Encoding Questions (n00b)

[stahlhart]

Probably best to start by describing my situation: I am (like many others) working on developing a procedure for transferring T-120 VHS tapes to DVD. The majority of these tapes are masters I recorded off of analog cable and satellite dish television; others are lower quality (i.e. higher generation) bootleg audio material, camcorder concert recordings etc. Nearly all have hi-fi stereo audio.

First question: would it be wrong for me to attempt to fit 2 hours of VHS tape onto a single 4.7Gb disc? I know that it's possible to if I lower the bitrate enough, but will the quality suffer too much?

Second question: my captured files are uncompressed .AVI; TMPGenc is encoding these as m2v+wav -- am I okay encoding the audio and video at the same time, since it appears that the audio format I'm getting out is 48KHz PCM, or should audio and video be encoded separately? I saw one web site (I think it was a link from one of the stickies here) that stressed that if you encode audio and video together that the audio will end up compressed and have to be decompressed in the authoring process -- but it seems to me that TMPGenc is already giving me an uncompressed audio file here.

Third question: TMPGenc seems to do a lousy job of estimating encoded file sizes -- if I use the wizard, it forces me to encode video down at about 3400Kb/s or so to get the files under 4096Mb, but when the process was finished, the m2v+wav were only about 2700Mb or so. Is that 4096Mb limit what my encoded video and audio should add up to prior to the authoring process, or do the files "grow" in size somehow during authoring and need to be encoded smaller than the specified limit?

Fourth question: TMPGenc runs quite slow on my XP2500+ system. I set up the specs per

http://dvd-hq.info/Compression.html

...and two hours of VHS video was going to take about 25 hours to encode (!). lordsmurf's recommeded settings resulted in a job that took 8 or 9 hours.

Is the highest quality setting for TMPGenc overkill for VHS video, or is this subjective and something I should decide on my own?

Thanks in advance for any suggestions or assistance...

C.K.

[reboot]

2 hours of VHS on dvd is respectable.

Tmpgenc is not the best at estimating time/size, use a bitrate calculator.
Files don't magically grow.
Authoring does take up some room, depending on the complexity and number of the menu's.

Tmpgenc is SLOW, period. 25 hours is about right, depending on your settings. Try Canopus Procoder Express, Mainconcept mpeg encoder, or CCE for much faster results.

IMHO tmpgenc's higest quality settings are WAY overkill for VHS.

[bugster]

You have set up Tmpgenc to produce m2v+wav files. Thats fine but wav is uncompressed audio which will take up too much precious space on your DVDr, resulting in you having to use lower bitrate for video and thus reducing the final quality. Use mp2 or Ac3 for audio. I see you are in the US, in that case I suggest Ac3 as some NTSC DVD players do not play mp2.

[stahlhart]

2 hours of VHS on dvd is respectable.

Tmpgenc is not the best at estimating time/size, use a bitrate calculator.
Files don't magically grow.
Authoring does take up some room, depending on the complexity and number of the menu's.

Tmpgenc is SLOW, period. 25 hours is about right, depending on your settings. Try Canopus Procoder Express, Mainconcept mpeg encoder, or CCE for much faster results.

IMHO tmpgenc's higest quality settings are WAY overkill for VHS.

I had a gut feeling that I wasn't imagining things; just wanted a second opinion to make sure -- I'm still new to this, and haven't made it completely out to the authoring/burning stage yet; tackling the demons one at a time.

I figured that there would be several trial runs until I came up with settings that were the best for the quality of the captured material and for a reasonable amount of time to produce. I think that I'm getting close, but still have more experiments to run. TMPGenc taking as long as it does to encode isn't helping any -- what I think I'm going to try instead is to capture a shorter clip, and perfect the quality there, then take on the whole two hours to make sure that the process runs clear to the end and doesn't barf at some point on the way.

I'm going to take a look at other encoders, too. I just started with TMPGenc since it seemed to be the most widely mentioned/used one I've seen, judging by web site guides. Thanks for the suggestions there.

C.K.

[stahlhart]

You have set up Tmpgenc to produce m2v+wav files. Thats fine but wav is uncompressed audio which will take up too much precious space on your DVDr, resulting in you having to use lower bitrate for video and thus reducing the final quality. Use mp2 or Ac3 for audio. I see you are in the US, in that case I suggest Ac3 as some NTSC DVD players do not play mp2.

I went for PCM at first for compatibility reasons -- I'm thinking that down the road, I may want to trade some of these television shows I'm archiving, so I was aiming for producing discs that would be compatible with the most players.

If I could get away with compressing the audio and still keeping compatibility, I'm going to shoot for that -- the audio on these tapes is just pedestrian hi-fi stereo television audio at most; I doubt that anything noticable would be lost compressing it (and being able to give the freed capacity to the video would be more than worth it).

I'll take a look at encoding it AC3; thanks for suggesting this.

C.K.

[reboot]

Defintely use AC3 2 chan stereo for most compatibility. At 224kbps, there's no (appreciable) loss of quality.
You can speed up tmpgenc, by selecting Motion Search Estimate (fast), without losing too much quality. You could also try a CQ-VBR encode, instead of 2 pass VBR. That'll cut time in half.
Again, the quality is up to you to determine if it's what you want.
You don't have to encode the whole file. Do 10 minutes of it, check your output. If it's not what you want, you've only wasted 10 minutes. If it IS what you want, you've only wasted 10 minutes

[stahlhart]

Defintely use AC3 2 chan stereo for most compatibility. At 224kbps, there's no (appreciable) loss of quality.
You can speed up tmpgenc, by selecting Motion Search Estimate (fast), without losing too much quality. You could also try a CQ-VBR encode, instead of 2 pass VBR. That'll cut time in half.
Again, the quality is up to you to determine if it's what you want.
You don't have to encode the whole file. Do 10 minutes of it, check your output. If it's not what you want, you've only wasted 10 minutes. If it IS what you want, you've only wasted 10 minutes

I'll experiment with those settings.

Any suggestions on an appropriate AC3 encoder? A plugin for TMPGenc (tooLame), or should I encode video and audio separately from the captured .AVI...?

Thanks again for the help. The learning curve on this hasn't been quite as bad as I originally thought it would be...

C.K.

[reboot]

I use ffmpeggui for AC3, and it's output is good on about 99% of players. There's always one that it'll choke on.
Tmpgenc dvd author has an ac3 plugin too, you can use that. There's a recent guide on it.
Always do audio separately (this is just my opinion)