Overview of transcoding
Transcoding converts an audio or video file into one or more other files to adapt the media for different network bandwidths, playback devices, and user requirements. ApsaraVideo Media Processing offers several transcoding types, including standard transcoding, Narrowband HD™ 1.0, Narrowband HD™ 2.0, accelerated transcoding, and resolution doubling.
Function introduction
After a video is uploaded, it enters the transcoding stage. You can use preset or custom templates to perform standard transcoding, Narrowband HDTM 1.0, Narrowband HDTM 2.0, or accelerated transcoding on your media assets.
Standard transcoding: Converts videos into different container formats and definitions based on your requirements. You can customize settings such as bitrate, resolution, and format.
Narrowband HDTM 1.0 transcoding: Intelligently analyzes video scenes, actions, content, and textures during transcoding to produce a video of the same quality at a lower bitrate, which helps reduce bandwidth costs.
Narrowband HDTM 2.0 transcoding: Uses a human visual system (HVS) model to shift the encoder's optimization goal from achieving the highest fidelity to providing the best subjective experience, saving bitrate while delivering a clearer viewing experience.
Accelerated transcoding: Shards and transcodes a video in parallel, increasing the transcoding speed by up to 5 times. Suitable for videos longer than 30 minutes.
Feature comparison
Item for Comparison | Narrowband HDTM 1.0 transcoding | Narrowband HDTM 2.0 transcoding | Accelerated transcoding | Resolution doubling transcoding |
Core technology | Enhances image quality using traditional algorithms and saves bitrate by preventing unnecessary data output. | Optimizes video using intelligent AI algorithms based on the best subjective experience. | Shards and transcodes a video in parallel to increase the transcoding speed by up to 5 times. | Uses a proprietary image quality restoration technology to remaster existing standard definition or damaged video content into UHD or restored versions. |
Scenarios |
Note Ensure that the source file has continuous timestamps before you start transcoding. Otherwise, issues such as transcoding failures or audio-video desynchronization may occur. Alibaba Cloud does not provide a solution for this issue. You must process the source file. | Suitable for source videos with poor quality. Note Narrowband HDTM 2.0 can perform adaptive optimization on different areas of the video. | Suitable for videos longer than 30 minutes. |
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Bandwidth savings (at the same bitrate) | Compared to standard transcoding, Narrowband HD™ 1.0 saves about 20% to 40% on bitrate. The actual savings depend on the bitrate of the source stream. | Narrowband HD™ 2.0 can save an additional 20% on bitrate compared to Narrowband HD™ 1.0. | Not applicable. | Not applicable. |