File wont play -but indicates that it is.

[samsc]

i think there is a faulty compressor preset - or output preset in compressor- or bug ( or change in quicktime documentation ) which puts conflicting information into the movie file - about the frame rate of the file.

I examined some files which 'did not play'-

and in quicktime player the frame rate shows are 24.97fps!
This is clearly not right. These are 'PAL' files and the indicated frame rate should be 25FPS - so clearly apple hasnt figured this out either.

Also in my pdf information - the time scale of the movie is wrongly indicated -

seems like compressor has some kindof bug when it is asked to convert files from one frame rate to another.

---

On one file i have which doesnt play - which i think was converted from ntsc to PAL using compressor -
For the very technical- the movie header information on one file says its time scale is 2500, its duration 11700. But the media handler says that the timescale is 2997 and the length 14040.
11700/2500 = 4.68, 14040/2997 is 4.684684 - the second ratio is not exact....

[jasonrudolph]

I think I ran into this on two shows. The files were photo-jpeg, encoded using compressor, and using presets I had made. The first show I ran into this, I wasnt able to figure out what was going on, the second show I was able to track it down to a specific file, and re-encoding it (oddly enough using the same preset) fixed it.
It doesnt seem to always happen, as I did batches of encoding where the files were all made using the sme program, with the same settings, etc, and it only happened on one file in the batch.

The probelm I would see, so that if anyone else runs into this they know, is that the file will freeze playback, but all other parameters are still controllable via DMX, i.e. color, intensity, position, etc. It really threw a wrench into my day when it happened, as I figured it was something else that had gone wrong with the server.

Jason

[samsc]

I think I ran into this on two shows. The files were photo-jpeg, encoded using compressor, and using presets I had made. The first show I ran into this, I wasnt able to figure out what was going on, the second show I was able to track it down to a specific file, and re-encoding it (oddly enough using the same preset) fixed it.

Jason

Which version of compressor?

compressor seems to be doing something wierd- and creating inconsistent information in the movie header - it threw me too.

I will see if i can find a workaround.

[samsc]

It doesnt seem to always happen, as I did batches of encoding where the files were all made using the sme program, with the same settings, etc, and it only happened on one file in the batch.
Jason

that file probably had the math error between the movie information headers i indicated above.
they are doing a frame conversion with non-accurate math.

one of my users reported using several different output codecs and it not working with any.
so it could be this...

[jzbdski]

Hi there,

Thanks for all your input.
I'll grab some screen shots of the HUD this afternoon, Tried to delve into the file info in Quicktime but only got the very basic stuff, no mention of Compressor used, Timecode or anything -are these QT Pro features ?

It's quite possible the files have been buggered about in Post before making it my way, their Aspect ratios have been squashed such that I've a 12:3 image in a 4:3 format so they could have been subjected to almost anything.

Cheers

Richard

[jasonrudolph]

Hi there,

Thanks for all your input.
I'll grab some screen shots of the HUD this afternoon, Tried to delve into the file info in Quicktime but only got the very basic stuff, no mention of Compressor used, Timecode or anything -are these QT Pro features ?

Compressor is apple's pro compression software that is a part of Final Cut Studio. It allows you to save presets of settings to encode files as, and allows you to do batches of files at once, so you can leave 1 or 100 files encoding and it will run until it finishes them.

[jzbdski]

Aha !

I've grabbed a couple of screen shots of my HUD.

In the situations where the synced layer doesn't run, it shows that it is 1 frame behind the layer it is syncing to. (both movie files are 125 frames, 720x 576 nd were encoded using a Blackmagic DeckLink DV codec)

When it plays fine, it shows that it is on exactly the same frame.

I'll post the images once I can get them across to this windoze box.

Does this explain anything ?

Cheers

Richard

[samsc]

Blackmagic DeckLink DV codec

can you explain what you mean by this- and where you saw such a description - can you double check?

If you are using a decklink codec- it will be uncompressed- and you have a totally different problem.