YouTube Live Streaming API Overview

The YouTube Live Streaming API lets you create, update, and manage live events on YouTube. Using the API, you can schedule events (broadcasts) and associate them with video streams, which represent the actual broadcast content.

The Live Streaming API is actually comprised of components of the YouTube Data API and the YouTube Content ID API. The Data API enables YouTube users to manage their YouTube accounts, while theYouTube Content ID APIenables interactions with YouTube's rights management system. However, all of the resources that make up the Live Streaming API are used only to create and manage live events.

This document is intended for developers who want to write applications to facilitate live broadcasting on YouTube. It explains basic concepts of YouTube and of the API itself. It also provides an overview of the different functions that the API supports.

Core concepts

broadcasts
Abroadcastrepresents an event that can be watched on YouTube as it happens. Broadcasts can also be recorded and saved as YouTube videos so that users can watch them after they happen.
streams
Astreamidentifies the audio-video content that is being communicated to YouTube. Each broadcast is associated with one video stream.
cuepoints
Acuepointrepresents an ad break that can be inserted into a live broadcast.

API use cases

The list below suggests several ways to use the API in your application:

  • Schedule broadcasts and define broadcast settings. Your application could enable users to predefine broadcast settings and then select the settings to apply to a particular broadcast.

  • Associate video streams and broadcasts.

  • Enable broadcasters to define information about a broadcast and its video (using theYouTube Data API) at the same time.

  • Simplify transitions between broadcast states (testing,live,etc.) and enable users to insert cuepoints.

Before you start

  1. You need aGoogle Accountto access theGoogle API Console,request an API key, and register your application.

  2. Register your applicationwith Google so that it can submit API requests.

  3. After registering your application, select theYouTube Data APIas one of the services that your application uses:

    1. Go to theAPI Consoleand select the project that you just registered.
    2. Visit theEnabled APIs page. In the list of APIs, make sure the status isONfor the YouTube Data API v3 and, if you are a YouTube Content Partner, the YouTube Content ID API.
  4. Familiarize yourself with the core concepts of the JSON (JavaScript Object Notation) data format. JSON is a common, language-independent data format that provides a simple text representation of arbitrary data structures. For more information, seejson.org.

Authorizing API requests

As noted above, the Live Streaming API uses functionality that is technically part of either the YouTube Data API or the YouTube Content ID API. You can use the Content ID API to provide YouTube with metadata, ownership information, and policy information for your assets. (A live video broadcast is an example of an asset.) The API also lets you claim videos and set ad policies for your videos.

This section explains the authorization requirements for requests to theContent ID API,which are different from the requirements for authorizing otherLive Streaming APIrequests.

Calling theData API
The API request must be authorized by the Google Account that owns the broadcasting YouTube channel.
Calling theContent ID API
The API request must be authorized by a Google Account that is linked to the content owner that owns the broadcasting YouTube channel.

Resources and resource types

A resource is an individual data entity with a unique identifier. The table below describes the different types of resources that you will interact with using the Live Streaming API.Technically, all of these resources are actually defined as part of either theYouTube Data API or theYouTube Content ID API.However, the liveBroadcast, liveStream,and cuepointresources are only used to create and manage live events.

Resources
liveBroadcast Contains information about an event that you are broadcasting on YouTube. A liveBroadcastresource is an extension of a YouTube video resource and sets video metadata that would be pertinent to a live broadcast but not to other YouTube videos.

As such, aliveBroadcastresource corresponds to exactly one YouTube video resource. In fact, theliveBroadcast resource and thevideoresource share the same ID. And after creating the broadcast using the Live Streaming API, you can use the YouTube Data API to provide additional metadata about the video.
liveStream Contains information about the video stream that you are transmitting to YouTube. The stream provides the content that will be broadcast to YouTube users. Once created, aliveStreamresource can be bound to exactly oneliveBroadcastresource. (Similarly, theliveBroadcastresource can only be bound to oneliveStreamresource.
cuepoint Inserts a cuepoint in the broadcast video stream, which might trigger an ad break. Use the liveBroadcasts.cuepoint method to insert a cuepoint during a broadcast.
video Represents a single YouTube video. As noted above, aliveBroadcastresource is an extension of avideoresource. You can use the YouTube Data API to update metadata about the video, such as the recording location or the regions where the broadcast will be viewable.
videoAdvertisingOptions Defines the advertising settings for a video (or broadcast). You use theYouTube Content ID APIto set advertising options.
asset Represents a piece of intellectual property, such as a movie or an episode of a show. In this case, the broadcast video is the asset. You will use theYouTube Content ID APIto create and manageassetresources.
claim Links a video to an asset that the video matches. You create a claim, using theYouTube Content ID API,to identify yourself as the owner of the broadcast video.
policy Defines rules that specify the circumstances under which you want your content to be viewable on YouTube or blocked from appearing on YouTube. You need to apply a policy to your broadcast video and can also specify a policy that YouTube will apply to user-uploaded videos that match your broadcast video.

Supported operations

The following table shows the different methods that the API supports:

Operations
list Retrieves (GET) a list of zero or more resources.
insert Creates (POST) a new resource.
update Modifies (PUT) an existing resource to reflect data in your request.
bind Links aliveBroadcastresource with aliveStreamresource or removes such a link.
transition Changes the status of aliveBroadcastresource and initiates any processes associated with the new status. For example, when you transition a broadcast's status totesting,YouTube starts to transmit video to that broadcast's monitor stream.
delete Removes (DELETE) a specific resource.

The table below identifies the operations that are supported for different types of resources. Operations that insert, update, or delete resources always requireuser authorization.In some cases,listmethods support both authorized and unauthorized requests, where unauthorized requests only retrieve public data while authorized requests can also retrieve information that is restricted to the currently authenticated user.

Supported Operations
list insert update bind transition cuepoint delete
liveBroadcast
liveStream

Partial resources

The API allows, and actually requires, the retrieval of partial resources so that applications avoid transferring, parsing, and storing unneeded data. This approach also ensures that the API uses network, CPU, and memory resources more efficiently.

Thepartparameter is a required parameter for any API request that retrieves or returns aYouTube Data APIresource. The parameter identifies one or more top-level (non-nested) resource properties that should be included in an API response. For example, aliveStreamresource has the following parts:

  • snippet
  • cdn
  • status

All of these parts are objects that contain nested properties, and you can think of these objects as groups of metadata fields that the API server might (or might not) retrieve. As such, thepartparameter requires you to select the resource components that your application actually uses. This requirement serves two important purposes:

  • It reduces latency by preventing the API server from spending time retrieving metadata fields that your application doesn't use.
  • It reduces bandwidth usage by reducing (or eliminating) the amount of unnecessary data that your application might retrieve.

Over time, as resources add more parts, these benefits will only increase since your application will not be requesting newly introduced properties that it doesn't support.

Tips and best practices

Claim your content

If you would like to show ads during your broadcast, you need to claim the broadcast video before the event begins. To claim content, you must be aYouTube Content Partnerparticipating in theContent IDprogram.

The process for claiming your live broadcast video is different than the normal process for claiming a video. When claiming live video, you need to create your claim before the video actually exists. The API does support this, and thelife of a broadcastdocument explains theYouTube Content ID APIcalls that enable you to create your claim.

Preview and test your content

Upon receiving your inbound video stream, YouTube can then broadcast that video on two different outbound streams:

  • Themonitor streamenables you to preview (and test) your video broadcast. It is a private stream that is only accessible to you. You can only transition a broadcast to thetestingphase if the broadcast's monitor stream is enabled. The monitor stream does not show ad breaks.

  • Thebroadcast streamis the stream visible to your audience. You can set the broadcast's privacy status to eitherpublic,private,orunlisted.(A private broadcast is only visible to users who have been explicitly invited to watch it, while an unlisted broadcast is visible to anyone with a link to view it.)

    You can choose to delay the broadcast stream so that it does not run concurrently with the monitor stream. By delaying the broadcast stream, you can have more fine-grained control over the time that you insert cuepoints into the broadcast.

    However, delaying the broadcast stream makes it difficult for your live presenters to interact with your viewing audience. In addition, delaying the broadcast increases the likelihood that viewers will discover key details about the event from sources other than your broadcast. For example, if you are broadcasting a sporting event on a 60-second delay, viewers might learn about critical moments in the event from other real-time news sources before actually seeing them in the broadcast.

YouTube recommends that you enable the monitor stream for your broadcast so that you can test your content. You should choose whether to also delay your broadcast based on your desire to control timing of cuepoints as opposed to your desire to interact with your audience or provide real-time coverage of an event.

Running midroll ads during a broadcast stream

During a broadcast, you can insert acuepointto indicate that an ad break should start in the broadcast as soon as possible or at a specified time. The ad break enables YouTube to run midroll ads during the broadcast.

Ad breaks have the following characteristics:

  1. It has a predefined length of time, which you set using thecuepointresource's durationSecs property. After the ad break concludes, viewers return to the live broadcast.

  2. When an ad break happens, an ad only plays in the video player for viewers who are watching the broadcast when the cuepoint is inserted. An ad does not run when viewers refresh the page where the broadcast is playing or when visitors start watching the broadcast after the cuepoint is inserted.

The sequence of steps below reflects the best practice for inserting an ad break during your broadcast:

Set time offsets

When inserting a cuepoint, you can specify that it should be inserted right away or that it should be inserted at a specific point in the broadcast. Your options depend on whether the broadcast stream for your video is delayed.

  • If your broadcast stream is not delayed, then you can insert the cuepoint immediately or use thewalltimeMs property to have the ad break start at a particular time.

    • To start the ad break immediately, call theliveBroadcasts.cuepointmethod. In the resource in the request body, set the insertionOffsetTimeMsproperty's value to0or do not specify a value for that property and do not specify a value for thewalltimeMs property.

      Important:Note that viewers do not see the resulting ad content immediately. There may be a delay of around 30 seconds before the ad content is visible to users. During that delay, your broadcast stream will still be visible to your viewers, and you need to watch the broadcast stream to determine when the ad content actually displays instead of your monitor stream.

    • To start the ad break at a particular time, call theliveBroadcasts.cuepoint method and use the walltimeMs property to specify the desired time. The property value is an integer that represents an epoch timestamp.

  • If your broadcast stream is delayed, then you can insert the cuepoint immediately as described above, specify a clock time as described above, or you can specify a time offset to determine when the ad break will start. The time offset specifies a point in your broadcast when viewers should see an ad.

    The offset value is measured in milliseconds from the beginning of the monitor stream for your broadcast. Note that if your broadcast has a testing phase, then the monitor stream starts when your broadcast transitions to thetestingstatus. Otherwise, your monitor stream starts when your broadcast transitions to thelivestatus.

    When inserting a cuepoint, set thecuepointresource's insertionOffsetTimeMs property to the desired offset.

Calculate the time offset value

To retrieve the offset value, call the YouTube Player API'sgetCurrentTimefunction for the player that is playing the monitor stream. Use the retrieved value to insert the cuepoint in the broadcast stream at that time.

The possible values for the offset time can be calculated as the following range:

[(elapsed_time - broadcast_delay + Δ), (elapsed_time - Δ)]

TheΔis a five-second buffer at the beginning and end of the possible time offsets when YouTube cannot precisely insert a cuepoint. For example:

  • A broadcast has a five-minute testing phase.
  • The broadcast stream is delayed 60 seconds after the monitor stream.
  • The broadcaster is inserting the cuepoint four minutes after the broadcast transitions to livestatus. (This is three minutes after the broadcast stream becomes visible.)

In this case, the possible range of offset times is[(485,000), (535,000)].

These times are specified in milliseconds, and are calculated using the following values:

  • elapsed_time=540000– The monitor stream has run for nine minutes (540 seconds, 540000 milliseconds) when theliveBroadcasts.cuepointmethod is called.
  • broadcast_delay=60000– The broadcast stream is delayed by 60 seconds, or 60000 milliseconds.
  • Δ=5000– The five-second buffer when the cuepoint cannot be reliably inserted.

Troubleshooting and error handling

The following guidelines explain how to resolve specific problems that may arise. Also refer to theerror documentationfor lists of errors that each API method might return.

  • When a broadcast transitions from onestatusto another, it may temporarily be assigned with another status while YouTube completes the actions associated with the transition. For example, if you send aliveBroadcasts.transitionrequest to change a broadcast's status fromreadytotesting,YouTube will set the broadcast's status totestStartingand then complete the actions associated with the status change. When all of those actions have been completed, YouTube will update the broadcast's status totesting,thereby indicating that the transition is complete.

    If a broadcast becomes stuck with atestStartingorliveStartingstatus, you need to call theliveBroadcasts.deletemethod and delete the broadcast. Then create a new broadcast, bind it to your live stream, and continue with the testing process.

    As noted in theliveBroadcasts.transitionmethod's documentation, you should confirm that the value of thestatus.streamStatusproperty for the stream bound to your broadcast isactivebefore calling that method.