incorrect error message

[Elliott]

When converting Prores 444 video to x264 with 4:2:0 color space, there is an error message:

[swscaler @ 0x7fabe280d400] full chroma interpolation for destination format 'rgb48le' not yet implemented

But since I am using -pix_fmt yuv420p, this error doesn't make sense. Full output below:

$ ffmpeg -i /Volumes/RAID/OLYMPICS/A007L2MC/A007L2MC/A007C013_140320_L2MC.mov -t 10 -pix_fmt yuv420p -vf "lut3d=file=LogC_to_Rec709.dat" LUT.mov
ffmpeg version N-62963-g656fe7e Copyright (c) 2000-2014 the FFmpeg developers
  built on May  4 2014 13:19:11 with Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
  configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-libass --enable-libbluray --enable-libfdk-aac --enable-libmp3lame --enable-libvpx --enable-libx264 --enable-libfreetype --enable-libopenjpeg --enable-libvorbis --enable-libtheora
  libavutil      52. 81.100 / 52. 81.100
  libavcodec     55. 60.103 / 55. 60.103
  libavformat    55. 37.102 / 55. 37.102
  libavdevice    55. 13.101 / 55. 13.101
  libavfilter     4.  5.100 /  4.  5.100
  libswscale      2.  6.100 /  2.  6.100
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Volumes/RAID/OLYMPICS/A007L2MC/A007L2MC/A007C013_140320_L2MC.mov':
  Metadata:
    major_brand     : qt  
    minor_version   : 537199360
    compatible_brands: qt  ARRI
    creation_time   : 2014-03-20 04:56:03
    timecode        : 04:34:23:05
  Duration: 00:01:13.99, start: 0.000000, bitrate: 333064 kb/s
    Stream #0:0(eng): Video: prores (ap4h / 0x68347061), yuv444p10le, 2048x1152, 316250 kb/s, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 23976 tbn, 23976 tbc (default)
    Metadata:
      creation_time   : 2014-03-20 04:56:03
      handler_name    : Apple Alias Data Handler
      encoder         : Apple ProRes 4444
    Stream #0:1(eng): Data: none (tmcd / 0x64636D74) (default)
    Metadata:
      creation_time   : 2014-03-20 04:56:03
      handler_name    : Apple Alias Data Handler
      timecode        : 04:34:23:05
File 'LUT.mov' already exists. Overwrite ? [y/N] y
[swscaler @ 0x7fabe280d400] full chroma interpolation for destination format 'rgb48le' not yet implemented
[libx264 @ 0x7fabe3004e00] using SAR=1/1
[libx264 @ 0x7fabe3004e00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
[libx264 @ 0x7fabe3004e00] profile High, level 5.0
[libx264 @ 0x7fabe3004e00] 264 - core 138 r2358 9e941d1 - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=36 lookahead_threads=6 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=23 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mov, to 'LUT.mov':
  Metadata:
    major_brand     : qt  
    minor_version   : 537199360
    compatible_brands: qt  ARRI
    timecode        : 04:34:23:05
    encoder         : Lavf55.37.102
    Stream #0:0(eng): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 2048x1152 [SAR 1:1 DAR 16:9], q=-1--1, 11988 tbn, 23.98 tbc (default)
    Metadata:
      creation_time   : 2014-03-20 04:56:03
      handler_name    : Apple Alias Data Handler
      encoder         : Apple ProRes 4444
Stream mapping:
  Stream #0:0 -> #0:0 (prores -> libx264)
Press [q] to stop, [?] for help
frame=  240 fps=7.6 q=-1.0 Lsize=    1277kB time=00:00:09.92 bitrate=1054.1kbits/s    
video:1275kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.184211%
[libx264 @ 0x7fabe3004e00] frame I:1     Avg QP:23.01  size: 31175
[libx264 @ 0x7fabe3004e00] frame P:239   Avg QP:23.52  size:  5329
[libx264 @ 0x7fabe3004e00] mb I  I16..4: 39.1% 59.5%  1.4%
[libx264 @ 0x7fabe3004e00] mb P  I16..4:  0.3%  0.4%  0.0%  P16..4: 20.3%  0.8%  2.9%  0.0%  0.0%    skip:75.4%
[libx264 @ 0x7fabe3004e00] 8x8 transform intra:58.7% inter:99.1%
[libx264 @ 0x7fabe3004e00] coded y,uvDC,uvAC intra: 23.1% 63.6% 25.4% inter: 2.6% 12.4% 0.3%
[libx264 @ 0x7fabe3004e00] i16 v,h,dc,p: 60% 22%  3% 15%
[libx264 @ 0x7fabe3004e00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 22% 10% 33%  5% 10%  4%  9%  6%  3%
[libx264 @ 0x7fabe3004e00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 13% 11%  6% 18%  8%  9%  7%  2%
[libx264 @ 0x7fabe3004e00] i8c dc,h,v,p: 59% 17% 19%  4%
[libx264 @ 0x7fabe3004e00] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x7fabe3004e00] ref P L0: 60.4% 10.6% 20.5%  8.5%
[libx264 @ 0x7fabe3004e00] kb/s:1042.86}}}

[Carl Eugen Hoyos]

Replying to spookybathtub:

When converting Prores 444 video to x264 with 4:2:0 color space, there is an error message:

[swscaler @ 0x7fabe280d400] full chroma interpolation for destination format 'rgb48le' not yet implemented

This does not look like an error message.

But since I am using -pix_fmt yuv420p

Use the format and the scale filter instead, mixing a filter chain with an old fashioned option that affects the filter chain cannot be unambiguous. FFmpeg cannot generally decide if it should convert the colour space before or after the provided filter chain. In this case it is actually undecidable afaict, since you may want to do the lut change in RGB48 but you may also prefer RGB24.