1280 vs 1080 in HDTV ...

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

.... is like 525 vs 480 in NTSC (retrace & vertical sync) but I haven't found
in print yet; line resolution vs usable picture; the 200 line discrepancy is
probably same + data.

where is the explanation ?

 

[Richard]

Archived from groups: alt.tv.tech.hdtv (More info?)

"Brass Hopper" <bore_ring@bellsouth.net> wrote in message
news:3k5Ke.1761$Kp.1003@bignews6.bellsouth.net...
> ... is like 525 vs 480 in NTSC (retrace & vertical sync) but I haven't
> found
> in print yet; line resolution vs usable picture; the 200 line discrepancy
> is
> probably same + data.
>
> where is the explanation ?

Some of the analog NTSC vertical raster of 525 lines is used for data and
sync information. Not each station steals the same amount of the raster
allocation. If you set the overscan to zero you will see that the displayed
overscan still varies in the vertical raster depending upon the station.
Thus 480 vertical raster was selected as a conservative standard for NTSC to
digital conversion, and is the fixed vertical raster of digital NTSC DVD.

Richard.

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

Actually there are 1125 lines in a 1080i raster. The extra lines form
the vertical blanking interval.
Then there are 2200 total samples per line with the active picture area 1920
samples wide. The extra samples form the horizontal blanking interval.

"Brass Hopper" <bore_ring@bellsouth.net> wrote in message
news:3k5Ke.1761$Kp.1003@bignews6.bellsouth.net...
> ... is like 525 vs 480 in NTSC (retrace & vertical sync) but I haven't
> found
> in print yet; line resolution vs usable picture; the 200 line discrepancy
> is
> probably same + data.
>
> where is the explanation ?
>
>

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

"D J" <nospam@nospam.com> wrote in message
news:1fSdnewTDPWHr2TfRVn-gw@scnresearch.com...
> Actually there are 1125 lines in a 1080i raster. The extra lines form
> the vertical blanking interval.
> Then there are 2200 total samples per line with the active picture area
1920
> samples wide. The extra samples form the horizontal blanking interval.
>
wherein http/atsc.org or elsewhere is the explanation ?

 

[Guest]

Archived from groups: alt.tv.tech.hdtv (More info?)

This is a SMPTE(Society of Motion Picture and Television Engineers)
standard. SMPTE 292 for serial bit streams, SMPTE 274?? for interlaced
video(or was that the embedded audio standard ) and SPMTE296 for
progressive video(I'm quoting thsese off the top of my head so they may not
be all correct), I don't think smpte has it on their web site for free, but
it could probably be found with a google search.
The ATSC is a standard that uses the MPEG2 bit stream and 8VSB for
transmission. The SMPTE data is probably somewhere in their materials, I
don't recall where.

"Brass Hopper" <bore_ring@bellsouth.net> wrote in message
news:Y%aKe.7388$7p.4496@bignews5.bellsouth.net...
>
> "D J" <nospam@nospam.com> wrote in message
> news:1fSdnewTDPWHr2TfRVn-gw@scnresearch.com...
>> Actually there are 1125 lines in a 1080i raster. The extra lines form
>> the vertical blanking interval.
>> Then there are 2200 total samples per line with the active picture area
> 1920
>> samples wide. The extra samples form the horizontal blanking interval.
>>
> wherein http/atsc.org or elsewhere is the explanation ?
>
>
>