HDV's mpeg2+mpeg2 v.s. DV's dv + mpeg2 workflow

[Brett Erskine]

When its all said and done whats truely going to look better on DVD? - HDV's mpeg2 or regular cameras like the XL2 or DVX100a with DV's standard compression?

(Keep in mind that HDV is forced to down res to 720X480 and compress yet again with MPEG2 to meet DVD's maximum standards)

Rather than turn this into a hypothetical numbers discusion lets see some FULL resolution frame grabs from the camera and then apply DVD's mpeg2 compression to it and repost the example here on this thread.

[Barry Green]

The proper camera to do that test with isn't on the market yet: the Sony FX1. Give it a month, and when it comes out, then we can run the test.

Using the FX1 will let you know because you'll be using the same camera, the same CCD's, the same everything, just changing the internal recording format from HDV to DV.

[Troy Lamont]

Brett,

That's really a no-brainer without the photographic proof. You're taking 720p or 1080i and downconverting it to 480i/p vs taking 480i DV and converting it to 480i/p MPEG2.

The higher resolution source will always win out, period.

I've done many tests with my HD1. I've compared the 4:3 640X480i to the 16:9 720X480i to the 720X480p MPEG2 and finally the 1280X720p all converted to 720X480i MPEG2 DVD. The higher res 720p wins out on final quality everytime.

I've done those tests with hardware MPEG2 decoders on a standalone DVD recorder as well as three different software decoders including MainConcepts MPEG Encoder (one of the best), Ulead's DVD Workshop 2 and a cheaper Roxio MPEG encoder.

(Keep in mind that HDV is forced to down res to 720X480 and compress yet again with MPEG2 to meet DVD's maximum standards)

Keep in mind that when you start will less (DV) and have to compress it (MPEG2) you'll end up with less.

Also, doing screen grabs doesn't show you motion artifacts that would be inherent to the downconversion.

Troy

[Dennis Hingsberg]

Troy,.

So from the perspecitve of work flow, is there a difference between editing HD footage then downconverting for DVD authoring, or just downconverting to 720x480 first and then editing and then authoring on DVD?

[Giroud Francois]

usually the final conversion is done AFTER any editing.
It is editing which brings losses.
So if you start high, convert to SD and edit it, there is no gain.
You already bring you signal to maximum quality possible for DV (that is pretty low), and editing it will only bring you to a "less than maximum".
In the contrary, editing an hi-quality signal, will probably bring less damages to the signal than will the final conversion to DV.
If working HD is not affordable for you, you can choose for a SD resolution with hi quality codec (like DVCpro50).
This keeps the filesize reasonable and works in regular resolution while keeping a better than DV quality.

[Troy Lamont]

Dennis,

Pretty much what Giroud stated.

I'd throw in a tidbit.

If you have DVD authoring software that allows you to only encode the MPEG2 edits and not re-encode the entire project that's already DVD ready, then it's pretty much a standoff. You can do the downconvert first with no additional huge tradeoffs in res if you're comfortable using the MPEG2 editor vs one that does TS natively.

Troy