When you upload a video, GiGa keeps the original file for download and creates a new file (the preview file) for streaming purposes.
This quality of the preview file is determined by 2 different factors : the size of the orginal file and the quality of the encoding. The higher the quality of the encoding, the longer it takes to encode.
When servers have a long queue of files to encode, the files are encoded as fast as possible. When the queue is empty, the encoding quality is maximum but it takes more time per file to encode.
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