Formac Devideon usage question

[curtw]

Last week, I used Devideon on my first long (>90 minute) movie. The online bitrate calculator (http://dvd-hq.info/Calculator.html) told me that with 192 kbps audio, I needed to keep the video's bitrate under 6.2 Mbps to fit on a DVD, so I chose a setting of 6.1 in the Devideon slider. Devideon then told me that the final product would take up 4.40 GB, so I figured I was all set. The final DVD image only ended up being 3.7 GB, and my Toshiba DVD player tells me that it's playing back at 5.7-5.8 Mbps.

Here's the problem: I don't know if this bitrate decrepancy is a "bug" in Devideon, or simply a function of the movie I was digitizing (I'm going on the assumption that the Toshiba is giving an accurate reading, which may also be flawed). This movie consists entirely of stationary camera shots. No dollying, tracking, panning or zooming at all. Each "shot" is typically 10-20 seconds in length. I'm guessing that it's possible that the MPEG encoder didn't "need" the extra bandwidth that a moving or zooming camera would cause?

I'd like to find out for sure before I move on to my next project, as it takes about 36 hours on a G3 to encode a 90-minute movie, and I'd like to get the total disc space allocation 'just right' in a single try next time (best quality without leaving any extra space).

Any insights out there?

[incredible]

6.2, 5.7 , 5.8 Mbit ....wow!

I think you really don't need that size of bitrate.

Also I think you don't need "devideon" with its few options!

There are 3 apps. I think they will do all jobs on a MAC you need.

Best quality: BITVICE!! Cause it brings best Quality using 2-Pass VBR encoding! But .... ist commercial and too expensive.

Easy: FFmpegX, this appl. contains all you need to encode .mov's, VOB's and m2v's

Also good quality and many options but a little complicated: Mediapipe or MMT. It let's you perfectly configure the encoding by setting strings which will be send to the mpeg2 encoder!. Gop sizes 4x4 and 2x2 values etc. etc. etc.

If you are going to encode a m2v stream for DVD use max. 5 Mbit, its enough!

Even if you check original m2v streams ripped from a commercial DVD and for example "MPEG Info X" gives you a value of 7.5 Mbit, that means its a PEAK value of the stream!
Professional m2v's are encoded using 2-Pass VBR!
That means for a average 5Mbit stream they set also 3Mbit minimum and 7.5Mbit maximum ... and thats why the mpeg header says 7.5!

Example, when you make a trip with your car and drive on the highway, you need 8h for 800km when driving at 100km/h
But during the trip sometimes you have a break and sometimes you rise up to 180Km/h (I live in Germany ) and the average will still about 100kmh .. so you still need 8h to get to your destination.


The very correct way to calculate a bitrate:

A DVD-5 contains 4,3 GB! not 4,7!

so 4,3 x 1024 = 4403,2 MB

Your Movie is 90 min so calculate 4403,2/90 = 48,92 MB per minute

48,92/60 = 0,815 MB per second

0,815 x 1024 = 834,97 KB per second

834,97 x 8 = 6679,81 kbit per second

Now the value is 6679 kbit! But this is the value for the muxed stream!
Maybe your audio stream gots 224kbit!

Then 6679kbit - 224kbit = 6455 kbit

Also leave some kbit for the muxing and DVD Data, so 6420 will be the best rate for your video to fit on a DVD-R if you really want to cause 5000 kbit are relly enough....

I did it and it worked perfectly

I think Divideon gots a bug .... it doesen't set the same rate to the encoder as you typed in!?


Markus

[curtw]

Also I think you don't need "devideon" with its few options!

Well, it's free when you buy their burner

If you are going to encode a m2v stream for DVD use max. 5 Mbit, its enough!

Not really. I'm using a 13-year-old off-the-air VHS tape as my source. You can probably imagine that this has more than a few flaws. If I had less than an hour's worth of material, I'd definitely keep it at 8 Mbps. at 90 minutes, the ~6 Mbps is acceptable *except* in the area of keeping really BLACK blacks. I don't know if this is a shortcoming of VHS, DV (my intermediate step for importing to the Mac), or Devideon. I suspect it's not Devideon, because iDVD has the same problem. Would one of the other MPEG encoders do a better job of keeping really solid black levels?

[incredible]

Well, it's free when you buy their burner

Well .... FFmpgX, MMT, Mediapipe ..... are also free and got much more options.
These app's are based on the "mpg2enc" engine and on some mjpgtools routines from sourceforge.net, they are developed better than Devideon from Formac.

Even Apples mpeg2 export engine ... quick ... but horrible!

the ~6 Mbps is acceptable *except* in the area of keeping really BLACK blacks.

What happens to the Black Bars??? Are they noisy at 6Mbit?? Do they get artefacts?
Thats why FFmpgX, MMT & Mediapipe got a Denoiser option to avoid encoding the noisy grain which gives you a lot of artefacts in your result.
Does Devideon got this option?

I never had problems encoing sources with black bars.

But you're right encoding old VHS material to high resolution and a good kbit rate cause encoding a low quality source with low quality settings gives horrible results.

But .... decoding .... denoising ... and encoding to mpeg2 on a G3 .... well this will take a loooot of time ... try to get at least a G4 800 at ebay you will "feel" the difference.

Some people capture their VHS Tapes at 352x288 at VCD seetings (cause this are more less VHS settings they say) but as I said ... horrible result when using a VHS Tape source.

[curtw]

Well .... FFmpgX, MMT, Mediapipe ..... are also free and got much more options.

but those options don't include DVD burning hardware. I may "graduate" to more complex tools eventually, but so far, Devideon seems to provide video/audio quality equivalent to iDVD2 and adds even more control over bitrate, so one can exceed 90 minutes.

What happens to the Black Bars??? Are they noisy at 6Mbit?? Do they get artefacts?

I'm not talking about letterbox bars here. I'm working with totally black screens, during opening and closing credits, and at times throughout the movie. And yes, there's a lot of artifacting. Same problem with ANY solid-color screen (in cartoons, etc.), but this is the first thing I've done with a lot of black. I'm thinking of trying my iMovie export at thousands instead of millions of colors, and see if that makes a difference, and reduces the number of "shades of gray" that the MPEG encoder tries to deal with.

Thats why FFmpgX, MMT & Mediapipe got a Denoiser option to avoid encoding the noisy grain which gives you a lot of artefacts in your result.
Does Devideon got this option?

I never had problems encoing sources with black bars.

I can mask black bars in iMovie, and get completely black letterbox bands from a "semi-black" source. The Devideon software recognizes these just fine, and the bands get encoded to MPEG properly. Like I said, that's not my problem.

[curtw]

FFmpgX, MMT, Mediapipe ..... are also free and got much more options.

I just looked at the specifics of these programs, and it looks like none of them can handle NTSC/DV files as an input. Is this correct? Basically, I *need* DV support, because that's what my iMovie output is. Devideon can accept a raw iMovie clip, or a longer stream exported "for iDVD," so it's perfect. As flexible as these tools are, if they can't take my output format as their input, I can't use them.

[schmeg]

Try MediaPipe. I believe it can handle DV input by using the "Quicktime Decode" pipe. It also has "Black&White Restore" options that will work wonders on captured video, and many more toys.

Support for MediaPipe lives here: http://mediapipe.sf.net