2020-04-05: 2K and original-quality outputs, portrait transcoding and scrolling-text font sizing

This large update changes more than a thousand lines and substantially rewrites transcoding logic. Four main changes: first, 2K and original-quality outputs, with the new 2K setting requiring updates to CMS groups, cms playback, API, fast slicing and retained MP4 settings. Second, portrait optimization for scrolling text, watermarks, bitrates and resolutions, preserving genuine portrait output rather than landscape with large black borders. Third, configurable scrolling-text font size with adaptive scaling. Fourth, video editing retains library filters so users no longer repeat filtering after each edit.

Updates

• One: 2K and original-quality transcoding. 2K uses 2560*1440; original quality retains source resolution and bitrate. An intelligent algorithm further compresses it while retaining quality and adding watermarks and scrolling text, producing files 30% smaller than the source. CMS permissions gain 2K and original quality; playback API and preview API are refined.
• Two: Thorough portrait-video optimization with clearer output, preserved portrait framing and adjusted resolution, bitrate, scrolling-text and watermark settings.
• Three: Added custom scrolling-text font size. Set one reference size and it adapts to all output resolutions.
• Four: Retain every library-filter state after video-information edits, greatly improving efficiency.
• Five: Added series display to collection pages for easier collection.