Rendering from AVI to AVI

[Jim Wainscott]

In TED I have a 2-hour project in which all clips are DV-AVI with uncompressed PCM audio.

I want to render it to a firewire drive for backup just in case something weird happens to my SCSI array.

If I select the DV-AVI option in the Render panel is it going to compress my source DV-AVI again or will it recognize the original as such and simply pass it through as single video and audio streams?

I don't have enough enough drive space on my firewire drive to store an rtv render.

Thanks for any help on this.

[GoceN]

Jim
is it going to compress my source DV-AVI again

No it will not DV compresion it still be DV, VT it will only pass through the project.

[Jim Wainscott]

Thank you! And Blessings!

I guess it would be safe then to assume the VT does not compress when the source project and destination render are the same format, only when they differ. Is this correct?

[ScorpioProd]

I'm sorry, but the answer you got was incorrect.

It would be a plus if the answer was correct, since that is how Premiere would do it, for instance, but that is not how Toaster works.

The difference is that Toaster is optimized to be a real-time out all the time kind of solution, so 100% of a project is converted to uncompressed D1 as the Toaster plays a project.

The same is true for rendering. IF you take a DV clip and drop it into TEd and do NOTHING to it but render it out, you are most defintately uncompressing and recompressing it.

The good news is as long as you're using a high quality codec like the Main Concept DV codec, you won't really take a visible quality hit.

See, in compression, it's the first compression cycle that does what damage is going to be done, really. When you take that and uncompress it and then recompress it again, just about all the compression optimizing was already done from the first compression and is still there, so the second compression will be clean and won't need to throw out much additional data.

[Jim Wainscott]

Scorpio,

Before receiving your message I did the render using the Microsoft codec (I have a dual Xeon 2GHZ Supermicro P4DC6+) and it looks like I got away with it. Quality hit wasn't noticeable.

When capturing via Microsoft codec I had to use minimal setup - no toastervision. I guess the codec you mentioned is a worthwhile investment.

When I rendered 130 minutes of video to the DV-AVI format I consumed nearly 40GB of hard drive space. The folks at Adobe said that you get 9 minutes of DV video per GByte hence I expected to only consume 130/9=14.4 GB. Can someone explain the discrepancy? Is it inefficiency with microsoft? Will the codec you mentioned consume less space? Was Adobe referring to the audio being intetrlaced within DV when they said 9 minutes/GB and if so why would separating the audio from video neary triple hard drive consumption?

Thanks to all for your help!

[ScorpioProd]

Well, you definately should get the MainConcept DV codec, it is high quality and definately more CPU efficient. (BTW, when you buy it, be sure to turn off the "fastest" mode in the encoder configuration of the codec, otherwise your quality won't be good.)

As for compressed size, DV is DV. DV uses a constant compression ratio of 5:1.

Not sure what the Adobe people were talking about, but it's not the correct data rate of DV. Neither is the 40GB you came up with.

DV, DVCAM and DVCPRO25 are all 25Mb/s formats. That's Mega bits, not bytes. So, dividing by 8 bits per byte, you're looking at 3.125MB/s. Add in audio and "packaging" of the video, and the normal value used for DV data rates is 3.5MB/s.

Since there are 3600 seconds in an hour, that would be 12.6GB/hour of DV. And for your 130 minutes that would be 27.3GB. (Of course this is based on the base 10 definition of "gigabyte", not the base 2 definition, but that's another kettle of fish.)

As for your audio question, there are two types of DV:

Type 1 has interleaved compressed audio.
Type 2 has an uncompressed PCM audio track as part of it.

Type 2 is prefered for Toaster use, and is what MainConcept uses. The size difference due to the extra audio space needed is a small difference, nothing like what you're seeing. The MS DV codec can be either type 1 or 2, depending on if you chose the interleaved audio or not.

[burnhamCG]

We are having trouble with dropped frames on 3 camera live switched shows going to RTV format. Also, this takes up a lot of disk space on a half hour show. After assembling segments in TED, adding titles, etc., we export the shows across a network to an MPEG server using the TMPGNC plug-in.

We tried the DV codec that came with the VT but when we exported to MPEG, the quality was really bad.

The Main Concept encoder is said to be better, but is it also real time on a dual 2Ghz Zeon machine? Is there some sort of codec that is between DV and uncompressed that we could use instead?

(A beginner)

[ScorpioProd]

You should be able to simulataneously switch and capture on a dual-Xeon 2.0 without problems. What kind of drive array do you have?

No DV codec actually comes with T[2]. The MS DV codec comes with Windows.

The Main Concept DV codec is higher quality and more efficient. Therefore, it can do real-time encoding on lower powered machines than the MS one can. But you need to see why you're dropping frames first.

Your dual-X 2.0 should be able to switch and capture while compressing to MainConcept DV.

As for an "inbetween" codec, the PicVideo M-JPEG codec is excellent. At its highest Q factor of 20, it is definately better than DV and yields as low as 2:1 compression. Your machine should be able to handle it in real-time with switching, but again, you should solve the frame dropping problem first.

[burnhamCG]

Thanks Eugene.

Here's what we have. The four Cheetah 73 SCSI drives are on a two channel Adaptec controller using W2K striping across all four. This measures 125-140 MBps on the little (inaccurate but free) Canopus drive test utility that I have. I thought this would be enough performance, but maybe I am missing something.


Supermicro P4DC6+ MOBO
Intel P4 Xeon 2.0 GHz CPU
Samsung 1 Gig RDRAM PC 800 Memory
Chenbro RM411 (A 3411) 4RU CASE
Seagate ST173404LC HDD
Supermicro PWS-024 PS
MSI MX44064MB Video Card
Newtek Video Toaster 2 CARD
Newtek SX-8 BOB
? ADS30016-0000 80/68 SCSI ADAPT
CBS30021-0000 SCSI Cable
LITE ON 32X12X40 CD RW
NEC FLOPPY DRIVE

We have Norton Antivirus and a LAN running on this machine. I will remove the Norton, but I need a way to turn off networking during production and then turn it back on again for MPEG export. Because there are various users, this has to be simple, preferably not involving the bios, rebooting, or re-installation of drivers. I wish there was a toggle switch for this.

Finally, the PIC Video Codec sounds great, but how do we get the M-JPEG files to MPEG? Is there a TMPGNC plug-in for this one as well?

Thanks in advance,
Charlie

[ScorpioProd]

OK, well, you have the same drives and motherboard as me. That should be working. The speeds are fine.

Not sure what to suggest.

People say anti-virus stuff can cause problems, so do try removing it and seeing if that fixes it. I keep my Toaster totally off network, so there's no anti-virus on it.

As for the PicVideo M-JPEG to MPEG question... DV, M-JPEG, etc. are ALL standard AVI codecs, so TMPGEnc and most other programs can read them natively.

It's not a "proprietary" codec like RTV, which would need a special plug-in.

[djlithium]

While the mainconcept DV codec is great, my suggestion would be the MJPEG codec from Morgan Multimedia. You may also want to check out their JPEG 2000 tools and the MJ2K encoding utilities.

While your system is not powerful enough to record directly to MJ2 format while switching, if you are able to render your material out to MJ2K you would be stunned how nice it looks and how small it is. Moving it over a network would be very easy at this point.

The morgan MJPEG codec is wonderful for real-time reocrding however. If you are able to check them out at
www.morgan-multimedia.com

[rbartlett]

There is a toggle switch for each network adapter you are using. Assuming you only have the single fast/gig-Eth port...


Start | Settings | Network and Dialup Connections->[<your network card>]

Hit: properties
ensure tick is in: Show icon in taskbar when connected

I choose to autohide my task bar and start menu, which reduces the need for windows to animate the task bar items.

Then you simply make your taskbar visible and right-click-disable on the network picon. This doesn't remove your configuration (although any network auth/config parameters may need re-initializing when you later restore the port. It simply puts the interface into a inactive state.

Re-activate by selecting again:
Start | Settings | Network and Dialup Connections->[<your network card>]


It is a lot easier to do than to describe in words.

Your network card will still handle network requests but the interruption should be so short that it will be almost like you've pulled out the ethernet "card".