Pixelation in animation movie

[socrates]

hi,

I have an animation movie in mkv format which comes to around 4.3 GB. As usual I tried to re-encode it to avi (xvid + ac3) using my trusted software TEncoder. When I did calculations with bitrate calculator, it suggested a video bitrate of 1780 to make avi of 1.6 GB. After the re-encoding process, the video showed too much pixelation. I re-encoded it with bit rate or 2450, the pixelation reduced substantially.
How can we know animation movie bit-rate, which is higher than regular ones? Is there any tool to calculate it or any special tool for its conversion? I use Win 7 64bit and in the past have had tried Avidemux, MeGUI etc but none seems to work except TEncoder. Someone in this site suggested it as incompatibility of Mencoder and Win 7 64bit. So I need suggestions to modify or add on to TEncoder please.
Thanks in advance

[enim]

I re-encoded it with bit rate or 2450, the pixelation reduced substantially.

We, my self and other members willing to help are still thinking, or guessing to be more precise that how your pixels or pixelation look like. Would you like to help us? When it comes to "think", I am all out bcoz it may require brain, i guess. Isn't it?

[manono]

When I did calculations with bitrate calculator, it suggested a video bitrate of 1780 to make avi of 1.6 GB.

It suggested? It only spits out a bitrate after you fill in the variables (length and file size). Apparently your requirements resulted in a bitrate too low for the video to be encoded in decent quality. Do something like lower the resolution or raise the filesize. Or, better yet, just do a quant 2 or 3 encode and let the filesize become whatever it has to for the quality you want. Or, best of all, if your player supports it do it for x264 video which will give you significantly better quality for that same filesize.

You were just asking for trouble anyway by shrinking the size nearly 60% (can't be more precise as I don't know the movie length or the audio bitrate), and using a codec that doesn't compress nearly as well as does the source video's codec.

How can we know animation movie bit-rate, which is higher than regular ones?

Like I said, you're using an outdated codec (XviD). But if you insist on using it, do a 1-pass quality-based quant encode. That's how you learn the bitrate needed for the quality you want. Since animation videos show mosquito noise pretty quickly, there's no reason to think the bitrate needed is less or even the same as for live-action movies.

[socrates]

hi,
thanks enim and manono for the suggestions