Terrestrial Digital TV encoding

Hi! I have a question about the encoding of contents for digital TV
transmission in the US. Regarding data fields (313 segments) and data
frames (626 segments), are these synonymous to fields and frames for
pictures using the NTSC standard?

On Nov 15, 12:09 pm, RMW wrote:
Hi! I have a question about the encoding of contents for digital TV
transmission in the US. Regarding data fields (313 segments) and
data
frames (626 segments), are these synonymous to fields and frames
for
pictures using the NTSC standard?

You can find most everything you want here.

http://www.atsc.org/standards.html

GG

On Nov 15, 3:36 pm, G-squared wrote:
On Nov 15, 12:09 pm, RMW wrote:
Hi! I have a question about the encoding of contents for digital TV
transmission in the US. Regarding data fields (313 segments) and
data
frames (626 segments), are these synonymous to fields and frames
for
pictures using the NTSC standard?

You can find most everything you want here.

http://www.atsc.org/standards.html

GG

Thanks, GG! I've actually been reading thru the standards since last
week. I just wanted a quick answer. I haven't encountered the answer,
yet, in my readings.

"RMW" wrote in message
...
On Nov 15, 3:36 pm, G-squared wrote:
On Nov 15, 12:09 pm, RMW wrote:
Hi! I have a question about the encoding of contents for digital TV
transmission in the US. Regarding data fields (313 segments) and
data
frames (626 segments), are these synonymous to fields and frames
for
pictures using the NTSC standard?

You can find most everything you want here.

http://www.atsc.org/standards.html

GG

Thanks, GG! I've actually been reading thru the standards since last
week. I just wanted a quick answer. I haven't encountered the answer,
yet, in my readings.

I haven't read the whole ATSC spec, but if you look up what a segment is, it
should answer your question. In NTSC a frame would have twice as many
*lines* as a field.

Tam

On Nov 15, 12:09 pm, RMW wrote:
Hi! I have a question about the encoding of contents for digital TV
transmission in the US. Regarding data fields (313 segments) and
data
frames (626 segments), are these synonymous to fields and frames
for
pictures using the NTSC standard?

In analog NTSC there are 262.5 lines in every field, 2 fields in a
frame, 227.5 cycles of subcarrier in a line and subcarrier is 3579545
Hz. These numbers are "etched in stone". Make any change on it and a
broadcast VTR will throw error codes all over the place. I only tell
you this to get a 'feel' for TV before digital.

When I record an ATSC feed off air and edit out the commercials with
VideoReDo (highly recommended), it reports the transmission bit rate.
Private Practice on ABC comes in under 9 megabits while Criminal Minds
reports 16.5 megabits. Dirty Sexy money that runs immediately
following Private Practice runs over 11 megabits. Granted ABC is 720p
and CBS is 1080i, they both come over a 19.34 megabit ATSC stream. The
point is the broadcaster controls the degree of compression so while
there is a relationship of data vs picture, it varies not only by
channel but also by the shows on the _same_ channel.

I believe this will help you out.

http://www.hdtvprimer.com/ISSUES/what_is_ATSC.html

GG