Remote Sound Mix Decisions & Reviews

Setting Expectations

Possible Sound Review Scenarios

Remote Sound Mix Review Spec

Possible Sound Mix Scenarios

Security Guidelines

Media Tracking

Remote Mixing - Local Media Copy

Change Log

Translations

This recommendation and guidance is meant for a wide audience and may not apply to your production. Please reach out to your Netflix Representative with any questions.

In this document, we lay out possible scenarios and options for remote sound mixing and sound mix reviews, as well as the risks and implications involved. Specific recommendations will be case-by-case depending on the needs of the production, capabilities of the post facility, preferences of the sound team, and regional considerations. To find the best solution, please contact your Netflix Representative.

Setting Expectations

Sound decisions are made in purpose-built mix and review rooms at post facilities with professional reference speakers tuned precisely to perform evenly across the audible spectrum. The rooms are built by acousticians to provide a very quiet environment and to work in concert with the speaker systems. They also allow for a shared experience for all creative decision makers. We want to be careful about how mixes and sound mix reviews are conducted. It can be detrimental to the quality of mixes if these are done in non-controlled environments or on consumer devices.

Sound editing, on the other hand, is very commonly performed at home and we should expect it to take place in the home during this time.

Potential Compromises

Calibration / Sound Accuracy - variability across devices
Differing creative perspectives - it’s more likely teams will have different impressions of the mix when they are reviewing it at varying times on varying equipment
Bandwidth limitations - compression introduced
Security of content - Large volume of uncompressed production image content outside the confines of a secure post facility and network

Possible Sound Review Scenarios

Each home speaker system and viewing room will be slightly different, and we can’t expect consistent results when critically reviewing in-progress mixes. Thus, we recommend creatives review sound mixes with headphones when they can’t review in a proper mix stage with the sound team.

Remote Sound Reviews (Sound at Facility or Home, Client at Home):

Suggested Headphones
- Beyerdynamic DT 770-PRO 80 Ohm or 250 Ohm
- Beyerdynamic DT 990-PRO 80 Ohm or 250 Ohm / DT-1990 PRO 250 Ohm
- Sony MDR-7506
- Audio Technica ATH-M50X
- Audeze SINE
- Audeze LCD-XC
- Sennheiser HD 300 Pro
- Sennheiser HD 660 S
- Shure SRH1840

Suggested headphones requiring external amplification - such as Schitt Magni or Chord Mojo or Apogee Groove

Audeze LCD-2, 3 or 4
Sennheiser HD 800, HD 820, HD 600, HD 650, HD 650 Pro

Levels: Full, but comfortable. Do not listen at low levels.

File Based Solutions
- Netflix Content Hub
  - Download quicktime with embedded 2.0 - preferred solution
  - Streamed 2.0 mix embedded in picture from Cuts bucket - alternative when download is not possible
- Netflix PIX account
  - Internal PIX quicktime download with embedded 2.0 - preferred solution
  - Streamed 2.0 mix embedded in picture - alternative when download is not possible
- Moxion
  - Internal quicktime download with embedded 2.0 - preferred solution
  - Streamed 2.0 mix embedded in picture - alternative when download is not possible
- Content Preview (Netflix service based) - when resources allow & IMF has been delivered
  - Stream 2.0 mix from Netflix app on any supported device for critical review
  - Stream 5.1 or Atmos as a confidence check only

Real Time Software Solutions
- Sohonet ClearView Flex
  - Remote review service with local servers in most regions. Requires hardware encoder box provided by Sohonet.
- Streambox Cloud Software Encoder & Streambox App
  - Remote live review service from HDMI or SDI source. Subscription pricing, fairly user friendly, stereo only.
- Source-Live
  - Allows for encrypted audio and video streaming from a digital audio workstation for real time review and client feedback.
- Evercast
  - Live editorial product would work for sound reviews. Potential self set up between sound team and clients
- Spotterfish
  - Works from finished file. Real time collaboration (integrated video chat), timelines run in sync, export markers to AAF for Pro Tools, affordable
- Soundwhale
  - Can be streamed from Pro Tools or finished file. Allows for real time collaboration - clients watch & listen as notes are addressed
- PIX Live Review
  - Works from finished file.
- Cinesync Frankie
  - Buffer and stream review all parties in sync. Solid performance, affordable subscription pricing.

Remote Sound Mix Review Spec

The below options are compatible for both PIX and for ‘Locked Cuts’ for Content Hub.

	PIX Standard	PIX Screening Room
Video Codec	H.264*
Colorimetry	Rec. 601, Rec. 709 or xvYCC**
Audio Codec	Low Complexity/"LC" AAC Audio(MPEG-4 Part 3 Advanced Audio)***
Container	.mov
Progressive Streaming	Fast Start
Frames Per Second	23.976, 24, 25, 29.97, 30, 50, 59.94, or 60****
Resolution	1280x720	1920x1080
Data Rate	2,400 kbps	10,000 kbps
Audio Data Rate	128 kbps	192 kbps
Audio Sample Rate	44.1 kHz or 48 kHz	48 kHz
Audio Tracks	Interleaved Stereo (Left/Right) or Interleaved Matrixed Stereo (Left Total/Right Total)

*Closed GOP; Compressed Movie Atom [cmov] and Edit Lists [elst] are not supported. Must be tagged H264, AVC tagged not accepted. Note: Telestream Vantage creates AVC tagged with H264 settings which is not supported across both systems.

**xvYCC will be treated as standard Rec. 709; values outside of the standard will be ignored.

***Note: This often appears as the "AAC" or "MPEG-4 AAC" option.

Other variants (Low Delay or High Efficiency) are not supported.

****Variable Frame Rate (VFR) and/or Frame Reordering is not supported.

Interlaced and progressive inputs are supported; interlaced sources will be deinterlaced.

Files must contain one track of video and can not have more than one track of audio. Files cannot contain text tracks.

Fast Start

Clips must include the Fast Start flag. With this flag, clips play back while they load. Without this flag, viewers must wait for the entire clip to load before the clip will play back. Clips without the Fast Start flag may not play back with PIX watermarking or DRM.

If the files are being exported from Avid, note that there is a known bug in Avid that causes files to be created without the Fast Start header, even when Fast Start is properly selected. If this occurs, QuickTime Pro or MPEG Streamclip (a free program available at www.squared5.com) can add Fast Start with a simple "Save As...", no need to re-encode.

If the files are being exported from Premiere, note that Adobe no longer supports H.264 MOV files. Use Adobe Media Encoder to export an H.264 MP4 as per PIX's specs. Then open the MP4 in MPEG Streamclip, and select File > "Save as..." MOV file. Note that Fast Start will be added during this save.

Content Hub - Preparing Editorial Assets

PIX - Prepare Media

Possible Sound Mix Scenarios

If working at the post sound facility is not possible, mixers may elect to work at home. We trust our crews when they feel their home systems are up to the task, and we hold them accountable if there are problems with the mix. Expect additional time in the mix schedule due to the sound team collaborating remotely. These will generally be one person mixes, or two mixers handling different elements in two locations. This could require significantly more time and patience.

At-Home Sound Mixing (Mixer at Home, Content/Hardware at Home)

5.1 or 7.1.4 (Atmos) speaker setups required
Mix room must be calibrated to reference level
We prefer if the room is also EQ’d and speakers meet Dolby SPL spec
Optionally send work-in-progress or finished mixes to ctsound@netflix.com for review

Security Guidelines

We recommend following our Home Studio Security Guidance for remote work. We are faced with uncertain circumstances and do not have the access to materials and resources that we normally do. With that in mind, please reach out to security if you have questions about our recommendations.

We are providing this guidance to support you in protecting our content. Most importantly, be safe and please use common sense. Be mindful of your surroundings and take all of the basic steps to keep you and your devices protected. Please ensure any content downloaded to home systems is deleted as soon as the reviews are complete.

Additional questions or concerns should be raised to sis@netflix.com and your Netflix Post Manager.

Media Tracking

All AV assets should be shared using approved systems and should be identifiable to the end recipient. We recommend the following guidelines:

Digital Transfers should use a secure and approved platform (e.g., Content Hub Workspace, PIX, Aspera). If you are unsure about a transfer tool - reach out to SIS@Netflix.com. Transfers on physical drives should be done using hardware encrypted drives with the passwords/keys sent separately.
Keep records of persons and organizations with access to content.
Burn in individualized watermarks for all video turnover materials.

Remote Mixing - Local Media Copy

To prepare for the possibility to continue the mixing process from home:

Copy all footage (editorial proxies) and reference sound elements to encrypted hard drives. Reach out to sis@netflix.com with questions about drive security or configuration.
Below are some suggested drives. Keys are often recommended when moving the most easily accessible material, combination drives are also good, but not as secure. Finally the Lacie’s are the least secure, but are encrypted with password. Minimum requirements for all hard drive encryption is 256bit AES. This is by no means an exhaustive list, but should help explain the type of drive security we are looking for. *Note: do not encrypt the media itself, as it then will not play when plugged in to your remote system.*

ALT (Mac-only): If you cannot acquire hardware encrypted hard drives in the time available and are working in a Mac environment both at the vendor’s side as the editor’s home setup, please format the drives you have to require a password to be accessed: Format as: "Mac OS Extended (Journaled, Encrypted)" which means the user is prompted to enter a password before the drive is mounted and files can be accessed.Here is information on formatting drives for Mac, with information on choosing the encrypted option:

https://osxdaily.com/2012/01/25/password-protect-external-drive-mac-encrypted-partition/

ALT (Windows-only): If you cannot acquire hardware encrypted hard drives in the time available and are working in a Windows environment both at the vendor’s side as the editor’s home setup, please use Windows Bitlocker to create password protected harddrives. Here is information on setting up Bitlocker within Windows:

https://www.pcworld.com/article/2308725/a-beginners-guide-to-bitlocker-windows-built-in-encryption-tool.html

Copy all picture editorial proxies, sound elements, stems and masters to WORKSPACES on ContentHub. This will provide a backup in the Cloud should you need it, but should be a secondary priority to creating the drives.

Create a daily back-up by copying all (Avid/ProTools) project files and new media created (sound elements, stems and masters) onto ContentHub.

A shared Google Sheet or alternative solution to track updates to the data should be maintained by the AE. This sheet should only be shared with individuals who need access to the sheet. Picture and Sound Editors in turn can download the new media from Content Hub and add to their existing projects.

Alternatively, you could look into sync tools to keep the media in sync between systems. Installing one of these programs, setting up “hot/watch” folders and passing bins back and forth could help to keep media up to date on all drives with minimal manual labour. The decision to use this process should only be made in close collaboration with the sound crew and it should be understood that most options to achieve this workflow can be both complex and labour intensive in set up. We recommend to only look into this option if someone on your team or at your vendor is familiar and comfortable with this process.

Change Log

7/27/2020

Added Apogee Groove to suggested headphone amps
Added Beyerdynamic DT-1990 PRO 250 Ohm, Sennheiser HD 300, 650 Pro to suggested headphones
Added Spotterfish, Cinesync Frankie to Real Time Software Solutions

4/21/2020

Added Sennheiser HD 380 Headphones to suggested headphone list
Added Streambox Software Encoder Information
Added Sohonet Clearview Flex information

3/27/2020

Under Remote Mixing - Local Media Copy, added sections "3. ALT (Mac-only) & 4. ALT (Windows-only)"
Formatting improvements
Under Real Time Software Solutions, added Source-Live

3/25/2020