[mythtv-users] IVTV Bitrate & Resolution

Michael T. Dean mtdean at thirdcontact.com
Mon Mar 26 15:03:20 UTC 2007

On 03/26/2007 09:30 AM, Cory Papenfuss wrote:
>> However, AIUI, 704x(480|576) is a "cut" resolution--which is supposed to
>> have clean edges.  DVD's with video at 704x(480|576) are supposed to be
>> played back with less overscan (though I don't know of any specific
>> players that actually do so).
>> Since the PVR-x50's do /not/ have clean edges on their recordings, my
>> recommendation is to stay away from 704x(480|576) unless transcoding
>> /and/ cropping.  Otherwise, you may stumble across some player that does
>> overscan less and you'll see black frame and/or jaggies and/or rainbow
>> edges on the TV.
>  	Hrm... I wasn't aware that was the purpose of 704x480.  I have yet 
> to ever see that implemented that way.  The players I've tried it on you 
> could see the video start playing cut, and then after about 0.1sec, 
> stretch to full screen.  I thought it had something to do with being 
> exactly 2x 352x480, or divisible by 16 or something.  </ignorance>

Well, as I mentioned, I haven't found any players that treat the 
resolution differently.  I figure that's probably the case since most 
players just output an analog signal that's overscanned by the TV, so 
they treat both D1 and cut D1 resolutions the same (meaning you lose a 
bit more visible picture in the 704x480--especially if it is 
cut--because it's overscanned the same as the 720x480).  Even the 
software players (at least on Linux) tend to assume you will set 
overscan (or crop, if not fullscreen) yourself.

So, since there's no real-world difference, there's little real-world 
reason to know the "theoretical" difference.  Therefore, it doesn't seem 
to get publicized too much.  I guess it's just my OC side that wants it 
done "right."  :)


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