ProblemsTransferring Camcorder Tape to DVD

[Tosh McCaber]

I have Pinnacle Studio 8, which after a year and a half, I have got round to using. I successfully transferred my first digital 8 movie on to the programme, but due to time commitments, saved it on the hard disk. It has been saved by Pinnacle as a .avi file. I am now unable to bring it back into the programme for editing, since the programme appears not to recognise it. Is there any way that this can be done?

Failing that, can the .avi file be used with the likes of Nero or Roxio, to create a DVD that would be able to be played on a domestic player?

[SilentlyScreaming]

First off, download GSpot codec revealer util from here (http://www.headbands.com/gspot/)
This will tell you what is wrong with the file, hopefully, or if no errors are found, then it will state the codecs (audio & video) used to encode this file. Let us know what it displays, could be divx/xvid/uncompressed etc.

[Tosh McCaber]

Here are the results:

Video:
4CC:dvsd Name: DVC/DV Video
Stat: 2 compatible codecs installed - DV video decoder- AVI Draw


Audio: Stream 1
Name: PCM Audio
Stat: PCM: No codec required

Do they give you any clues?

Tosh

[SilentlyScreaming]

IF you have the time and hard disk space to experiment, try something like VirtualDub (http://www.virtualdub.org/).
There may be a more elegant/easier/quicker solution, but you should be able to load your troubled AVI file, and re-encode it to different codecs. Maybe try just converting 2 minutes into a few different codecs (or maybe try uncompressed (HUUUGE file size)), and seeing which then work with your video editor.
Completely different train of thought... is your AVI file larger than 4Gb? If so, is your hard drive NTFS or FAT formatted?
Anyone else got an idea?

[criticalmass]

I'm using Vegas 6 and DVD Architect 3 for editing/authoring and burning to DVD. Perhaps I can assist?

First, the file structure of a playable video DVD isn't .AVI or .MPG, although MPEG compression is essential for DVD.
I'll stick to the basicsas far as I can so as not to confuse the issue. First, you need to know the structure of the filesystem of a playable video DVD. Yes, it has a filesystem because it is just a data disk with a series of files containing 1s and 0s. Arrange the filesystem correctly with the right things in it and you have a video DVD.

There are two directories on a video DVD - VIDEO_TS and AUDIO_TS. Curiously, the AUDIO_TS directory is always empty, and some DVDs don't even have it. That's because the audio is embedded within the video encoding.

The VIDEO_TS directory is the critical one. In the VIDEO_TS directory there are three file types - VOB files, an IFO file and a BUP file.

The VOB files are video objects, essentially the actual playable video. No VOB file is larger than 1GB and if two or more are needed then they are contiguous, that is one ends and the next begins seamlessly for playback purposes. Each menu-item in a menu based DVD has a VOB file associated with it, so the player knows where to start and finish when you select it from the menu.

The IFO file contains menu structures (if the DVD is menu-based), or information about the VOB files for the player codec to use.

The BUP file is a backup of the IFO file. If the IFO file somehow becomes corrupted, then the player will use the BUP file to locate the playable VOBS and play them as required. If you get both the IFO and BUP files corrupted (a large scratch, for example), the DVD is unplayable.

Now, back to that uncompressed AVI file you have. Editing an AVI file just makes an edited production, and no more. It's way too big to fit on a DVD mostly, so it has to be compressed into an MPEG2 file, usually known as an MPG file.

This requires a process called rendering. The rendering software (usually part of the editing software bundle) takes this AVI file on a frame-by-frame basis and turns it into the MPEG file, a heavily compressed video file which DVD authoring software can them turn into IFO, BUP and VOB files. MPEG compression is hairy stuff so I shall gloss over how it works. You don't want to know about I frames, B frames and P frames, or discrete cosine transforms and matrix scanning anyway. Neither do I.

Rendering is a matter of choosing a bit-rate in megabits per second that allows acceptable image quality whilst keeping the size of the rendered file small enough that it doesn't overflow a 4.7Gb (single-layer) or 8.5Gb (double-layer) DVD. It's a trial-and-error thing in many ways, but I have determeined certain sets of parameters as far as maximum bit-rate, average bit-rate and minimum bit-rate that allow me to happily burn 1 hr 35 min movies onto a single-layer DVD-R.
By adjustment I can maximise bit rates for smaller duration productions and still not overflow the 4.7Gb limit (I only have a single-layer burner).

DVD has a maximum video bit-rate of 9.8Mbps, and an overall maximum bit-rate of 10Mbps, to allow for audio bits as well. Image quality suffers as video bit-rate is reduced, but you have to reduce it to fit the whole program onto your DVD. The trick is knowing how low you can go in video bit-rate before it begins to look crook. As a guide, I render video at a maximum of 8.5Mbps whenever possible, try to average about 6.8Mbps and allow a minimum of 192Kbps. The more action or fast movement in each frame of video the greater the number of bits that have to be rendered, so variable bit-rate rendering is almost universally used to optimise the quality of the images. So you can see how there is a bit of guesswork required uuntil you have experience and know what combinations work well for you.

The next step is Authoring. Even an MPG file when burnt onto a DVD isn't necessarily a playable DVD, although many cheaper players will in fact play it. It won't have any menus, for one thing, and if it is larger than 2Gb then you can't burn it onto an ISO DVD because the ISO standard is limited to a 2Gb filesize as a maximum. Authoring gets around these problems.

Authoring software re-processes the rendered MPG file into those IFO, BUP and VOB files I mentioned earlier. Surprise, surprise, they actually occupy more room than the original MPG file! I find that a 3.35Gb MPG file when run through DVD Architect will swell to a handy 4.7Gb - perfect for a single-layer DVD video. Chapters and menus are also added in the authoring stage, although some editing software allows chapters to be added in the edit and these are recognised by the authoring software. This depends on whose software you are using.

To burn your playable DVD, just use Nero (or any other decent burning software) to create a data disk on your DVD - this is somewhat easier than creating a Video DVD, and the end result is identical anyway. Drag the VIDEO_TS and AUDIO_TS files to the contents window, set the burn in action and voila! - a playable video DVD. Some burning software gets anally-retentive about creating video DVDs, but if you create a data DVD with those two directories and their contents, it will be a playable DVD and identical to a DVD burnt as a video DVD anyway. Why burning software draws the distinction between the two is a mystery to me. I have burnt over 600 Video DVDs using this method - it works!

Now, the sting in the tail! Even though this is a playable DVD, many brand-name DVD players won't play it!

The reason is the media descriptor byte, burnt into the DVD, either when it is made, or when it is burnt in your drive (this depends on whether you are using DVD-R or DVD+R). Commercial video DVDs have one descriptor, and it is different from that of a computer-burnt descriptor.

All is not lost, however, because the cheaper "generic" DVD players will play almost anything that physically fits into the loading-tray, including computer-burnt DVDs. So will any compatible computer DVD-drive. It's just the big brand names decided to write code into their ROMS to prevent computer-burnt DVDs being played, possibly as a misguided anti-piracy measure. I won't buy a DVD player that can't play my own DVDs!

So that's a primer on video DVDs. Hope you find it useful.