Mpeg 2 bitrates

[doot]

Hi, I was just wondering what other people thought of the bitrates that mpeg 2 was in relation to DivX/Xvid. Like if I have an Divx at 1200Kbs whats the highest Mpeg 2 bitrate I can go with it. There must be a point where its not worth to go too high as I wouldn`t see any improvment in the out put.

I guess I`m looking for a comparison table of the most used encoders and their bitrates for the same quality in video.

Thanks

[aamir12345678]

Divx uses at least 4 times better compression than mpeg2 DVD. If it is a clean source, I would simply convert the resolution (640x480 Divx = 720x480 DVD) and multiply the bitrate by about 4.5. I would go with an average of 5400. Later.

[mmasw]

Divx uses at least 4 times better compression than mpeg2 DVD. If it is a clean source, I would simply convert the resolution (640x480 Divx = 720x480 DVD) and multiply the bitrate by about 4.5. I would go with an average of 5400. Later.

well, if I agreed with this I probably wouldn't say anything....but obviously I don't agree.

First of all, the notion that this supposed 4:1 compression ratio has any controlling relevance is ludicrous. There are literally millions of DivX videos floating around and there was no consistency to their creation or purpose. The only information Doot gave was 1200Kbs as bitrate. His Divx file could be a 5 year old DivX3.11 Alpha file. And it could be in some PAL resolution derivative with a non-standard framerate.

For what it's worth, I've converted quite a few DivX files to MPG2 and while I don't have unbreakable rules in the method, I do have some observations from experience.

For Instance....if the resolution of your DivX file is 352 X 240, I don't see much advantage in increasing that resolution. I'd leave it at that; it's a dvd-compliant resolution. I generally play my dvd's on a 32" Sony with 'hdtv' capability, and I can almost never see a difference between 352 X 240 or 720 X 480.....it tends to 'play' the same.

Mainly, the quality of the Divx should control your choices. If it's average quality, I'm willing to bet you'd be hard pressed to see a difference between a conversion to 352 X 240 @ 1500Kbs compared to 720 X 480 @ 5400Kbs. There is just not enough data in your source file to warrant that high a converted bitrate.

Simply Doot, there are far too many subjective factors. You need to instruct yourself on whats best. What I would do is this: use VDub to create a 1 minute sample video from your file. Splice in some high motion and some light and color transitions. Then create some test MPG's with different bitrates and resoulutions. Then author them to a RW disc so YOU can judge what is best.

As far as encoders, I'm partial to TMPGEnc because it seems quite stable and I like it's filters. I also am familiar with frameserving to it thru VDub, which is sometimes quite handy when converting some of these newer AVI files.

[doot]

Divx uses at least 4 times better compression than mpeg2 DVD. If it is a clean source, I would simply convert the resolution (640x480 Divx = 720x480 DVD) and multiply the bitrate by about 4.5. I would go with an average of 5400. Later.

If I go with 5400 I wouldn`t be able to get the whole 113 mins on 1 dvdr, and yes it is quite clean. for a divx.



Thanks for the info mmasw, i`ll have to try a test mpg. All I gotta do now is find a cheaper RW dvd. As for the one made it freezes playing at certain times but if you skip a frame it will carry on. Plays ok in my DVD rom drive so its not the DVD, guess my player didn`t like the TDK disc.

But apart from the freezing I am pleased how I converted a NTSC avi to PAL with AC3, I just with that Tmpenc wasen`t so slow.

Doot

[duhmez]

Anothr issue, surprisingly, the WORSE the quality of the divx file, the more bitrate it;s gonna need to not get MORE WORSE. Bad quality has alot of noise and needs more bitrate when transcoded not to suffer.
If it;s 113 min video and high res, keep it highres and ive it all the bitrate to fill the disk.

[aamir12345678]

mmasw, I assumed from the bitrate he gave me of his Divx (1200 kb/s) that it was high-quality. I did say to confirm that it is a clean source. I DID ASSUME. SHOOT ME!!!

[jimmalenko]

mmasw, I assumed from the bitrate he gave me of his Divx (1200 kb/s) that it was high-quality. I did say to confirm that it is a clean source. I DID ASSUME. SHOOT ME!!!

[aamir12345678]

You never stop being "A Jackass."

[jimmalenko]

You never stop being "A Jackass."

ease up, my pakistani friend.