Monday, February 16, 2004

VHS2DVD Process Streamlining

Slowly streamlining the process. Currently, I'm using a 4-head VHS VCR to capture an analog OTA signal of Law and Order and ER every week (6 hrs/week) with the goal of putting 2 episodes on a single DVD to play in my set-top player. (The Sony, not the Toshiba SD-2109 which won't read recordable media...) Playback for capture is done on a S-VHS VCR (yes, I should probably use a S-VHS VCR upstairs to do the intial recording... but hey, what I'm taping is more about the story then the video quality, audio is clean which is worth more then a slight amount of video noise). I have a 4x6 card stuck to the front of the VCR upstairs to remind me what is taping when so that I change tapes on the proper days.

Playback and capture is easy enough, I don't listen/watch the episode as I'm capturing except for spot-checking to make sure audio sounds clean and audio levels are proper. I start a new capture AVI at every commercial break, and even sometimes grab commercials into short 40-second AVIs. Law and Order shows typically have a 2-3 minute intro, 4 main segments of 9-15 minutes each, then the credits segment which is a minute or two. Since I'm going to DVD, it's just as easy to leave them as seperate files and just combine them into a single track when I author the DVD. In fact, that gives me the option when I encode to do the credits segment at a low bit-rate to save space (usually encode those at 4000 or 5000 kbps instead of the 6000 kbps that I use for the rest of the show). I usually read a book, catch up on SlashDot or other e-mail while I'm doing the capturing, keeping a quick-eye on the progress to make sure no frames get dropped and to see when commercial breaks show up.

Cropping out the commercials (or extra lead-in / lead-out) is done in VirtualDub using the Direct Processing Mode. I've found that this is a good bit faster and less frustrating then trying to set the edit points in TMPGEnc (VDub is much more responsive when scrolling through the video). Since I'm not doing any filtering or re-compression of the AVI, speeds are on the order of 60-90fps (2x-3x normal speed). A faster hard drive would speed up this process. Again, pretty much a hands-off process, it takes maybe a minute per segment to find the scene-breaks, mark my start/end points and start the conversion.

Right now, I'm not doing any filtering / clean-up of the video signal. And unless I get a super-fast encoding machine, I definitely won't be using TMPGEnc's noise reduction (which seems to be extremely slow). As it is, my P4 1.6GHz laptop takes about 6 hours to encode 1 hour of material. With noise-reduction, that figure jumped to 12-18 hours per hour. Since I'm only able to encode using the laptop atm (the capture box isn't stable again...) trying to do TMPGEnc noise-reduction could quickly put me behind if I have more then 8 or 10 hours of source material per week to encode. These captured episodes aren't worth that amount of time to clean them up.

Once I've converted to M2V+WAV, I open up TMPGEnc DVD Author (TDA), create two tracks (one for each episode), add and rearrange the segments in each track, edit the menu text and then start the processing (which creates the VIDEO_TS folder contents). Authoring time takes maybe 5-10 minutes, and processing time takes 30 minutes (pulling the M2V+WAV files across the LAN).

Open up the VIDEO_TS folder, figure out how much of the disc space is in use (usually 3.7-4.0 Gb), and then I create PAR2 recovery data for all of the files in the folder. Either a 16Mb or 8Mb block size works well, with enough recovery blocks to fill the DVD up to around 4.3Gb. Some folks move their PAR2 files to another folder on the DVD, but I've just been leaving the PAR2 files in the VIDEO_TS folder. Makes it easier to verify the disc later and my Sony DVD player doesn't seem to mind that those files are in the VIDEO_TS folder.

Fire up ImgTools Classic to create an ISO of the proper UDF type, which gets written to my machine with the DVD recorder on it (different box then the one that I author the DVD on). That takes another 30 minutes (maybe 2 minutes to setup, then runs on its own). But while that runs I can be authoring another DVD, or capturing more video or doing cutting. I tried just putting the AUDIO_TS and VIDEO_TS folders on a data DVD using Roxio 6, but my copy doesn't create UDF DVDs that the Sony DVD player will recognize. (I suspect, according to what I've read elsewhere, that Roxio 6 is creating UDF 1.05 DVDs, but the standard requires UDF 1.02.) Not a big deal, using ImgTools is about as easy as copying the files over to the other machine directly. Burning the ISO at 2x in Roxio 6 takes around 30 minutes.

All told, I'm not spending an inordinate amount of time actively managing the process (there's a lot of "bulk processing" time involved), and I usually have the DVD ready the day after I do the capture. I'm still exploring various filters in VirtualDub to see if I can clean up the video signal in a reasonable amount of time. e.g. I'm currently trying out the vxVHS filter, but on my AthlonXP 2600+ I'm only seeing 3.5fps throughput which is way too long if I want to run 6-8 hrs/week of video through it. I may go back to using the "Smoother" filter at a setting of 10 or 20. I had stopped using it because it made things look muddy on the TV upstairs (looks okay on the computer), but that might have been a mis-configured TV (contrast was set to maximum). "Smoother" was a fairly quick filter (15-18fps) and I'd have the option to do my border fills again to get rid of tracking noise at the bottom of the frame.

Labels: VideoCapture

posted by Wuphon's at 12:56 AM