Carpenter01 wrote:I dont have this problem, even on youtube, it has almost perfect quality.
http://www.youtube.com/watch?v=ZZmHM8fFxPU
I can barely notice the difference between the raw video, and the rendered MP4.
Are you kidding?
And that's 1080p downscaled to 1366x768 (I'm too lazy to download full video to make fullsize screenshot). Everything is blocky and blurry as hell.
Nielo TM wrote:GPU video encoding is much faster than CPU encoding
proof?
http://compression.ru/video/codec_compa ... arison.pdf starting from page 99.
x264 with "ultrafast2" preset is fastest there. "superfast 1-pass" has same speed and quality that Intel QS encoder.
And CUDA is even slower and has even worse quality...
And imagine speed of 6-core intel CPU
Nielo TM wrote:and has the ability to provide higher efficacy.
In video encoding "efficiency" is quality/bitrate. Hardware encoders are worst here, since software encoders could provide same quality at much (2x-4x) smaller bitrates.
Nielo TM wrote:But it's not easy developing software to run on parallel processors.
It's not the main problem. The main problem is GPU's architecture which is very ineffective for any compression.
In short: GPU has a lot of cores, that could do only one simple task with different data. E.g. multiplication of hundreds of matrices. But that's not what video encoding requires! For adequate quality it should use complex algorithms that GPU's couldn't run effectively because of its architecture. So only very basic algorithms are avaivable for GPU, that results in low quality. And there is not much to do with that.
GPU is like factory with thousand of stupid workers. That do everything using only their hands, they can't do complex task and they all can be trained to do only one task. So product quality is low. But since there are thousand of them - productivity is high.
CPU is like factory with 4-10 robots. They can do any task, than can work wery fast and with very high precision. So they can produce same product with the same low quality with the same productivity OR high-quality product with much lower productivity.
Still h/w is ok for encoding video for portable devices, but it shouldn't be used for final video encoding for video distribution (It is just disrespecting people that would download your video).
E.g. youtube use it for encoding their video. Now you now why they has such horrible quality
And they are developing WebM, that has even lower quality at even bigger bitrate (I've tested couple months ago - for same video WebM version has +30% bitrate and lower quality).
On the other hand check vimeo... On the same video it has -20% bitrate and has much better quality.
But one of x264 dev's (DS) works with intel (but because of NDA he can't say much) and they are improving intel QuickSync hardware (= new chips, not software), so in future intel CPU's it should be a lot better (but still far from x264).