title: How to extract 16-bit PNG frame from lossless x264 video
body: <p>I encoded a series of 16-bit grayscale PNGs to a lossless video with the following command:</p>
  
  <pre><code>ffmpeg -i image%04d.png -crf 0 -c:v libx264 -preset veryslow output.mp4
  </code></pre>
  
  <p>I am now trying to verify that the conversion to video was truly lossless by pulling out the PNGs at the same quality.  The command I'm using:</p>
  
  <pre><code>ffmpeg -i output.mp4 image%04d.png
  </code></pre>
  
  <p>However, this is outputting 8-bit PNGs.  I've tried various options I've read about such as <code>-vcodec png</code> and <code>-qscale 0</code> but so far nothing appears to make it output 16-bit PNGs.</p>
  
  <p>How do I extract all frames from the video at the same quality as they were going in?  Or did I make a mistake in creating the lossless video in the first place?</p>
  
  <p>Edit: I get this error message when trying to use <code>-pix_fmt gray16be</code>.</p>
  
  <blockquote>
    <p>[swscaler @ 0x7fef1a8f0800] deprecated pixel format used, make sure
    you did set range correctly</p>
  </blockquote>
  
  <p>Full output:</p>
  
  <pre><code>ffmpeg -i output.mp4 -pix_fmt gray16be  image%04d.png
  ffmpeg version 3.3.1 Copyright (c) 2000-2017 the FFmpeg developers
    built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.1 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
    libavutil      55. 58.100 / 55. 58.100
    libavcodec     57. 89.100 / 57. 89.100
    libavformat    57. 71.100 / 57. 71.100
    libavdevice    57.  6.100 / 57.  6.100
    libavfilter     6. 82.100 /  6. 82.100
    libavresample   3.  5.  0 /  3.  5.  0
    libswscale      4.  6.100 /  4.  6.100
    libswresample   2.  7.100 /  2.  7.100
    libpostproc    54.  5.100 / 54.  5.100
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
    Metadata:
      major_brand     : isom
      minor_version   : 512
      compatible_brands: isomiso2avc1mp41
      encoder         : Lavf57.71.100
    Duration: 00:00:09.76, start: 0.000000, bitrate: 1337 kb/s
      Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuvj444p(pc), 512x512, 1336 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
      Metadata:
        handler_name    : VideoHandler
  Stream mapping:
    Stream #0:0 -&gt; #0:0 (h264 (native) -&gt; png (native))
  Press [q] to stop, [?] for help
  [swscaler @ 0x7fef1a8f0800] deprecated pixel format used, make sure you did set range correctly
  Output #0, image2, to 'image%04d.png':
    Metadata:
      major_brand     : isom
      minor_version   : 512
      compatible_brands: isomiso2avc1mp41
      encoder         : Lavf57.71.100
      Stream #0:0(und): Video: png, gray16be, 512x512, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc (default)
      Metadata:
        handler_name    : VideoHandler
        encoder         : Lavc57.89.100 png
  frame=  244 fps=0.0 q=-0.0 Lsize=N/A time=00:00:09.76 bitrate=N/A speed=  21x    
  video:4038kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  </code></pre>
  
  <p>I'm happy to use a non-ffmpeg solution if there is one.</p>