Blockyness, Could it be the BLUE surface CDROMS????greenspun.com : LUSENET : Video CD : One Thread
I followed all the rules but the VCD came out with problems.
There was blockyness when played on the Pc that made it, and on the Sony DVD. 1) The source video came from 8mm, then captured on an ATI AIW PRO, on VCR2 format (352x240). 2) Then it was edited on Adobe Premier 5.1rt, and came out as ATI YUV9 (352x240),(looks really good in the monitor), 3) Then it was run thru XING encoder on the CDVIDEO setup, to aquire the specifications of white book. The Mpg files looked fine. I even defragemented the drive to give it better performance. 4) Then the 7 sections of mpg video where moved to the NTI cd writer application (Ver4),to adjust the VIDEOCD2.0 burning set up, it accepted all the files with no problem. 5) Next I ran a SIMULATION of the cd burning on 4X speed, which turned out successful, 6) Then I burned the cd, at 4x Writing speed and it turned out successful. So the VCD was apparently perfect. 7) Next I inserted it on the DVD Sony 300, and it recognized all the chapters with no problem. 8) When it started playing the blockiness was terrible. The sound was Ok. If I could get rid of the blockyness it would be great. 9) Then I took it back to the Pc, on the same drive that made the VCD to see of the problem was on the DVD PLAYER. But the same thing happened,the play back on the PC was terrible.
10) So the question is WERE IS THE PROBLEM?
I used a FUJI CD-R, with blue surface. COULD IT POSSIBLY BE THE MEDIA????? I burned the CD-R at 4x, was it too fast...SHOULD I HAVE DONE IT 1x??????????? The CD RECORDER is MEMOREX.....I have burned other multimedia CDroms that have turned ok. So far...this is my fist failure...
The PC is a : COMPAQ PRESARIO 5360/ 450MHZ/ AMDK6-2/10GIGS/ 64RAM/ ATI AIW PRO video capture card. PREMIER 5.1RT/ AFTER EFFECTS 4.0/PHOTOSHOP 5/SOUND FORGE 4/XING ENCODER/DIRECTOR 6/
THANKS FOR THE TIME YOU'LL TAKE TO SOLVE THIS PUZZLE. BYE
-- Carlos Moreno (carl@firstname.lastname@example.org), October 02, 1999
I can see two things here: First, your encoder. Xing is fast and all that but two things against it are it's expensive, and it really doesn't do filtering. In any case the blockiness during playback could be caused by your decoder (player or PC) not keeping up with some of the info it has to unravel to create the pix, and therefore retains good info from a previous successfully decoded block; viola-blockiness. Even Hi-8 will have some noise that is not evident on playback of the original tape; it's this noise that makes the encoder's job difficult: it wastes its resources trying to encode this noise, wasting precious bits that could have gone to encoding actual useful picture info instead. DVMPEG and Panasonic are two encoders I use and these have filters you can experiment with (like low-pass and smoothing). The filters and their levels of sophistication in any MPEG encoder probably helps towards higher quality output more than most other parameters during encoding. An MPEG file on a PC may not show blockiness because the PC can force itself to adapt varying data bit rates, etc., but once recorded to VCD this can show up. Realize that the one limitation of VCD is constant bit rate. I don't know why but creating identical VCDs one recorded at 2x and the other at 4x on identical media (Kodak Silver+), the one recorded at 2x plays more smoothly than the one made at 4x, which will always be a bit more jerky and blocky. Perhaps you should indeed consider recording at 2x and at 1x and compare results. Lastly, you didn't say what type of video you had on that 8mm. But generally, videos which include a lot of scene changes, fast movement, and fast brightness change rates from frame to frame produce more blockiness compared with talking heads type scenes. Even the best MPEG encoder will be fazed and produce blockiness in the final file if you force fast movement on it like scenes with rapid camera pans. There is little Xing can do to alleviate this limitation; however, in DVMPEG and Panasonic there are facilities to manually force keyframes (I-frames) when the next frame, upon inspection, is markedly different from the one preceding it. Forcing I frames manually can make encoding tedious and longer and the resulting filesize probably bigger but the output quality will be much better in terms of smoother motion and very minimal blockiness.
-- EMartinez (email@example.com), October 03, 1999.