MiniDV to Xvid - best setting (bitrate etc)?

[Xad]

What would be the best setting to use for xvid in terms of bitrate (and anything else) in order to keep the encoded video quality as close to the original quality as possible?

I've been playing around with settings and at first set it to 640 x 480 and bitrate to around 2300 (in order to fully use up dvdr). The quality is excellent, but i'm wondering is that setting good to use? Can i go higher? Or should i think about going lower? I've read one thread where one person mentioned they use 1500kb but i was hoping to get more peoples views. I've noticed that using the high bitrate i used uses a lot of cpu power.

So what is the best bitrate setting to use with xvid in order to keep the final video as close to the same quality as the original MiniDV video?

Thanks

[jimmalenko]

There is no universal "best" - the best is what gives you the results you desire.

Many here advocate the use of CQ mode set at 2 or 3, which is like a one-pass VBR that should be nice and quick and give you pretty good quality. It will only use as much bitrate as it needs, so it probably won't fill up the disc.

[Xad]

Is this the CQ mode you mention:

?

Also, this method doesn't give any pixelating/artifacts does it? Similar to that you get when you use to low of a bitrate?

[jimmalenko]

A setting of 1 or 2 shouldn't give any pixelation whatsoever. You'd really need to do some short sample encodes yourself using 1 through to about 5 to see where your threshold of quality sits.

[junkmalle]

Is this the CQ mode you mention?

yes, Quantization mode is constant quality.

Also, this method doesn't give any pixelating/artifacts does it? Similar to that you get when you use to low of a bitrate?

At a quantization value of 2 you have to look at enlarged still frames to see any difference between the input and output. At 3 you can see a little macroblocking if you look at still frames but it's not really noticable at normal playback speeds. At 4 you start to notice macroblocks at normal playback speeds if you look very closely. 1 is the best quality setting -- but the file will be comparable in size to your source DV.

No matter what Q value you use, final output size (average bitrate) will depend on the content. Although obviously, for a given source the file size will get larger as Q gets smaller.

[Xad]

nice one, thanks for the help guys

[Xad]

It shows that the average bitrate is around 4700kb if i set it to quantization value of 2 - is that normal?

[junkmalle]

It shows that the average bitrate is around 4700kb if i set it to quantization value of 2 - is that normal?

Yes. It can vary pretty widely depending on the source. Anywhere from around 1000 to 6000 kbps. Noisy video doesn't compress well. Shakey hand-held video doesn't either.

But say for example you used a Q value of 4 and get a 2000 kbps result. Then you encode the same video using 2-pass VBR with an average of 2000 kbps. The two encoded videos will be almost identical.

[Xad]

Sorry to bump this topic, but just wanted to know, what resolution does everyone use for there MiniDV to Xvid conversions?

I used 640x480 but i was thinking about leaving it as close to the original resolution which is something like 720x??? or something i think - or is this a bad thing in terms of optimisation/image quality?

What does everyone else use?

[junkmalle]

Newer versions of Xvid support picture aspect ratio settings so you could leave your video at 720x480 and set the picture aspect ratio to 4:3. But not all software and hardware support that so I usually resize to 640x480. Sometimes 480x360 or even 320x240 for low quality stuff.