Worth converting Library to x265?

General Discussions
1

Hey guys,
With x265 touting that it can save 50% storage requirements while maintaining the same quality (over x264), that’s a somewhat enticing offer. In fact, in the few tests I’ve done, I’ve been able to save more like 75% with more or less an imperceptible loss in visual fidelity. I am maintaining all of the original audio tracks by just doing a passthru of the audio files, and so far I am happy with the results.
Before I go converting my entire library though, are there any downsides to this? I know x264 has a wider adoption rate, so more files may need to transcode when streaming to other devices, but how quick is the adoption rate of x265? Will this be very temporary, or will it likely take as long as x264 took to gain widespread adoption?
Anything else you can think of that would be helpful would be great… :slight_smile:

1080p x265 10bit transcoding
2

Don’t do it unless you have a blazingly fast CPU in your server, with hardware transcoding support for HEVC 10 bit.
(And I mean decode and encode support)

Reason:

  • activate a subtitle = transcoding (in many cases, at least)
  • sync content to a mobile device = transcoding
  • reduce the available bandwidth (particularly with remote connections) = transcoding
  • activate “Automatically adjust quality” in clients = transcoding
1 Like
3

Thanks for the reply Otto,

I don’t necessarily need sync, I don’t generally sync my media to anything, I just stream everything.

Activating subtitles would be a problem, especially for all the foreign titles I have. Can you elaborate a bit more here? Are there certain subtitle types that don’t work well? Or do we know exactly WHY it’s causing a transcode? If worse comes to worse, I could burn in the subs for those movies negating that issue, but… That’s not totally ideal.

What do you mean by “Reduce the available bandwidth”?

And if “Automatically adjust quality” is not selected in the client, it can still direct play on devices that support, yes?

4

There are numerous client types which cannot handle all subtitle formats. So if you have many media which require subtitles, you want to avoid pixel-based subs (VOBSUB, PGS), because these are badly supported. The best supported are SRT subtitles.
ASS are a special case: while they are text-based, they do support very elaborate formattings. And not all clients can perform these. So either the client is rendering the text without formattings (less-than-ideal, but probably bearable in most cases) or it asks the server to burn-in the subs = transcoding.
Of course, usually only anime fan-subs are actually using the special abilities of the ASS format…

If the client sets an upper limit for the bandwidth to use. And if this bandwidth happens to be lower than the bandwidth of your file = transcoding.
Bandwidth can also get limited by:

  • your server, if you define an upper limit for remote clients to use
  • if the client has to resort to a Relay connection, which is limited to 1mbps for regular users and 2 mbps for Plex Pass holders
  • if the user activates “Automatically adjust quality”, because this cannot seamlessly transition between direct play and transcoding, so it transcodes all the time – even if there is enough bandwidth for direct play

There are a lot of device quirks, which prevent direct playing or direct streaming from working correctly. Like, for instance on some smart TVs, if you select not the first audio stream and you activate a subtitle as well, you get always transcoding (because otherwise, you’d get A/V sync issues).

So you should kinda always expect transcoding, particularly with less-than powerful clients (because those have the worst codec support and the most quirks) and if clients are remote.

5

Thanks! I think I understand a bit better now :slight_smile: I will try a bunch of different scenarios to see what I can and can’t handle… I was waiting for ThreadRipper 2 to come out before upgrading, but for the moment I think what I have will work, but I will definitely do some more testing to see what’s what…

6

Hi there, I’m hoping to get a related question answered. I have a Quadro P2000 setup with hardware Encode and Decode. Most of my library would be 1080P. Should I be concerned about tone mapping and washed out colors if I use a 10bit profile to rip movies?

I see the posts about 4K HDR color and have watched videos, but some say that transcoding 1080 x265 is fine. Are they using the 8 bit profile?

7

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.