Skip to main content

TECHNICAL GUIDE

Slingshot Proxy Transcoding and Best Practices

Steve Higdon
  • Updated

Every EVO includes Slingshot and ShareBrowser, which are two applications included within the EVO Suite of workflow tools. Slingshot is a powerful automations engine with built-in transcoding capabilities. It's used to create the Preview Proxies (ShareBrowser Previews) that are critical for many ShareBrowser features. Slingshot may also be used to create Edit-Ready Proxies.

ShareBrowser Previews

When you store media files on your EVO shares, several important things happen.

First, Slingshot will index (i.e., catalog) the contents of your shares. This index identifies media files and establishes ShareBrowser database records to help your team track and find all of its data.

Second, Slingshot creates a Preview Proxy for each media file. This Preview Proxy is a low resolution, low bitrate version of the video or audio file, which is used in the ShareBrowser applications. These Preview Proxies are used in ShareBrowser Desktop Application, and ShareBrowser Web App, as well as the ShareBrowser panels and extensions available for various production applications (Adobe Premiere Pro & After Effects, Apple Final Cut Pro, and DaVinci Resolve). If your original video is in 16:9 aspect ratio, the Preview Proxy will be in 640x360 resolution. Still images and graphics will get a thumbnail to be displayed in ShareBrowser.

Default Preview Proxy parameters are established in the Media Proxy preset, and should be manually enabled for each share. Available options for the Preview Proxy include a timecode window burn, and a custom watermark. NOTE: to ensure that ShareBrowser features work optimally, it is recommended that all Media Proxy parameters, other than the optional timecode and watermark, should remain at their default settings.

Should I enable Preview Proxies on the EVO share I just set up?

In most cases, yes. Preview Proxies are essential for many ShareBrowser and Nomad features.

Best Practices: Preview Proxy

  • Preview Proxies should be stored in a dedicated share on one of your EVO Logical Disks. Most EVOs will already have a share named ‘sys-sb-proxies’ (or similar) for just this purpose.
  • Do not enable user access to proxy share. This share, and the proxies within, are used by the ShareBrowser applications to access the Preview Proxies.
  • Do not set a quota for the proxy storage share.
  • Do not enable the recycle bin for the proxy storage share.
  • Do not establish the proxy storage share on the default zsystem Logical Disk.
  • Do not modify the codec, resolution, etc. for the Media Proxy preset used to create the ShareBrowser Preview Proxies.
  • The only parameters of Preview Proxies that should be modified by users are the Timecode Burn and Watermark options. Note: Changing any of these options will cause ALL Preview Proxies to be re-transcoded on the next index cycle. That can be a long process that may significantly impact your workflow.
  • You should Enable Preview Proxies for all shares in most typical media production workflows.
  • Use Nomad to download proxies for offline editing.
  • We recommend that the proxy share, along with your data (including the ShareBrowser database), should be backed up (and verified) regularly.

Edit-Ready Proxies

An additional feature of Slingshot is the ability to transcode Edit-Ready Proxies. Edit-Ready Proxies are optional proxy files that can be used in off-line or mezzanine workflows. While the ShareBrowser Preview Proxies that we discussed above are of a very specific format to maintain compatibility with the various ShareBrowser applications, Edit-Ready Proxies can be configured to suit the requirements of your specific workflow. Edit-Ready Proxy parameters are established in the default Edit Proxy preset, and are manually enabled for each share. Codec, resolution, container, timecode, watermark, etc. can be customized to meet your needs. Editors can download Preview Proxies and/or Edit-Ready Proxies using Nomad.

Not everyone needs to enable the Edit-Ready proxy feature. If off-line editing isn't a significant part of your workflow, you probably don't need Edit-Ready proxies. Even for those teams that sometimes want to edit with proxies, it may not be necessary to enable this feature. Some users are satisfied to use the ShareBrowser Previews as edit proxies. Still others may have edit proxies created in some other way (in camera, separate transcode hardware, Adobe Media Encoder, etc.). But, if your workflow would benefit from having a standardized edit proxy as a global setting- then you should consider enabling Edit-Ready Proxies.

Automatic or manual? Unlike ShareBrowser Preview Proxies, Edit-Ready Proxies have both an automatic mode and a manual mode. When set to AUTOMATIC, the transcode operation will be triggered on the next scheduled index. For selective generation of Edit-Ready Proxies, you can set this feature to MANUAL. Using the Manual mode, Edit-Ready Proxies will only be transcoded for files that are user-selected in ShareBrowser (right-click menu, create preview/proxy). To optimize your ShareBrowser environment for automatic background transcoding of Edit-Ready Proxies use the ENABLED setting. To conserve both processing power and storage capacity, consider using the MANUAL setting. We usually recommend that users start their Edit-Ready Proxy experience using the MANUAL mode. The MANUAL mode allows you to dedicate processing and storage resources only to those proxy files that are specifically necessary.

Before enabling Edit-Ready Proxies, it's important to determine exactly what type of proxy files you want to work with. The Edit-Ready Proxy feature can transcode most source files into H.264, mp4, or various Apple-certified ProRes codecs. Choose the desired codec, resolution, and other parameters of the Edit-Ready proxy after careful consideration and discussion with your post production team. There is a single, global preset that will control proxy files generated using this Edit-Ready Proxy feature.

Best Practices: Edit-Ready Proxy

  • Edit-Ready Proxies are stored in the same dedicated share that is also used for Preview Proxies.
  • Use Nomad to download proxies for offline editing or mezzanine workflows.
  • Do not enable user access to the proxy share. It is not necessary (or recommended) that users mount the Proxy Share.
  • Do not set a quota for the proxy storage share.
  • Do not enable the recycle bin for the proxy storage share.
  • Do not establish the proxy storage share on the default zsystem Logical Disk.
  • The parameters of the preset that control the generation of Edit-Ready Proxies can be customized to your requirements, including Timecode Window Burn and Watermark options. Note: Changing any of these options will cause ALL previously transcoded Preview Proxies to be re-transcoded. That can be a long process that may significantly impact the rest of your workflow.
  • We recommend that the proxy share, along with your data (including the ShareBrowser database), should be backed up regularly.

Frequently Asked Questions

What about path-based proxies?

Slingshot typically stores proxy files on a dedicated share which is used by the ShareBrowser application. The proxies are organized relative to their corresponding database records, and are not intended to be directly accessed by users. The Nomad utility can be used to extract and download path-based proxies.

Is it possible to have proxies generated more quickly?

You may be able to raise the CPU limit which controls how much processing power can be taken up by transcoding operations. Go to Slingshot > Index/Proxy tab to adjust the CPU limit for Preview or Edit-Ready proxies.

For additional processing power, you may include the processing power provided by a Mac or Windows workstation, or another EVO. The Transcode Accelerator (TCA) plugin distributes files among multiple devices to speed up proxy transcoding jobs by way of parallel processing. 

Is it possible to control when those processes occur?

You can schedule when transcoding operations are allowed to occur. Go to Slingshot > Index/Proxy tab > Schedule to set up a schedule to limit transcoding operations to particular hours of the day.

How do I know if EVO is currently transcoding proxies?

You can tell that EVO is transcoding by logging in to the EVO control panel and observing the following:

  • Disk Activity and CPU graphs in the header of EVO control panel will show activity.
  • Click on the bell icon at the top of the page to open the System Tray to view messages relating to the status of index and proxy operations.
  • Go to Slingshot > Automations tab > choose Indexing Tasks from the drop-down menu. For each EVO share there will be an Index operation. There will also be transcode operations for those shares that have those options enabled. The State column will indicate the process is either Waiting, Running, or Paused.
  • The SNS Transcode Accelerator plug-in, if installed, may provide further visibility into the progress of Slingshot Transcode jobs.

During transcode operations, there is no indication showing the percentage of completion, or estimated time to completion of current transcode operations.

How do I know if my files have ShareBrowser Preview Proxies or Edit-Ready Proxies?

In ShareBrowser, media files that have an associated ShareBrowser Preview Proxy will display a thumbnail (for images and graphics), a first-frame thumbnail for video, or a waveform image for audio files.

ShareBrowser Web App won’t provide the option to download a proxy if a proxy does not yet exist for a particular file.

Can I have different Edit-Ready proxy presets for different projects or different shares?

The Edit-Ready proxy is intended to be a global, 'house standard' preset. Only one preset can be selected.

What happens if I change the parameters of the proxy presets?

All existing proxies will be re-transcoded to incorporate the changes. Use caution when changing parameters, as this change may trigger the re-transcoding of many existing media files.

How do I use proxies transcoded by Slingshot in my NLE?

There are several ways to use Slingshot proxies for offline editing. Please see related articles.

Default Presets, Technical Details

The following information describes the technical details of the default SharewBrowser Previews and default Edit-Ready Proxy files, as of EVO v7.

ShareBrowser Preview Proxy

  • Codec: H.264
  • Container: MPEG-4
  • Resolution: vertical resolution is set to 360 pixels.
  • Aspect ratio: preserve original
  • Bitrate: variable, typically less than 500kbps
  • Storage footprint: approximately 225MB per hour of content
  • Default preset name: Media Proxy
  • Options (can be enabled by admin)
    • Timecode window burn 
    • Watermark

Edit-Ready Proxy

  • Codec: ProRes 422 Proxy
  • Resolution: preserve original
  • Aspect ratio: preserve original
  • Bitrate: variable.
    • Approximately 50 Mbps HD
    • Approximately 200 Mbps UHD
  • Storage footprint: variable
    • Approximately 24GB per hour of HD
    • Approximately 100GB per hour of UHD
  • Default preset name: Edit Proxy
  • Options
    • Timecode window burn
    • Watermark
    • Customize codec, resolution, container, etc.

Related articles