Question / Help Why does NVENC look so bad / why is there no true high quality option for it?

[yongyung]

Hey guys, I like to encode with NVENC, since my GPU is usually not as stressed as my CPU. Just comparing the presets on local recordings, lossless looks great, high quality with a ridiculous bitrate like 64M looks great, but everything below that just not so much. Even 16M looks basically worse than shrouds stream (twitch.tv/meclipse), even though he is streaming with a far lesser bit rate (3.5M, but using the x264 CPU encoder with medium preset).

Am I doing something wrong? Why is there no option that achieves a good compression ratio for NVENC?

 

[Cryonic]

Because the NVenc is not capable of giving you the same quality what x264 with a powerful CPU can achieve.
Deal with it, it is great at high bitrates, but at low bitrates suitable for streaming, x264 is the way to go.
Need more oomph? Get a 6-8core i7 or Xeon and be happy. Or build a second PC, for encoding only, with the same i7 or Xeon starting with 6 cores. Expensive, but thats the best you can get right now.

 

[yongyung]

>Because the NVenc is not capable of giving you the same quality what x264 with a powerful CPU can achieve.

Why? There aren't any custom encoding limitations API wise that I'm aware of.

 

[Cryonic]

It is a simple hardware limit and cant be avoided so far.
Forget about VCE, Quicksync or NVenc if you want quality and low bitrate at the same time, thats it.

 

[yongyung]

>It is a simple hardware limit and cant be avoided so far.

Can you provide a source on that? As far as I know NVENC just uses the programmable pipeline to encode the video stream, so there shouldn't be any hardware limits except for performance.

Edit: According to this https://a248.e.akamai.net/f/248/10/...10c&file=NVENC_VideoEncoder_API_ProgGuide.pdf and "2.7.2.2 Coarse Control by overriding Preset Parameters" you can override the preset parameters...

 

[Cryonic]

Well you see how it works here. You can tweak it, but believe when people actually tell you that all hardware encoders will look like poop compared to x264 at lower bitrates (3500 and below, thats what is common across most streaming sites).
This stuff is designed to allow people with crappy machines to stream or do local recording without hitting the CPU with a hammer. But for quality - use the CPU and thats your only option so far.