| Author |
Message |
homepc
Guest
|
 Posted:
Sat Sep 25, 2004 10:00 pm Post subject:
virtual dub question |
|
|
I used virtual dub to reencode an XviD vbr avi that had qpel coding. I used
DivX compression and 2 passes for the video.
My question is, what is the difference between 1 and 2 passes? The 1st and
2nd pass appear to be identical. I used the 2nd pass to add a cbr audio and
it worked fine. But I am not too thrilled about the video quality. Static
views are good, but views with lots of motion are blocky.
Does anyone have an tricks I should be aware of?
|
|
| Back to top |
|
 |
Jason Sperry
Guest
|
| Posted:
Sun Sep 26, 2004 7:52 am Post subject:
Re: virtual dub question |
|
|
On Sat, 25 Sep 2004 13:00:59 -0500, homepc wrote:
| Quote: | I used virtual dub to reencode an XviD vbr avi that had qpel coding. I used
DivX compression and 2 passes for the video.
My question is, what is the difference between 1 and 2 passes? The 1st and
2nd pass appear to be identical.
|
2 passes give you something that you could call a better quantizer
distribution.
| Quote: | I used the 2nd pass to add a cbr audio and
it worked fine. But I am not too thrilled about the video quality. Static
views are good, but views with lots of motion are blocky.
Does anyone have an tricks I should be aware of?
|
Try increasing the bitrate. 75% of the bitrate you get after doing the
first pass will usually gives you good results.
Another possibility why you get blocky artifacts is because your computer
isn't fast enough to process all the frames during playback. I had the same
thing when dealing with HDTV capture (1280x720 resolution). Installing
ffdshow fixed that problem. |
|
| Back to top |
|
|
homepc
Guest
|
| Posted:
Sun Sep 26, 2004 10:33 pm Post subject:
Re: virtual dub question |
|
|
When I reencode audio I need to decompress the audio to wave and then
compress it again while making the new avi file. Does this apply to video
as well? Do I have to decompress the video and then compress it again, or
does virtual dub do this on the fly during the 2 passes?
"Jason Sperry" <jsperry@yahoo.com> wrote in message
news:1oqpqps1mrzk3.1hzwsponrwuru$.dlg@40tude.net...
| Quote: | On Sat, 25 Sep 2004 13:00:59 -0500, homepc wrote:
I used virtual dub to reencode an XviD vbr avi that had qpel coding. I
used
DivX compression and 2 passes for the video.
My question is, what is the difference between 1 and 2 passes? The 1st
and
2nd pass appear to be identical.
2 passes give you something that you could call a better quantizer
distribution.
I used the 2nd pass to add a cbr audio and
it worked fine. But I am not too thrilled about the video quality.
Static
views are good, but views with lots of motion are blocky.
Does anyone have an tricks I should be aware of?
Try increasing the bitrate. 75% of the bitrate you get after doing the
first pass will usually gives you good results.
Another possibility why you get blocky artifacts is because your computer
isn't fast enough to process all the frames during playback. I had the
same
thing when dealing with HDTV capture (1280x720 resolution). Installing
ffdshow fixed that problem. |
|
|
| Back to top |
|
|
|
|
|
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in