Multi-resolution and transcoding

[djotaku 3]

Because I now have Emby, I wanted to try and rip a blu Ray without any transcoding. I can watch it fine on any Ethernet connected computer, but I know I'd buy pushing it with WiFi or power line Ethernet. When I told Emby to transcoded to 720p 1Mb/s the transcoder went to 100% and couldn't keep up.

 

So I have a question about a multi-resolution setup. Let's say I transcoded with handbrake to 720p, but it ends up being 720p 10Mb/s or something else too high. If Emby has to transcode that, is it any less taxing because it's already 720p and is just changing the bit rate?

[Luke 37240]

In theory if the video doesn't have to be scaled, then yes that could help.

[djotaku 3]

OK. I'll give it a shot over the next few days and let you guys know

[dark_slayer 103]

Historically the brunt of work done to transcode a video is in the following order in regards to taxing your cpu

-Changing codec (most taxing)

-Changing bitrate

-Changing framesize

-Changing container aka muxing (least taxing)

 

Then there is a little bit of Tom foolery that gets introduced by the combination of audio and video in a single file. For a two hour long movie, the video portion is usually 10x as large as the audio portion, and by comparison transcoding hd audio to another codec may likely take less resource than resizing every frame.

 

Any thing that can be offloaded will lower your overall usage, that being said if you are starting with a high quality 720p encode and needing it trans-rated down to 1Mbps you'll still see a hefty tax. I doubt you'll shave even 10% off with a simple frame size adjustment, but I'd be interested to see your findings. I used to do a lot of comparison tests like this, so everything above is a mixture of those results and guessing ... Not to be taken as end all knowledge on the subject (which I don't happen to possess)

[djotaku 3]

Sorry it has taken me so long to get back. Been busy. Anyway, in general when I create a 720p version and provide that using the directory structure expected by Emby, it tends to work. On some computers that's probably going to be OK as-is and on others it may need a slight bit of bit-rate changing. My current setup is really pushing the requirements of Emby - an older DualCore processor and I think my VM only has 1 or 1.5GB of RAM allocated to it. I look forward to upgrading it at some point.