Bitrates

Dan Sherman wrote on 6/12/2006, 4:33 PM
Posted earlier about project that plays fine on stand alone DVD player and NTSC TV.
But,---on LCD projector there was a freeze problem.

NOW,---client says the DVD is kicking back to the main menu during playback at a point where it should not even be storpping.
And the last time she viewed the DVD, the audio was missing from two interview segments!?
I find no problems with it in either my computer or stand alone players.

It has been suggested that the birate was set too high and that some machines can't handle 8000 mps. So I set it back to 45 hundred.
This project is only 40 minutes long, so there's lots of room
Will test the newly burned DVD tomorrow.

Another suggestion is that the disc is flawed, scratched or dirty.
Are there any other things I should be looking for.
I have to deliver 15 hundred of these this week and this is frankly making me uneasy!
Don't want to have to pay for two replications!!!
Need the experts here.
Thanks.

Comments

johnmeyer wrote on 6/12/2006, 5:43 PM
It has been suggested that the birate was set too high and that some machines can't handle 8000 mps. So I set it back to 45 hundred.

Is this the ONLY thing you changed? Same media? Same burning app? Same burn speed? etc. etc.

I ask this because if this is the ONLY thing you changed, I'll sure be interested to hear if this fixes the problem. I've read a lot of things about rendering at lower bitrates can make the disk more compatible. At first I completely rejected this idea, but I can now see that if the disc exhibits a high error rate on the player, for whatever reason, that the time it takes to slow down the disc and re-read the disc, might cause the player's buffer to underflow and therefore hang up or glitch.

Supposedly all players are required to be able to play continuously at data rates up to 10,000 kbs (including audio).

Anyway, let us know what happens.
Dan Sherman wrote on 6/14/2006, 4:40 AM
Burned at about half the bitrate, 4700.
DVD performed falwlessly.
Project is for school board whick has some older players.
Something to keep in mind,---trimming back the bitrate will make the disc more compatible.
Sol M. wrote on 6/14/2006, 1:51 PM
Supposedly all players are required to be able to play continuously at data rates up to 10,000 kbs (including audio).

This is the requirement, but it is believed that many manufacturers do not produce hardware that meets these requirements.

Another issue is using PCM audio instead of AC3 audio. If you do, the overhead will be much greater. Using AC3 is always recommended.

I try to keep my entire bitrate (audio+video) below 9000kbps. I usually never encode the video at a higher bitrate than 7000-7500kbps, because there doesn't appear to be any increase in quality past that point (as some tests appear to confirm).