View Full Version : Is it possible to put 24 Bit PCM audio on a DVD video?

2006-12-11, 10:35 PM
does anyone know if that's compatible? can it be done?

2006-12-11, 11:11 PM

PCM Possibilities
Linear PCM is uncompressed digital audio like the audio on a CD-Audio. In DVD-Video, however, both 48kHz and 96kHz sample rates are supported, as are 16-, 20-, and 24-bit word lengths. Theoretically, this means that the PCM audio on a DVD-Video may be much higher resolution than on a CD.

2006-12-12, 12:13 AM
thanks. I thought so. but when I add a 24 bit wave thats 2304 kbps in dvd architect and then look at "optimize dvd" it shows it as 1536. I don't get it. if I try to use that in architect I don't know if it's going to resample it or something or screw it up or what.

2006-12-12, 12:19 AM
what I'm really worried about is compatibility. I'm making a DVD to share and I don't know if it will screw up in some people's players

here's another quote fron that link:

Unfortunately, while it is possible to create a DVD-Video soundtrack with high-resolution audio, it is not possible to guarantee that the viewer will actually hear the sound at full resolution. Many DVD-Video players decimate 96kHz audio to 48kHz prior to D/A conversion, and some players also truncate 20- and 24-bit samples to 16 bits. In addition, the majority of DVD-Video players on the market provide only two outputs for discrete audio channels.

^so would that cause quantization errors or whatever or would it just sound like 16 bit?

2006-12-12, 11:31 AM
the thing with 24bit is that most "normal" ppl have computers with soundcards that can only play maximum 16bit anyways and in the event that 24bit is encountered it is crudely changed to 16 by truncating, while the proper method which gives best sound is dithering it down. I'm not sure how many standalone players support 24bit playback to be honest, especially considering that many traders are using very cheap DVD players these days because they have maximum compatability with home-burned discs.

you could burn a short test disc with 24bit audio and try it on several standalone dvd players to see if any glitches occur, and take a tap from the digital out and check it with bitviewer (http://tobybear.de/p_utilbag.html) to see if the player is spitting out 24 or 16bit audio. Only thing is, this doesn't test the analog outputs (!)... so, first thing is to determine that your player (also try some different makes/models) is positively capable of spitting 24bit out, then to test the analog outs (which could well be different), you would need to create your own truncated 16bit from the 24bit and find a fade where you can hear it sputtering (from not being dithered properly) then listen carefully for those artifacts. It can be quite subtle, but this is the only way I can think of right now to test for this.

if you find anything out, please share the info as it seems nobody really knows the answer at this time... (or else, somebody else please post and set things straight for me).

2006-12-12, 02:21 PM
I think this outdated info.... I haven't seen much that is NOT 24/192 anymore. :hmm: my DVD player has optical outs. don't they all?

2006-12-12, 02:35 PM
as I recall mine is coax but that doesn't determine max bitdepth it is capable of on playback

2006-12-12, 02:41 PM
yes I know... i was just pointing out that it seemed outdated since we weren't discussing optical. Doesn't yours do 24/192? google search yields lots of results. Mine is a Denon. I bought it at least 8 years ago. maybe more.... actually it may be 24/96. I can't remember..... and we weren't discussing optical vs digi coax maybe I was talking to myself. :lol

I do think the compatibility issues with DVDs were really early issues like 1996 early.. I haven't run into any problems recently. dif media dif player etc.... no problemo. Do people still have problems?

2006-12-12, 09:44 PM
thanks for the input everyone.

I just made a dvd with architect and added the 24 bit audio @<hidden> 2304 kbps

gspot or questionman don't tell me what the audio bitrate of the files is so I don't know if architect kept it like that

like I said, under "optimize dvd" it was telling me that the audio bitrate was gonna be 1536

anyways, I burned it and tried it on 3 different players. the audio did not sound nearly as good as it did before i put it on the dvd, and then when it got to this one bassy part, it just started clipping all the bass

I guess I'm gonna go back and replace the audio with the properly resampled and dithered 16 bit

2006-12-12, 10:19 PM
Hey rocknroll. DVD Architect will not support 24 bit audio, as you found out, it automatically dithers to 16 bit. DVD Lab Pro 2.0 will support a 24 bit, 48k audio track. I'm not sure about 96k, so I'd stick w/ 48k. It would seem it all depends on the capabilites of your receiver and DVD player. Here's a paragraph taken from a DVD Demystified FAQ:

Linear PCM is uncompressed (lossless) digital audio, the same format used on CDs and most studio masters. It can be sampled at 48 or 96 kHz with 16, 20, or 24 bits/sample. (Audio CD is limited to 44.1 kHz at 16 bits.) There can be from 1 to 8 channels. The maximum bit rate is 6.144 Mbps, which limits sample rates and bit sizes when there are 5 or more channels. It's generally felt that the 120 dB dynamic range of 20 bits combined with a frequency response of around 22,000 Hz from 48 kHz sampling is adequate for high-fidelity sound reproduction. However, additional bits and higher sampling rates are useful in audiophile applications, studio work, noise shaping, advanced digital processing, and three-dimensional sound field reproduction. DVD players are required to support all the variations of LPCM, but many subsample 96 kHz down to 48 kHz, and some may not use all 20 or 24 bits. The signal provided on the digital output for external digital-to-analog converters may be limited to less than 96 kHz and less than 24 bits.

2006-12-12, 10:32 PM
ah yes. I knew something was up. thank you.

2006-12-12, 10:57 PM
You're welcome. Kinda hard if you don't have Lab Pro 2.0 though. One thing I should add is that Lab Pro will tell you that "Normal DVD Players only support 16 bit audio"...whatever that means, might be a bad sign, who knows. But I have done "test" renders, and it initializes the 24 bit audio packet w/o any problems, unlike Architect. I am going to be working on a DVD very soon here, of which I have a 24 bit fileset. I'll see what happens on my players, then return to this thread when I have my results. Shouldn't be but a couple weeks max. This is an interesting subject.

2006-12-13, 08:04 AM
1536kbps is the "normal" steam available on DVDs, I believe, while 8000kbps is used for video. Maximum data steam of a DVD player is 9600kbps. I'm not 100% sure, but I think that as long as you don't peak above 9600kbps with combined audio/video rate, you should be fine, so try encoding your video at a lower bitrate.

2006-12-13, 03:45 PM
1536kbps is the "normal" steam available on DVDs, I believe, while 8000kbps is used for video. Maximum data steam of a DVD player is 9600kbps. I'm not 100% sure, but I think that as long as you don't peak above 9600kbps with combined audio/video rate, you should be fine, so try encoding your video at a lower bitrate.

Yes, I did encode the video at 7000 to make room for the audio bitrate, so there were no problems there. The issue is just with 24 bit audio.

2006-12-18, 09:53 AM
Basic 24 bit FAQ (http://24bit.turtleside.com/)
24-bit "audio-only" dvd-video: Lplex (http://audioplex.sourceforge.net/)

2006-12-20, 01:32 PM
O.k. I have successfully created a DVD-Video with 24/48 audio, and not only that, but 24/96 audio as well. For the 24/96 bitrate of 4608 kb/s, I had to render my video at a max bitrate of 5000 kb/s. I was working w/ a Hi8 master, and cannot tell a difference in picture quality versus a 8000 max bitrate. This brings new meaning to the picture being half the experience, and the audio being the other half. Literally. Your DVD player must be capable of outputting a 96k signal, as well as your receiver. Otherwise it will be down-sampled to 48k and not use all 24 bits. This was accomplished with DVD Lab PRO 2.0. Again, Sony DVD Architect is not capable of this. But working w/ 24/96 WAV's can be tricky, because most programs will not work with WAV files over 2GB in size. SoundForge, Vegas included in those programs which cannot handle it. But there is a loop hole, so to speak. If there are any questions about that, I can answer them.

2006-12-20, 02:29 PM
final cut has supported 24bit PCM audio for years

you pc people and all your complicated shit :lol ;)

2006-12-20, 03:25 PM

2007-01-02, 02:36 AM
Excellent. Thank you for your input.