Speex vs Nellymoser 비교

 

 라이센스 타입  Nellymoser는 정형화되어있는 코덱입니다. 거기에 반해 Speex는 오픈소스 입니다. 그 말인 즉, Speex는 라이센스 제약없이 인코딩, 디코딩 할 수가 있습니다.

 Nellymoser is closed format codec whereas Speex is opensource which means that files created using speex can be decoded or encoded without any licence requirement.

 Flash Player 요구사항  Nellymoser는 Flash player 6이상 지원하지만, Speex는 Flash Player 10버전을 필요로 합니다. 10버전에서는 Speex 지원은 하지만 잡음이 발생하는 버그가 있었지만, 버전 10.0.22.87 에서 버그 수정되었습니다.

Nellymoser works from Flash player 6 onwards whereas Speex requires atleast Flash Player 10. Although speex works with flash player 10 but there is a audio disturbance bug on listener end which was fixed in version 10,0,22,87.So player 10,0,22,87 and above is recommended.

 음질

 Speex는 음성에 최적화 되어있습니다. Nellymoser과 비교했을 시 좀 더 좋은 음질을 기대할 수 있습니다.

Speex is optimised for speech so better quality is expected from speex as compared to our old Nellymoser codec.

 대역폭 요구사항

 Speex는 Nellymoser보다 좀 더 작은 대역폭으로 좀 더 나은 음질을 제공합니다

Speex delivers better quality than Nellymoser using less bandwidth as compared to speex.our tests revealed that the quality with nellymoser becomes usable at 8(16kbps) where as in case of speex it is 3 (9.80 kbps).The highest quality in Speex uses 42.2 kbps thats half of the bandwidth being used by nellymoser which is 88.2

 인코딩 음질  Speex는 11 Level의 quality를 제공해주고 있습니다.(0~10).  0이 최저음질이고 10이 최고음질입니다. Nellymoser는 5가지 종류로 음질을 Setting 할 수 있습니다. (5, 8, 11, 22, 44).  5가 최저음질이고 44가 최고음질입니다. 

* 좀 더 나은 음질에는 더 많은 대역폭을 필요로 합니다. 이는 대역폭이 충분하지 않을 때 소리울렁임(choppy sound)을 야기합니다.

 Speex provides more flexibilityby giving 11 levels of quality to choose from (0-10).0 is lowest and 10 is highest audio quality. Nellymoser gives 5 settings(5,8,11,22,44) ,5 is lowest and 44 is highest quality.Remember more is the quality higher is the bandwidth requirement which may lead to choppy sound when sufficient bandwidth is not available

 

 

Speex Nellymoser
Quality (encodeQuality) Required bandwidth in kbps Quality(mic.rate) Required bandwidth in kbps
0 3.95 5 11.025
1 5.75 8 16
2 7.75 11 22.05
3 9.80 22 44.1
4 12.8 44 88.2
5 16.8    
6 20.6    
7 23.8    
8 27.8    
9 34.2    
10 42.2    

 

 

Speex Quality , Bandwidth and filesize table
Quality (encodeQuality) Required bandwidth in kbps Per minute file size in KB
0 3.95 28.9
1 5.75 42.1
2 7.75 56.7
3 9.80 71.7
4 12.8 93.7
5 16.8 123.0
6 20.6 150.8
7 23.8 174.3
8 27.8 203.6
9 34.2 250.4
10 42.2 309.0

Test and Results: The encodeQuality for speex codec becomes quite usable from 4 (12.8kbps) although 3 can also be used for very low bandwidth requirements.It was also noticed that almost no processor overhead was there.So this codec will not add any load to applications requiring heavy processor.

 

*source : http://askmeflash.com/article/2/speex-vs-nellymoser

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