Category assignments and random selection counts for watermarks and scrolling text, multi-GPU transcoding, and improved GPU utilization

This update revisits the GPU transcoding logic, which had not received much attention for a while. It now supports multiple graphics cards: however many your server has, it uses them all. Each new job is assigned to the least-utilized card. New jobs stop starting when the memory usage of every card is nearly 100%, effectively maximizing utilization. We also made adjustments to scrolling text and watermarks.

Changelog

1. Added resolution, bitrate and frame-rate settings for segment ads, so their parameters can be adjusted.
2. GPU transcoding now supports animated-image watermarks and simultaneous processing across multiple GPU cards, greatly improving utilization. Each new job automatically uses the least-utilized card. New jobs pause when every card's memory usage approaches 100%, then resume when memory becomes available.
3. Added category assignments for watermarks and scrolling text. When multiple watermarks or scrolling-text items are configured and assigned to categories, they apply only to the corresponding category.
4. Added random selection of watermarks and scrolling text. Set the desired number separately for each type, and every transcoding job randomly uses 1 or more image watermarks or scrolling-text items.
5. Added horizontal mirroring. When enabled, the transcoded picture is mirrored horizontally, which can correct certain short-video camera issues or make random watermarks and text in a video less recognizable.
6. Fast slicing can generate directly downloadable mp4 URLs, processing the source video by default. Normal transcoding continues to use the transcoded MP4 for this purpose.
7. Fixed image encryption also affecting images that disguise TS segments, causing playback failures.
8. Improved image-to-txt conversion. When enabled, the original image displays no content; changing the URL extension from jpg to txt converts it automatically to txt.
9. Added Azure Blob Storage to cloud-storage synchronization.

Resource-usage screenshot of a server with two graphics cards:

The memory usage of both 2 graphics cards is nearly at its limit simultaneously.