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• Encode HEVC/H.265/HDR Video for YouTube from 10bit Pro-Res using FFmpeg

  30 janvier 2018, par Rodrigo Polo

  I want to have an HDR YouTube video published, my source file is either an Apple ProRes or DNxHR using a chroma subsamplig 4:4:4 or full RGB, both 10bit, so the original source file has all what is needed in order to be encoded into a 10bit 4:2:0 H.265/HEVC (HDR).

  I have followed some answers listed here, reviewed lots of different approaches, tried out many different commands without success, colors aren’t right when using only FFmpeg, to much red, when using only Adobe to encode into H.264 with the recommended settings on their support page, the results is darker, here are the commands I’ve using :

  I have tried this :

  ffmpeg \
  
  -i input.mov \
  
  -c:v libx265 \
  
  -tag:v hvc1 \
  
  -crf 21 \
  
  -preset fast \
  
  -pix_fmt yuv420p10le \
  
  -x265-params "colorprim=bt2020:transfer=smpte2084:colormatrix=bt2020nc:master-display=G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,10):max-cll=1000,400" \
  
  -c:a libfdk_aac \
  
  -b:a 128k \
  
  -ac 2 \
  
  -ar 44100 \
  
  -movflags +faststart \
  
  output.mp4

  And this :

  ffmpeg \
  
  -y \
  
  -hide_banner \
  
  -i input.mov \
  
  -pix_fmt yuv420p10le \
  
  -vf "scale=out_color_matrix=bt2020:out_h_chr_pos=0:out_v_chr_pos=0,format=yuv420p10" \
  
  -c:v libx265 \
  
  -tag:v hvc1 \
  
  -crf 21 \
  
  -preset fast \
  
  -x265-params 'crf=12:colorprim=bt2020:transfer=smpte-st-2084:colormatrix=bt2020nc:master-display="G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,1)":max-cll="1000,400"' \
  
  -c:a libfdk_aac \
  
  -b:a 128k \
  
  -ac 2 \
  
  -ar 44100 \
  
  -movflags +faststart \
  
  output.mp4

  I have also tried using MKVToolNix in order to insert the metadata into the encoded HEVC/H.265 file with the following command :

  /Applications/MKVToolNix-9.7.1.app/Contents/MacOS/mkvmerge \
  
  -o output.mkv \
  
  --colour-matrix 0:9 \
  
  --colour-range 0:1 \
  
  --colour-transfer-characteristics 0:16 \
  
  --colour-primaries 0:9 \
  
  --max-content-light 0:1000 \
  
  --max-frame-light 0:300 \
  
  --max-luminance 0:1000 \
  
  --min-luminance 0:0.01 \
  
  --chromaticity-coordinates 0:0.68,0.32,0.265,0.690,0.15,0.06 \
  
  --white-colour-coordinates 0:0.3127,0.3290 \
  
  input.mp4

  But the result is the same and YouTube don’t recognize the file as an HDR file, it does only with the first FFmpeg command and with the file encoded with Adobe Premiere, but the colors don’t look well, so, maybe I’m getting some concept wrong, thanks for your help.

• hwcontext_vdpau : implement av_hwdevice_get_hwframe_constraints()

  13 janvier 2018, par wm4

  hwcontext_vdpau : implement av_hwdevice_get_hwframe_constraints()
  In addition, this does not allow creating frames contexts with sw_format
  
  for which no known transfer formats exist. In theory, we should check
  
  whether the chroma format (i.e. the sw_format) is supported at all by
  
  the vdpau driver, but checking for transfer formats has the same effect.
  Note that the pre-existing code adds 1 to priv->nb_pix_fmts[i] for
  
  unknown reason, and some checks need to account for that to check for
  
  empty lists. They are not off-by-one errors.
  

  • [DH] libavutil/hwcontext_vdpau.c

• Trying to tonemap 14-bit grayscale video

  12 janvier 2018, par Trevor

  I’m trying to generate h.264 video from raw 2-byte gray video (14-bit range encoded in 16-bit values). I can do something like :

  ffmpeg -f rawvideo -pix_fmt gray16le -s:v 1280x720 -r 60 -i input.raw -c:v libx264 output.mp4

  And I get video but it’s pretty dark, not sure if it’s clipping, doing a linear remap, or storing the 16-bit data and VLC is doing the remap. ffprobe is reporting Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuvj444p(pc), 1280x720, 108 kb/s, 60 fps, 60 tbr, 15360 tbn, 120 tbc

  I was figuring I’d use the tonemap filter to make a better mapping. I added a filter before the output file with -vf.

  • tonemap=hable errors Impossible to convert between the formats supported by the filter 'graph 0 input from stream 0:0' and the filter 'auto_scaler_0'
  • zscale=transfer=linear,tonemap=hable errors Impossible to convert between the formats supported by the filter 'Parsed_tonemap_1' and the filter 'auto_scaler_1'
  • zscale=transfer=linear,tonemap=hable,zscale=transfer=bt709,format=yuvj444p errors code 3074: no path between colorspaces

  I’m not sure where to proceed from here...