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Essami
10-18-2009, 03:53 AM
How would you go from 50p (or even 25p) to 24p?

Im in PAL land and have a PAL GH1 and just got myself an HD tv and a ps3 blu-ray player and its been a little difficult to figure out how to make a good blu ray.

Best image so far Ive got is burning a 720 50p to blu-ray. Im using Vegas 8 and DVDA myself.

Anyone have any workflow advice?

Sami

Martti Ekstrand
10-18-2009, 04:30 AM
The most common practice is just to slow down 25 to 24 frame for frame and then either just slow down audio the same or time stretch it by 4%. The former audio method is typically inaudible for all but pitch perfect hearing musicians, the latter can create artefacts especially on sparse sounds but again mostly it's inaudible and somewhat slower depending on your harder. If on mac this can be done very easily with Cinema Tools.
Why do you need to do this - are you going to strike a film print?

MovieSwede
10-18-2009, 04:32 AM
If you shoot 25P you have 2 options.

Either you encode it as 1080/50i with 2:2 pulldown = 1080/25P

or you make a 4% speedchange in post and create a 1080/24P encode.

Its very easy in Vegas.



If you want your project to be the same length, just render to the PAL DV template with no changes as described in the previous procedure. Vegas software will perform field rendering and frame blending, which will look just fine.

If you want to match the way feature films are transferred to PAL, follow these steps:

Render your 24p project using the NTSC DV 24p (inserting 2-3-3-2 pulldown) template.

Start a new project using the NTSC DV 24p (720x480, 23.976 fps) template.

On the General tab of the Preferences dialog, select the Allow pulldown removal when opening 24p DV check box.

Add the NTSC 24p DV rendered clip to the Vegas timeline.

Right-click the clip, choose Switches, and then select Disable Resample.

Set the ruler format to Absolute Frames.

Press Ctrl+End to move the cursor to the end of the clip.

Copy the cursor position to the clipboard:

a. Press Ctrl+G to select the cursor position in the status bar.

b. Press Ctrl+C to copy it to the clipboard.

c. Press Esc.

Change the project format to PAL DV (720x576, 25.000 fps).

In the Project Properties dialog, choose None (progressive) from the Field order drop-down list.

Return the cursor to the previous position:

a. Press Ctrl+G to select the cursor position in the status bar.

b. Press Ctrl+V to paste the value you copied in step 8.

The cursor should move to a location about 96% of the way through the clip.

From the Options menu, select Enable Snapping.

From the Options menu, deselect Ignore Event Grouping.

Hold Ctrl and drag the end of the clip until it snaps to the cursor.

You’ve just sped up the clip by about 4%, exactly matching the 24p material to 25p frame locations and stretching the audio to match.

Verify that the audio event's pitch shifting is tied to its stretching length:

a. Right-click the audio and choose Properties from the shortcut menu to display the Event Properties dialog.

b. Verify that Classic is selected in the Method drop-down list.

c. Verify that the Pitch change: Lock to stretch check box is selected.

d. Click OK.

Render the project:

a. From the File menu, choose Render As. The Render As dialog is displayed.

b. Choose a drive and folder from the Save in drop-down list, or use the browse window to locate the folder where you want to save your file.

c. Type a name in the File name box, or select a file in the browse window to replace an existing file.

d. Choose Video for Windows (*.avi) from the Save as Type drop-down list.

e. From the Template drop-down list, choose PAL DV.

f. Click the Custom button.

g. On the Video tab of the Custom Template dialog, choose None (progressive scan) from the Field order drop-down list.

h. Click the Save Template button and save this template as PAL 25p DV for future use.

i. Click the OK button to close the Custom Template dialog.

j. Click the Save button to render your file.

Essami
10-18-2009, 06:15 AM
Why do you need to do this - are you going to strike a film print?

I'd hope so :D It's Blu-Ray format that doesn't support 25fps.

Sami

Cranky
10-18-2009, 09:58 AM
I'd hope so :D It's Blu-Ray format that doesn't support 25fps.
720p50 is not good for you? Try packaging your 1080p25 into 1080i50, most likely it will work fine.

Essami
10-18-2009, 10:10 AM
720p50 is not good for you? Try packaging your 1080p25 into 1080i50, most likely it will work fine.

It works ok if you shoot 50p and keep it in 50p. But I have footag I want to use in slow motion as well. So doing 50p footage on a 50p timeline slowed down makes it look not as good as 50p slowed down on 25p timeline.

Martti Ekstrand
10-18-2009, 10:18 AM
There's no reason to use a 50p timeline for this - just export the result to 50i from a 25p timeline.

Essami
10-18-2009, 11:07 AM
There's no reason to use a 50p timeline for this - just export the result to 50i from a 25p timeline.

Can you elaborate? Im not sure I follow, you say use a 50p timeline but you also tell to export from a 25p timeline?

50p material on 50p timeline works great if I want to export as 50p to burn to blu-ray. But I do think I notice a difference playing back slowed down material whether its played back on 50p or 25p timeline. I will make a little more careful tests. Are you of the opinion I shouldnt see any difference?

Sami

Martti Ekstrand
10-18-2009, 12:09 PM
In theory you shouldn't but in practice different NLEs can suddenly do odd things. When I do slow-mo of the 720 50p material I metatag it to 25 fps before importing to Final Cut Pro just to be sure it really plays back frame by frame without any frame blending funkiness.

Essami
10-18-2009, 12:49 PM
In theory you shouldn't but in practice different NLEs can suddenly do odd things. When I do slow-mo of the 720 50p material I metatag it to 25 fps before importing to Final Cut Pro just to be sure it really plays back frame by frame without any frame blending funkiness.

Im using Vegas Pro 8 and I dont believe theres any way to metatag footage in it. I dont know Final Cut Pro so Im not familiar with it.

But if you're on a 50p timeline and have 50p footage in it and you slow that down to 50% doesnt it add frames just like if you were slowing down 25p footage on a 25p timeline by 50%?

Essami
10-18-2009, 12:59 PM
ok, so I guess you are all saying to render to 50i for burning to blu ray. Sorry it was confusing since I dont see any possibility to burn any resolution 50i blu-ray disc in DVDA. Should this be possible?

-EDIT-
According to wikipedia it is... http://en.wikipedia.org/wiki/Blu-ray_Disc

Gotta look into this...
-/EDIT-