How to Determine Capture Bitrates vs. Target Media?
 

First thought was DVD-Video, but why not also BD to reduce compression?

For DVD-Video
Compression to DVD-Video: I was intrigued by lordsmurf’s recent suggestion on a thread concerning VHS capture (for DVD-Video) to use AIW MPEG-2 capture of 15 mbps and then encode down to MPEG (9.8 mbps max?) to fit DVDs . Does this provide a better result than initially capturing at DVD bitrate settings?

Would this apply to Hi-8 as well?

For Whatever Target Media, DVD-5, DVD-9, BD, or even the hard drive
All of my tapes are SD. I understand the VBR bitrates discussed in the guides and not looking for HD here, but am interested in using increased capacity to reduce compression; preserving as much definition of the original recordings as possible. Any progression beyond DVD-Video (DVD-5, DVD-9) to BD (BD25?) is interesting.

Does it make sense to capture 2 hour VHS (1 camcorder tape, the rest from TV/cable/satellite) beyond DVD-Video (5, 9) bitrates for encoding to BD?

Ditto for Hi8 2 hour?

Ditto for Digital8 and MiniDV 1 hour?

I think the first suggestion you're going to get is that you're looking at it from the wrong direction. Don't capture at your delivery target bitrate. You want to capture with a lossless compressed format. That's your new master file. That way you can transcode down to whatever your target bitrate is, but if you capture at that you're locked in and have to re-capture if you change your mind or want to change something.

Erich

Your point is well taken and I certainly do not want to build an oversized capture/encode simply to fill larger disc space. What I am trying to get at in the latter segment above, in an admittedly not very enlightened fashion (not much experience, but some reading), is:
- Given a lossless (or less loss) capture and the codecs that work with BD-R, can a "better" SD video product be achieved - not solely due to, but also if - larger file sizes are possible through BD?
- Also, I may be capturing straight to MPEG and it may or may not be desirable to capture beyond DVD-Video spec. That is part of the reason for the first par. above, concerning lordsmurf's suggestion. And I understand that MPEG is one of the codecs compatible with BD (again questioning utility of higher bitrate/encode possible for BD)
- At this point on Amazon for instance, a spindle of 50 Verbatim BD-R 25 GB discs is less expensive than the same of DVD+R DL discs.

The problem with capturing straight to MPEG, at any bitrate, is that it is a lossy compression format. Yes, higher bitrates would mean less compression artifacts, but it is still lossy, and any re-encoding just adds to the compression artifacts. Using BD disks would let you use the newer H.264 encoding vs the DVD MPEG-2, but at SD resolution VHS tape sources I'm not sure you'd visually see a difference compared to using the highest quality settings for the DVD encode. You'd certainly fit more files onto the BD disk if that's your main concern.

Erich

Hi Erich,

Imagine the following scenario:

You have a client who needs 6 VHS tapes transfered to DVD as quickly as possible. You tell this client that you perform restoration services which will improve the quality of their tapes. The client respectfully declines reiterating that they need their deliverables ASAP.

In this situation I see two potential courses of action:

a) Capture lossless AVI via ATI AIW capture card & HuffYUV via VirtualDub, then re-encode lossless AVI to mpeg-2 using TMPG, HCenc, or another encoder, then burn a menuless DVD using the mpeg-2 file.

or

b) Capture DVD spec mpeg-2 with ATI AIW capture card via ATI MMC TV, then burn a menuless DVD using the mpeg-2 file.

One factor worth considering in this situation is the power of the computer you would be using for editing and encoding. This is an extreme example, but if an encode of a 2 hour AVI file takes longer than 24 hours, I feel as if a significant amount of time is being wasted.

Comparatively, the time required for the second option only involves mpeg-2 capture, DVD authoring, and DVD burning.

DVD and BluRay disk formats have different encoding specs. An MPEG encoded for DVD won't be compatible with BluRay, and MPEG encoded for BluRay won't be compatible with DVD, even if you use the same bitrate for both. DVD is more universally playable by more players, including older players, tan BluRay disc is. You can burn MPEG to BluRay disc as "data", but some players won't read it -- when many players see a BluRay disc they expect authored Bluray, not MPEG data files.

DVD double-layer can contain 3 hours of high quality DVD, although you can expect a direct-to-DVD recording to look a little worse than the tape itself because tape noise and other defects become imbedded as digital artifacts that don't exist on analog source. Cleanup would require re-encoding and further degradation, while simple cut-and-join edits will require a smart-rendering editor to avoid further damage.

Lossless formats avoid all this damage and allow you to encode to multiple formats, including formats for internet posting (you can't post DVD or BluRay as-is to the internet) without changing the original capture. Once you have the formats you want, you don't have to save the capture.

The "utility layer" you mention was not designed for edits or cleanup without loss.

It's up to you.

Point taken about the system speeds and encoding times. I'm most definitely spoiled by my iMac Pro in that regard. AviSynth+Vdub2 run thru my QTGMC and TIVTC scripts and output to Prores files at almost 60fps, and I just converted a 1 hour long Prores file out of Davinci Resolve to DVD-mpeg with Compressor in 7 minutes.

Erich

[QUOTE=ELinder;60948AviSynth+Vdub2 run thru my QTGMC and TIVTC scripts and output to Prores files at almost 60fps, and I just converted a 1 hour long Prores file out of Davinci Resolve to DVD-mpeg with Compressor in 7 minutes.[/QUOTE]You mean you went from lossy to more lossy? Very glad they're not my videos. What's more amazing is that 60fps and 23.976 speeds aren't valid for DVD, unless you're saying something entirely different.

To paraphrase Monty Python, yes, I'm doing something completely different. :)

Oh. Then you're not making DVD's. You're just downgrading for some reason. That's what I thought.