OK, i did some searching but i couldn’t find an answer on this topic.
I’m wondering if it’s possible to do higher quality transcodes to save bandwidth with out killing quality. I don’t know if such a feature exists yet by simply editing profiles, but if it doesn’t it’d be nice to have. (and if it does exist please tell me how!)
Here’s where i’m coming from:
Most of my streaming is done on roku devieces, and most of my source files are incompatibe files that need to be transcoded.
Now, it is possible to encode a file that has very acceptable quality using x264 1080p with just 1.5mbps (it doesn’t look as good as the source obviously, but it’s not bad at all, a lot of people would be surprised with the results!)
From what i can tell, plex uses a single pass encode when it transcodes, probably using the fastest settings possible. This means that a 720p 4mbit stream actually looks worse than a 2 pass 1080p 1.5 mbit encode, that of course takes much longer to encode.
I understand why this is done. 2 pass encodes are much slower, and the quality problem can be easily solved with more bitrate anyway (1080p 8 mbit streams look great)
The thing is, it’d be very nice to have the choice of very slow encodes if it means saving bandwidth in a lot of situations. I understand i would need a beast of a server to accomplish this, but it might just be worth it for a lot of people.
So, if there isn’t a way to to this right now, I request that this becomes an option. I understand why this feature would be useless for a lot of servers out there. But let’s not forget the rate at which CPU performance advances. In a few years i see no reason why top of the line CPU’s wouldn’t be able to handle multiple high quality streams using 2 pass encodes.
If anything i just wanted to put this out there, and some debate or comments would be nice. Thanks in advance!
Just to make sure I’m understanding, you’re suggesting using a 2 pass transcode for on-the-fly transcoding? As opposed to an option to pre-transcode content, and do it using multiple passes?
Yes, that's what i'm suggesting. On the fly 2 pass trasncode. Although i guess it would be nice to have a multi-pass pre-transcoded content if it only used that content on certain devices.
Now, again. I realize this might seem somewhat silly given the much, much higher CPU requirements for a 2 pass encode, and maybe a "slower" (higher quality) setting. But like i said, CPU performance should not be an issue in just a few years, even for multiple transcodes with much higher quality settings.
Also. Does plex use x264 for transcodes? Because if it does, simply having access to the quality profiles they use would be very useful; maybe this is doable right now and i just don't know.
It depends on the format that is appropriate for the particular client, but generally, yes. In the not too distant future the transcode parameters will be a bit more customizable.
Thanks for the quick reply. That's great news! I'm guessing when that happens the clients will get an option for 1080p with lower bitrate than 8 mbits as well.
2021 clean-up: implemented (option to control transcoding quality)
