VS10 dvd compatible file

[brianbrian]

Following on from Ken's recomendation that after editing is all done, then we should convert/render to a dvd compatible file before proceding to the authoring and then the burn stage - my question is how does VS10 know that rendering has already been done so it doesn't repeat the process at the burning stage ?

Also, if we come back later, and wish to change the authoring stage and reburn, is the prior rendered dvd compatible file used automatically, or do we have to load it ?

Finally, if my dv camera has an audio spec of PCM digital 16 bit 48kHz Stereo, then is there any point my creating a dvd compatible file with Dolby Digital or is it best to stick with straight forward Pal dvd (4:3) ?

Thanks
Brian

[Ken Berry]

1. As with any editing program worth its salt, VS can analyse video to see what its properties are, and as long as they are, according to its data, DVD compliant, it will not re-render it in the burning module as long as 'Do not convert compliant mpeg files' is ticked. Otherwise, it will re-render according to the properties contained in the 'project properties' window above the Do not convert box if those properties differ in any way from those of the mpeg-2.

2. I am not quite clear what you mean here. If, after you have been in the burn module, and have quit and saved the project, when you re-open Video Studio, the project and the burn module, the DVD-compliant mpeg-2 you previously rendered should be there in the burn module. But if you quit but did not save the project, then it will not. Nor will it be if you open VS then simply go to Share > Create Disc, without opening the project.

3. PCM audio is the highest quality audio which, with an added "L", can be burned to DVD. You can always select it and it will always play in any stand-alone player. The only reasons why you might not want to use it are primarily space (the more compressed audio formats like Dolby or mpeg layer 2 produce smaller files and will thus allow you to burn more video to the DVD). Or else you want to use the surround sound effect of Dolby 5.1.

I am not sure, though, that what you are really meaning to ask is whether changing the audio format will require a full re-rendering of the whole project (including the video component, and thus with loss of quality)? The latter is a valid question, and I am not sure I have a definitive answer. However, on the basis of considerable empirical experience (of changing the audio but not the video component) it would appear that the re-rendering which may occur is only to the audio component. In other words, I at least have never noticed any degradation of the video component when I have done this.

[brianbrian]

Thanks again Ken
1. Am I correct then in thinking that in the burn stage, VS10 will first look in the file directory to see if there is already a dvd complient file, and if it finds one then it doesn't re-render ? In that case, when we save a dvd complient file, does it have to be the same file name as the project file and in the same directory as the project file so VS10 is able to locate it ? Or is the name and location of the compatable file, saved in the project file ?

3. All I am saying here is that since my camera doesn't produce a Dolby Digital sound track, then there is no point in my generating a pal dvd compatible file with Dolby Digital in it - as I understand, you cannot put something in if it wasn't there in the first place ?

Brian

[Ken Berry]

What happened to "2."???

As for 1, if you already have your mpeg-2 in the burning timeline, VS only needs to look at that -- regardless of its name or where it is located -- to assess whether it is DVD-compliant. The burning module is precisely that -- a separate module, in effect a separate program or sub-program, which works seamlessly with VS.

In other words if in the editing mode you use Share > Create Video File > DVD, you have produced a DVD-compatible mpeg-2. You close the project at that point and open a new one to empty the timeline. You then go to Share > Create Disk and the burning module opens. You insert your mpeg-2 and tick the 'do not convert' box. Build your menu, and go to the final burning page. At this point, as the computer is whirring away, one of things it is doing is analysing the mpeg-2 to see if it *needs* further rendering. If it is already DVD-compliant and the 'do not convert' box is ticked, it will not convert. Simple as that.

3. Only a relatively small (but growing) number of cameras record using Dolby dual channel stereo, let alone 5.1. But that is no reason not to use that audio format for producing your DVD. The main reason for using Dolby stereo is of course that it is compressed and thus takes up less space than the high quality LPCM audio format. More video can thus be fitted on the same disc. Ditto for mpeg layer 2 audio which produces files of roughly the same size and quality as Dolby stereo. And as I said in my post above, I am pretty sure that the re-rendering which occurs does not affect video quality, only the audio stream.

Dolby 5.1 is another matter. If you start off with dual channel stereo, be it LPCM, Dolby 2 channel stereo or mpeg layer 2, you can only at best make 'virtual' channels to fill out the 6 channels in 5.1 audio. But it is nonetheless possible to think of situations, even with home projects, where you could take advantage of all or most of these channels. You would use not only the original audio, but any added music or voiceover comments, or even sound effects, could be used in the extra channels to full effect. So again, depending on your workflow and intentions, there could be an advantage in converting the audio to Dolby 5.1.

My own recommendation, if you are indeed going to convert, would be to do it at the Share > Create Video File stage, using the Custom setting to change the audio to Dolby... I try as far as possible to avoid allowing such conversions to take place during the burning process.

[brianbrian]

Ken
You said : In other words if in the editing mode you use Share > Create Video File > DVD, you have produced a DVD-compatible mpeg-2. You close the project at that point and open a new one to empty the timeline. You then go to Share > Create Disk and the burning module opens. You insert your mpeg-2 and tick the 'do not convert' box.

Is it vital here that you close the project, then re-open it and only load the dvd-compatible file (i.e. you've got rid of the project file) ?

Presumeably when burning is complete and you close the burn menu, the project will be saved - and this time the project file will contain authoring information as well as the edited stuff ?

Finally - going back to my first problem - frame jerking. If i play back the dvd-compatible file, there is no jerking, but if I play back the final dvd the jerking now appears. Does this mean that the problem has been introduced via the authoring stage ? Incidentally, I have checked file preferences and the field order is LFF which should match my dv camera.

Brian

[Ken Berry]

The importance of closing the project after editing and producing your DVD-compatible mpeg-2, is that if you don't, Video Studio automatically inserts your *project* file into the burning timeline, and rendering will thus occur again. VS simply ignores the fact that you have already rendered it into a separate mpeg-2 as that is not what appears in the burning module. At that point, that is all it is concentrating on as in effect, the burning module is a separate program. Rendering in the burning process causes a lot of people a lot of trouble.

I should add here that some people *always* do their rendering during the burning process. In other words, they finish their editing and jump the Share > Create Video File step, and go straight to Share > Create Disc. And they do this successfully all the time. Other users use this method successfully most of the time, but occasionally have problems, but many others can never use it successfully. Every user has to work out what works for them; and at least be aware that there is an alternative workflow which works most of the time.

Now if you are worrying about saving the project at the end of the burning process, but worried about closing the project and opening a new one after editing, you can skip the 'close your project and open a new one' step after producing your DVD compatible mpeg-2. When you go to Share > Create Disc, your project file will appear in the burning module, and you should then remove it manually and substitute it with the mpeg-2. The effect is the same. It is just a matter of remembering to do it. But that way, your original project file is still open from VS's point of view.

Now as to saving, all I can say is that there is saving and there is saving. When you finish burning and close the burning module, you will have noticed that Video Studio auto-saves. And I am sure you think it auto-saves to the project file. But unfortunately, it does not -- though where exactly it does save to, I am not sure. That auto save is only effective while you keep VS open. In other words, if you close the burning module, but while VS remains open, think you want to burn another copy or vary something in the menu, then you just re-open the burning module and all is as it was. But if you close VS and then go back to burn another copy, I think you will find you have to build your menus etc afresh.

The only way of which I am aware to save your menu and other burning settings into a project .vsp file, before pressing the final Burn button, is to close the burning module, and you will be asked if you want to save your work. If you click yes, then the settings will be saved permanently. You then have to re-open the project and go into the burning module, and click through the various pages to get to the final burning page again. Very klutzy, I know, but there you are. Maybe others will have a better suggestion, and I hope they jump in here if they do.

As for your jerky video, I just don't know -- if you have followed each of my suggested steps, and most importantly manually inserted the mpeg-2 into the burning timeline and ticked the Do Not Convert box. It still sounds like a Field Order problem to me, but that could only occur if you either did not produce an mpeg-2 using LFF (but you say you did) or you did not tick the Do Not Convert box, and so VS used the default properties set out in the pane above that box, and which by default, may use either UFF or Frame Based instead of LFF.

[brianbrian]

Ken - I'll read through the file save stuff tomorrow after a good nights sleep !!! The jerking frames problem, I'll start again and do it one more time just to make sure I'm doing it correctly - probably wont be until the weekend though. Thanks again.
Brian