High-speed transcoding boosts the transcoding speed by 5 times to 30 times by splitting a video into multiple segments and concurrently transcoding the video segments. This feature is suitable for scenarios such as news, events, and important content that require high timeliness. This topic describes the high-speed transcoding feature and how to create a high-speed transcoding job in the ApsaraVideo Media Processing (MPS) console.
Background information
MPS provides the offline transcoding service. MPS must obtain a complete video file before MPS can start a transcoding job for the video file. MPS does not transcode a video file in real time when the video file is being transmitted and a transcoding job takes an amount of time to complete. The following figure shows the video transcoding process.
Factors that affect the transcoding duration
The transcoding duration of each video varies according to the video duration, file size, complexity of transcoding parameters, and job priority. Examples:
More time is consumed to transcode videos with longer duration, larger size, or higher frame rate, bitrate, and resolution.
More time is consumed to transcode videos with more complex codec and higher compression ratio. In most cases, the transcoding duration for AV1 files is longer than that for H.265 files, which in turn is longer than that for H.264 files.
More time is consumed by transcoding jobs that are more complex. In most cases, audio and video enhancement jobs take more time than video transcoding jobs, which in turn take more time than audio transcoding jobs. Audio transcoding jobs take more time than container format conversion jobs.
If the number of jobs submitted at a time exceeds the limit or the computing resources are insufficient, the jobs assigned with lower priorities are processed after the jobs assigned with higher priorities are complete. In this case, more time is consumed for lower-priority jobs.
High-speed transcoding
If queuing and transmission bandwidth are not considered, video stream processing is the most time-consuming part in most transcoding jobs. Accelerating video stream processing is the key to speed up transcoding.
For jobs that involve video transcoding, MPS splits the input video into multiple segments and concurrently transcodes the video segments in multiple transcoders by using an intelligent transcoding engine and powerful cloud resource scheduling capabilities. This significantly reduces the time consumed for transcoding. The following figure shows how high-speed transcoding is implemented.
Feature description
Item | Description |
Speed boost | The transcoding speed can be boosted by 5 times to 30 times depending on the properties of the input video. You can specify the expected speed boost for an MPS queue for high-speed transcoding, such as 5 times, 10 times, 20 times, or 30 times. Note The actual speed boost is calculated based on the following formula: Video duration/Transcoding duration. The video duration is the total duration of the output video. The transcoding duration is the duration from the time when the job is submitted to the time when the job is complete. |
Scenarios | High-speed transcoding is supported only for specific videos and transcoding types. We recommend that you use high-speed transcoding for videos that are longer than 30 minutes, or videos that require high frame rates, ultra high definition, and audio-visual enhancement. For more information, see Limits. |
Policy | If you submit a video that is not supported by high-speed transcoding to an MPS queue for high-speed transcoding, the video is transcoded in the regular way by default. You can also configure the system to not transcode the video. |
Procedure
Enable an MPS queue for high-speed transcoding.
Log on to the MPS console. In the left-side navigation pane, choose Global Settings > MPS Queue and Callback.
Click Create MPS Queue. In the dialog box that appears, select Boosted from the MPS Queue Type drop-down list. Set the Maximum Speed and Conditional Transcoding parameters based on your business requirements.
Create a high-speed transcoding job.
When you submit a transcoding job in the MPS console, by calling an API operation, or by creating a workflow, specify an MPS queue for high-speed transcoding as the MPS queue to use.
View the results of the high-speed transcoding job.
Log on to the MPS console. In the left-side navigation pane, choose Tasks > Job Management. Find the high-speed transcoding job and click Details in the Actions column to check whether the transcoding job is successful and the actual speed boost.
View the bill for the high-speed transcoding job. For more information, see View your bills.
Optional. Modify the configurations of the MPS queue for high-speed transcoding.
Log on to the MPS console. In the left-side navigation pane, choose Global Settings > MPS Queue and Callback. Find the MPS queue for high-speed transcoding, click the
icon in the Actions column, and then select Configure MPS Queue for High-speed Transcoding. You can modify the Maximum Speed and Conditional Transcoding parameters for the MPS queue for high-speed transcoding.