DVD standard and the process....

[vasudev71]

Hi,

I'm planning to buy HP200e Firewire DVD Writer.
I would like to transfer DV video (NTSC) to DVD+R/DVD+RW.
I have questions on the Audio part on my DVD disc.
The DV audio is usually 2-channel 16Bit WAV file.
How do I convert this WAV file to be compatible with DVD specs?
Should I use SoftEncode to convert this as a AC3 or a PCM file?

Ulead DVD Workshop 1.2 now supports PCM Audio WAV file which is compatible with most of the set-top DVD players.

I would appreciate any help from experts.

VS

[Arky]

You have a number of options when authroing Audio tracks for DVD:

# PCM (i.e. the native audio standard of what you capture over firewire, except that it's demuxed from the video, obviously!)

# AC3 (Softencode, or Scenarist will convert WAVs / PCM into AC3 for you)

#DTS - this requires the Minnetonka DTS encoder, but is really only appropriate / worthwhile if you have multichannel audio source, which is unlikely with DV (although the DV format does allow for four channels, with two of them being "voiceover"). To be honest, home authorers do not really need to concern themselves with DTS. It also takes up a horrendous amount of disk space, too, which is another reason why DVD-R home authorers don't use DTS - this is for the commercial projects which can be easily pressed to larger capacity disks.

# MPEG1 Layer 2. This is the older of the options - you can create this using LAME (NOT the MP3 version!), or you can use TMPGEnc.

I suggest you author with either AC3 or with MPEG1-Layer 2, because they both allow a decent level of compression, and are therefore easy to fit onto DVD-R projects. They are both widely compatible, but AC3 does have the edge over MPEG1-Layer2 when it comes to this point.

Do bear in mind that the DVD spec DEMANDS that all audio is sampled at 48khz, which is fine for you since DV captured audio is natively 48khz. I recommend using a bitrate of between 192 and 384 kbps, according to what space you have left over after your video MPEG encoding, which I would argue has precedence over audio, in most situations.

Arky ;o)

[vasudev71]

Hi Arky,

Thanks for your reply.
I like your detailed explanation on my question.

As you said, the DV audio is default PCM 2-channel 48Khz. Right?
If I convert this WAV file to AC3, is this AC3 a 2-channel Dolby
Digital file?. Also, if I convert the PCM WAV file to AC3, will there
be a quality loss in the AC3 file?
Is the 2-channel Dolby Digital AC3 compatible with every DVD player out there?

Also, you said in your last paragraph, that AC3 has a edge over MPEG-1 Layer2. What does this exactly mean?

BTW, Arky did you read my topic titled "DV to DVD Breakthrough techniques"?

Any suggesstions, comments?
I'm surprised by your silence on this topic.

Thanks.

VS

[Arky]

YES, the DV audio is default PCM 2-channel 48Khz.


If you convert this WAV file to AC3, this AC3 file WILL be a 2-channel Dolby Digital file.


If you convert the PCM WAV file to AC3, there will be a *marginal* quality loss in the AC3 file, mainly dependent on the bitrate you decide to use (space always being a factor here, unfortunately). Virtually ANY audio-compression system invokes some form of selective data "pruning", to save space. Sony's ATRAC algorithm (as used on MiniDisc) has, in common with Fraunhofer's ubiquitous MP3 format, a strategy of selective removal of high frequency 'bits' which are judged to be inaudible to the human ear, under general listening circumstances. I am not entirely sure of the exact method employed by Dolby Laboratories (this is not general public knowledge) in any case, I can assure you that, at least at higher bitrates (e.g 384 kbps) you are going to be *very* hard-pushed to tell the difference between the AC3 and the original WAV. I would be wary, for high quality jobs, of pushing audio bitrate below 192kbps, and would certainly recommend going higher if disk-space allows.

If you want higher quality then I'm afraid you will have to do without the compression, and leave your Audio as .wav, or for ULTIMATE audio quality, DTS (but bear in mind what I said before). Personally, I recommend AC3 as the best all-round compromise. Why not try AC3 compression, if only to hard disk, and play it back and judge the quality for yourself? I don't think you will be disappointed. When you are next out shopping, take a look at the back covers of the DVDs in your local store, and see just how many of the big-name titles, from big-name studios, use AC3 as their compression system.


The 2-channel Dolby Digital AC3 should be compatible with *virtually* every DVD player out there which is Dolby licensed (most of them are these days, simply because many Hollywood DVD titles use AC3, and without this licensing they'd be very little use to anyone wishing to play blockbuster movie titles!)

AC3 has an edge over MPEG-1 Layer2 in terms of compatibility with standaalone players, in that there are a few (and only a few) that apparently do not take kindly to MPEG1-Layer 2 audio.



LoL - yes, I DID read your message on the Etymonix method, and I actually SAVED the webpage at the time of reading it, to investigate further before commenting! :)

Unfortunately, I've been working nights recently so I haven't yet had an opportunity to try your method out. Rest assured that I fully intend to, though, and I'll let you know how I get on. It's always nice to see fresh ideas and methods, and I'm like a sponge when I see them - if only time was never a factor!! :(

Cheers, let me know if you need any further clarification on the above, and I'll do my best to assist.


Arky ;o)

[Arky]

Incidentally, since you enquired about the compatility of AC3, it seems appropriate for me to point out something which I suspect you already know, but which you may have overlooked.

If you are looking for the best compatibility, then the DVD-R format is arguably a little more widely-compatible than the DVD+R format. I'm not saying that DVD+R does not have it merits - I'm just saying that I would recommend, for compatibility, the Pioneer AO4 instead of the HP drive. Of course, I'm assuming you are authoring for playback on standalones...


Arky ;o)

[Doom9]

Arky, based on the latest tests in CT DVD+R is as compatible as DVD-R these days... and DVD+RW should be more compatible than DVD-RW. (though I have a DVD-R/W burner myself but I got it for free and I'm rather glad that I didn't had to make the format decision;)

[auenf]

Originally posted by Arky
YES, the DV audio is default PCM 2-channel 48Khz.

uhh, DV Audio is either:

PCM 2/4 channel 48khz/32khz 16-bit/12-bit

most commonly it is 2ch, 48khz, 16-bit (some camcorders default to 32khz, so check beforehand).

as far as i know, the only firewire capture card that can separate the 4channels capable in DV(CAM) is Canopus DVStorm, but im pretty sure you're only working in 2ch anyway, just load up the avi in a program where you can check the stream settings, otherwise you'll end up with high pitched audio stream when it is upsampled.

Enf...

[Arky]

ok, fair comment - I must be a couple of months out of date then, but I am happy to stand corrected ! ;)

Even in light of the latest findings, though, I am still content that I made the 'right' decision for me, by buying the A04.

As they say in SouthPark: "I learned something today!"


Arky ;o)

[auenf]

Originally posted by Doom9
Arky, based on the latest tests in CT DVD+R is as compatible as DVD-R these days... and DVD+RW should be more compatible than DVD-RW. (though I have a DVD-R/W burner myself but I got it for free and I'm rather glad that I didn't had to make the format decision;)

just wait till the end of the year when sony should be releasing their DVD-R/W, DVD+R/W and CD-R/W all in one drive...

Enf...

[Arky]

Originally posted by auenf


uhh, DV Audio is either:

PCM 2/4 channel 48khz/32khz 16-bit/12-bit

most commonly it is 2ch, 48khz, 16-bit (some camcorders default to 32khz, so check beforehand).

as far as i know, the only firewire capture card that can separate the 4channels capable in DV(CAM) is Canopus DVStorm, but im pretty sure you're only working in 2ch anyway, just load up the avi in a program where you can check the stream settings, otherwise you'll end up with high pitched audio stream when it is upsampled.

Enf...

Sorry, I was just assuming that vasudev71 was using the camera in the default 2 channel mode, rather than the 2+2 (4ch) mode. According to my Sony manual (TRV900) this is only necessary when you want to add a voice over using the camera's mic input. In the three years that I've had mine, I've never seen the point in this, when it can easily be added during the editing process on the PC.

As I see it, there is additionally, no need to upsample, if you add the voice over during editing, rather than record it to camera, using, for example, 32khz.

I've never altered the settings on my camera in this particular regard, and thus my cam outputs 2ch 48khz, right "out -of-the-box".

...Or am I missing something here..? :(


Arky ;o)

[auenf]

Originally posted by Arky

I've never altered the settings on my camera in this particular regard, and thus my cam outputs 2ch 48khz, right "out -of-the-box".

...Or am I missing something here..? :(


Arky ;o)

cam we have at home is defaulted to 32khz

Enf...

[Arky]

ok, no great cosmic mystery in the unveiling then, just a difference in manufacturer defaults - glad we cleared that one up, I was beginning to get a little bewildered by that! :eek: :confused:

RIGHT, now I can go to bed and get some sleep without that playing on my mind...

Regards,


Arky ;o)

[AudioVideoMaster]

Thanks for the heads up on the release news. A DVD-R/W, DVD+R/W and CD-R/W all-in-one would be rockn'! Do you have any ideas on how much this would retail for?

Thanks!

Originally posted by auenf


just wait till the end of the year when sony should be releasing their DVD-R/W, DVD+R/W and CD-R/W all in one drive...

Enf...