Hi,

Mastering a DVD at the moment and have run into the problem of DVDSP 'bitrate too high' warning. Some research suggested it's the audio which I want to burn at 24bit 48K (i.e. max spec for DVD) so I removed the audio and it burnt fine so this is clearly the issue. I still want the best audio I can get so does anyone know any way round this or the best audio compression I can get away with (I compress everything in Compressor first)?

Thanks,

Geoff

Hopefully this will help:

From wikipedia-

"The official allowed formats for the audio tracks on a DVD Video are:
--PCM: 48 kHz or 96 kHz sampling rate, 16 bit or 24 bit Linear PCM, 2 to 6 channels, up to 6144 kbit/s. N.B. 16-bit 48 kHz 8 channel PCM is allowed by the DVD-Video specification but is not well-supported by authoring applications or players.

--AC-3: 48 kHz sampling rate, 1 to 5.1 (6) channels, up to 448 kbit/s

--DTS: 48 kHz or 96 kHz sampling rate, 2 to 6.1 channels, Half Rate (768 kbit/s) or Full Rate (1536 kbit/s)

--MP2: 48 kHz sampling rate, 1 to 7.1 channels, up to 912 kbit/s

DVDs can contain more than one channel of audio to go together with the video content, supporting a maximum of 8 simultaneous audio tracks per video. This is most commonly used for different audio formats—DTS 5.1, AC-3 2.0 etc.—as well as for commentary and audio tracks in different languages."



-Jon

Cheers Jonathan. Did some calculations and if I stick with 2 channels of audio at 48K 24bit looks like the maximum bit rate for the video is about 7.2kb/s - I had it set at 8.2 (though the average was at 6.9) so maybe that's the problem. Good old Wikipedia - didn't realise that to calculate the bit rate of PCM audio you simply multiply the sampling rate x bit depth x no. of channels. So for stereo at 48K, 24 bit it's 2304 kb/s. I then used an online DVD bitrate calculator to get the 7.2 max bitrate.

Will try it tomorrow!

Geoff

Will try it tomorrow!

Geoff

Please report back as to the results. I'm curious as to the outcome.

Cheers,

-Jon

Jonathan,

It worked - set the max bit rate in Compressor to 7.2 which meant the highest average bit rate allowed was 6.1. Seemed a bit low but the video looks fine on my relatively modest HDTV. Another bitrate calculator suggested 7.4 would be OK but I played it safe. I might try using 16bit audio as this would allow about 8.2 as the max bitrate, to see if I can see any difference in the video resolution.

Obviously all this depends on the length of the video - mine as about 40 minutes.

Next problem is how to get menu text to look anything like acceptable in DVDSP!!

Geoff

Very glad to hear it worked. That's good news.

Thanks much for the update.

-Jon