The live recording feature records live stream images in real time according to the recording template bound to the push domain name, subsequently generating the corresponding recording files and storing them in Video on Demand. A recording callback notifies you of the information of a recording file. The file format of the recording part of is sharded. When a sharded file is recorded, a callback will be generated, mainly including the start and end time of recording, the recording file ID, the file size, and the download URL for the recording slices. To receive recording callbacks, you need to configure a callback template, specify a server address for the callback, and bind the template to your push domain name. When a recording event occurs, the CSS backend will send the recording file information to the specified server.
This document describes the callback message notification fields sent by CSS to users after a recording file callback event is triggered.
Notes
This document assumes you already know how to configure and receive callbacks.
Recording files are stored in the VOD console by default. Therefore, you need to activate VOD first and make sure it does not have overdue payments.
If a recording task is created by the CreateRecordTask API, the recording callback returned will not include the stream_param parameters of the push URL. They will be included if a task is created using another method.
If HLS recording resumption is enabled, a callback will be triggered only for the final recording file. No callbacks will be sent when push is interrupted.
Recording Event Parameters
Event type
Event Type
Value
Live recording (Document)
event_type = 100
Common callback parameters
Parameter
Type
Description
t
int64
The time (Unix timestamp) when the notification signature expires.
The default validity period of a callback notification from Tencent Cloud is 10 minutes. After the time specified by the `t` value elapses, a notification will be considered invalid. This can prevent network replay attacks.
The value of `t` is a decimal Unix timestamp, which is the number of seconds that have elapsed since 00:00:00 (UTC/GMT time), January 1, 1970.
sign
string
The Security signature. `sign` = MD5(`key` + `t`). Tencent Cloud splices the encryption key and `t`, generates an MD5 hash of the spliced string, and embeds it in callback notifications. Your backend server performs the same calculation when it receives a callback, and if the signature matches, it indicates that the notification is from Tencent Cloud.
Note
You can set the callback key in Feature Configuration > Live Stream Callback, which is used for authentication. We recommend you set this field to ensure data security.
The VOD file ID, which uniquely identifies a file in VOD.
record_file_id
string
The recording file ID.
file_format
string
The file format. Valid values: flv, hls, mp4, aac.
task_id
string
The ID of a recording task, which is returned by the CreateRecordTask API and is valid only if the task is created by the API.
start_time
int64
The recording start time.
end_time
int64
The recording end time.
start_time_usec
int
The recording start time (microseconds).
end_time_usec
int
The recording end time (microseconds).
duration
int64
The duration of the recording file, in seconds.
The difference between start_time and end_time may deviate from the duration value under normal circumstances, especially in cases of weak network connections and push streaming anomalies, where the deviation can be more significant.
file_size
uint64
The recording file size, in bytes.
stream_param
string
The push URL parameters (custom).
video_url
string
The download URL of the recording file.
media_start_time
int
The PTS when the stream is first pulled for recording. This is not necessarily the PTS of the first frame of the recording file.
record_bps
int
The bitrate, in kbps, of the transcoding output recorded.
callback_ext
The JSON object string.
The JSON object includes multiple fields:
video_codec indicates the video codec.
resolution indicates the resolution of the pushed stream.
session_id indicates the recording task ID.
These are all additional fields of a recording callback. We recommend you do not rely your business logic too much on them.
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