This topic describes common issues and solutions for the live-to-VOD process.
How many on-demand videos are generated during recording?
The number of videos generated during a live stream varies based on the recording period that you specify and the number of interruptions during the live stream. During a live stream, an on-demand video is generated each time the recording period is reached. By default, the system considers a live stream to end after a three-minute interruption. In this case, an on-demand video is generated based on the content recorded until the interruption.
For example, the recording period is set to 30 minutes and the live stream is interrupted 38 minutes after it starts. In this case, ApsaraVideo VOD generates a 30-minute video and an 8-minute video.
What do VOD transcoding templates do?
A video-on-demand (VOD) transcoding template is a transcoding configuration that the VOD service uses to automatically transcode recorded videos.
If the template specifies a standard and a high definition stream, two streams are generated after a video is transcoded.
You must create the transcoding template in the ApsaraVideo VOD console before a live stream starts.
Can I disable transcoding?
Yes. To disable transcoding, you can use the VOD service's No Transcoding template. This template uses the original video for playback. However, only the MP4, FLV, M3U8, MP3, and WEBM formats support direct playback without transcoding.
Disabling transcoding is not recommended because it can cause noticeable stuttering in high-bitrate live streams. If you disable transcoding, you can manually submit a job to ApsaraVideo Media Processing to perform transcoding later. For more information about related operations in ApsaraVideo Media Processing, see Audio and video transcoding.
What is automatic synthesis?
This is because video-on-demand automatically generates one video file per recording epoch.
For example, if the recording period is set to 30 minutes, two on-demand videos are generated for a one-hour live stream. If automatic production is enabled, ApsaraVideo VOD automatically produces a video based on the two on-demand videos when the live stream ends. After the production, ApsaraVideo VOD returns the ID of the produced video in callback mode. In this case, you obtain three videos in total, including two on-demand videos and one merged video.
What can you do with automatic synthesis?
Typically, users set a short recording epoch for faster playback.
In this case, an on-demand video is generated in ApsaraVideo VOD for playback every 10 minutes after the live stream starts. You can enable automatic production so that ApsaraVideo VOD can automatically merge all 10-minute on-demand videos into a single video. You can also manually call an online editing operation to perform video production.
Will a video be generated if only one video is provided?
After automatic production is enabled, ApsaraVideo VOD performs video production regardless of the number of videos generated.
For example, if you set the recording period to 30 minutes but the live stream lasts for only 20 minutes, a 20-minute on-demand video is recorded in ApsaraVideo VOD. In addition, a 20-minute video is produced from the only mezzanine file.
Is synthesis asynchronous?
Synthesis is an asynchronous process. You can check its status using the callback in the response. For more information, see How to configure live-to-VOD.
What is a production and transcoding template ID?
A production and transcoding template ID is the ID of a transcoding template after you enable automatic video production. ApsaraVideo VOD can automatically transcode produced videos after automatic production is enabled, which is similar to transcoding of on-demand videos.
This template ID does not need to be the same as the recording template ID.
For example, you can select a recording and transcoding template to generate only one stream of the standard definition for quick playback. For a produced video, you can select a production and transcoding template to generate streams of multiple definitions, such as high definition, ultra high definition, and 2K. This way, intermediate on-demand videos are transcoded in a low bitrate for quick playback. The complete video of the live stream is transcoded in multiple bitrates after the live stream ends.
Can I perform composition without transcoding?
Yes. You can use the VOD service's No Transcoding template as the production and transcoding template.
What is the maximum number of videos that can be merged in automatic video production?
Up to 40 videos can be merged in automatic video production. For example, if the recording period is set to one hour, only the videos recorded within the first 40 hours are merged in automatic video production. Therefore, we recommend that you set an appropriate recording period.
What is an appropriate recording period?
One video is generated after a recording period ends. For example, you set the recording period to 30 minutes. If the live streaming duration is 20 minutes, one video is generated in ApsaraVideo VOD. If the live streaming duration is 70 minutes, three videos are generated in ApsaraVideo VOD.
We recommend that you set the recording period to the default value of one hour if you do not need on-demand videos for quick playback. You can set the recording period based on your business needs. Generally, we recommend that you set a recording period longer than 20 minutes.