How far have you pushed the DVD Bitrate before having playback problems?

I don't make many DVDs . . . . . possibly a few dozen a year, so my experience is very limited.

I use 7.8mbps as standard and have never had any problems on my 3 DVD players, all of them old and one a real cheapo.

However, last year I put my daughter's wedding onto a DVD-R and gave it to my mother in law.

She played it on a cheap 15" CRT TV with a built-in DVD player.

There were 2 videos on the DVD. The first was a short "highlights only" one encoded at 7.8mbps and the other was 90+ minutes of the whole caboodle encoded at around 4mbps.

I was surprised to see the first part apparently dropping frames etc. occasionally and told her she needed a new player.

However, when we got to the second bit, the playback was perfect, which suggested to me that it was possibly my 7.8mbps encoding that was a little bit too high for some players.

I have been told that replicated discs can be encoded at a higher bitrate than computer generated DVD-Rs, so probably 8mbps would be perfectly safe for a replicated DVD whilst 7.5mbps might be the absolute maximum for a DVD-R.

Another point, is that we have this temptation to squeeze the last bit of speed out of the bitrate but I think you will probably find that anything over 7mbps will not have any noticeable improvement in quality.

In fact you could probably go quite a bit lower without experiencing any degradation of image quality.

Let's work out what percentage of DVD players are likely to deal with various higher bitrates.

That would be difficult to do at best; given all the DVD player brands and models manufactured over the years.

In my experience, a maximum video bit rate of 7.2 has yielded no playback problems, but I have had playback problems using bit rates higher than that.

However, video bit rate isn't the only cause of playback stuttering or skipping. Equally important is the audio bit rate; PCM audio (AIFF) is much more demanding than AC3 (Dolby Digital) and the quality of the media also plays a role in playback stability. And last, but certainly not least, the condition of the DVD player can be a concern. Most people have no idea that the laser lens needs cleaning routinely.

-DH

As David pointed out there are so many variables that it is a virtually impossible task.

Possibly the best solution would be to encode at a maximum of 7.5mbps, with which the majority of players will have no problem, and clearly warn prospective customers that the playback quality of computer generated DVDs cannot be guaranteed on all machines and some folk may need to upgrade.

7.0 up until recently.
7.2 usually.
7.9 is a disaster.
7.8 only on software players on Macs.
7.2 is reliable on software players for PCs.

For me, there is no visually discernible difference between these settings.

This information is anecdotal and utterly unreliable because it's left over from the bad old days when AC3 audio had to be encoded manually as a separate operation. I never mess with bitrates any more.

bogiesan

7.2 is reliable on software players for PCs.

Except when using Windows Media Player. I've yet to find a bit rate that will make WMP a stable player for DVDs. Use a real DVD player application like PowerDVD when on a Windows system.

-DH

I also provided a figure that almost always works . . . . . 7.8mbps.

I have been wondering whether shooting NTSC or PAL will affect the results?

Most PAL DVD players can play NTSC but I don't believe the reverse is true. I wonder whether PAL DVD players are more tolerant with regard to high bitrates?

It's something I have never heard mentioned before and could possibly be a factor.

Before you blame the bit rate, you need to determine the actual cause of the choking. Was Windows Media Player used to play the disc? If so, try another player since WMP is notorious for poor DVD playback. Use real DVD player software like PowerDVD. If it still chokes, then it could be the brand/quality of media used. Many players will choke on poor quality media like Memorex.

The top reasons for DVD player problems on a Windows system include:

· Using Windows Media Player
· Using poor quality media
· Windows computer's resources are weak, e.g.; poor graphics card or cheap RAM
· Background processes or other open applications using too many system resources
· Video bit rate too high
· Audio rate too high

-DH