Can't get good quality recording SNES at 60fps

Edit history:

Madzombie: 2005-05-24 11:06:00 pm

2005-05-19 05:04:13 pm

pidgeons

Having gotten annoyed with messed up flickering effects etc. I'm trying to get a proper 59.94fps recording of my SNES speedruns. I followed the instructions of recording at 640x480, using avisynth to convert the 29.97fps capture to 59.94fps. The problem is that the colour and brightness data seem to go out of sync. Having investigated further it seems like this problem started when I captured it. This is shown in the images at the bottom, the top one being pre- filtering and the bottom one post-filtering. Loon around Link to see that the colours aren't correct. I am using a Radeon X800XT VIVO with s-video connection. The problem also happened when I used the composite connection. Does anyone have any suggestions that might help me solve this?

Thread title:

Trevor

2005-05-19 06:17:28 pm

that's weird if you're getting flickering effects after splitting the fields in avisynth. it's a low res game; every two fields correspond to one line. I'd guess that the strange color ghosting was a side effect of the smart bob filter but I don't know...that's just weird. is it a very bad problem? what about in scenes where the whole screen is moving?

Madzombie

2005-05-19 06:28:21 pm

pidgeons

It's actually worse where the whole screen is moving. Probably the best (well, worst) example is when jumping off the pyramid at the start of the dark world. If you look really closely you can see that it also happens before the filter is applied, it's just a lot more noticable afterwards. If i have to record at 30fps then I'll do so, but other people have SNES runs recorded at high quality so it should be possible.

StrangenessDSS

2005-05-19 08:59:08 pm

Sleeping Terror

Try using AviSynth's Bob - just replace "SeparateFields" with "Bob", and don't use any VirtualDub filters. Does that work any better?

Ekarderif

2005-05-19 09:11:30 pm

Your almighty lordship

Try deinterlacing but not applying the bob filter and instead resize it to a better resolution. It requires deinterlacing no matter what, but the vertical resolution after simple deinterlacing should come out to be what it was originally.

Trevor

Edit history:

Trevor: 2005-05-19 10:01:01 pm

2005-05-19 09:59:43 pm

well, I found a solution to the chroma sync problem that you can try. http://www.avisynth.org/Merge

with this, theoretically you could save another copy of the capture AVI (cutting off the appropriate number of frames to compensate for the chroma delay) and then fully replace the chroma of the first AVI with that one's, and there you go. do you understand what I mean?

Madzombie

Edit history:

Madzombie: 2005-05-19 11:33:47 pm

2005-05-19 11:06:06 pm

pidgeons

Edit: Ok, things just got a lot more difficult. I was checking and the colour delay only happens every 2nd frame. The even numbered frames have perfect colour, but the odd numbered ones take the colour from the frame before. It's like this on the original too, before I apply the deinterlacer. I don't know why but something must have gone wrong when capturing it. It seems to only have recorded the colour data from half the frames, but the brightness data from all of them.

Trevor

2005-05-20 02:14:32 pm

you could try different driver revisions for your device. maybe your current set is buggy or something. are they up to date? if they are, you could still try earlier versions.

on that Merge function page, there's a function mentioned that will apply a temporal smoother on the chroma channel and you could try that too I guess. it might 'curb' the problem.

other than that I'm kind of stumped. Huh?

marshmallow

2005-05-21 02:01:26 pm

Jack of all Trades

Speaking from my own ignorance, why do people want to record at 60 fps for an SNES game? 30 worked fine for me. I only got weird effects when it was at its default of 15fps or whatever.

Andy_Olivera

2005-05-21 03:24:04 pm

Quote:

Speaking from my own ignorance, why do people want to record at 60 fps for an SNES game? 30 worked fine for me. I only got weird effects when it was at its default of 15fps or whatever.

Because games are meant to be played back on a TV, the signal is interlaced, or draw every other line(half the frame; called a "field") every 1/60th of a second. The systems use this to their advantage by updating the picture with every field, rather than every whole frame. This allows smoother motion, but also increases artifacts.

Most capture cards can grab both fields(which gives you the 720x480 resolution). Since computer monitors are progressive displays, the interlacing artifacts are much more noticable than they would be on a TV, therefore you need to get rid of(or at least minimize) them. There are three ways you can do this:

1. Blur the fields together, preserving all 60 fields worth of movement in a 30fps file. The blurring is invisible at 30fps, but looks odd when paused. This is the closest method to what you see on a TV.
2. Seperate the fields into 60 distinct half-resolution progressive frames. Works, but can sometimes introduce excessive flicker because the fields weren't meant to be seen seperate. This is how Nate creates the HQ files.
3. Remove half the fields(and half the movement). Allows progressive frames at 30fps, but movement isn't as smooth. Has the side effect of making items disappear completely, when they should be flashing.

As you can see, none of them is perfect. The general consensus is that #2 is preferrable.

[quote]Speaking from my own ignorance, why do people want to record at 60 fps for an SNES game? 30 worked fine for me. I only got weird effects when it was at its default of 15fps or whatever.[/quote]
Because games are meant to be played back on a TV, the signal is interlaced, or draw every other line(half the frame; called a "field") every 1/60th of a second. The systems use this to their advantage by updating the picture with every field, rather than every whole frame. This allows smoother motion, but also increases artifacts.

Most capture cards can grab both fields(which gives you the 720x480 resolution). Since computer monitors are progressive displays, the interlacing artifacts are much more noticable than they would be on a TV, therefore you need to get rid of(or at least minimize) them. There are three ways you can do this:

1. Blur the fields together, preserving all 60 fields worth of movement in a 30fps file. The blurring is invisible at 30fps, but looks odd when paused. This is the closest method to what you see on a TV.
2. Seperate the fields into 60 distinct half-resolution progressive frames. Works, but can sometimes introduce excessive flicker because the fields weren't meant to be seen seperate. This is how Nate creates the HQ files.
3. Remove half the fields(and half the movement). Allows progressive frames at 30fps, but movement isn't as smooth. Has the side effect of making items disappear completely, when they should be flashing.

As you can see, none of them is perfect. The general consensus is that #2 is preferrable.

Madzombie

2005-05-24 11:05:07 pm

pidgeons

I managed to solve the "bob" issue. It seems that my capture card was putting an odd number of lines above where the image begins. This meant that, when deinterlaced, there were an odd number of black lines at the top on one frame and an even number on the other frame, causing the bobbing. Hopefully the colour issue will be as simple to solve.