Post processing advice requested

[Bill Clo]

Got an interesting situation here that I could use some help with. I recently recorded a copy of Battlestar Galactica on VCR. I haven't ever fooled with video capture before, and didn't capture it on hard drive - I only thought of that after the fact. I experimented with VirtualDubmod and did a capture from the VCR to hard drive, converting it to DivX along the way. (I don't have 150-200gb of hard drive space to do a Huffyyuv codec capture).

I plan to edit it to remove the commercials, and have to decide what to do next. It is at 4GB now, and I figure on being able to get it down to about 3gb after the commercials are removed. I wanted to get it down to 3 CDs (2.1gb), no more. So I have several questions.

I used PCM audio, 32khz, 16bit, mono sound (VCR only outputs mono sound, unfortunately). IF I tried Divx audio, VirtualDubMod would crash every time (something about not enough wave tables or some such). So my first question is what is the best sound type for this situation? I am not sure what the max frequency or bitrate to use for TV style sound. I could be too high, thereby wasting bitrate in the encode. Second question is what is the max bitrate for a TV broadcast? I used 1500kbs during the encode, but frankly, can't see much difference between 1500 and a test run of 1000kbs. Would I do as well with a lower rate, like 700-900kbs, plus audio?

Assuming that I edit and re-encode the movie, how do I go about outputting it to a VCR and putting it back on a tape? I have an acquaintance who wants to watch the movie, but doesn't have a computer, and a second fellow who hates to watch on computer - he wants to watch on his TV...

Equipment-wise, I have an Visiontek GF4 TI 4600, with TV in and out capability, an Abit NF7-S (onboard sound) and an old 1996 era VCR (no S-Video connector amd mono sound).

All help would be appreciated.

[jggimi]

Bill,

Your question was moved to the Analog Capture forum, where, hopefully, you'll get specific assistance.

I took the liberty of changing the thread's description to make it clear what you are looking for. "Need help with Divx out to VCR format" reads as if you want to record a DivX video onto tape.

Now, to your specific questions. "DivX Audo," if I recall correctly, wass a specialized codec from the pre-MP3 days, and came from the same group who created DivX 3. But these days, MP3 is the most commonly used compression methodology for audio tracks, though there are many others. In my case, I'd leave the sampling rate untouched, and probably select 64kbps for the monaural track.

Your question about not seeing differences with higher bitrate may be due to your MPEG-4 capture, which is not recommended. If you insist on capturing straight to DivX, you may want to use DivX Networks DivX 5.1 Guide (http://www.divx.com/support/guides/DivXGuide51.pdf), which includes some recommended settings for live capture that may help.If you've not already done so, you should start with the Capture FAQ (http://forum.doom9.org/showthread.php?s=&threadid=32575) and the Capture Guide (http://www.doom9.org/capture/start.html).

[Bill Clo]

I do want to transfer an DivX file to Video tape. After alot of stumbling around on the Net, I found this site that at least tells how to go about setting up the Tv out:

http://www.earthmagic.org/?ti4200

As for the original capture, I know, it isn't recommended to do an DivX capture, but I had no real choice - I also tried Xvid, and didn't like it. I've only got about 40gb of hard drive space left, and a Huffyuv capture was out of the question - it would have been 150-200gb!

Of course, after I edited out the commercials, the audio is way out of synch, even though I told Virtualdubmod to synch to audio. So I have to start over, with a different encode rate, and then re edit the whole darn thing. :(

[jggimi]

I do want to transfer an DivX file to Video tape.Your questions were mainly about video capture technique. Yes, you do want to use your Video Out to record to tape, but that's a much simpler process than capture or editing, as you've figured out, and the specifics will depend on your video card and driver. Apparently, you've found a guide that will meet your needs for your particular TV-Out.

I'd like to amend my comments earlier, after re-reading your initial post. It appears you want to use the PC only for editing, and store your end results on video tape: "Tape -> DivX -> DivX -> Tape." I recommend leaving your audio in WAV format, since it will not be stored in digital format, and editing while in WAV is easy to do in AviSynth or Vdub and its variants.

In order to edit out commercials, you'll need to break on a key frame (I-frame) with any MPEG source, such as DivX. This may or may not be a problem to you depending on settings.

You won't like your "Tape -> DivX -> DivX -> Tape" results, since each transfer is lossy. Try a small sample.. even if the audio is out of sync, you can make a test run, and you'll see continual image degradation.

If it were me, I'd buy a second disk drive, and capture in HuffYUV, and use AviSynth for editing, since it takes no additional disk space. This is what I normally do for capture prior to encoding to MPEG-1, 2, or 4. Of course, I'd also want to eliminate the original "tape" capture, so I'd wait for the SciFi channel to rebroadcast the content, as they are sure to do. But again, that's just me.

To avoid additional lossy reencodings, you might experiment with making the edits in AviSynth and then "playing" the AviSynth script when recording to tape ... if your PC could keep up. That way, you'd eliminate one additional lossy transfer.

[Bill Clo]

You're full of good ideas here. Thanks.