View Full Version : Real-time DV to MPEG2 encoding


Brian Dombrowski
August 3rd, 2005, 06:14 AM
Does anyone have experience using hardware-based DV to MPEG2 encoders such as the ADS DVD+DV "box" or other CODEC hardware?

I'm basically looking for opinions on what people think of various hardware DV to MPEG2 CODEC solutions versus software based CODECs.

Thanks in advance,

Brian D.

Devin Eskew
August 3rd, 2005, 08:29 AM
From what little opportunity I've had to use one (Very expensive) I was very impressed with the overall speed and quality. That being said they have just been too expensive in the past to really consider purchasing one. More times that not it blows software encoding away. Which chip set were you looking at? i.e. brand. Don't overlook software encoding as it is fast enough and costs considerably less. Main Concept and Sorensen put out some nice encoding. Don't worry others will be along shortly to sing the praises of Pro-Coder and TMPGEnc. Any of these choices are good. What are you planning to do with it? Do you have a tight deadline that requires speed above all else? I guess I'm wondering why you are looking at the hardware side.

Brian Dombrowski
August 3rd, 2005, 09:26 AM
Well, the ADS Tech DVD+DV hardware can be had for about $160 now. That will take DV in via firewire, transcode to MPEG2 in hardware, and then stream to the PC over USB 2.0 in real-time.

There are two reasons I'm looking at this solution. One is it's a way to leverage my very stable 800 MHZ PIII system. The other is that I can go live direct from the DV camera to MPEG2 on the PC in real-time w/o having to serialize the time required to run a soft CODEC. This is assuming that a soft-CODEC needs to be run after transfering the DV to the PC, and that it can't run real-time.

Do any software CODEC run real-time, or near real-time from a DV stream to a PC? If so, what kind of performance is required of the PC's hardware?

Thanks,

Brian

Devin Eskew
August 3rd, 2005, 09:48 AM
Sorry I thought you were looking at the Canopus MVR-D2200 which starts at
$1,449.00, there are others that run a great deal more. As for "real time" I might ask what your destination is: DVD, Web, VCD? Also are planning on doing any editing of the footage? The ADS Tech DVD+DV from what it appears would be like the Canopus 100 or 300. Heres the link I checked out: http://www.adorama.com/VDPYIDVDPDV.html

It is basicly a "pass through" device like the Dazzel DV Bridge, while true it "encodes" this is no where near what what I thought you meant. This may be a good device to start with, however if you are really into this I think you'll be up-grading it within a year. This is a VERY basic system that gives you editing and basic authoring abillity. Without timebased correction and a few other goodies such as the Canopus 300, you will run into issues from time to time capturing from a deteriorated analog source the the 300 would correct for you. This means "dropped frames" in most cases. There are many programs that can show your capture in real time. The question remains, what are you looking to do with it. If its just placing home movies on disc, then this is the way to go! If you want more, you may want to consider spending a little more. Your system spec's are on the edge of what is out right now. 800Mhz may not quite be fast enough. For comparison here are the "minimum" specs to run V-6 & DVD-A3:

# Microsoft® Windows® 2000, XP Home, or XP Professional
# 800 MHz processor (2.8 GHz recommended for HDV)
# 200 MB hard-disk space for program installation
# 600 MB hard-disk space for optional Sony Sound Series Loops & Samples reference library installation
# 256 MB RAM (512 MB recommended for HDV)

Hope this helps, let me know what your looking to do, and I'll get you more info!

Brian Dombrowski
August 3rd, 2005, 12:06 PM
Hi Devin,

There are three uses I have planned. (1) and (2) assume a DV camera as the source with firewire output.

1) Take live camera shots and go straight to MPEG2 to disk. So, thats tapeless transfer from DV camera to disk as MPEG2. I would then edit using Adobe Premiere 6.5, which supports MPEG2 source clips, and finally author DVD using Ulead DVD Workshop 2.0. This would save me tons of time when I know my final destination is DVD only.

2) Just like (1) above, but also save to the camera's miniDV tape so that I have original footage saved in DV for future projects where MPEG2 ain't going to cut it. (no difference as far as CODEC in this scenario.)

3) Take composite video in from either VHS or Hi8 and transcode to MPEG2 for DVD authoring using Premeire 6.5 and Ulead DVD WS 2.0.

So I really don't need much of the software bundle that comes with ADS DVD+DV plus product, since I have better NLE and authoring tools already. What I'm trying to avoid is all that time the PC spends transcoding to MPEG2, and also the disk space required to store DV, when I only really need MPEG2 for the particular project.

One thing that concerns me is the level of control over MPEG2 compression settings the ADS Tech DVD+DV box gives me. That could be an issue. Any thoughts or comments on this one?

Thanks,

Brian

Boyd Ostroff
August 3rd, 2005, 12:28 PM
Have you considered just using a standalone DVD recorder with firewire input connected to your camera? These are getting less expensive and the one I have does a very nice job at the HQ (1 hour) setting.

Devin Eskew
August 3rd, 2005, 12:32 PM
[QUOTE=Brian Dombrowski]

1) Take live camera shots and go straight to MPEG2 to disk. So, thats tapeless transfer from DV camera to disk as MPEG2. I would then edit using Adobe Premiere 6.5, which supports MPEG2 source clips, and finally author DVD using Ulead DVD Workshop 2.0. This would save me tons of time when I know my final destination is DVD only.


Live camera is a nice thought, however I think you will run into issues with either:
1. Your system not being fast enough to encode and captue at the same time, however if your just getting a talking head with little action, you should be fine.
2. Your "pass-through" via the box, may not be able to keep up with sustained through-put. I have played around with a Dazzel one of my students brought in and it promised the same thing. What it ended up doing was storing the capture when it couldn't keep up, and then had to encode to DVD anyway. Thus no time was really saved by going this route.
3. I personally have had poor results when encoding to MPEG-2, edit and re-encode for delivery. It tends to be compression upon compression.


2) Just like (1) above, but also save to the camera's miniDV tape so that I have original footage saved in DV for future projects where MPEG2 ain't going to cut it. (no difference as far as CODEC in this scenario.)

That should be fine, a word of caution, the more gizmo's you run your DV camera via firewire through, the more of a chance to have something go wrong with a capture. Best bet is to directly plug into your computer.


3) Take composite video in from either VHS or Hi8 and transcode to MPEG2 for DVD authoring using Premeire 6.5 and Ulead DVD WS 2.0.


This is what this device is best for!!! Use it and abuse it, this is how most do transfers from analog. Word of caution, most newer devices feature copy protection i.e. if what you are tring to capture is copy protected, the "pass-through" will either be dark, or not capture. However this is an item most cheap pass-through devices do not bother putting on their products so beware.



One thing that concerns me is the level of control over MPEG2 compression settings the ADS Tech DVD+DV box gives me. That could be an issue. Any thoughts or comments on this one?


When I go back over the on-line product info, in every instance it says "Capture" before almost every product claim.
"Capture in real time", while this is true it implies that somewhere along the line it will need to "encode" MPEG-2. This tells me that you will end up waiting at some point. It's a good price to try out, however just don't expect it to deliver the moon. If you are realistic about it then you won't be dissapointed. good hardware encode to MPEG-2 is out there, I've just never heard of it at anywhere near this price. As for the options it will give you? The variable bit rate is nice, but I think you will find FAR more control over your encode using Premier or Unlead. Hope this helps, if you have any questions let me know!

- Devin

Dan Euritt
August 3rd, 2005, 05:02 PM
Take live camera shots and go straight to MPEG2 to disk. So, thats tapeless transfer from DV camera to disk as MPEG2. I would then edit using Adobe Premiere 6.5, which supports MPEG2 source clips, and finally author DVD using Ulead DVD Workshop 2.0. This would save me tons of time when I know my final destination is DVD only.

there is a major flaw in that workflow, and it's with the concept that premiere 6.5 "supports" mpeg2 source clips.

the only "support" you will see there is a complete re-encoding of everything that you put into the premiere 6.5 timeline, so the picture quality will be garbage... the golden rule with mpeg2 is to *never* re-encode it!

there are also issues with creating ac3 audio, which is a really good thing to put on a dvd... if your encoders don't do it, how do you plan to encode it?

take a close look at all the options before committing to anything... the only good reason you have for being stuck on a pIII would be a budget issue, there are much better alternatives if you have the money.