|
|
有个软件叫DRF Analyzer,是用于分析每帧的Q值也就是DRF值,可以给出很详细的报告,DRF的均值越高,质量就越好,当然标准差越小越好
比如:War.of.the.Worlds.2005.EXTENDED.DVDRip.XviD.DTS.INT-BMDRU中CD1的分析报告如下:
DivX DRF Analyzer v0.9.5 Report!
File Name: F:\MOViEZ\DVDRiP.NEW\12.02.05.War.of.the.Worlds.2005.EXTENDED.DVDRip.XviD.DTS.INT-BMDRU\BMDRU-WTW-CD1.avi
FourCC: XVID
Codec: XviD0039
Resolution: [ Width: 704 Height: 384 ]
Frame Rate: 23.976 frames per second
The Video has 56910 frames [ 00:39:33 ]
Average Frame quality is MEDIUM[Average DRF/quantizer is 4.23]
Standard Deviation: Quality is MEDIUM[Std. Deviation is 1.30]
Image Resolution is HIGH
The file has Packeted Frames!
There are NO frame drops ( NO drops is better )
Recomended Resolution: [560x304] (Target DRF/quantizer=2.8)
Performance Caracteristics:
Macroblocks per frame: 1056 ( Poor Playback in Slow Computers, PIII450 or better required )
The Width is multiple of 32
Kilobits per Second: 1641.77
Kilobits per Frame: 68.45
Kilobits per Macroblock: 0.065
Bits per Pixel: 0.26
Frame Type Statistics :
I Frames: 0.98%
P Frames: 61.37%
B Frames: 37.65%
S Frames: 0.00%
N Frames: 0.00%
(More Advanced Codecs use B and S frames)
Frame Quality Statistics :
DRF=1&2:7771.4%
DRF=3:1947834.6%
DRF=4:1644729.2%
DRF=5:802414.2%
DRF=6:757113.4%
DRF=7:40557.2%
DRF=8:00.0%
DRF=9:00.0%
DRF>9:00.0%
KeyF/DeltaF:0.99%
KeyDRF<4:558
KeyDRF=4:0
KeyDRF>4:0
AverageKeyDRF:2.00
MAXDRF:7
AverageDRF:4.23
Deviation:1.30
http://www.geocities.com/analyzerDRF/
从其报告可以看出,此片的平均帧质量为中等,标准差为中等,分辨率为高.因此报告建议:
降低分辨率以提高每帧的质量;提高标准差的方法是控制Q值的分布,尽可能减少较大Q值的帧,由其是I帧和P帧的Q值
当然不能完全依靠这个软件来评价片子的质量,应结合片源质量并用肉眼仔细观察各静态画面和动态画面的质量.
可以通过看SAMPLE和用analyzerDRF结合起来分析,以判断DVDRIP的优劣 |
|
发表于 2007-3-24 10:26:23
