mastered using a technique called "telecining" to pad out those 24 frames to 30 frames, which leads to visual artifacts. Rather than simply playing an ISO of a DVD, you will actually be better off converting them and using the "detelecine" option in Handbrake. Set it to a variable framerate with a peak of 29.97 and turn "detelecine" on in the picture settings. This will detelecine as needed, if detected, and eliminate the telecining artifact inherent in DVDs. More info on that here:
https://trac.handbrake.fr/wiki/Telecine

johnodd4
01-03-2015, 02:01 PM
Ok here is the basic's then you are trying to convert a dvd from dvd to mp4 with 5.1 channel surround sound and send it to a apple tv.

While keeping the dolby digital 5.1 intact on the file it's not easy but i can help you and you are i am sorry to say going to need handbrake.

How to get 5.1 out of a mp4 using handbrake.

you are going to load your dvd into handbrake under audio tab in handbrake you select 5.1 in the mix down option once the video has finished being converted you will have a mp4 with dolby digital this is if your system is truly 5.1 surround sound and not 5.1 stereo surround sound.

There is also a issue that the apple tv might not support the 5.1 channel.

KDUK
01-03-2015, 04:44 PM
Thanks for the reply guys. And thanks for sticking with my post...I kinda started and it went from there!

I was hoping that the software I bought would be able to handle what I needed - which sounds like encoding two sound channels, one AAC and one A3C passthrough which delivers the DD 5.1 Surround. The ATV can definitely handle this, and the file I encoded with Handbrake did deliver DD 5.1 Surround to the Sonos.

The Sonos can definitely handle true DD 5.1 and I've watched Sky Movies and DVD's via the DVD player (how quaint!) that have delivered proper DD 5.1 sound.

So it does look like I've done my £30!

Thinking forward, perhaps ditching the ATV and going with a Roku which supports many more file formats - ie MKV - would be a better option.

Otherwise it might even be that the DS Video app for the Samsung TV would play the MKV files with DD 5.1 sound direct from the NAS. The equivalent iOS apps on iPad/iPhone can play the files offline on the devices where DD 5.1 is not a concern...it's only the TV with Sonos where this matters.

So thanks again. Welcome any more comments, definitely a learning curve and it is very interesting (at least I think so, my wife begs to differ but enjoys the results!!).

Cheers
Kerry

Lifeisabeach
01-03-2015, 11:18 PM
Ok here is the basic's then you are trying to convert a dvd from dvd to mp4 with 5.1 channel surround sound and send it to a apple tv.

While keeping the dolby digital 5.1 intact on the file it's not easy but i can help you and you are i am sorry to say going to need handbrake.

How to get 5.1 out of a mp4 using handbrake.

you are going to load your dvd into handbrake under audio tab in handbrake you select 5.1 in the mix down option once the video has finished being converted you will have a mp4 with dolby digital this is if your system is truly 5.1 surround sound and not 5.1 stereo surround sound.

There is also a issue that the apple tv might not support the 5.1 channel.

There is no such thing as 5.1 stereo surround. Stereo is, by definition, 2.0 (left and right. 2 tracks. Period). You "may" want to set Handbrake to create for 2 tracks: 2.0 AAC and Auto Passthrough (or AC3 Passthrough). Auto Pass will automatically remux an AC3 track without transcoding it. If you actually set it as "simply" AC3, it will needlessly re-encode the track, which will result in some loss in fidelity. ATV will automatically use the AC3 track if you tell it that it's connected to a receiver that can decode it (somewhere in the options). Otherwise it and other devices will default to the 2.0 AAC track.

And the ATV does in fact support 5.1 "channels". Well if it's AC3 (Dolby Digital). It doesn't support DTS 5.1 (or any DTS variation). This is a "passthrough" option and requires a receiver that supports AC3 decoding.

KDUK
01-04-2015, 04:06 AM
There is no such thing as 5.1 stereo surround. Stereo is, by definition, 2.0 (left and right. 2 tracks. Period). You "may" want to set Handbrake to create for 2 tracks: 2.0 AAC and Auto Passthrough (or AC3 Passthrough). Auto Pass will automatically remux an AC3 track without transcoding it. If you actually set it as "simply" AC3, it will needlessly re-encode the track, which will result in some loss in fidelity. ATV will automatically use the AC3 track if you tell it that it's connected to a receiver that can decode it (somewhere in the options). Otherwise it and other devices will default to the 2.0 AAC track.

And the ATV does in fact support 5.1 "channels". Well if it's AC3 (Dolby Digital). It doesn't support DTS 5.1 (or any DTS variation). This is a "passthrough" option and requires a receiver that supports AC3 decoding.

Thanks for this - and understand. It is set to AC3 passthrough as the second track in Handbrake so I think that is done correctly.

"if you tell it that it's connected to a receiver that can decode it (somewhere in the options)" - where would I set this, within ATV? I have Dolby set to on. Do I need to have 16 bit selected also within the audio options (I think it is automatic at present)?

I believe Sonos is a receiver that supports AC3 decoding, certainly within the Sonos settings it tells me that the audio in feed is Dolby Digital 5.1 when the source is sending such audio, for example Sky Movies or an appropriately encoded MP4 file via ATV.

alicepattinson
01-04-2015, 05:05 AM
Thanks to this thread i learn a lot about mp4 and dolby digital 5.1. :)

Lifeisabeach
01-04-2015, 04:09 PM
"if you tell it that it's connected to a receiver that can decode it (somewhere in the options)" - where would I set this, within ATV? I have Dolby set to on. Do I need to have 16 bit selected also within the audio options (I think it is automatic at present)?

That's it. Leave it on auto.