Video transcoding is also referred to as video encoding. During this process, a video file is converted from one format to another. This ensures that the video can be viewed across various devices and platforms.
Video transcoding has evolved significantly over the passage of time. The need for video transcoding emerged due to the rapid change in digital media and the increase in the need for video content in different formats such as MP4, WebM, WMV, HLS, etc. Primarily, video transcoding was merely limited to the change of video files from one device to another where software was installed in appliances. However, over the passage of time, cloud video transcoding has completely revolutionized contemporary video transcoding.
The term video transcoding is digital to digital conversion of data. In most cases, there is a need to transcode videos to satisfy the circumstances mentioned below:
- When a potential device does not render support for the original video format.
- When a potential device has limited capacity, in such a scenario, the quality of the media file needs to be reduced to cater to the new format.
- To convert obsolete and unsupported file types into a format that is supported by the device.
Video transcoding is a two-tier process. The first tier comprises of video decoding where the original file type is converted to an uncompressed format. The second tier involves the re-encoding process where the video is transferred to the new device in the desired format.
One of the primary reasons why video transcoding is done is to ensure universal playback. For instance, a video uploaded in MP4 format is transcoded in HLS to playback on iOS devices. On the other hand, transcoding also solves bandwidth congestion and video quality issues. If a 720p video is ingested, a transcoder will derive its multiple renditions such as 480p, 360p, and 240p. These renditions will be delivered to the end user as per their local bandwidth condition overcoming network congestion.
Types of Transcoders
VIDIZMO has three distinct types of transcoder:
1. VIDIZMO Cloud Encoder: By default, all media uploaded on VIDIZMO are transcoded using the VIDIZMO Cloud Encoder. The transcoder converts media files into multiple formats and renditions.
2. Azure Media Services (AMS): Azure Media Services enables SaaS clients to deliver content globally on any virtual device using cloud computing. AMS offers services such as live or on-demand streaming, encoding, transcriptions, audio and video indexing and content protection. AMS transcodes media files in limited formats and renditions. If a client uses AMS, storage and transcoding both will be done using the service irrespective of the chosen/preferred content provider.
3. On Premise Encoder: For clients that have on-premise VIDIZMO deployment can make use of their local encoder to transcode the content.
VIDIZMO encoding profiles represent a subset of the encoding techniques in different media files. Thus, encoding profiles provide the ability for users to choose the video profile that best suits a given stream.
Every Account/Channel uses the encoding profile by the selected transcoder. These profiles are classified by the video, multi-bitrate (HLS and Smooth Streaming) and closed captions.
Every category comprises of different output formats, renditions, bitrate of media files, codec, etc. These categories can be enabled or disabled on every Account/Channel as required. Moreover, all profiles are setup on per transcoder basis and are thus defined by a Web Administrator.
On VIDIZMO, every transcoder has its set of encoding profiles and workflow. This comprises of a set of activities that can be performed such as the creation of thumbnails. Encoding and transcriptions are applicable for AMS clients only.
VIDIZMO’s transcoders can be used for a variety of purposes:
- Uploading content to storage
- Capturing thumbnails. For instance, during file upload by submitting content to AMS transcoder to capture 3 set of thumbnails, i.e., large, medium and small
- Update thumbnails of media
- Submit content for transcoding where the transcoder will download content directly from storage (Cloud and AMS encoders) and transcode it
- After transcoding, the transcoder uploads the content to storage and sends the response to VIDIZMO to update media file