• New: Added a control for colour space that reference will be converted to prior calculating metrics, the list can be adjusted in FFMetrics.conf (see FFMetrics.conf.example) (#185)
• New: Pixel format mapping & default pixel format can be specified per metric in FFMetrics.conf (see FFMetrics.conf.example).
  Logic for converting ref's colour space changed:
  Previously ref colour space was not changed if it is yuv420, yuv422 or yuv444 and converted to yuv420 otherwise.
  Now the conversion depend on what selected in ref's colour space control, pixel format mapping and default pixel format defined per metric.
  If "No conversion (default)" is selected in the colour space dropdown:
  - For PSNR, SSIM & XPSNR the ref's colour space is not changing.
  - For VMAF the ref's colour space is converted using pixel format mapping.
  If anything else is selected in the colour space dropdown:
  - For PSNR, SSIM & XPSNR the ref's colour space will be converted to the selected value.
  - For VMAF the ref's colour space will be converted to selected value if it is supported (yuv*), otherwise it will be converted using pixel format mapping.
  In any case, distorted files are converted to the final ref's colour space as before.
• New: Frames count shown in metric value popup (#179)
• Change: Templates for getting thumbnail and bad frames adjusted (less warnings in log and thumbnal extraction should work for streams without duration).
• Change: Option -probesize 50M is added to all templates (FFMpeg's default is 5M). This increases some operations accuracy and removes some log warnings.
• Bugfix: Swapped ref & main in XPSNR template. Based on FFMpeg manual, the order for PSNR, SSIM and VMAF should be [main][ref], but for XPSNR -- [ref][main].