Convert RAW images to BMP format

I received a .raw frame format (here is a sample) which contains the raw pixel values of a frame. And I've been told I can convert it to an image (.bmp or .png) using FFMpeg using following command. However, when trying, it doesn't work.

dd bs=16 dumpB4EncodeHLSAfterEncodeBuf1200IP_TS/dumpedYuv/image-1140.raw |  ffmpeg -f rawvideo -video_size 2160 2160 -pixel_format nv12 -i - yuv.bmp

What is the problem? Is there any ways to avoid use of dd and purely do it from FFmpeg?

Here is the error:

dd: unrecognized operand ‘frame.raw’
Try 'dd --help' for more information.
ffmpeg version 3.4.8-0ubuntu0.2 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.5.0-3ubuntu1~18.04)
  configuration: --prefix=/usr --extra-version=0ubuntu0.2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libavresample   3.  7.  0 /  3.  7.  0
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100
pipe:: Invalid data found when processing input

And if I use ffmpeg directly:

ffmpeg -video_size 2160x2160 -pixel_format nv12 -i frame.raw yuv.bmp

I will get this error:

ffmpeg version 3.4.8-0ubuntu0.2 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.5.0-3ubuntu1~18.04)
  configuration: --prefix=/usr --extra-version=0ubuntu0.2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libavresample   3.  7.  0 /  3.  7.  0
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100
[image2 @ 0x5605e52bb4c0] Format image2 detected only with low score of 5, misdetection possible!
Input #0, image2, from 'frame.raw':
  Duration: 00:00:00.04, start: 0.000000, bitrate: 1244160 kb/s
    Stream #0:0: Video: rawvideo (NV12 / 0x3231564E), nv12, 2160x2160, 25 tbr, 25 tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> bmp (native))
Press [q] to stop, [?] for help
[rawvideo @ 0x5605e52bea00] Invalid buffer size, packet size 6220800 < expected frame_size 6998400
Error while decoding stream #0:0: Invalid argument
Finishing stream 0:0 without any data written to it.
Output #0, image2, to 'yuv.bmp':
  Metadata:
    encoder         : Lavf57.83.100
    Stream #0:0: Video: bmp, bgr24, 2160x2160, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
    Metadata:
      encoder         : Lavc57.107.100 bmp
frame=    0 fps=0.0 q=0.0 Lsize=N/A time=00:00:00.00 bitrate=N/A speed=   0x
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)
Conversion failed!

Updated Answer

Now that we know the correct size and format, we can do the conversion easily with ImageMagick:

magick -depth 8 -size 1920x1080 rgb:frame.raw result.png

Or, as you wanted, with ffmpeg:

ffmpeg -y -f rawvideo -s 1920x1080 -pix_fmt rgb24 -i frame.raw  image.bmp

Original Answer

You raw file is either not NV12 or not 2160x2160. NV12 uses 1.5 bytes per pixel, which would mean you should have

2160 * 2160 * 1.5 = 6,998,400 bytes

but you actually have 6,220,800 so there is something wrong with your information - either the file is incomplete, or it is not that format or it is not that size.

If it was NV12, the first 2160x2160 bytes would be the greyscale (or Luminance/Y) channel, but even if we get the first 2160x2160 bytes as greyscale and ignore any trailing colour information, it is still wrong:

head -c $((2160*2160)) frame.raw | magick -depth 8 -size 2160x2160 gray:- image.bmp

Please check and identify the provenance and characteristics of your raw data.