#ffmpeg -i RedVelvetHappiness.mov -acodec opus -vcodec nvenc_hevc -profile:v main -preset:v slow -tier:v high -refs 8 -b:v 4M -maxrate 4M -bufsize:v 4M -qmin 1 -qmax 50 -map 0:0 -map 0:1 -y happiness_hevcgtx960.001.mkv

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'RedVelvetHappiness.mov':
  Metadata:
    major_brand     : qt  
    minor_version   : 537199360
    compatible_brands: qt  
    creation_time   : 2014-08-01 19:09:21
  Duration: 00:03:46.39, start: 0.000000, bitrate: 176069 kb/s
    Stream #0:0(eng): Video: prores (apch / 0x68637061), yuv422p10le(bt709), 1920x1080, 174526 kb/s, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 24k tbn, 24k tbc (default)
    Metadata:
      creation_time   : 2014-08-01 19:09:21
      handler_name    : Apple Alias Data Handler
      encoder         : Apple ProRes 422 HQ
      timecode        : 00:00:00:00
    Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2014-08-01 19:09:21
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74) (default)
    Metadata:
      creation_time   : 2014-08-01 19:17:54
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
[libopus @ 0x311f660] No bit rate set. Defaulting to 96000 bps.
Output #0, matroska, to 'happiness_hevcgtx960.001.mkv':
  Metadata:
    major_brand     : qt  
    minor_version   : 537199360
    compatible_brands: qt  
    encoder         : Lavf57.25.100
    Stream #0:0(eng): Video: hevc (nvenc_hevc) (Main), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=1-50, 4000 kb/s, 23.98 fps, 1k tbn, 23.98 tbc (default)
    Metadata:
      creation_time   : 2014-08-01 19:09:21
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
      encoder         : Lavc57.24.102 nvenc_hevc
    Side data:
      unknown side data type 10 (24 bytes)
    Stream #0:1(eng): Audio: opus (libopus) ([255][255][255][255] / 0xFFFFFFFF), 48000 Hz, stereo, s16, 96 kb/s (default)
    Metadata:
      creation_time   : 2014-08-01 19:09:21
      handler_name    : Apple Alias Data Handler
      timecode        : 00:00:00:00
      encoder         : Lavc57.24.102 libopus
Stream mapping:
  Stream #0:0 -> #0:0 (prores (native) -> hevc (nvenc_hevc))
  Stream #0:1 -> #0:1 (pcm_s16le (native) -> opus (libopus))
Press [q] to stop, [?] for help
frame= 5428 fps= 59 q=-0.0 Lsize=  113705kB time=00:03:46.39 bitrate=4114.4kbits/s speed=2.47x    
video:110812kB audio:2758kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.119038%