AVS Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
3,703 Posts
Discussion Starter #1

In the early 80's, tv shows, in order to save money, began using digital video tape to edit tv shows. I believe Star Trek The Next Generation was to first to do so as it was ILM, which created the effects for their pilot episode, pioneered the technique. Series continued to shoot on 35mm film (at either 24-the frame rate of film, or 30 frames per seconds, the frame rate of video), but after developing, the film was then transferred to digital tape. Thus, all shows (leading up to the advent of film like quality digital cameras) now exist on Digital tape masters. Enter internet streaming. Encodes are made from the master video tape to create a streaming video file. And here is where we run into issues.

 

As I understand it, the 'jitter' we see in older material is due to the encoding process not taking into account the frame rate of the original master digital tape (if I'm wrong, please correct me).

 

 As long time Netflix Instant Watch viewers probably know, Starz Play offered some of the worst looking encodes of all of it's films and tv, new or old. Extreme jitter in all their material (which did improve in the last year or so during it's availability on IW) during left/right camera pans. This week, a former Starz controlled older series, Highlander, was re-added to their inventory. I was curious as to how it would look compared to the encodes Starz had. The picture looks a little brighter, crispier than the washed out, faded looking prints Starz had, and the severe 'jitter' was gone, but still present in scenes with panning nonetheless.

I'm curious, is there some way that this can ever be corrected...is there something that just isn't being done because it's more expensive or time consuming? Again, the 2 episodes I sampled are infinitely better than what I recall from watching a year ago, but are we simply stuck with all older shows possessing this visual annoyance when a streaming file of them is created?
 

·
Registered
Joined
·
8,889 Posts
"Judder" or "jitter" is often caused by adding non-existent frames to make a 24 fps source 30 fps. It can also be created by the encoder using certain methods where a pan is analyzed and broken into a few full frames far less than you would get at a higher bitrate. This latter technique was discussed years ago here by a Microsoft engineer who was working on their encoder. And it is probably very hard to get rid of once introduced into the stream.
 

·
Registered
Joined
·
3,703 Posts
Discussion Starter #3

Thank you. It's a little mystifying how this phenomenon can't be solved completely. I thought it was just affecting some older shows, but Charmed looks terrible as well (Judder during camera pans).
 

·
Registered
Joined
·
2,818 Posts
The problem could be "solved" on the encoding end if streaming services began to support 60 fps video. You'd still get 3:2 judder on the scenes shot at 24 fps just as you did when viewing them on 60Hz TV in the past few decades, but not this blended frames issue.
 

·
Registered
Joined
·
8,889 Posts
The decoders on DVD and BD players and streaming players can decode 24 fps without judder. The problem is people encoding a film who don't know what they doing perhaps believing that the default setting on the encoder is all they need. Makes you wonder who they hire to do this stuff? I recall posts on forums like this when DVD started by people who thought that there might be an interesting job at studios authoring DVDs. Then they found out how much (or little) it paid.
 
1 - 6 of 6 Posts
Top