Reducing Bitrate of avi's, is killing me !!

[computerB]

i have a HD full of avi movies, many of which are too high in bitrate,
for you see, i have a divx compatible stand alone player., that only handles, files @ 800kbps or less, the ones that are higher skip, and cause a lot of stress.

i have been attempting to encode, a number of videos, with a lower bitrate, using AviRecomp, VDub, VdubMOD, etc, and the result is always really crapp, for instance today, i finished encoding a 1.4GB avi, with a bitrate of 2400kbps, to an avi with 700kbps, which ended up making a 380mb file, which is understandibly terrible quality..

So PPLLLLEASE can you tell me how to create high quality encodes at low bitrates, ie, most widescreen dvd rips, are around 2 hours, with a bitrate of around 700k, and they look crisp, smooth, etc...

PLZZ, ive spent weeks googling and searching the main forumss hehe

MY hand hurt, from sitting on the comp all day... :eek:

[Didée]

Rule of thumb: halving the bitrate quarters the quality. So, for 2400 -> 800 kbps you can expect (800/2400)^2 = 0.111... , meaning if the 2400 kbps source is "100% visual quality", then the reencoded 800 kbps one will be low as 11% visual quality :)

I have my severe doubts that your sources were legally obtained.

[computerB]

"I have my severe doubts that your sources were legally obtained." ??

is there anyway, to lower the bitrate without halving the size ?
ie, if a 700mb avi, is 1700kbps, instead of halving the bitrate, as ive been doing, and ending up with a 400mb file, is it possible to make larger file, saving some quality. or does it all depend on the bitrate.. ??

[CWR03]

So PPLLLLEASE can you tell me how to create high quality encodes at low bitrates, ie, most widescreen dvd rips, are around 2 hours, with a bitrate of around 700k, and they look crisp, smooth, etc...
We'd be glad to help you re-encode your DVD's at a high quality/low enough bitrate for your standalone player. If you don't have the DVD's, you have illegally obtained copyrighted material. It may be time to re-read the forum rules (http://forum.doom9.org/forum-rules.htm).

[computerB]

will doing 2pass encodes, result in better quality ???
because im getting errors, when trying 2 passes

[CWR03]

Perhaps you should try something simpler, like AutoGK. After you've ripped a DVD and loaded it into AutoGK, use the figures Didée gave you to determine your output size.

[computerB]

as far as i have seen, AutoGK only had 1cd, 2cd, etc as sizes, i didnt see any bitrate input, etc etc. besides, it conflicted with other software so i had to remove it, i was rather keen on Vdub, and the like.

Perhaps, you guys can clear up the VBR "Variable Bitrate" issue, does Xvid use this method ? because in s=my encodes, the more detailed and faster scenes look slightly worse.. any further help is well appreciated

and as for legality issue, which is laughable, these vids, if you must know are from membership sites, and divx on demand, and so forth. i havent broken any laws.

[computerB]

Oh just remembered, if a movie is in DivX3-Low Motion, will encoding it to Xvid, (leaving the filesize and BR the same) result in slightly jerky picture /. ? or any problems ?.. :cool: :cool:

[CWR03]

and as for legality issue, which is laughable, these vids, if you must know are from membership sites, and divx on demand, and so forth. i havent broken any laws.
You yourself referred to DVD sources which you do not own, which is what made your comments suspect.

As far as VBR goes, any 2-pass MPEG-4 encode, whether it's DivX, XviD or x.264, is variable bitrate. Using a single-pass fixed bitrate will always result in blocky video and artifacts unless you use a really high bitrate. A quick description as to how MPEG-4 works: one compression factor is grouping areas of like color together so instead of each pixel having its own color definition, a group of hundreds may share the same color. Another is "replacing" the picture: if the subsequent frame hasn't changed except for a small area of motion, then only the changed portion of video gets new data; the rest is kept. The third is where VBR comes into play: in constant bitrate, each frame gets roughly the same bitrate. If the scene changes a lot, like with a camera pan, in order to save space the video pixels are enlarged. Do a freeze-frame in a long camera pan and you may see only a few hundred individual blocks, where the aspect of the frame would normally be a half-million or so pixels. With VBR the scenes with little or no movement get less bitrate since they require less, and the faster scenes are encoded with a higher bitrate to preserve detail.

Re-encoding from DivX3-Low Motion to XviD shouldn't result in jerky playback, as long as you don't alter the framerate. You will lose some quality, since both are lossy conversions.

[computerB]

just watching an encode now, to see the results, only problem is flat colors, being pixelated, i guess the hallmark of a low bitrate, but is there a way to minimize or remove this ?? ie filter, or specific frames with a higher bitrate etc...

any help {?}

[Teegedeck]

Radically reduce resolution. Like halfing it. And the worse your source is (usually on-demand-video is not well-encoded, I hear) the worse it reacts to recompression. No wonders to be expected here, it'll never look exactly good.

[computerB]

ive been looking at Nandub, and i see things like BR curve, and a lot of other options, which i have no idea what effect they have on a video, maybe one of you guys, has experience with it,

[computerB]

also, does 10mbps (max. bitrate on dvd player) equate to about 1000kbps ?

[Teegedeck]

No, more like 10,000 kbps.

[manono]

as far as i have seen, AutoGK only had 1cd, 2cd, etc as sizes, i didnt see any bitrate input, etc etc. besides, it conflicted with other software so i had to remove it, i was rather keen on Vdub, and the like.

It shouldn't conflict with anything. Anyway, I'm with CWR03 in recommending AutoGK. You can make it for any size you like, and not just 1 CD, 2 CD, etc. (Hint: tick the Custom Size box). You're correct in that you can't fill in the bitrate, just the file size. If you need to know the bitrate you'll get for a given file size and file length, well, that's what a bitrate calculator is for. If your player can handle ave bitrates of only up to 800, I suggest you get another player, as most can handle much more than that. You say that you'd prefer to use VDub, but AutoGK uses VDubMod, and it'll make the hard choices for you (such as choosing the resolution). Judging from your statements and questions, you're not quite ready to do the whole thing yourself. For example:

also, does 10mbps (max. bitrate on dvd player) equate to about 1000kbps ?

No.