Delivery file formats

When sending your master in for grading or DCP mastering purposes, we suggest you follow the following guidelines.

 

File based delivery

Tape is no longer in general use in the industry.  SATA Hard-drives/USB portable drives are the transfer medium of choice.  There is a plethora of file formats and codecs that can be used.  Each having quality constraints.  In general, the larger the files are per second of content, the better the quality of the file (10bit/12bit, 4K, less compression).  This is an important issue and should have been worked out a long time before it gets to a finishing house.

 

Internet Delivery

From DropBox to HighTail or good old FTP, the internet is getting faster every day making more and more economical to send files over the internet.  At FR we welcome internet based delivery.  If required, we can make a FTP server available at additional cost, however, DropBox, Hightail is welcome.

 

Image file formats

Image Sequence formats
  • 16-bit-TIFF

  • 10-Bit DPX

  • OpenEXR (Variable bit depth)

Single File Codec formats

  • All ProRes derivatives in MOV container

  • All DNxHD/DNxHR derivatives in MXF containers

  • XDCAM and other H.254/H.265 in XMF Containers

  • XDCAM and other H.254/H.265 in XMF Containers

  • H.264/H.265/MPEG2 in MP4 Containers or transport streams

It is recommended that better than 8 bit depth mastered content is used (10 or 12) as visual artifacts will result (Steppy cross fads. Steppy Sky/gradients)

 

Colour Space

This is the most overlooked area of the mastering process.  When mastering to a DCP, a clear understanding of the colour space specification used is required.  Otherwise the conversion from your working colour space into the Digital Cinema XYZ colour space calculations can be incorrect diverting from the producers intent.  Typically your colour grader or Editor should know the answer to this.  Commonly, most will work in Rec.709 with BT.1886 (2.4 gamma) targeting broadcast TV/DVD/BluRay, however, when getting into higher quality levels of colour, the options explode..

Typical mastering colour spaces

  • Rec.709 with SMPTE BT.1886/2.4 Gamma

  • Rec.709 2.2 Gamma

  • Rec.709 2.35 Gamma

  • P3 DCI

  • P3 D65 (White Point)

There are advantages and disadvantages depending on your final deliverables and target market.  Your Editor/Colour grader should be able to walk you through these issues.

If no source information is supplied, we default to Rec.709 using SMPTE BT.1886 as that is what you should be using in general if not targeting P3.

 

Frame Rates

Frame rates are also a very confusing issue when it comes to DCP mastering.  Typically you “should” target a 24fps “Interop” type DCP (Interop being the name of the first generation of DCP).  It is the most compatible type of DCP used and what most of the films around the world are distributed in.  However, many content producers end up going to a DCP after the fact.  Ie, they did not plan to.  This brings the issue of converting from 25 or 30/29.97 frames per second to a 24 frame per second DCP.  Obviously this requires a compromise, be it slowing the content down, 25 to 24, making it slightly longer and requiring a audio streatch.  Or doing a 30/29.94 conversion to 24fps.

Typically we require content be delivered in 24fps with Audio STEMS matching the pictures.  If any extra work is required to “make it work” this will result in extra costs.

SMPTE DCP is the answer

The next generation of the DCP is called the SMPTE-DCP. It is the Version 2.0 of the DCP. It allows support for common frame rates used around the world.  This allows a frame for frame conversion to a SMPTE-DCP.  However, the support for SMPTE-DCP is not ubiquitous.  There is no guarantee your SMPTE-DCP will work when rocking up to a random Cinema.  However, at this stage, any festival friendly cinema or general large exhibitor should now support SMPTE-DCP.  Finishing Room recommends the use of SMPTE-DCP going forward.  We are now at a stage we should expect the support of SMPTE-DCP playback.

 

Audio

Quality

The audio quality of a DCP is very high.  It is 48KHz typically or 96KHz/24bit as compared to CD, 44.1KHz/16bit.  In reality it is as good a quality as the Dubbing stages it is produced upon.  As such, you should attempt to supply the best quality audio you can.

Target 5.1

In a cinema, you always have at least 5.1 or better sound systems.  It is highly advised that even if you only have a stereo Lt/Rt channel mix that a fo-5.1 conversion be applied.  Ie turning the Lt/Rt into a L/R/C/LFE/Ls/Rs mix.  This is especially important on Ads/PreShow as it fills the room with more audible sound giving it more impact, espeically if in preshow and the audio is not as loud and you are batteling other noise such as a conversation in the next row.

Supply STEMS or a file per channel

Typically when supplying multi channel files, each channel is in a separate file. These files are called STEMs. These should have names that clearly designate their purpose.  And if possible list out in the following order..

ChannelFilenameDescription
1MovieName_1_L.wavLeft
2MovieName_2_R.wavRight
3MovieName_3_C.wavCentre
4MovieName_4_LFE.wavLow Frequency Effects
5MovieName_5_Ls.wavLeft Surround
6MovieName_6_Rs.wavRight Surround
7MovieName_7_Lrs.wavLeft Rear Surround
8MovieName_8_Rrs.wavRight Rear Surround

A 48KHz, 24bit WAV is the prefered file format.

If audio is supplied in other formats or is not synced with start of picture, this will require extra work and as such extra cost.

 

Targeting DCP Scope and Flat Resolutions

All cinemas around the world are typically setup for two specific screening ratios.  Flat and Scope.  There is also a ratio called FULL, but it is typically not supported by most cinemas.  The Automation systems only follow the most common Flat/Scope ratios.  As such, when going to a DCP, you need to match up the ratio of your production to the best-fit for either Flat or Scope.

FLAT (1.85:1)SCOPE (2.39:1)FULL (1.9:1)*
FLAT (1.85:1)SCOPE (2.39:1)FULL (1.9:1)*
2K1998 x 10802048 x 8582048 x 1080
4K3996 x 21604096 x 17164096 x 2160

As an example and what is most common, when going from a typical HD 1920×1080 master to a DCP, the Flat container is best fit at 1998×1080.   (1998 pixels subtract 1980 pixels)/2 leaves 39 pixels of black on each side of the image.  Naturally, for 4K, simply double the numbers.

Should I remaster to the correct Ration/Resolution?

Yes, if possible, this is highly recommended as it is what all cinemas around the world are designed to show.  However, this can introduce compromise that needs to be discussed with your production people.

 

Always Remember

When producing a film, your day is filled with compromise. Doing your best to make the best decision for the creative integrity of your film.  At the finishing room we believe that the right decision is the informed decision.  Don’t be afraid to ask questions.