Capturing then encoding vs Encoding

[discofever]

Sorry about the title, didn't know what else to call it.

I just wanted to get everyone's opinion on capturing and encoding vs encoding.

At the moment I am using dvd maestro (aka spruce) to encode video, but am looking at capturing the video into Motion Jpeg then letting Cinema Craft encode it to the bit rate I want. This is all fine, except what about CBR encodes of 8Kbps and 8.5Kbps?

Everything I was taught is saying that capturing it, then reencoding it to something that could have been done once is not only a waste of time, but will also effect (affect?) the quality.

Just curious about what you think.

[chickenmonger]

Two questions to help narrow down the potential answers:

Are you planning on editing your captured video?
What is your computer's performance bottleneck (disk space, processor, etc)?

[discofever]

Video's coming from digibeta.

Video is put to dvd once encoded. Computer is no problem, it can store several Motion Jpeg's. Black Magic 8/10bit is out of the question though (file size too big)

I'm just concerned about the loss of quality. If it's captured then encoded would the degradation of quality be negilible, or would it stand out compared to just doing an CBR8 encode in Spruce?

[phXql]

Use Huffyuv to capture the video. motionjpeg was made to trick human eyes, not encoders. you will lose quality if you capture in mjpeg. Huffyuv is lossless.

[discofever]

Thanks for the advice with Huffyuv.
We tried several different codecs and came to the conclusion that Motion Jpeg is what we wanted/needed. We looked at huffyuv, but Black Magic already has it's own 8/10bit encoder, so we could go with that if it was needed.

[Boulder]

If you use ffdshow's mjpeg at highest quality, I bet you won't notice any visual difference between that and a HuffYUV-encoded file. Capturing straight to MPEG2 is out of the question when you want quality so you're on the right track.

[foxyshadis]

Capturing straight to mpeg2 is no big deal, if you dump enough bitrate at it. Try at least 20mbps for SD or 50mbps for HD for top quality. In fact it's always higher quality than mjpeg at the same bitrate (unless you use a matrix that restricts high frequencies, but you can do that with mjpeg too), it's just that mjpeg is faster and usually uses much higher bitrates, but if both are hardware accelerated, speed difference is unimportant. If you have to get below 10mbps, mpeg2 is a vastly better choice, mjpeg starts looking pretty lousy. AVC is better yet, but if you don't have the power you can't do that.

Since you're re-encoding from a lossy source either way, start with the highest possible quality that you can capture in realtime to.

[Alex-Kid]

DV codec is also good choice for SD video (28 mbps). I don't know what about HDV and processor power.

Saludos

By ALEX-KID

[PhillipWyllie]

I assume your capturing analogue SD video(720*576/480) video. I can capture uncompressed in the YUY2 colour-space no problem with my SATA2 drives. It's best not to compress at capture time as any compression(unless it's lossless will affect quality/capturing efficiency, in fact any compression at any time affects quality. 8Kbps and 8.5Kbps Don't you meant 8Mbps? Anyway CBR video encodes is a big no-no, you have a decent MPEG-2 encoder in CCE(basic, SP, SP2, pro, presto???) that you should utilise in VBR mode. Is this a professional venture? If so I'd invest in a fast HDD array(as much as you can afford). If you do then any subsequent projects can be done at the highest quality by capturing uncompressed. In fact CCE prefers uncompressed YUY2 video(it encodes this faster).

[discofever]

Yeah, I meant 8Mbps, sorry about that.

After being away for a month, they decided to go ahead and just use Decklink Uncompressed 8Bit anyway (which I suggested in the first place but no one listened to me...)

@PhillipWyllie: What's wrong with CBR encoding?

I work for a professional DVD company as an encoder, and even though I've been doing it for a year and a half, coming on two years now, I don't really know anything behind what I'm doing. I know how to do it, but there's still a lot of stuff that I don't know the Why of.

[PhillipWyllie]

...@PhillipWyllie: What's wrong with CBR encoding?...It's not efficient in terms of bit allocation. In CBR the quality will vary, in VBR the quality will remain much the same.

[spyros78]

Capturing straight to MPEG2 is out of the question when you want quality so you're on the right track.

Why is that? I worked in a professional DVD company a few years ago and that's how everything was encoded! Digibeta straight to CinemaCraft or Spruce encoder using VBR. Capturing the tape is a waste of time if you have access to professional equipment as discofever has.

[spyros78]

In fact I'm surprised most people advise him/her to capture the content. Both CinemaCraft and Spruce provide DeckControl and encode on real time. and yes, vbr only, ideally with manual adjustments should you need to.