Compressing 2-hour long movie to DVD- best path

[Mike Petrucco]

I have a 1:54 long movie shot in 1080p30, and it is ready for deliery. My 720p output for viewing on a WDTV looks great. My SD DVD however, is not. I used Compressor's preset for 120-minute DVD, but put the resizing filter to maximum quality (statistical prediction) and left it as progressive. I viewed on two different DVD players (both ~5-year old with output on composite to larger widescreen LCDs), and it looks only so so. I am wondering:

For a 120 minute movie, should I do it on a DL DVD and not compress it as much? Is that what is normally done for something this long?

[Shaun Roemich]

Are you using PCM audio? On a 2 hour disc, that will leave precious little for video. Chances are your video data rate is something ridiculously low like 2 mbits/second. Try re-encoding the asset using AC3 Dolby Digital.

[Mike Petrucco]

I am using the default AC3 audio compressor preset which uses 156 MB of the 4.7 GB.

[Shaun Roemich]

Thanks for responding. I'm now fresh out of ideas.

[Mike Petrucco]

Thanks. I'm not so much having a glitch or rogue setting issue. It's more of a question of what is standard or normal practice for putting two hours on DVD. Is it typical to do a double layer disk or use a single layer at the lower bitrate (which is approximately average 5.0 Mbps)?

[Shaun Roemich]

Well, the problem with burned DL DVDs is they are more prone to playback issues on consumer DVD players than single layers (which are STILL not quite 100%...)

[Shaun Roemich]

And I assume you're using VBR during compression and not CBR...

[Mike Petrucco]

Yes, I am using 2-pass VBR.

[Robert Lane]

Mike,

None of the standard MPEG-2 presets in Compressor will yield the best results; I don't know the name of the thread just offhand but if you do a search for my recent posts you'll find one where I've posted screenshots of exactly the settings you need for best possible output from Compressor. Those settings may or may not allow your program to fit on a DVD-5 (single layer) but if not then use DL.

[Mike Petrucco]

I remember that post, but am unable to find it so far. I will keep looking. I do think that I have a decent handle on the settings, and my output is not horrible. I think I need to get some second opinions on it, as I am so used to seeing HD now, that I think I may not be looking at it objectively. I will run a test of a short duration and do the current settings I am using vs. a higher bitrate and see I have all that much difference.

[Vito DeFilippo]

I find in my experience that videos approaching two hours long quickly start to suffer quality issues from the forced lower bitrate. The difference is quite dramatic even between 1:45 and 1:55. Whenever I have one longer than, say 1:40, I always wonder if it's going to look like crap.

Check out this bitrate calculator:

Bitrate Calculator

A quick check shows that a 90 minute video with audio at 224 allows a pretty respectable video bitrate of about 6550. At 105 minute video drops this to 5580. A two hour video drops to 4850.

That being said, I usually work on PC with ProCoder, so I don't know if Compressor is better at lower bitrates or not.

[Robert Lane]

Mike,

I don't think this is the post I was originally thinking of but it's the same information recycled:

http://www.dvinfo.net/forum/non-line...artifacts.html

[William Hohauser]

Try compressing a small section (perhaps a part that really doesn't look good) to NTSC DV anamorphic. Play that section back on a NTSC monitor straight from the computer and compare it to the same section on the DVD. If it's 90% the same then you probably are not going to get much better. If the NTSC DV section looks significantly better then recompress that section to DVD using the same settings you used for the HD sequence. Burn it to DVD and see if it's any better. I have had better luck with some HD formats by making a NTSC DV version first. HDV was that way for me. ProRes HD has worked well directly to DVD but 2 pass is needed for projects with lots of visual detail.

[Mike Petrucco]

Robert- thanks. I had just found it myself and all checks out. I had learned from that post and had also picked up the Compressor 3 Guide by Brian Gary based on your recommendation a while back. I think this is most likely boiling down to bit rate, but am not sure yet.

William- I can try that out as well and see what I get.

[Robert Lane]

Mike,

Post a screen-shot - if possible - of the same scene in the FCP timeline (at 100% viewer size) and the same in DVD playback either on DVDSP or the Apple DVD player and let's see if in fact you've got unwarranted degradation.