With the adaptive bitrate feature, the playback bitrate of a live stream can change smoothly based on network conditions. This ensures a smooth playback experience under changing network conditions.
Notes
After creating a template, you can bind it with a playback domain name. The binding takes effect in 5-10 minutes.
A playback domain can be bound with multiple adaptive bitrate templates, and an adaptive bitrate template can be bound to multiple playback domains.
Each adaptive bitrate template can have up to 15 streams.
For the adaptive bitrate feature to work, the player needs to support adaptive bitrate.
The video codec and GOP value must be the same for all streams in the same adaptive bitrate template.
Adaptive bitrate playback URLs support only the HLS and WebRTC playback protocols. For URL construction rules, see URL Generator.
The adaptive bitrate feature for live streaming requires the simultaneous output of multiple streams at different resolutions to ensure seamless switching during network fluctuations. Each stream configured in the template corresponds to an independent transcoding process. All streams are started simultaneously during playback, and each stream is billed separately.
The transcoding configuration template for live adaptive bitrate supports the face blurring feature, which can blur faces and specific objects. To use this feature, you need to submit a ticket to request support. In an adaptive bitrate template, even if multiple substream templates enable the face blurring feature, the fee is charged only once. Enabling this service incurs live transcoding fees and MPS II fees.
Creating an Adaptive Bitrate Template
1. Log in to the CSS console and go to Feature Configuration > Adaptive Bitrate.
2. Click Create template and complete the following settings:
Basic settings: Include template name and template description. For details, see Basic Information.
3. Click Add stream to add a new stream to the template. You can add up to 15 streams for a template.
4. Click Save.
Basic Information
Basic Information
Required
Description
Template name
Yes
Please enter 1 to 10 characters.
The adaptive bitrate template name. It only supports letters and alphanumeric combinations and does not support pure digits.
The substream name cannot be duplicated with existing transcoding template names, adaptive bitrate template names, and substream names.
Template description
No
The live adaptive bitrate template description supports only Chinese, English, digits, spaces, underscores, and hyphens.
Subtitles & simultaneous interpretation
No
The subtitle & simultaneous interpretation feature is disabled by default and can be enabled manually.
To enable this feature, you need to bind a subtitle & simultaneous interpretation template. Select a subtitle & simultaneous interpretation template to bind based on your business requirements.
You can preview and view the effects of the subtitle & simultaneous interpretation template.
You can adjust the subtitle & simultaneous interpretation template at any time based on business needs.
The live subtitling & simultaneous interpretation feature can convert speech into subtitles in real time during live streaming. For details, see Live Subtitling & Simultaneous Interpretation. Using this feature incurs live transcoding fees and MPS ASR/translation fees. For billing rules, see Billing.
Stream Information
Substream Configuration Category
Substream Configuration Item
Required
Description
Basic Information
Transcoding type
Yes
The optional transcoding types, include standard transcoding and TSC transcoding.
Stream name
Yes
Please enter 1 to 10 characters.
The substream template name. It only supports letters and alphanumeric combinations and does not support pure digits.
The substream name must not duplicate existing transcoding template names, adaptive bitrate template names, or substream names.
Video Parameters
Video quality
No
You can choose Smooth, SD, HD or FHD. After you select a value, the system will automatically enter the recommended video bitrate and height, which can be modified.
Video bitrate (Kbps)
Yes
Output video bitrate. Value range: 101Kbps - 8000Kbps. Only multiples of 100 are supported.
Video resolution (px)
Yes
By default, you set the height of the output video.
The input value is the height value. You can switch to Set by Long and Short Sides, where the input value is the short side value.
Value range: 2-3000. The value must be a multiple of 2. The other side will be auto-scaled.
Video Encoding
No
The default is Original encoding. You can select H.264, H.265, H.266, or AV1.
The codec for all the streams in the same adaptive bitrate template must be the same.
Frame Rate & GOP
Video frame rate (fps)
No
You can choose to keep the original frame rate or set a video frame rate. By default, the original frame rate is maintained.
The video frame rate setting value range: 1 fps - 60 fps.
GOP(seconds)
(Unit: s/sec)
No
The GOP is not specified by default. Value range: 1-6.
The higher the GOP, the higher the latency. A smaller GOP may potentially lead to stuttering. The GOP for all the streams in the same adaptive bitrate template must be the same.
Audio Parameters
Audio Encoding
No
Options include Auto and AAC. The default is Auto.
Auto adaptation: The system automatically matches the optimal encoding.
When AAC is manually selected, LEB (WebRTC) playback may be abnormal.
Sample rate and channel can be configured only when audio coding is set to AAC. When Auto is selected, only audio bitrate can be configured.
Audio bitrate
(Unit: Kbps)
Yes
You can choose to keep the original bitrate or set the audio bitrate. The default is to keep the original bitrate.
Set audio bitrate value range: 32kbps - 500kbps.
Sample Rate
No
Displayed only when audio coding is set to AAC.
You can select Keep original sample rate or Set sample rate. The default is Keep original sample rate.
After you select Set sample rate, the available options include 44100Hz and 48000Hz, with 44100Hz selected by default.
Audio Channel
No
Displayed only when audio coding is set to AAC. Options include Mono and Stereo, with Stereo as the default.
Advanced Configurations
DRM encryption
Yes
The feature is disabled by default and can be manually enabled.
To enable this feature, go to DRM Management to configure the DRM key.
DRM schemes including Widevine, FairPlay, and NormalAES are supported for HLS playback. For FairPlay encryption, you need to upload the certificate you obtain from Apple to your player.
Encryption types: default Widevine, optional Fairplay, and NormalAES.
The switch is disabled by default and can be manually enabled. After it is enabled, SEI can be passed through.
Parameter limit
No
Parameter limits are disabled by default.
After a limit is enabled, if you enter a value higher than the original, the original will be used. This can avoid video quality issues caused by using high video quality settings to transcode videos of low quality.
Binding a Domain Name
1. Log in to the CSS console and go to Feature Configuration > Adaptive Bitrate page.
2. Bind a domain name in either of two ways:
Bind a domain to an existing template: Click Bind Domain Name in the top left.
Bind a domain name after creating an adaptive bitrate template: After the adaptive bitrate template is created, click Bind Domain Name in the notification box.
3. In the domain binding window, select the template and playback domain you want to bind. You can bind multiple playback domains at the same time. Click Confirm to complete the binding.
Unbinding a Domain Name
1. Log in to the CSS console and go to Feature Configuration > Adaptive Bitrate page.
2. Select the target template and click Unbind.
3. In the pop-up window, click Confirm.
Modifying a Template
1. Log in to the CSS console and go to Feature Configuration > Adaptive Bitrate.
2. Select the target template and click Edit on the right to modify it.
3. After modification, click Save.
Deleting a Template
Attention:
If a template has been bound to domains, you need to unbind them before you can delete the template.
You cannot delete an adaptive bitrate template that has the subtitles & simultaneous interpretation features enabled.
Once the template is deleted, it cannot be recovered. Please proceed with caution.
1. Log in to the CSS console and go to Feature Configuration > Adaptive Bitrate.
2. Select a live streaming adaptive bitrate template that is not associated with a playback domain, and click Delete.
3. Confirm whether to delete the current live streaming adaptive bitrate template, and click Confirm to delete it.
