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| twoolfe |
| Posted: Aug 23 2002, 09:58 AM |
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I run an AbitKT7, 825 Athlon with a Ati all in wonder 138AGP
video card & latest Ati drivers, 383meg RAM plenty of spare disk room.
operating system was Win2Kpro service pak 2.
I have been having fantastic results with V D running MP4 v2 with
a very good compresson rate. An example a 25 min episode of Detective
Sherlock Holmes running slightly over 90 megs.
Sunday last, my computer whiz eldest {age39} said "Dad, SP3 is out you
really should upgrade". I should know when it's running right don't
screw with it, But..
With no other changes than the SP3 upgrade, my compression rate has
dropped to 1:13:1 or so if I'm lucky and that 90 meg file ballooned
to nearly 500 meg. this is with the same source, my vcr plying the
identical tape. If I capture with no compression and try to dub
intenally to the MP4 v2 I get roughly the same results.
Any suggestions would be appreciated, it's un usable like this. I
really really don't want to do a complete reinstall to get the system
useable again.
J W Hey Carson Ca  |
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| ProfDrMorph |
| Posted: Aug 23 2002, 04:03 PM |
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open the configuration window of the codec ( there's a button to do this when you have the codec/compression list in front of you ) and lower the bitrate to about 20% of it's current value.
The higher the bitrate is, the more bits the codec will use per second and thus the file will become bigger and be of higher quality.
90mb for 25mins... either you get a lot of blocks or you use a low resolution.
I recommend you upgrade to DivX5 (Standard version is enough) since it should compress more efficiently ( better quality at the same bitrate ) than MP4v2. |
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| twoolfe |
 Posted: Aug 23 2002, 04:15 PM |
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it's the same bitrate I was previously running slider set midrange 3K
the divx 5 codex gives me aprox the same sized file around 400meg
The only changes that could affect anything was the change from service pak 2 to service pak 3 |
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| ProfDrMorph |
| Posted: Aug 24 2002, 09:59 AM |
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maybe you forgot audio compression |
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| twoolfe |
| Posted: Aug 24 2002, 03:24 PM |
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OK here are the figures before {ch7} and after {ch8} both aprox 24:30 long. I took this off the file information on VD.
Ch7 before the upgrade SP2 to SP3
320x240 15fps 22052 frames MSmpeg-4 v2
445 key
1262/8883/16853 {3861K} Key frame
0/3795/17650 {80091K} Delta frame
Audio 11025Hz mono
FILE SIZE 102,952,960
Ch 8 after the upgrade
320x240 15fps 22046frames MSmpeg-4 v2
363 key
2127/9180/19400 {3255K} Key Frame
979/14825/36459 {313930K} Delta frame
Audio 11025Hz mono
FILE SIZE 342,102,016
I can see what is happining but not why or what to do to correct it. My settings are the same for both as is the hardware. Only the service pack was changed.
I have no idea what I'm doing here as I'm a video dummy and am just trying to either save my old tape or do a CD for the grandkids computer.
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| ProfDrMorph |
| Posted: Aug 24 2002, 03:44 PM |
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could you please post your capture settings like compression and so on? |
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| twoolfe |
| Posted: Aug 24 2002, 04:41 PM |
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Settings in VD compression for capture
mpg=4 v2 key every 8 sec
compression 75
datarate 3000 all default settings
audio 11.024 Khz 8bit mono
Source tuner ATI all in wonder 128 AGP
fed from VHS tape at SP rate
Observed Compression starts at 241:1 w/black screen
by 30 sec of film drops to aprox 11.9:1
by 1 min stablises around 10.3:1
This in a test just finished. on the same tape.
In pre upgrade captures it was running around 30:1 or so as I remember I really wasn't watching at the time, just smiling as the system ran. |
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| ProfDrMorph |
| Posted: Aug 25 2002, 09:06 AM |
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try lowering your datarate to 450 |
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| twoolfe |
| Posted: Aug 25 2002, 02:20 PM |
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{headskritches} That brought it down. I'm sorry to seem so stupid but could you tell me what happened there. As far as I know 3K was the setting that was in there before the SPchange. where were all those delta frames comeing from?
I rather like to know what this machine is doing.
Thanks
J W Hey  |
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| ProfDrMorph |
| Posted: Aug 25 2002, 04:42 PM |
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Either the datarate was at 300-450 or there was a bug in the codec that caused the codec to use another bitrate than the one you specified before you installed the new SP.
Datarate ( usually called bitrate ) tells the codec how much bits it may use per second. Usually you specify a value in kbit/sec. A bitrate of 128 e.g. would mean that the codec will use at most 128000 bits ( = 16000 bytes ) for one second of video. AFAIK MS-MPEG4 doesn't interpret 1k as 1000 but as 1024 what means that a bitrate of 128 would be 131072 bits ( 16384 bytes ) per second.
On2 VP3 even uses kilobytes per second instead of kilobits per second. |
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| twoolfe |
| Posted: Aug 25 2002, 06:06 PM |
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AHHHH Thank you VERY much. This explains a lot of things about how this works. This forum is a lifesaver.
J W Hey
Compton Ca USA |
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