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| jcsston |
| Posted: Nov 18 2002, 05:16 AM |
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Matroska Dev
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I have some that I think is a bit funny.
A local TV station broadcasts Star Trek Voyager reruns Late Sunday Nights. I programmed my computer to record them.
Now whenever I compress them using DivX my average bitrate is around 480kbit no matter how high the bitrate is set even on two pass. Now at first I thought my filters was doing this but even with different filters my output size is the same 150MB, even for different episodes. In DivX I have all the Mpeg4 Enhancements enabled and the Pycovisual to Strong. When I watch the compressed video it look okay to me.
I use ATI TV to record them to MPEG-1 320x240 at 8Mbit could this cause them to compress so well?
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Use the Matroska file format |
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| fccHandler |
| Posted: Nov 18 2002, 06:23 AM |
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Administrator n00b
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IMHO, 320 x 240 is "lo-res", but hey, whatever works for you. If you're happy with it, then we are all happy for you! 
BTW (someone correct me if I'm wrong) but in my experience "Psychovisual enhancements" makes not one bit of difference in the size of the output file?
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May the FOURCC be with you... |
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| BaronVlad |
| Posted: Nov 18 2002, 09:31 AM |
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Terrorhörnchen
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| QUOTE (fccHandler @ Nov 18 2002, 12:23 AM) | IMHO, 320 x 240 is "lo-res", but hey, whatever works for you. If you're happy with it, then we are all happy for you!
BTW (someone correct me if I'm wrong) but in my experience "Psychovisual enhancements" makes not one bit of difference in the size of the output file? |
Hi fccHandler,
I think you are right, with both 
320*240 is very low and your problem should be because of MPEG1, I had many movies in MPEG1 that i wanted to compress with DivX into 700 MB. No Chance, they always were about ~400 MB in the end, no matter, what bitrate I had.
I also made the experience, that there was no difference in filesize between "Psycho"-movies and "Non-Psycho"-movies.
You should capture directly with VDub (Codecs Huffyuv or MJPEG) at a higher resolution (Full PAL/NTSC if possible) and then (resize to a smaller resolution !!! and) compress into DivX, it is better quality. Or you can try MPEG2 recording (i.g. using PowerVCR) and then let GKnot do the compression for you.
Or you are just happy, that your files are so small that you can burn them easily an a normal CD-R
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Hochachtungsvoll
BaronVlad
Deutsch >> Capture FAQ - Capture Guide
Englisch >> Capture FAQ - Capture Guide |
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| jcsston |
| Posted: Nov 18 2002, 09:16 PM |
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Matroska Dev
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Well I also tried capturing at 640x240 MPEG-2 and the end result was the same.
BTW Capturing with VirtualDub isn't an option since the show comes on at 3:00AM. VDub VCR doesn't work with my Ati Aiw.
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Use the Matroska file format |
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| BaronVlad |
| Posted: Nov 19 2002, 08:05 AM |
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Terrorhörnchen
Group: Moderators
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| QUOTE (jcsston @ Nov 18 2002, 03:16 PM) | | VDub VCR doesn't work with my Ati Aiw. |
??? Then your ATI AIW is the only ATI AIW that doesnt work with VDub VCR, normally it works wonderful.
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Hochachtungsvoll
BaronVlad
Deutsch >> Capture FAQ - Capture Guide
Englisch >> Capture FAQ - Capture Guide |
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| jcsston |
| Posted: Nov 19 2002, 07:15 PM |
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Matroska Dev
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Well it works with the timer but I can't get it to change channels automatically.
My processor is an T-Bird 650Mhz and it cannot play 640x240 DivX that well and that's why I'm stuck with the miserly low resolution of 320x240. But it's better that my previous setup 250mhz 15fps 
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Use the Matroska file format |
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| jcsston |
| Posted: Nov 19 2002, 10:30 PM |
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Matroska Dev
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After reading about it online I finally downloaded the fddshow filter.
It can play my DivX 640x240 smooth!
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Use the Matroska file format |
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| jcsston |
| Posted: Nov 25 2002, 01:47 AM |
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Matroska Dev
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Well this Sunday I got another episode and this time I captured it at 640x240 MPEG-2 and compressed it at 640x240. Guess what the file size was at the max bitrate. 312MB  And it looks a good bit better than before  and I can still fit about 3 on cd. (at a bitrate slightly lower than the max)
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Use the Matroska file format |
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| Spire |
| Posted: Nov 25 2002, 01:53 AM |
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Unregistered
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| QUOTE (jcsston @ Nov 24 2002, 05:47 PM) | | Well this Sunday I got another episode and this time I captured it at 640x240 MPEG-2.... |
If you're going to increase the resolution on one axis, you're much better off doubling the vertical resolution; e.g., 320x480. This will preserve both fields of the original video, resulting in much better motion. |
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| jcsston |
| Posted: Nov 25 2002, 02:02 AM |
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Matroska Dev
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Wow that was a fast reply.
Anyway in the ATI MPEG-2 setup should I enable or disable the deinterlacing?
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Use the Matroska file format |
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| Spire |
| Posted: Nov 25 2002, 02:05 AM |
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Unregistered
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If you're capturing with a vertical resolution of 480 (which I recommend), you should definitely disable deinterlacing. |
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| jcsston |
| Posted: Nov 25 2002, 02:23 AM |
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Matroska Dev
Group: Moderators
Posts: 553
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Joined: 3-November 02
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Thanks
I'll try 320x480 with the Smart Denterlace filter in VDub.
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Use the Matroska file format |
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| fccHandler |
| Posted: Nov 25 2002, 03:55 AM |
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Administrator n00b
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Even today, many television shows (and Voyager too, probably) are shot on film, so for best results I recommend under Video->Frame Rate, click Inverse Telecine "Reconstruct from fields - adaptive", and set Smart Deinterlace to "blend instead of interpolate" for when the IVTC fails.
Motion will be smoother, image will be sharper, and you'll get better compression with the frame rate reduced by 4/5.
Hope this helps.
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May the FOURCC be with you... |
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| outlyer |
| Posted: Dec 11 2002, 04:05 PM |
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Spanish Section Mod
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| QUOTE (jcsston @ Nov 18 2002, 06:16 AM) | Now whenever I compress them using DivX my average bitrate is around 480kbit no matter how high the bitrate is set even on two pass. Now at first I thought my filters was doing this but even with different filters my output size is the same 150MB, even for different episodes. In DivX I have all the Mpeg4 Enhancements enabled and the Pycovisual to Strong. When I watch the compressed video it look okay to me.
I use ATI TV to record them to MPEG-1 320x240 at 8Mbit could this cause them to compress so well? |
Although thread has went a bit off-topic  I'll give you my 2 cents on the original question: Modern codecs, like DivX, usually respect you'r bitrate settings BUT if they're too agressive they'll be ignored: if a frame needs only X bits to get a "100%" quality, the codec wont give it more than X bits.
You can get an appropiate bitarte with a bitrate calculator, in this case, doing some rough numbers and using gordian knot it gives a high objective quality (based on dimensions, duration and bitrate), so it fits to what I said above |
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| S_O |
| Posted: Dec 11 2002, 05:31 PM |
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Vdubmod Alpha Testing Team
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| QUOTE | | Even today, many television shows (and Voyager too, probably) are shot on film, so for best results I recommend under Video->Frame Rate, click Inverse Telecine "Reconstruct from fields - adaptive", and set Smart Deinterlace to "blend instead of interpolate" for when the IVTC fails. |
All star-trek-series are shot on film, you should be able to use IVTC.
I record sometimes from TV, too, but in PAL 25fps, is there any way to reconstruct the original 24fps here? I´ve read they use speed-up, the film plays faster than normal, but anyway there is interlacing, how does the interlacing come into the film in PAL? Is it reversibly? |
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