Considerations for HEVC
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Before you add HEVC as an available codec for your video streaming, be sure to consider the benefits versus the additional costs that are associated. While the HEVC codec is more efficient and will subsequently provide lower CDN usage and a better playback experience in general, how significant these benefits will be depends upon your audience possessing devices that can support HEVC. Because support for the HEVC varies by platform, HEVC stream usage potential might not be significant for your audience. And while adding HEVC streams is not an additional direct cost from Ooyala, it does typically mean you will have more encoding costs. This is because you will typically need by HEVC (h.265) and AVC (h.264) stream support, meaning HEVC is an additive codec rather than a replacement.
Customer Considerations for Adding HEVC Streams
Before adding HEVC to their profile, customers should consider the following issues:
- Bitrate and bandwidth savings. Compared with H.264, adding the HEVC codec will provide approximately 30% bitrate savings. For playback at the same resolution, HEVC will therefore require approximately 30% less bandwidth. In addition to some CDN savings, audiences will enjoy a higher quality of experience (higher resolutions will be achieved at the same bandwidth).
- Increased transcoding time and costs. HEVC codecs will typically double the amount of transcoding needed per asset, because unsupported devices will still need the AVC assets. Increased transcoding time increases transcoding costs. Because HEVC cannot be appended to an existing asset, adding HEVC to already transcoded assets will require the reprocessing of those assets.
- Support for the HEVC codec is limited. Therefore, based on anticipated audience consumption for the supported environments, customers should determine whether the device coverage they gain is worth the additional transcoding costs.
Supported Environments for HEVC
The following browsers support the HEVC codec:
- Microsoft Edge: Windows 10+ hardware with HEVC decoding
- Safari: With MacOS High Sierra
App Environments Supporting HEVC
- Android: Android 5+ devices, and only devices that have either hardware or software decoders for HEVC. The Ooyala Player will confirm at run-time, prior to playback. whether an HEVC decoder (hardware or software) is available on the device. Additionally, since our stream encoders are generating CMAF HLS to be compatible with iOS devices, only MPEG-DASH streams are supported with HEVC.
- iOS: iOS 11 plus A10+ Chips (iPhone 7 and greater models). Additionally, iPhone 6 (A8 chipset) can support HEVC). iPhone 5 has some support with the A7 chip, but cannot support the higher bitrates compared to the later chipsets.
Note: For older Apple devices: On some older devices, support for HEVC is also affected by the resolution and frame rate (fps) of the video. However, Ooyala does not support these older devices, in order to reduce the risk of a bitrate ladder ramp that fails. Devices in this category include:
- iPhone 6, iPhone 6 Plus, and iPad Air 2 working with HEVC video that was captured at no greater than 1080p/240 fps.
- iPhone 5s, iPad Air, and iPad mini (Retina models) working with HEVC video that was captured at no greater than 1080p/60 fps or 720p/240 fps.
In addition to environment limitations, the following functional limitations will block the ability of a browser and/or device to receive HEVC assets:
- For Web players, if autoplay is blocked by the browser settings, it will not be possible to test whether the HEVC codec is supported. As a result, the device will always receive AVC manifest during this playback session.
- For Android, only MPEG-DASH streams are supported with HEVC.
Supported Features/Combinations for HEVC
Ooyala currently supports the following HEVC Media Formats:
- Streams in the following packaging types:
- Clear HLS
- Clear MPEG-DASH
Note: HEVC streaming with DRM is not yet supported.
Unsupported Environments when using HEVC
Because HEVC encryption uses the CMAF specification when using a single manifest, devices unable to support the CMAF standard cannot be supported. These include:
- iOS 9 - devices
- Android 4.4 and lower devices, and Android devices otherwise lacking h.265 decryption hardware
Unsupported Features/Formats with HEVC
Ooyala currently does not support the following features with the HEVC codec:
- Streams with Multi-Audio Tracks (only single audio track streams are supported)
- HEVC with Server-side Ad Insertion (SSAI)
- Adding HEVC CODEC to an asset without full reprocessing. If a customer already has HLS in h.264, the h.264 streams must be reprocessed when adding HEVC. This is the same for DASH.