ApsaraVideo Live:Get started with RTS

Procedure

1. Activate ApsaraVideo Live

2. Add an ingest domain and a streaming domain

3. Add CNAME records

4. Associate the streaming domain with the ingest domain

5. (Optional) Configure SSL certificates

6. Enable RTS

7. (Optional) Configure custom URL signing

8. Generate ingest and streaming URLs

9. Start RTS-based stream ingest

10. Start RTS playback

Activate ApsaraVideo Live

1. Log on to the Alibaba Cloud official website. In the top navigation bar, choose Products > Media Services > ApsaraVideo Live. The ApsaraVideo Live homepage appears.

2. Click Activate Now.

3. On the ApsaraVideo Live activation page, select Pay-By-Traffic as the metering method. Read and agree to the ApsaraVideo Live Terms of Service.

4. Click Activate Now.

Add an ingest domain and a streaming domain

To use RTS, you must add an ingest domain and a streaming domain.

1. Prepare domain names.

   • If you do not have one, register one with Alibaba Cloud Domain Names. 

   • To provide services in the Chinese mainland, you must apply for an Internet Content Provider (ICP) number for your domain name.

     Note

     • To try the basic features, select a live center in a region outside the Chinese mainland and set the acceleration region to Outside Chinese Mainland. This eliminates the need for ICP filing.

     • If the ingest and streaming domains are subdomains, ICP filling is required only for the primary one.

2. Log on to the ApsaraVideo Live console.

3. In the left-side navigation pane, click Domain Names. The Domain Management page appears.

4. Click Add Domain.

   To add a subdomain, append a prefix to the domain name you have registered. The subdomain does not require separate registration. Ensure you can differentiate between the ingest and streaming subdomains.

5. In the Add Domain Name step, configure parameters as needed.

   Important

   When you add a domain name for the first time, ApsaraVideo Live verifies its ownership.

   

   Show parameters

   Parameter	Valid value	Description
   Domain Type	Streaming Domain Ingest Domain	The type of the domain name. It cannot be modified once set. Note You cannot add a domain name as both an ingest domain and a streaming domain.
   Domain Name	N/A	Enter the domain name that you want to accelerate. Note the following: In most cases, use a subdomain as an accelerated domain name. Example: demo.aliyundoc.com. ApsaraVideo Live does not support wildcard domain names, such as *.aliyundoc.com. Duplicate accelerated domain names are not allowed. If the error message The specified domain already exists is displayed, check whether the domain name is added to other cloud services such as ApsaraVideo VOD. You can add up to 20 domain names to ApsaraVideo Live for each account. If the average daily peak bandwidth of your domain names exceeds 50 Mbit/s, you can submit a ticket to increase the quota of domain names. Make sure that the quota increase does not incur business risks. Content served from the domain name must meet the compliance requirements of ApsaraVideo Live. Note The specified subdomain must belong to the same Alibaba Cloud account. If not, an error message appears.
   Acceleration Region	Chinese Mainland Global Outside Chinese Mainland	If the streamers or viewers are located in the Chinese mainland, select Chinese Mainland. If they are located around the world, select Global. If they are located in countries and regions outside the Chinese mainland, including Hong Kong (China), Macao (China), and Taiwan (China), select Outside Chinese Mainland. In the following cases, ICP filing is required: Acceleration Region is set to Chinese Mainland or Global. Acceleration Region is set to Outside Chinese Mainland, but the selected live center is in Chinese Mainland. For further guidance, see How do I select the acceleration region for a domain name?
   Live Center	See Supported regions.	A live center provides media processing services in the cloud, such as snapshot capture, recording, transcoding, and production studio. The live center of an ingest domain must be located in the same region as that of the associated streaming domain. This parameter cannot be modified once it is set. For further guidance, see How do I select a live center.

6. Note down the generated CNAME record for use in the next step.

   

Add CNAME records

Before you use RTS, you must add CNAME records at your DNS provider to map your ingest domain and streaming domain to the CNAME that is assigned by ApsaraVideo Live. The following example shows how to add a CNAME record when your DNS provider is Alibaba Cloud. For information about how to add a CNAME record at other DNS providers, see Add a CNAME record.

1. Log on to the Alibaba Cloud DNS console.

2. In the left-side navigation pane, click Domain Name Resolution. The Domain Name Resolution page appears.

3. Find the domain name for which you want to add a CNAME record and click DNS Settings in the Actions column.

4. Click Add DNS Record and configure the parameters that are described in the following table.

   Parameter	Description
   Record Type	Select CNAME from the drop-down list.
   Hostname	Specify a prefix for the domain name. For more information about regular prefixes of domain names and sample domain names, see the following table.
   DNS Request Source	Use the default value.
   Record Value	Enter the CNAME that you obtained.
   TTL Period	Use the default value.

   Prefix	Sample domain name	Description
   demo	demo.aliyundoc.com	The subdomain name.
   @	aliyundoc.com	The root domain name.
   *	*.aliyundoc.com	The wildcard domain name.

5. Click OK.

Associate the streaming domain with the ingest domain

To ingest and play streams, you must associate the streaming domain with the ingest domain.

1. In the left-side navigation pane, click Domain Names. On the page that appears, find the streaming domain that you added and click Domain Settings in the Actions column. You are directed to Streaming Management > Basic Settings.

2. Click the Stream Ingest Information tab.

3. Click Add Stream Ingest Information or the Edit icon next to Ingest Domain and select the ingest domain that you want to associate.

(Optional) Configure SSL certificates

For security reasons, if you want to implement RTS in a native browser, you must configure Secure Sockets Layer (SSL) certificates for the ingest and streaming domains. For more information, see Configure HTTPS secure acceleration.

Enable RTS

1. Log on to the ApsaraVideo Live console.

2. In the left-side navigation pane, click Domain Names. The Domain Management page appears.

3. Find the streaming domain for which you want to enable RTS and click Domain Settings in the Actions column.

4. On the page that appears, choose Streaming Management > RTS.

5. Turn on RTS.

6. In the dialog box that appears, choose RTS 1.0 and turn on HTML5 Auto Transcoding.

   The WebRTC of native browsers does not support B-frames and the AAC audio format. To ensure smooth playback, HTML5 auto transcoding performs adaptive transcoding.

   • If you use a browser to play a stream that contains B-frames and AAC audio, the B-frames are removed and the audio format is converted. You are charged for standard transcoding fees.

   • If you use a browser to play a stream that contains AAC audio but does not contain B-frames, the audio format is converted. You are charged for audio-only transcoding fees.

   • If you use a browser to play a stream and have configured a transcoding template, HTML5 auto transcoding and the transcoding template both take effect. The transcoding is billed only once.

   • If you use native SDK to play a stream, transcoding is not required because the SDK supports B-frames and the AAC audio format.

   Note

   • After you enable RTS, wait a few minutes and then check whether the configuration takes effect.

   • To associate an ingest domain with multiple streaming domains, see Bind a sub-streaming domain to a main streaming domain.

   • RTS and standard streaming can share the same streaming domain. However, we recommend that you configure a separate streaming domain for RTS because RTS uses User Datagram Protocol (UDP) while standard streaming uses Transmission Control Protocol (TCP).

(Optional) Configure custom URL signing

URL signing protects resources on origin servers from unauthorized access and downloads. By default, it is enabled for a domain name.

You can use the default or custom URL signing settings based on your business requirements. To use the custom settings, specify the Primary Key, Secondary Key, and Validity Period parameters.

1. In the left-side navigation pane of the ApsaraVideo Live console, choose Domain Names. On the Domain Name Management page, find the streaming domain for which RTS is enabled and click Domain Settings in the Actions column.

2. Choose Streaming Management > Access Control.

3. Click the URL Signing tab. Then, click Modify.

4. Configure the URL signing settings. The following table describes the parameters.

   Parameter	Description
   Authentication Type	Streaming domains in ApsaraVideo Live support only Type A signing. Note If URL signing fails, HTTP status code 403 is returned. In this case, you must recalculate the signature. Invalid MD5 value Example: X-Tengine-Error:denied by req auth: invalid md5hash=de7bfdc915ced05e17380a149bd760be Invalid timestamp Example: X-Tengine-Error:denied by req auth: expired timestamp=1439469547
   Primary Key	After you add a domain name, ApsaraVideo Live generates a random primary key. You can modify the primary key.
   Secondary Key	Specify a custom secondary key.
   Validity Period	The signed URL can be used to initiate stream ingest or streaming requests only within the validity period. Persistent connections are established for stream ingest and streaming. Stream ingest and streaming requests that are initiated within the validity period are not dropped after the validity period expires. New stream ingest and streaming requests fail to be initiated after the validity period expires.  The default validity period is 1 day or 1,440 minutes. You can specify a custom validity period. The minimum value is 1 minute. There is no upper limit.

Generate ingest and streaming URLs

You can generate ingest and streaming URLs in ApsaraVideo Live console or construct them by using the concatenation rules.

Start RTS-based stream ingest

We recommend that you use the RTMP format for RTS-based stream ingest. In the following example, OBS Studio is used to ingest streams over RTMP. OBS Studio also supports ingesting RTS streams based on WebRTC-HTTP Ingestion Protocol (WHIP). For more information, see Use OBS to ingest an RTS stream. For other methods, see Stream ingest for RTS.

1. Download and install OBS Studio. Download link: OBS Studio.

2. Launch OBS Studio.

3. In the menu bar, select File > Settings.

4. On the Settings page, select Stream and configure the following information:

   

   Parameter	Description
   Service	Select Custom...
   Server	Enter the signed ingest URL generated. Example: rtmp://demo.aliyundoc.com/app/stream?auth_key=1543302081-0-0-9c6e7c8190c10bdfb3c0************
   Stream Key	Leave this parameter empty.

5. Optional: On the Settings page, click Output and configure the following parameters to remove B-frames.

   • Output Mode: Advanced

   • Keyframe Interval (seconds, 0=auto): 1

     Note

     We recommend that you set a keyframe interval no greater than 3 seconds. This example uses 1 second.

   • CPU Usage Preset (higher = less CPU): veryfast

   • Profile: baseline

   • Tune: zerolatency

   

6. Go to the homepage of OBS Studio. Find the Sources section, add a source, and click Start Streaming.

   

Start RTS playback

The following table lists the players integrated with RTS SDK for RTS playback. Alibaba Cloud RTS provides demos for both mobile and web clients.

• Players:

  Player	References
  ApsaraVideo Player for mobile clients	Native SDK
  ApsaraVideo Player for web	Web SDK

• For information about the RTS demo, see Play an RTS stream.

Compatibility with standard live streaming

By default, browsers supporting WebRTC can play RTS streams with Opus audio format, so transcoding is not required. When you use OBS Studio for stream ingest, the default audio format is Opus.

Verify the latency of RTS

You can add a time calibrator URL during stream ingest to verify the latency of RTS by comparing the streaming time with UTC.

For example, in OBS Studio, go to the homepage, add a time calibrator URL in the Sources section, and then click Start Streaming.