Mixing slides and 'normal video' in one VTS ? / DVD with audio cd's

[TheJez]

Hi all,

I'm thinking of an application to make something similar to DVD+Audio. The idea is to have a menu structure to select an artists, and then select an album from the selected artist. So far so good. Then there should be a VTS containing the audio of the selected album (in either mpeg audio or ac3). The video that should go along with it, consists of stills indicating what artist/album/track is being played. On each track transition I want to put a chapter point. The problem is that stills have a length of 'x' seconds. (If the song > 255 seconds, I can use 2 or more stills for the particular track.) However, tracks are mostly not exactly 'x' seconds long, but 'x' seconds and a few (audio)frames. What I want to do, is make a VTS consisting of still frames of a certain length, padded with additional I-frames or P-frames (indicating no change) to make up the full length of the audio track, and then put in a next still frame with length 'x' seconds (padded again with I or P frames) for the next audio track etc.

Two questions:
- Does the DVD standard allows this ?
- Is there any application/library/source code available that might help creating such a VOB-file ?

Anyway, in the end, I want to create an application that automatically creates such a dvd for me from a directory structure containing ripped audio cd's, so including creation of the menus, the mpeg or ac3 audio and the VTS's per album.
(Optional: adding subtitles that indicate the time position within the song...)

Thanks,

TheJez

[violao]

Originally posted by TheJez
...The problem is that stills have a length of 'x' seconds. (If the song > 255 seconds, I can use 2 or more stills for the particular track.)...
If you are referring to "cell still time" - this is not a still's length, but the length of the time the still is displyed after a playback reaches the end of a particular cell. Therefore you need to set cell still time to 0 and the playback will continue according to the navigation structure of your DVD.

[TheJez]

Thanks Violao,

So you're saying that slide in a normal slideshow is created by making a cell containing a single i-frame, with a 'cell still time' of 'x' seconds ?

So if I want a still with a length of e.g. 300 seconds and 4 video frames, I can do this by making three cells: One with an i-frame and a 'cell still time' of 255 seconds, followed by a cell with the same i-frame and a 'cell still time' of five seconds, followed by a cell containing the same i-frame four times (with cell still time of 0).
Right ?

Below I have a picture of what a VTS can look like, with a cd with two tracks (one of 300 seconds and 4 frames, and one of 200 seconds and two frames)

http://home.hccnet.nl/j.zuiderhoek/vts.bmp

(I've ordered DVD Demystified, so I hope this book will provide me with enough details to implement this...)

Thanks,

The Jez

[violao]

If your cell contains still video and background audio then it's playback duration is determined from duration of audio stream. Therefore you don't need "cell still time", just mux mpeg still with some kind of supported audio with DVD compliant mux and you're done.

If you want to show different pictures within the same audio track then you need to segment that audio track and mux those segments with mpeg stills to separate cells. Combine the cells to a single PGC so that you can make the playback seamless by setting cell's "seamless linked in PCI" flag.

You only need cell still time if you have mpeg still with no audio stream and want it to advance automatically (after 1-254 seconds), or if you want to pause video track at the end of cell from whatever reason. 255 means infinite pause (like in menu stills).

[TheJez]

Thanks a lot, your answer makes things a lot easier to implement. I don't want different pictures within the same track, just a picture telling what artist/album/song is playing, maybe with a scan of the cd cover of the current album etc.
So I'll just go for 'single cell tracks', each cell containing one i-frame, seamless linked, one PGC per album. Shouldn't be too difficult... :scared:

Take care,

The Jez