video bitrate

[cL0N31]

suppose i have some vdeo file... i convert the file with divx at 1000kbps bitrate of video... i play the newly created divx video quality and like the quality of it... now again i take the source video file and decide to make mpeg2 file out of it and need the exact or about the same video quality i got in my divx file
quesion: in order to achieve that do i always have to use the same bitrate for mpeg2 as i used for divx? if not give me the chart which explains which mpeg2 bitrates equal to divx bitrates in terms of quality... thank you

[Nelson37]

How many bananas do you need to make an apple pie?

The two types of encoding are totally different, have different abilities, and generally are used to create files for different playback equipment. There is no direct correlation between bitrates used in the different encoders. Using the same bitrate for both will result in a crappy looking MPG, or a DIVX that is much too large.


Roughly 2.5 to three times is generally agreed to be equivalent, but the real answer is "it depends..."

[guns1inger]

There is no direct correlation. Bitrate is determined by space and running time. However the closest to a rule we have is that conversion from Divx to mpeg-2 requires 3 - 4 times the bitrate to maintain similar quality. You usually won't get exactly the same quality because you are re-encoding with a lossy codec, so even more data will be shed, even with a high bitrate, and because usually you have to resize the image back to a DVD compliant resolution. Divx/Xvid also use certain features of PC playback to hide compression artifacts - lower gamma curve, deblocking playback software etc - that you loose when you convert, so all the flaws become much more obvious on your TV.

If you have the original video source then you are better off converting that to mpeg-2 directly, rather than converting to low bitrate Divx first (and depending on the resolution, 1000kbps is a very low bitrate), or getting a Divx capable player so you don;t have to convert it back at all.

[cL0N31]

again thank you very much