[Libav-user] Error encoding in dnxhd : Invalid frame size 1440x1080i.

[francesco at bltitalia.com]

Hi to all
I'm attempting to encode in dnxhd 85M but I receive an error:

ffmpeg -i clip2A_1s.mp4 -c:v dnxhd -b:v 80M -pix_fmt yuv422p test.mxf

the result is:

ffmpeg version 3.2.1 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.3.0 (GCC)
  configuration: --enable-shared --enable-gpl --prefix=/mingw
--enable-pthreads --enable-libx264 --disable-debug
  libavutil      55. 34.100 / 55. 34.100
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.100 / 57. 56.100
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'clip2A_1s.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp42avc1        
    creation_time   : 2016-10-18T16:13:15.000000Z
  Duration: 00:00:01.04, start: -0.000021, bitrate: 6735 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p,
1920x1080, 6467 kb/s, 25 fps, 25 tbr, 25 tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2016-10-18T16:13:15.000000Z
      handler_name    : ?Video Media Handler      
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo,
fltp, 183 kb/s (default)
    Metadata:
      creation_time   : 2016-10-18T16:13:15.000000Z
      handler_name    : ?Apple Sound Media Handler
Invalid frame size: 1440x1080i.

According to valid dnxhd profiles the profile exist with frame size
1440x1080i and 90Mbps.  What I'm missing ?
regards
Francesco