Before Replication: Compatibility Doubts

[Steven Donovan]

I have a 90 minute movie that I've authored to DVD with Adobe Encore 2.0 (that one sentence cost me weeks, by the way). I've tested it on my el cheapo ($25) DVD player, and everything is fine.

So far, so good.

However, to be thorough before going to Disc Makers for replication, I tested it on a number of other DVD players. It worked fine on most of them, but there were two problem units.

On both machines, the Main Menu came up, but the cursor to "Play Movie" sometimes did not. When it did (after re-loading) and "Play Movie" was selected, the opening shot of the movie quickly froze and either shut down the machine, or eventually skipped and stuttered into playing the movie.

Since this opening shot was encoded at a higher bitrate than the rest of the movie (8.4 Mbps as opposed to 6.4 Mbps for reasons I won't get into), I decided to re-encode it to the average 6.4 Mbps bitrate to see if that made a difference.

It did on one player, but not the other.

The player it solved the problem for was brand new. The movie now plays perfectly in that machine.

The other player was a years-old Sony model, and still experiences the freeze and stutter at the beginning - before going on to play the rest of the movie just fine (including a couple sections that were encoded at the higher 8.4 Mbps bitrate??).

I'm somewhat befuddled as to what to do next.

What I can't answer is the following:

Is this a problem the older player is having because of encoding/bitrate issues (i.e., my problem), or DVD-R media issues (i.e., its problem)? By the way, I'm using high quality DVD-R (Taiko Yuden).

This older machine plays regular Hollywood (i.e., replicated or pressed) DVD's just fine. Further, in the past, it has been able to handle various burned DVD's (though they were not feature length).

I've been told (by Disc Makers) that the problem could just be a compatibility issue that will go away once the project is replicated, i.e., if the DVD plays just fine on most machines, it probably isn't an authoring problem.

However, I feel uneasy about this, as I'd obviously like to build as much player compatibility into the disc as I can before running off several hundred (nonrefundable) copies.

Any suggestions?

Thanks,

Steve

[Steven Donovan]

Here's an update:

I just got back from my sister's house, where I ran a couple more tests on the older DVD player (Sony DVP-NS300).

Basically, I re-encoded the opening shot of my movie to an even lower bitrate, this time setting it to 5.5 Mbps instead of 6.4 Mbps. There was a significant difference in the way the DVD performed.

While it still didn't play properly, it DID always come up with the "Play Movie" cursor ready to go on the Main Menu, and it DID always start playing smoothly...

...until it hung, froze, and skipped again.

My point is, it played smoothly for a longer period at the lower bitrate. This seems to indicate an encoding/bitrate issue. Further, it seems to indicate that if I try encoding at an even lower bitrate, the DVD may actually start playing properly in this older machine.

I'm probably going to try encoding the opening shot at 4 Mbps tomorrow. My question is: How low can/should I go?

Another question is: If I encode the opening shot at 4 Mbps, is there a problem if the next sequence jumps to the average movie bitrate of 6.4 Mbps?

I worry that I may be denigrating the opening shot (or jeopardizing the transition to the next sequence) for the 95% of DVD players that can already play the movie at the higher bitrate, to make it compatible with the 5% that can't.

Anyway, I'm still working on it.

Steve

P.S. Just a reminder: This older player DOES play the movie just fine once it gets past this opening shot, which lasts about 30 seconds. It skips and stutters and eventually locks into the next sequence, which is encoded at the movie average bitrate of 6.4 Mbps.

[William Osorio]

Steven:
Did you converted the audio files to DOLBY AC3?? or you're using PCM??
That could lead in to a playing issue too.
Here is the math::
----------------------------
Minutes = disc capacity (GB) x 400
--------------------------
Bit rate (Mbps)

Don’t forget about audio, so if you like to use 6Mbps video compression and 1536kbps (48kbps PCM) you need to ad 7.536 into the formula.

4.7 x 400 = 1880 = 1 hour, 23 minutes, 9 seconds
--------- -----
7.536 x 3 = 22.608

If you know how long will be your program, you can calculate the maximum possible bit rate.

Maximum bit rate (Mbps) = disc capacity (GB) x 400
-----------------------
Minutes x 3

For example
4.7 x 400 = 1880 = 5.22 Mbps
---------- ----
120x3 = 360

With that information, means that encoding your video @ 5.0Mbps with a 128kbps Dolby Digital audio stream you have a perfect amount of space left over for the menus.

------------------------------------------

1-Try a different media also.
2- don't go over 7.5 bit rate encoding
-----------------
Things to remeber when authoring::
1- need to set first disc action (play intro, FBI intro etc and to jump from there to menus etc)
2- region system
3- after last track plays to jump or to stop in any particular place.

William Osorio

[Mark Williams]

Steven,

I have worked with discmakers on several replication projects that turned out with no DVD rejects. This is what I have learned.

- Use a very good DVD-R disc for your master. Do a search and you will probably find out that TAIYO YUDEN premium is considered by most to be the best of the best.
- Be sure your audio is PCM or AC-3 and not mpeg.
- Handle you master with extreme care by the edges.
- Burn master at a lower speed than the maximum.
- Of course try it out on as many different DVD players as possible which you have done already.

Also, after reviewing your comments I don't think bitrate is your problem. I burn my masters at 7500kbs CBR for the video and let the audio make up the balance. My projects are less than one hour in length thus the higher bitrate for better video quality.

Hope this helps,

[Steven Donovan]

William and Mark, thank you both for your replies.

Bitrate Budgeting is no longer the issue (though it started out as the primary issue). This 90 minute movie is a compliation of shorts, the vast majority of which have been transcoded to a 6.4 Mbps bitrate. A few, however, needed to be transcoded at a higher bitrate (8.4 Mbps, which is what Encore gave me on its "Automatic" setting) because of effects/motion "pixilation" issues. One such Asset was the opening shot of the movie, approximately 20 seconds long. When I transcoded it at the higher bitrate setting, a couple DVD players had trouble playing the beginning of the movie - though they were eventually able to "sync up" and play the remaining 99% of the movie (including sections encoded at both the 6.4 and 8.4 bitrates).

I then lowered the opening shot bitrate to 6.4 and this solved the problem on one of the problematic DVD players (a brand new machine). It did not solve the problem on the older machine. So I lowered it again, this time to 5.5 Mbps, which allowed the older machine to play the opening shot for several seconds longer before it froze and/or skipped. Again, the older player could still play the 99% of the movie after the opening shot.

My plan to transcode the opening shot at an even lower bitrate (4 Mbps) seems to have hit a snag: Encore won't let me do it. Even using a 4 Mbps CBR Custom Preset, Encore reports a "Transcoded" bitrate of 5.5 Mbps.

Maybe it's a sign I should give up.

My plan now is to take the DVD (with the 6.4 Mbps opening shot) to an electronics store and test it on as many DVD players as I can. If it works, I may just have to take a leap of faith and go to the Replication House.

Anyway, thanks again for reading.

Steve

[Nate Weaver]

Steven, I think your issue is a media compatibility issue, not an authoring or encoding one.

Lowering the bitrate on the problem shot is allowing the player to get farther through the problem spot, but I think it's experiencing the same issue, that it just doesn't like that media.

You can get a little bit more to the bottom of it if Disk Makers allows you a check disk to sign off on. That would be the piece to take to Best Buy for testing or whatever.

You were on the right track thinking the bitrate could have been too high for the player, but now that it's down to 5.5, I think you've ruled that out. Now the bitrate is just too high for how well the mech is being able to read it (which is to say, poorly).

I've authored quite a few dual-layer/DLT projects with large runs, I never had a problem with 6.5mbs. My personal limit was 8.5, including multiple audio streams, titles, and sometimes another video track as well. And I was the one that always got forwarded the end-viewer complaints that came in via email :-)

[Steven Donovan]

Thanks for your message, Nate.

Two things of note, before I sew up this Thread:

1. I found out in the Adobe Forums that the bitrate numbers I have been quoting, those reported in the (transcoded) bitrate column of Encore 2.0, are in fact the ADDITIVE bitrates for both audio and video. Because I encoded using PCM instead of AC3 (Dolby Digital), the actual "video only" bitrates are the numbers I've quoted MINUS 1.5 Mbps (bitrate for PCM). This means most of my movie is actually encoded at a video bitrate of 4.9 Mbps (6.4 - 1.5) while three of the shorts are encoded at a video bitrate of 6.9 Mbps (8.4 - 1.5). Thus, with an overall average movie bitrate around 5.0 Mbps (which fills up most of the disc), this is about as low as I want to go.

2. I tested the 6.4/8.4 disc in about 20 DVD players at Frye's, Best Buy, and Circuit City (all conveniently located near the same intersection!). I tested it in standalone DVD players, low and high budget, every brand name (some of which I didn't even recognize); I tested it in DVD/TV combo units; and I even tested it in el cheapo portable DVD players. About 2 dozen units in all.

It played in every single one of them.

The Bottom Line: I'm going to Disc Makers for Replication.

Again, thanks for your message. It makes me feel better about my decision.

Steve

[Bryan Aycock]

If you get a good read off of any DVD player, then your disc can be replicated just fine. Once replicated, there will be NO issues with ANY DVD player, as all DVD players must meet specific criteria. All of those compatibility problems are a result of the DVD-R, and will go away once replicated, because it's an entirely different process than burning.