In order to properly review Netflix Original Content, the tools you use must be properly set up so as not to introduce any technical issues. This section will take you through the appropriate steps to ensure your QC station is in the best possible working order for reviewing Video and Audio assets (IMFs) in the Download QC mode.
If you have received an IAB IMF with Atmos Audio delivered in the IMF, please see the Atmos QC Section for IAB specific QC information.
Elements of a QC Station for Download QC
A QC station needs the appropriate equipment in order to handle the Netflix Content that you will be QCing. They are:
- A computer capable of frame accurate playback of final content at unity with the intended deliverable. Find a detailed description of "unity environment" here.
- At Netflix, systems that meet these requirements are the Rhode/Schwartz Clipster, Colorfront Transkoder, DaVinci Resolve, and Grey Meta Iris.
- Branded Content QC partners are neither mandated nor limited to these tools to achieve playback.
- Frame accurate playback is required when reviewing content.
- A 4K/HDR Capable monitor that is at least 50 inches wide.
- The larger the monitor, the easier it will be to find image related issues.
- UHD Premium Certified monitors can be used to review content
- Production Monitors are more flexible in control, such as:
- Dolby Maui & Pulsar
- Sony BVM X300 / X310
- Sony PVM X550
- Due to the high end nature of the monitors used, the issue flagged might not be as identifiable on other setups, so being as specific as possible (location, line of dialogue, or action) is very important in helping those reviewing the report find where the issue is.
- A 5.1 Surround Sound setup and Headphone connectivity.
- The 5.1 mix must be reviewed in a properly set up 5.1 environment.
- The 2.0 audio tracks can be reviewed in headphones.
- A hard disk storage system, be it internal RAID or SAN Storage
- Your storage environment will need to be able to handle many files that are over 200GB each.
- An isolated environment. The room should not be located near a noisy area or street. If it is, then soundproofing materials need to be utilized to minimize external sound leak into the QC room. The room should also not contain windows, or those windows should be blocked.
Once this hardware is properly installed, make sure to test all functions before performing QC on Netflix assets. No issues should be missed or introduced due to the tools used in QC.
Tuning the QC Room for Download QC
A QC room should have the 5.1 speakers set up in the proper locations, with three in the front, two in the back and the LFE on ground. A high end consumer system should have the proper speakers and quality hardware needed to perform Download QC.
Before starting QC, play 5.1 content through the speaker system. Make sure that any spatial or environmental effects are coming through the correct channels and that all speakers are functional and in good working order. i.e.: clear of interfering signals, not impacted by static, and playing audio levels consistently.
Each speaker should be set to a reference level of 79dBspl. Send a test tone through the system to make sure that all speakers in the system are at the same level. Some systems may utilize a microphone to analyze and calibrate the output levels.
Make sure there is good separation between the speakers, especially the Left and Right channel speakers. The room should be large enough to allow for good separation, and allow for the operator to be in the middle of the front and rear speakers.
Also be sure to test 2.0 audio through headphones. Reference headphones should be used. Make sure that each channel comes through clearly and that stereo effects are properly occurring in the headphones.
Calibration Best Practices
Calibration procedures vary between facilities, software, and hardware configurations, but they should all share the same goal of producing standard color space targets.
- Setting Black Level
- Use a PLUGE pattern to set black level
- Setting White Level / Peak Luminance
- Use Contrast pattern (near-white) to ensure no clipping is occurring as the signal approaches reference white video level.
- Use backlight or contrast control to adjust reference white to desired luminance target (i.e. 100 cd/m2 for SDR)
- Measuring Greyscale
- Measure at least 11 steps (0-100% at 10% increments)
- Adjusting Greyscale to hit target luminance and chromaticity
- Adjust using RGB gain and/or RGB bias to achieve desired white point and luminance at each greyscale level.
- Reset White & Black Level
- After adjusting gain/bias, repeat #1 and #2
- Measuring RGB Primaries and Ramps
- Adjust as needed to hit target color primaries
NOTE: Calman software, by Portrait Displays, includes a “Netflix Video Monitor” workflow template which offers a step-by-step guide for going through an SDR calibration. The first step of this workflow is to define your desired targets, which should correspond to the standards referenced above.
Software setup may vary depending on what kind of content and what system you are reviewing on.
There are several systems that can handle the kinds of IMFs that Netflix receives. Clipster and Fuze from Rhode/Schwartz, Archimedia Atlas and Grey Meta Iris, Transkoder Colorfront, and DaVinci Resolve are all systems that can open, playback and scrub through IMF packages. A proper set up ensures that no issues are induced by software/hardware conversions that may otherwise not exist in the source asset.
It can be practical to have the same QC operator perform the HDR and SDR pass of a downloaded IMF because they will have more insight and context on the second viewing. There is no specific reason which order each QC task is completed (HDR or SDR first), but since the HDR is the base file, it might help to start there just to ensure the file itself is whole and has no significant errors.
Asset QC Setup and Error Code Glossary
The majority of IMF Download QC will be through the Asset QC tool. All materials you need can be downloaded from the request page and this is where the QC operator will log the issues found. During your QC pass, you should have the QC report up for editing or a blank word processing document open to take notes and add issues as they are found.
Be sure to know and review Netflix's Error Code Glossary. This document contains all the definitions of error codes that Netflix utilizes. This guide also gives an idea of which severity should be flagged for each error code depending on how the issue occurs.