# HD Broadcast



## ccapps3428 (Jan 2, 2006)

This may seem like a silly question, but how does a network control what shows are broadcast in HD and which are not? Can older shows be broadcast in HD? I guess I'm not clear on how all the HD works from the 'broadcast' side yet.


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## RCinFLA (Oct 4, 2006)

First distinguish between digital transmission and HD transmission. The old analog US TV system was call NTSC. The new digital transmission is called ATSC. 

A broadcaster can do digital transmission without doing HD. HD is defined as 720p or 1080i. There is 1080p but no transmissions available on this and not likely for a long time.

ATSC can have multiple sub-channels. Typically the -1 channel is where they carry HD and -2 to -4 sub-channels for SD (480i). 

For a broadcaster to transmit HD they need the source material to be HD. Most of the networks transmit their programs in HD after 8pm EDT. Many of the network soap opera's are now in HD.


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## Rasputin13 (Oct 24, 2006)

Exactly. In other words, the tv program/movie must be filmed with HD equipment in order to be broadcast in HD.


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## 4DThinker (Dec 17, 2006)

Or originally FILMED (on film) to then be digitally captured in HD, then broadcast. I'm noticing many older movies now showing up in HD even though they were broadcast on TV and sold on DVD in SD many years ago. If a TV show was originally shot on film, then there is enough resolution to re-digitalize the episodes in HD.


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## Stewart Vernon (Jan 7, 2005)

Film has a higher "effective" resolution than the highest HD. Basically that means they can go back to any movie shot in film, and as long as the film is clean and in good condition they can scan in the frames and get the same quality HD as if it was shot in HD digital today.

Movies that have computer enhanced special effects may need to have those effects reapplied again with new computers if they were not applied at a high enough resolution originally (for example what Paramount has been doing in re-doing the original Star Trek TV series using original film + new computer effects).


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