Электроника

 
15 | 12 | 2018

In order to compare the Motion Wavelets Codec with others the example movie stream was compressed by Motion Wavelets Codec as well as by the latest DivX Pro5 codec and Microsoft Media Codec V.8.

 

1. Method of comparison

To have numerical estimation of the quality of each codec the compressed files were decompressed back to the uncompressed format (RGB24 bit color space) by using the decoding drivers of DivX Pro5 and Microsoft Media Codecs. Next, the original uncompressed AVI file (having no artifacts) was compared to the restored files (including coding artifacts). The mean Peak Signal to Noise Ratio (PSNR) was calculated as the measure of the difference between two video files.

Next screen short shows how typically the original and restored files were processed by PSNR checking software. The original movie is shown at the left window, the restored movie is shown at the right window, while the bottom window displays the difference of luminance between two files and the values of PSNR. The PSNR is measured in dB (higher value corresponds to better quality).

2. The results are summaries in the next tables

A. MotionWavelet vs. DivXPro5 at low bitrate (450kbps)

1. Given bitrate (equal file size):

Codec Name

FileSize

PSNR [dB]

Gain in PSNR

Motion Wavelets

3535 KB

37.07

 

DivXPro5

3550 KB

36.31

-0.76 dB

2. Given PSNR (equal quality):

Codec Name

FileSize

PSNR [dB]

Gain in file size

Motion Wavelets

3535 KB

37.07

-32%

DivxPro5

4672 KB

37.05

 

B. MotionWavelet vs. DivXPro5 at typical bitrate (600kbps)

1. Given bitrate (equal file size):

Codec Name

FileSize

PSNR [dB]

Gain in PSNR

Motion Wavelets

5126 KB

38.33

 

DivXPro5

5432 KB (*)

37.10

-1.23 dB

DivXPro5

4898 KB (*)

36.90

-1.42 dB

(*) two nearest values of file size

2. Given PSNR (equal quality):

Codec Name

FileSize

PSNR [dB]

Gain in file size

Motion Wavelets

5126 KB

38.33

-39 %

DivXPro5

7108 KB

37.63 (**)

 

(**) the highest value of file size and PSNR obtained for DivXPro5

C. MotionWavelet vs. Microsoft Media Codec V.8 at low bitrate (450kbps)

1. Given bitrate (equal file size):

Codec Name

FileSize

PSNR [dB]

Gain in PSNR

Motion Wavelets

3535 KB

37.07

 

V.8

3276 KB(*)

35.78

-1.29 dB

V.8

3830 KB(*)

37.01

-0.06 dB

(*) two nearest values of file size

2. Given PSNR (equal quality):

Codec Name

FileSize

PSNR [dB]

Gain in file size

Motion Wavelets

3535 KB

37.07

-8%

V.8

3830 KB

37.01

 

D. MotionWavelet vs. Microsoft Media Codec V.8 at typical bitrate (600kbps)

1. Given bitrate (equal file size):

Codec Name

FileSize

PSNR [dB]

Gain in PSNR

Motion Wavelets

5126 KB

38.33

-0.55 dB

V.8

5956 KB (*)

38.88

 

(*) nearest value of file size

2. Given PSNR (equal quality):

Codec Name

FileSize

PSNR [dB]

Gain in file size

Motion Wavelets

5126 KB

38.33

-16 %

V.8

5956 KB

38.88 (*)

 

(*) nearest value of the quality

3. Conclusions

It can be concluded that Motion Wavelets Codec outperforms DivXPro5 codec, providing more than 40% less file size under the same quality at normal bitrates (when artifacts become small and video has good quality). Motion Wavelets Codec outperforms Microsoft Media Codec V.8 codec providing about 10-15% less file size under the same quality.