Slideshow encoding bitrate

I’m using Photodex ProShow to make mpeg-2 videos of photo slideshows. The photos are pretty high res btw, something like 3264x2448.

ProShow allows me to manually set the video bitrate for encoding. How do i tell what’s the correct bitrate to set? It shouldn’t be too small of course so that the high-res pictures remain high-res, but i’m guessing it also shouldn’t be too big because there’s a limit to how good the photo quality can possibly be, so bitrates that are higher than necessary would just be wasting space.

Is there a way to calculate this? I want to encode with the best necessary bitrate for quality, space not being an issue as long as it’s not wasted space.

the resolution of the photos is irrelevant, because the video will be 720x480 for DVD, or 1080 if you are making HD video. As to bit rate, it depends on the amount of space you need to fill. Leave it at the highest quality setting unless you wish to compress into a smaller space.

Yes it will ultimately be 720x480 for NTSC DVD.

The default settings in the mpeg-2 exporter has bitrate set to 5073 kbps. I can’t help wondering if things will look better if i double this number or so, though as i said before, how do i tell where’s the limit where higher bitrate wont make things look better and will just waste space.

Since a lot of the video will be static (unchanging) use a VBR encoding setting if you can.

[QUOTE=kingIZZZY;2168288]Yes it will ultimately be 720x480 for NTSC DVD.

The default settings in the mpeg-2 exporter has bitrate set to 5073 kbps. I can’t help wondering if things will look better if i double this number or so, though as i said before, how do i tell where’s the limit where higher bitrate wont make things look better and will just waste space.[/QUOTE]

Usually around 8k is the point of diminishing returns. A lot depends on the type of transitions you are using, and effects like zoom, pan or rotate. Still images require very little, only the transitions will show the effects of low bitrate. Also, if there is audio, that needs to be factored in. The max bitrate for DVD-Video is around 9k or slightly above.

Since a lot of the video will be static (unchanging) use a VBR encoding setting if you can.

Actually most of the slides have transforms and transitions, zooming into and panning around pictures (which is also why i was worried about keeping the picture’s high res through encoding)

Unfortunately Photodex ProShow doesn’t have a VBR option…

So how do i calculate the next best CBR ?

Again, keeping in mind these two factors, 1: i’d like highest quality possible (space is not an issue, though-) 2: not overdoing it till space will be wasted on excess bitrate.

Your low bitrate will show only on transitions and pans, but since you are not looking at those, I would use highest bitrate that will put the show on DVD5 disc. This is not video(movie).

[QUOTE=CDuncle;2168387]Your low bitrate will show only on transitions and pans, but since you are not looking at those, I would use highest bitrate that will put the show on DVD5 disc. This is not video(movie).[/QUOTE]

I could technically use 9999 Mbps then, because the slideshow isnt so long and i can fill up a whole DVD. My question is, wont high bitrate become excessive and unnecessary at some point and it wont add anything to the quality, because i’d optionally want to fill up the DVD with other extras.

To illustrate, i’m imagining that for example maybe encoding the slideshow at 5 Mbps would bring the photos quality to its best-ever-possible potential, and anything lower will make poorer quality. Encoding at 8 or 10 Mbps is also feasible, but won’t do any better in quality than 5 Mbps, and thus will pretty much just waste space which i’d like to use for optional content.

9999 kbs is theoretical, most players will accept 8000 and lower.
If you can do your show at 5000 it is fine. You can go lower than that, but if you burn to disc you are not saving anything since it is 4.7GB.
If no disc is required, than I would try 3000 and see how they come out, file will be smaller.
Because if you could use VBR it would come to much lower for actual slide, not moving parts.
I would say enywhere between 1 to 2000.

[QUOTE=kingIZZZY;2168393]I could technically use 9999 Mbps then, because the slideshow isnt so long and i can fill up a whole DVD. My question is, wont high bitrate become excessive and unnecessary at some point and it wont add anything to the quality, because i’d optionally want to fill up the DVD with other extras.

To illustrate, i’m imagining that for example maybe encoding the slideshow at 5 Mbps would bring the photos quality to its best-ever-possible potential, and anything lower will make poorer quality. Encoding at 8 or 10 Mbps is also feasible, but won’t do any better in quality than 5 Mbps, and thus will pretty much just waste space which i’d like to use for optional content.[/QUOTE]

One technique that works pretty well is to encode it at max bitrate, (figure 8k), then if you want to shrink it later on you can use DVDShrink to bring the size down. Shrink will do a better job than initially encoding at a low bit rate, because it does use variable bit rates.