謝謝大大的回覆。

想請教一下：「流量」，這個東西是在網路上播放時候順輰度的意思嗎？那如果已在放在我的硬碟時，那還會有差嗎？

另外附上 potplayer的影片資訊：

第一個 720x420
General
Format : AVI
Format/Info : Audio Video Interleave
File size : 1.17 GiB
Duration : 1h 59mn
Overall bit rate : 1 404 Kbps
Video #0
ID : 0
Format : MPEG-4 Visual
Format settings, BVOP : 1
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Muxing mode : Packed bitstream
Codec ID : DX50
Codec ID/Hint : DivX 5
Duration : 1h 59mn
Bit rate : 1 200 Kbps
Width : 720 pixels
Height : 420 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.132
Stream size : 1.00 GiB (85%)
Writing library : DivX 6.6.1.4
Audio #1
ID : 1
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Codec ID : 55
Codec ID/Hint : MP3
Duration : 1h 59mn
Bit rate mode : Constant
Bit rate : 192 Kbps
Channel(s) : 2 channels
Sampling rate : 44.1 KHz
Compression mode : Lossy
Delay relative to video : 26ms
Stream size : 164 MiB (14%)
Alignment : Split accross interleaves
Interleave, duration : 33 ms (1.00 video frame)
Title : Audio Stream


第二個 854x480
General
Format : AVI
Format/Info : Audio Video Interleave
File size : 955 MiB
Duration : 1h 59mn
Overall bit rate : 1 116 Kbps
Writing application : MEncoder Sherpya-SVN-r23404-4.2.0
Writing library : MPlayer
Video #0
ID : 0
Format : MPEG-4 Visual
Format profile : Advanced Simple@L5
Format settings, BVOP : 2
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default (H.263)
Codec ID : XVID
Codec ID/Hint : XviD
Duration : 1h 59mn
Bit rate : 974 Kbps
Width : 854 pixels
Height : 480 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.079
Stream size : 833 MiB (87%)
Writing library : XviD 1.1.2 (UTC 2006-11-01)
Audio #1
ID : 1
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Codec ID : 55
Codec ID/Hint : MP3
Duration : 1h 59mn
Bit rate mode : Constant
Bit rate : 128 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Compression mode : Lossy
Delay relative to video : 33ms
Stream size : 109 MiB (11%)
Alignment : Aligned on interleaves
Interleave, duration : 24 ms (0.72 video frame)
Interleave, preload duration : 504 ms
Writing library : LAME3.97