Ooyala Transcoding Service (OTS)
- converting video content into multiple streams of varying bitrate and resolution appropriate for all target devices
- encryption and packaging for DRM
- storing processed content and delivering via a content delivery network (CDN) to expedite playback
OTS Run-time WorkflowThe following figure shows what occurs to a video asset after being loaded into Backlot.
Source FilesSource files are videos that have been loaded into Backlot (see Ingestion). They represent the input into the transcoding process. Each video file consists of a container that includes:
- video codec
- audio codec
Processing ProfileA processing profile mandates the number, formatting, and characteristics of the encoded streams that the transcoding process will generate for an ingested asset, such as:
- encoding settings (such as such as content width, resolution, and video and audio bitrates; see Encoding Settings)
- delivery protocol (see Delivery Protocols)
- output formats (see Supported Output Formats)
Encoded Stream Files
Encoded stream files represent the output of the transcoding process. Transcoding produces a collection of specific streaming formats that are optimized for playback across various platforms and devices. These files reside in a storage location (origin) that the CDN can access for delivery.A variety of validations can be performed to ensure the correctness of the encoded stream files. If you would like some or all of the following checks to be performed, contact your Ooyala account representative. Choose from the following types of validation:
Pre-Transcoding Video Quality Check
- Frame rate
- Color space
- Bit depth
- Aspect ratio
- Chroma subsampling
- GOP size
Pre-Transcoding Audio Quality Check
- Frame rate
- Compression mode
Post-Transcoding Output File Check
- Duration mismatch
- Presence of streams based on the processing profile
- Presence of manifest
- Peak signal-to-noise ratio (PSNR) validation
Playback SupportOoyala supports streaming to the following players:
- Player V4
- Mobile SDK for iOS
- Mobile SDK for Android
- Player V3 (Deprecated), which includes Flash Player V3 (Deprecated) and HTML5 Player V3 (Deprecated)
Setting up OTSDuring customer onboarding, you work with your Ooyala representative to define your transcoding requirements and design your transcoding policies.
Every customer starts with a default profile that provides for basic output streams (such as MP4 and HLS streams at various bitrates) and no DRM or encryption. Your Ooyala representative helps you customize one or more processing profiles to implement your transcoding policies. For more information, see Transcoding Setup.
Regardless of how you load a video asset into Backlot (via the OIS, the Backlot UI, or the Backlot REST API), transcoding begins automatically according to whatever processing profile you have - default or customized. You can even customize multiple profiles so that, if you use OIS with a manifest file, you can choose which processing profile to apply to an asset during the transcoding process.
Your viewers will view your content on many different device types, in different countries, under different circumstances, and over different connections where the bandwidth varies widely. One of the key challenges with streaming video is finding the right balance of bitrate (amount of bits in one second of video) and resolution (amount of pixels in a second of video) for each viewer’s connection and device.When determining which encodes to create, consider the following:
- Playback environment
- Security requirements
- Playback quality and its associated operational costs
- Number of encodings - The more encodings you have, the more options the player has to optimize content for the device and available bandwidth. The number of encodings available to your account is determined by the encoding profile that you choose.
In-Region Ingestion and TranscodingLeveraging Azure’s Media Service, Ooyala Ingestion Service and Ooyala Transcoding Service support ingestion and transcoding of video assets performed in your local region. This reduces transcoding time and keeps content geographically contained. In-region ingestion is supported for files uploaded using the Backlot API, FTP, or Aspera.
To see whether your account is eligible for in-region ingestion and transcoding, contact your Ooyala account representative.
- Not supported for processing profiles that include asset files in Flash format
- Not supported for processing profiles that mix clear and DRM assets
- Does not support multi-DRM configuration for the same muxing format
- Does not support thumbnail
- Does not support closed captions
Transcode Processing Queue
The standard processing queue for VOD content follows FIFO (first in first out) logic. Every customer can process 10 jobs in parallel - additional assets remain in the queue and are processed based on FIFO.
In addition to the standard processing queue, an express processing queue is available. The express processing queue can process 5 jobs in parallel. A job in the express processing queue gets higher priority than jobs in standard processing, and is picked ahead of jobs in the standard processing queue. The express processing queue also uses FIFO logic, and any more than five assets submitted to this queue remain queued until an open slot is available.
See here for more details about express processing.