Analog to DV Conversion Question

hhb · 20th May 2006, 17:59

Hello, followed the recent thread here about peer to peer for NSV, which reminded me that some folks here understand computer video technology in great depth, which I do not. Am hoping some one can clue me about what's actually going on in the process described below:

Setup
Live, wireless dv transmission to remote sc server via NSVCap
Live audio transmission from mixer to remote sc server via NSVCap

Video
DVmini camcorder A/V out to 5.8 Ghz transmitter via RCA.
Receiver to converter box via RCA
Converter box to wireless laptop via firewire
Firewire stream to NSVCap via software bridge
VP6.1 encoding at 300 kbs/25 FPS
Audio
Audio stream via mixer to NSVCap
Raw AAC encoding at 32 kbs stereo

5.8 wireless dv transmission seems to work well -- inside (through walls, from 1st to 3rd floor, etc) and outside (okay at varying distances so far, transmits cleanly from outside to inside receiver/laptop).

Problem
When dv from remote cam gets to NSVCap, preview is fine, but online display (webpage player and winamp) shows the bottom two pixel lines incorrectly, sometimes black, sometimes slightly gray, sometimes just movement, which makes me think it's an interference problem.

But both 2.4 -- doesn't perform well otherwise either -- and 5.8 transmitting include the same, bottom 2-pixel line result, maybe suggesting it is an interlace prob.

Adding to my confusion about cause, FFDShow/Dscaler filters correct the display entirely, using either of two methods: TomsMoComp deinterlacer with vertical filter, or dscaler temporal noise filter with default setting -- without noticeable image quality loss.

Question
In the above described scenario, can someone tell me what is actually going on? Is the bottom, two pixel line problem simply interference in the wireless dv transmission, or is it an interlacing problem or what? Read (at http://100fps.com/) that both raw DV and analog (RCA to converter box output) are interlaced, tried both filters mentioned above with success, but mostly got confused about what the root of the problem actually is.

As far as I'm concerned, the fewer filters needed, the better, so am looking for an explanation of exactly what is causing the problem in the first place. Thanks for any advice and for any pointers to relevant info.

hhb

toqer · 20th May 2006, 18:30

Just crop from the bottom using either nsvenc /config or ffdshow.

hhb · 20th May 2006, 18:44

Thank you for the tip. For some reason, and unfortunately for this situation, cropping the bottom 2-3 pixels lines with NSVCap or with FFDshow has no effect on the display -- the problem pixel lines just "move up" and are still included in a non-filtered video screen display.

Have even tried extreme crops (50 pixels for example) using both methods. Screen is cropped, but still includes the problem 2-pixel lines at bottom.

hhb

slavas · 20th May 2006, 23:41

***268; what resolution you trying to encode? maybe its not multiple of 16...

hhb · 21st May 2006, 01:04

Testing at 320 x 240. But your suggestion made me realize that NSVCap stream preview is okay, no problems with the bottom 2 pixel lines there, so maybe encoding is the faulty step -- VP6.1 with 300 KBS target.

On the other hand, without wireless dv signal and its dv to analog then back to dv conversions, straight firewire yields perfect display. Wish I knew more about this, obviously.

Thanks -- hhb

hhb · 22nd May 2006, 18:05

Today, Monday, May 22, 2006, am testing the 5.8 wireless video setup outside from now (about 2 pm EDT) until dark (around 8 pm EDT). Would appreciate anyone who reads this and has a moment to check out the webpage display:

http://plankroadnetstreams.com/pr-ra...ine-survey.php

Audio is just music, no mic commentary today. Video has little content. Different combos of the 8 Jack Russell Terriers who live here (cam shots are views of the dogyard) will be moving around.

When there's time to spare, will man the cam for better content, but the rest of the time, the view will be wide angle with just random terrier crossings. Full sun until about 4 pm EST. After that, a more saturated view in full shade.

The webpage player is the NSV Active X version -- only a 168 KB download. Thanks to any of you who have a moment and are willing to take a look. Am interested in how it comes across, so please feel free to comment, and thank you.

hhb

john@ROCKNTV1 · 28th May 2006, 12:06

i have run in to this my self,with a dual diplay set up.
on my machine i have a setting that allows "OVERSCAN"
for out put to tv... this is where i made the fix

john

20th May 2006, 17:59	#1
hhb Senior Member Join Date: Jan 2006 Posts: 133	Analog to DV Conversion Question Hello, followed the recent thread here about peer to peer for NSV, which reminded me that some folks here understand computer video technology in great depth, which I do not. Am hoping some one can clue me about what's actually going on in the process described below: Setup Live, wireless dv transmission to remote sc server via NSVCap Live audio transmission from mixer to remote sc server via NSVCap Video DVmini camcorder A/V out to 5.8 Ghz transmitter via RCA. Receiver to converter box via RCA Converter box to wireless laptop via firewire Firewire stream to NSVCap via software bridge VP6.1 encoding at 300 kbs/25 FPS Audio Audio stream via mixer to NSVCap Raw AAC encoding at 32 kbs stereo 5.8 wireless dv transmission seems to work well -- inside (through walls, from 1st to 3rd floor, etc) and outside (okay at varying distances so far, transmits cleanly from outside to inside receiver/laptop). Problem When dv from remote cam gets to NSVCap, preview is fine, but online display (webpage player and winamp) shows the bottom two pixel lines incorrectly, sometimes black, sometimes slightly gray, sometimes just movement, which makes me think it's an interference problem. But both 2.4 -- doesn't perform well otherwise either -- and 5.8 transmitting include the same, bottom 2-pixel line result, maybe suggesting it is an interlace prob. Adding to my confusion about cause, FFDShow/Dscaler filters correct the display entirely, using either of two methods: TomsMoComp deinterlacer with vertical filter, or dscaler temporal noise filter with default setting -- without noticeable image quality loss. Question In the above described scenario, can someone tell me what is actually going on? Is the bottom, two pixel line problem simply interference in the wireless dv transmission, or is it an interlacing problem or what? Read (at http://100fps.com/) that both raw DV and analog (RCA to converter box output) are interlaced, tried both filters mentioned above with success, but mostly got confused about what the root of the problem actually is. As far as I'm concerned, the fewer filters needed, the better, so am looking for an explanation of exactly what is causing the problem in the first place. Thanks for any advice and for any pointers to relevant info. hhb Last edited by hhb; 20th May 2006 at 18:22.

20th May 2006, 18:30	#2
toqer Winamp's Little Stalker (Member) Join Date: Mar 2004 Location: under a bridge Posts: 788	Just crop from the bottom using either nsvenc /config or ffdshow. Winamps Only Karaoke TV station, Live from the 7 Bamboo in San Jose California

20th May 2006, 23:41	#4
slavas Major Dude Join Date: Apr 2003 Location: kaimas Å¡alia AnykÅ¡ÄiÅ³ Posts: 680	***268; what resolution you trying to encode? maybe its not multiple of 16... http://slavo.gigas.googlepages.com/

21st May 2006, 01:04	#5
hhb Senior Member Join Date: Jan 2006 Posts: 133	thank you Testing at 320 x 240. But your suggestion made me realize that NSVCap stream preview is okay, no problems with the bottom 2 pixel lines there, so maybe encoding is the faulty step -- VP6.1 with 300 KBS target. On the other hand, without wireless dv signal and its dv to analog then back to dv conversions, straight firewire yields perfect display. Wish I knew more about this, obviously. Thanks -- hhb Last edited by hhb; 21st May 2006 at 01:28.

22nd May 2006, 18:05	#6
hhb Senior Member Join Date: Jan 2006 Posts: 133	request Today, Monday, May 22, 2006, am testing the 5.8 wireless video setup outside from now (about 2 pm EDT) until dark (around 8 pm EDT). Would appreciate anyone who reads this and has a moment to check out the webpage display: http://plankroadnetstreams.com/pr-ra...ine-survey.php Audio is just music, no mic commentary today. Video has little content. Different combos of the 8 Jack Russell Terriers who live here (cam shots are views of the dogyard) will be moving around. When there's time to spare, will man the cam for better content, but the rest of the time, the view will be wide angle with just random terrier crossings. Full sun until about 4 pm EST. After that, a more saturated view in full shade. The webpage player is the NSV Active X version -- only a 168 KB download. Thanks to any of you who have a moment and are willing to take a look. Am interested in how it comes across, so please feel free to comment, and thank you. hhb

20th May 2006, 18:44	#3
hhb Senior Member Join Date: Jan 2006 Posts: 133	Thank you for the tip. For some reason, and unfortunately for this situation, cropping the bottom 2-3 pixels lines with NSVCap or with FFDshow has no effect on the display -- the problem pixel lines just "move up" and are still included in a non-filtered video screen display. Have even tried extreme crops (50 pixels for example) using both methods. Screen is cropped, but still includes the problem 2-pixel lines at bottom. hhb

28th May 2006, 12:06	#7
john@ROCKNTV1 Registered User Join Date: Apr 2006 Location: i have broken not a single rule and you deleted my sig craigF.. OK MY TURN CRAIGF and smelter thank for bumping bulks flame post Posts: 641	hi hellen i have run in to this my self,with a dual diplay set up. on my machine i have a setting that allows "OVERSCAN" for out put to tv... this is where i made the fix john

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