Is my setup a Transcoding one ?

topgazza

I think this is the right forum.

I have been worrying about what NAS to get that would, when required, transcode my Plex library of films. My concern is the ability of NAS boxes to handle the transcoding required from say, 4k to HD or UHD to HD, my current TV is HD so unless BluRay or DVD I have assumed transcoding will be required for any film not of that type.

Then someone suggested that as my current setup was an iMac with multi cored i7 processor with my films on a WD MyBook external drive connected to iMac by USB, backed up to another external drive, the iMac would handle the transcoding when playing a film on my TV. Everything is hard wired with CAT 6 cable. Plex server sits on my iMac

Is this the case in people experience ? Does this remove the need for a powerful but expensive NAS as my only use is films ? I assume I need to upgrade Plex to Premium to get transcoding or is that only for software transcoding.

Any help appreciated

bubblegum57

You should just try running plex on the imac.

Depending on the file type, you might not need to transcode.

The imac has a more powerful cpu than any nas i can see from this list

                                                Plex NAS Compatibility                       
                                                                                                                                                                                                                                                                                                                                                                                                                                NAS Compatibility List | Plex Support                                                                                                        The following spreadsheet provides information about compatible NAS devices as well as basic capability information. View Plex NAS Compatibility Guide...                                                                                                                                                                                                                                                                                                                support.plex.tv

mickevh

I normally council that the best way to deal with real time transcoding is to not bother and avoid it: Instead, store your movies in a format all your playback device can read without requiring real time transcoding, even if that means storing two copies - one super duper full fat super-mega-HD (or whatever the latest superlative is) for the "big" TV (where PQ matters) and one basic mpeg2 stereo version for the little TV's, ipads, phones etc. where PQ doesn't matter and you don't need 7-channel surround sound.

For sure, that will cost you some more in storage, but save you all the angst of worrying about whether you have NAS with powerful enough processors and you can spend the money you save on processors on more storage. (not to mention, it'll run cooler, quieter (and a tiny bit less lekky) as the CPU fans won't need to blowing up a whirlwind keeping it all cool.) If all a NAS has to do is "serve files" pretty much anything will do - serving files is a really low CPU activity.

Thence, to produce the "transcoded" low PQ version, you could use your Mac and do each one offline (once) in order to get the PQ and files size "just so" (if you can be bothered) using Handbrake and the like.

Transcoding is a highly CPU intensive task - at time of posting I believe it's still the case that you can throw as much processing power as you like at it and it will still take more if it were available. In order to keep transcoding "real time" within the capabilities of the host system, something has to be sacrificed to "keep up" - either PQ, stream size or both. And with mutliple streams running concurrently, it gets even worse.

Whereas if you run a one time offline transcode with Handbrake et al, you can literally let it run for hours (like 24) and get the ultimate in PQ/filesize (depending on how much you want to experiment.) But once you've got a satisfactory result, you never need to do it again.

I suggest the starting point is to assess the capabilities of all your playback devices (streamers, TV's, tablets, phones,, whatever) and see what the "lowest common denominator" is and thusly that informs what the "low quality" version needs to be and see if you can live with it. MPEG2 is widely supported and these days you might find everything supports H264 and it's derivatives.

But, if you don't want to got to all that trouble, then there are plenty here who know the NAS market and can doubtless say what's what.

topgazza

Thanks all

I 99% watch the films on my TV which is a Sony HD. Files are in .mkv format so I'm guessing they are being transcoded anyway to MPEG 2 or WMV or similar. I dont see requirement to watch them on anything else other than the TV so I'm guessing the iMac is already transcoding with Plex Server which I only run on the iMac. Plex client on the Firestick which has the clent app on

bubblegum57

Play a movie, via plex on the Firestick. Press ok, in the top left corner it should say direct play or transcode?

Tried this on a shield,so might be different on firestick.

mickevh

MKV is a "container" rather than a "format." MKV (by design) can wrap itself around lots of different formats, so to truely know what's within, one need to have a look with MediaInfo or something similar:.

So, for example, if you take a DVD (which IIRC are all mpeg2) and rip it to an MKV, it's still mpeg2 inside. Or, if I take a H265 file (which my ancient media streamer cannot play) and wrap it in an MKV container (which my media streamer understands) it still won't play because it's an H265 inside. An analogy I like is that if you send me my bank statement in French (which I don't speak) and take it out the "plain" envelope and wrap in in a pink one, I still won't understand the content as it's still French. De rien.

One way you might determine whether your iMac is transcoding or not, is to take a couple of sample files and drop them into a "bog standard" SMB/CIFS share and see if you TV plays them OK. If so, it's probably not transcoding. You could even try shutting down PMS to be sure.

Also, you might pull up the process monitor (sorry I forget what it's called on MacOS) and watch the CPU performance graph, kick off a movie and see what happens. If the CPU stays lowish - it's probably not transcoding, if it jumps up to 100%, it probably is. Might be worth checking out a few titles to see whether there's any trend.

topgazza

Its activity monitor on a mac. I'm pretty certain most are H264/5 but next time I rip I'll check the setting but I've never had a problem with any of them. they all play well and at exceptional quality for the modern films anyway. Some of the very old ones are straight MPEG4 as well but majority are, as you say, hidden in the mkv container. I'll see whats happening when playing if I can

next010

If you have an old smart TV from 10 years ago then its media player might be very basic and only support MPEG2/WMV video which was the bare minimum required for DLNA support.

Over the years TV makers improved the media support on their TV's and most these days will play all the common formats so you dont need that powerful a NAS to actually stream stuff to the TV, even basic NAS CPU's can handle old uncommon video types and transcoding audio if needed.

Though the TV cant be that old if it has a Plex client ? unless your using the DLNA server mode of Plex.

topgazza

TV is 6 years old and seems to support most formats. DLNA server is selected. Client sits on the Firestick which is plugged into the TV of course. I think everything is 1080p, and those I can identify seem to be H264 and a few are MPEG4 so I guess as my TV accepts those as well as AVI and a few others it probably isnt transcoding. I might try a codec, from a UHD/4k film maybe, that isn't supported and see what happens

next010

Yeah transcoding would be required for the TV , it wouldn't have H.265/HEVC support.

The FireTV from 2nd generation has H.265 support but 1st gen does not.

The thing about Plex clients is that on some platforms it's just a skin over the internal media player, so in the case of the FireTV it is likely not using a custom made media player tailored to the hardware just whatever basic video player Amazon made for it.

So if the stock media player does not support something then Plex server transcodes but on FireTV you have the option to use MrMC to connect to the Plex server, this will decode all media on the FireTV and avoid transcoding on the server.

Of course whether the FireTV is up to the task of playing all media types on its own depends on a few things. But if it works for everything then you dont need a high end NAS or pay for plex pass transcoding support, a low end NAS capable of running Plex server is all thats needed and leave MrMC handle video duties on FireTV's.