All posts by Igor Ridanovic

Can I Shoot 720p and Deliver 1080i or 1080p?

Yes, but check with your network first.

Budgetary requirements may necessitate that you complete production and post production in a smaller size standard like 720p and upconvert the final delivery to 1080i or 1080p.

This can be accomplished. You can even shoot standard def and deliver high definition master but as with any upconversion there is a price to pay in terms of quality.

While most viewers will not spot the difference between a show originated in 1080 23.98p and a show shot in 720 59.94p with Varicam your network may have very specific guidelines defining the acceptable percentage of a show that is allowed to be upconverted.

Post Production, Technical Info

AAF, AFE, OMFI?

File formats for exchange between platforms.

These formats facilitate migration of projects between different editing platforms. They are commonly used for bringing a project over from an offline NLE to an online NLE.

AAF, AFE and OMFI contain additional information EDLs are not capable of storing such as multiple video layers, titles and effects.

AAF – Advanced Authoring Format

AFE – Avid File Exchange

OMFI – Open Media Framework Interchange Format

Post Production, Production

What is 24p?

Universal mastering frame rate.

24p where “p” stands for “progressive” is a universal mastering frame rate which allows easy conversion to other frame rates used around the world. Motion picture film has used the 24p approach for years. Video suffers from multitude of standards used in different countries (sometimes in a single country) so creating a master that will convert well into other standards is of great importance.

It is always possible to make standards conversions but they may come with a quality loss. The frame rate is not the only property that determines how a master will convert but it is arguably the most important one. Masters created at 24p (or more often 23.98p) are appropriate for versioning to any existing standard with the least amount of quality loss.

It is also important to consider the difference between 24p and 23.98p (more precisely 23.976p). True 24p HD is rarely used in the United States.

Post Production

3:2 (2:3) Pulldown in HD

Used in the United States for film to tape transfers

Also known as 2:3 pulldown this process makes it possible to transfer 24fps film to 30fps videotape (really 29.97 but that’s another discussion). The goal is achieved by holding longer an extra field every other frame of video [Fig. 1].

3:2 pulldown is alive and well in 1080 59.94i HD standard. It works exactly the same way as in SD video. Anything that was originally shot in 24fps film or 23.98p HD and transferred to 1080 59.94i will consequently have 3:2 pulldown.

720 59.94p HD standard also uses a similar method to 3:2 pulldown to achieve a 24fps look on tape when shot with Varicam.

Advanced Pulldown 24pA

A variation on standard pulldown

The standard 3:2 pulldown is a means of converting 24 fps film to 30fps videotape. It is achieved by holding every other field of video. The field cadence of standard pulldown is 2:3:2:3.

The cadence of advanced pulldown is 2:3:3:2. It was designed to be less computationally intensive when restoring the material back to 24fps (inverse telecine). NLEs that support advanced pulldown have an easier job than those which don’t. When restoring the material back to the original progressive video the “BC” video frame is ignored by the NLE [Fig. 1].

It is important to consider whether advanced pulldown will work throughout your entire 23.98p workflow before deciding to shoot with this option. Projects finished in 29.97 fps will generally not be affected by the choice of either standard but mixing and matching the two methods in the same timeline may introduce artifacts.

advanced pulldown explained

Fig. 1. Advanced Pulldown

Organizations

EBU

European Broadcasting Union.

EBU is an professional organization of European broadcasters and beyond. One of the concerns of EBU is development of television recommendations.

http://www.ebu.ch/

Organizations

DVB

An organization that establishes international DTV standards.

Digital Video Broadcasting (DVB) is an international consortium that proposes international digital television standards and promotes digital television.

http://www.dvb.org/

Organizations

DCI

A body providing D-cinema standards recommendations.

DCI (Digital Cinema Initiatives) is a consortium of major Hollywood studios gathered around a common goal of providing specifications for D-cinema. The goal of the organization is to standardize tools and processes used for digital film distribution.

http://www.dcimovies.com/

Organizations

ATSC

The regulatory body behind DTV standard.

ATSC (Advanced Television Systems Committee) is a group that proposed standards for Digital Television (DTV) in the Unites States. The standards were later implemented into federal regulations by the Federal Communications Commission (FCC).

http://www.atsc.org/

Equipment

XDCAM HD Format

Sony acquisition format.

XDCAM HD is a high definition extension of Sony’s XDCAM (SD). The camera records files onto inexpensive rewritable optical media housed in a special cassette. The media is more advanced than Blu-ray disc and holds 23Gb of information. The cameras have the ability to record standard definition video in DVCAM mode.

XDCAM HD works only in 1080 size in either interlaced or progressive modes. It provides the following frame rates: 23.98p, 25p, 29.97p as well as interlaced frame rates: 50i and 59.94i.

As members of the Sony CineAlta family the XDCAM HD camcorders have advanced features such as true variable frame rate recording (4-60 fps), time-lapse, low resolution proxy creation and others.

The format uses 4:2:0 sampling and records highly compressed MPEG HD 8 bit signal to tape at 35Mb/second maximum. While these specifications are not the best on paper the image produced and recorded by XDCAM HD is quite good and the camera system is very rugged and designed with field use in mind.