Linked by Brooss on Tue 15th Mar 2011 23:32 UTC
Benchmarks A comment on the recent article about the Bali release of Googles WebM tools (libvpx) claimed that one of the biggest problems facing the adoption of WebM video was the slow speed of the encoder as compared to x264. This article sets out to benchmark the encoder against x264 to see if this is indeed true and if so, how significant the speed difference really is.
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RE[2]: Nice
by galvanash on Wed 16th Mar 2011 23:32 UTC in reply to "RE: Nice"
galvanash
Member since:
2006-01-25

Same setup, only change is the source is 1280x720 and the bitrate is set to 2000.

x264

Commandline: x264.exe -o sintel_trailer_2k_720p24.mp4 sintel_trailer_2k_720p24.y4m --profile baseline -B 2000 --preset slow --threads 1 --psnr

Avg PSNR: 53.647
FPS: 7.23
Filesize: 10702KB
Actual Bitrate: 1678.26Kbps

webm

Commandline: vpxenc.exe -o sintel_trailer_2k_720p24.webm sintel_trailer_2k_720p24.y4m --good --cpu-used=0 --target-bitrate=2000 --end-usage=0 -p 1 --psnr

Avg PSNR: 52.067
FPS: 3.35
Filesize: 10118KB
Actual Bitrate: 1548.36Kbps

Conclusion

Encoding speed relative to x264 stays about the same (this is much better than previous versions of webm at this resolution). Quality is a mixed bag. Webm looks much better during low motion scenes (detail is higher), but suffers during high motion (smearing). Overall quality is about the same imo.

Ill do a full battery of tests offline (multi-threaded too) and put a comparison together with graphs and links to the output files. Will probably take me a few days.

Reply Parent Score: 2

RE[3]: Nice
by lemur2 on Thu 17th Mar 2011 01:27 in reply to "RE[2]: Nice"
lemur2 Member since:
2007-02-17

Quality is a mixed bag. Webm looks much better during low motion scenes (detail is higher), but suffers during high motion (smearing). Overall quality is about the same imo.


When people see high motion in real life, they actually perceive it as a blur. It is perhaps a mistake to demerit WebM for having this characteristic.

When h264 videos have to make compromises on quality per bit, which happens in high motion scenes, the compressed video exhibits artefacts ... little extraneous bits that aren't there in the original scene. The human eye doesn't do anything similar when people are looking at scenes real life.

Just saying.

Edited 2011-03-17 01:28 UTC

Reply Parent Score: 2

RE[4]: Nice
by galvanash on Thu 17th Mar 2011 01:33 in reply to "RE[3]: Nice"
galvanash Member since:
2006-01-25

To my eye the smearing/blurring looked worse in this particular example, and the artifacts you speak of that x264 often generates were barely visible. I have seen examples that fall in line with what you speak of and I also find webm often looks better, but in this case it didn't. I'm just trying to be as fair as possible.

Reply Parent Score: 2