Inverse Telecine Processing - Removing Pull-Down


Many HD camcorders - such as Sony's HVR-V1U and Canon's Vixia series - now offer the ability to record 24p (24-frame progressive) to emulate the visual "feel" of film recording. But before it is recorded to HDV tape, 24p material  captured by the image sensor is often inserted into an interlaced 60i (60 fields per second) HDV stream - a process called "telecine".

To maintain the visual benefits of 24p through post production, it is necessary to extract the original 24p signal from its encapsulation in 60i.  This is done using a technique called "inverse telecine" or "pulldown removal".  After inverse telecine processing the resulting file is again 24p (23.976), and is now ready for a 24p editing workflow.
Depending on many parameters, removing telecine is not always straightforward, so many capture applications and non-linear editors do not include the feature.  All CineForm products provide inverse telecine processing in the HDLink utility.  In addition, Aspect HD and Prospect HD/2K include inverse telecine processing using the Premiere Pro capture interface.


For improved visual fidelity, also consider this: All CineForm products offer real-time inverse telecine processing when capturing live 24p material (embedded in 60i) through an HDMI interface as included on Sony's HVR-V1U and Canon's HV20.  In this mode, the 60i signal output by the camcorder (through HDMI) is prior to MPEG compression.  When HDMI sources are captured direct-to-disk into CineForm Intermediate with "inverse telecine" selected, the resulting files have much higher visual fidelity than those recorded to HDV tape.  This is because CineForm Intermediate offers lighter compression, twice the chroma fidelity, and higher bit-depth precision than MPEG recording.  This visual fidelity benefit is especially important for projects in which substantial post processing (keying, compositing, color correction, etc) is being applied.  See our HDMI Tech Note for more details.  NOTE: HDMI recording requires use of the Blackmagic Intensity card.

To Extract 24p Using HDLink:

In the HDLink Prefs window (shown above), select the Frame Rage Change option that says "Remove 3-2 Pulldown:.

Then click 'OK' and begin capturing or converting your footage.

To Extract 24p Using Premiere Pro (via Firewire):

Make sure your camera is plugged in, turned on, and set to HDV Playback Mode.

Launch Premiere Pro and load the Capture Panel (F5 on your keyboard) and click on the 'Settings' tab as shown in the screen below.

In the Capture Settings section, slick on the 'Edit...' button.

Premiere Pro HDV Capture Settings

From the Capture Settings dialog box, click on the 'CineForm HDV Settings...' button as shown in the image below. If you can't see that button, then your camera is not connected properly.

Premiere Capture Settings

In the CineForm HDV Capture Settings window, select the 'Remove 3-2 pulldown' option as shown in the image below. Then click 'OK' to close the CineForm HDV Capture Settings window and then click 'OK' again to close the Capture Settings window.

CineForm HDV Capture Settings window.

Then capture your footage and the resulting files will have a frame rate of 23.976.

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