increasing the bitrate = will it increase quality

[perfection]

I have a capture card and use honestech TVR 2.0 as my software for capturing TV programs. I usually capture and record in mpg-2 format suing a CBR of 4000 and video size 320 x 240.

I use the mpgs as movie clips and DO NOT require to use them as standards for creating VCDc or S-VCDs or DVDsI am not interested in a

My queries
1) If i record in mpg-1 at a bitrate of 4000 will the quality be the same. then what is the difference between the two

2) If i increase the bitrate thru a convertor like McFunSoft to lets say to6000 will quality actually improve ? (and vice-versa too?)

3) If i record at two times the size i.e 640 x 480 is it the same at playing back a 320 x 240 video in windows media player at 200 % or not?

I know these are very basic questions but i am a newbie at video capturing and need to clarify and satisfy my curiousity

[Abond]

1) Mainly it depends of encoder. But for this resolution and bitrate, no, it will be the same. I do not know the difference between them, sorry. What I think about it is there is a difference in overall file structure (although this is not big difference).
2) No
3) No. Actually the quality is much better at 640x480. How to explain - when you play 320x240 at 200% quality would suffer very much due to upsizing the picture. When you play 640x480 at 200% the upsizing is lower and therefore the quality do not suffer soooo much. Maybe I am wrong here, because I never would use this veery very crappy programm called Windows Media Player

[Nelson37]

#3 requires some careful examination.

Taking a 320x240 image and blowing it up to 640x480 will degrade it greatly. This is NOT repeat NOT what happens when you change your capture res.

The first thing to understand is that you are not actually changing your capture res. This resolution for every card is fixed, a hardware constant, and is not user changeable. What the user specifies is how the fixed capture is resized to arrive at a final resolution. These resize algorithms are built-in to the hardware or drivers and is in almost all cases inferior to a software resize applied later.

Most cards native capture is very close to 640x480. The vertical res of 480 captures both fields and does not throw away half the available information as a resize to 240 does. This is the difference with MPG 1 and 2 as MPEG1 does not support interlacing.

Also, some cards automatically apply a smoothing filter at lower resolutions. As in the case of the automatic resizing filter, these are in almost all cases inferior to a software smoother applied later, at the users discretion.

[Abond]

@I don't know very good the capture cards, but I use Hauppauge 250 PVR with hardware mpeg2 encoder. Do you think the same applies to it?
I didn't think so, that is why my suggestions.

[thecoalman]

CBR of 4000 and video size 320 x 240.

....is WAY overkill for that resolution.


You'll won't see much if any difference bewteen the same footage captured using 2000. On the other hand if you capture at a higher resolution you'll see an improvement. 352x240 should be used for bitrates between 1000 and 2000. Less than 1000 and the video rapidly deteriorates as you go lower, higher than that and your just wasting disc space. If you want to use a higher bitrate for better quality use a higher resolution. You can go as high as 720x480 with 4000.


See the bottom of this page for a guide: http://www.digitalfaq.com/dvdguides/capture/intro.htm

[Capt.Video]

GIGO, Garbage In Garbage Out. If you dont have good quality at that res at 4mbs, then your outta luck. Max bitreate for MPEG2 at that res is gonna be 2mbs, even that is a bit over kill. What Im saying is over 2mbs for 1/2 D1, your not going to gain anything. Heck, most of my MPEG2s I do at full D1 (720X480) is only 3mbs CBR, and looks almost identical to source DV!

Id say look at the source video, if its the tuner than your going from analog to digital. If you can capture at full D1, Id try that, but my experience is your not going to be fully satisfied.

If you can cap full D1 off something like a DirecTV unit, your quality is going to be noticable better, but its still not what you would expect.

I transfer videos off my DirecTivo and process them, they are very good quality, but short of a DVD in comparison.

The only other way to get outstanding quality from TV transmission is DVB, you can search Google and here for that to learn more.

Good luck,
Andrew

[thecoalman]

Heck, most of my MPEG2s I do at full D1 (720X480) is only 3mbs CBR, and looks almost identical to source DV!

I would say that's WAY underkill.... :P If there's a lot of motion you're going to see a lot of noticeable macroblocking. You'll also see it "solid" shifting colors like the sky. When comparing to DV you have to take into account the source. If you have a very high quality source you can see a difference even at 8000CBR.

See the first two pics here:

https://www.videohelp.com/forum/viewtopic.php?t=257651