• Compression Techniques

  Decoding prores results in no video

  Posted by Stephen Ratkovich on October 12, 2018 at 1:57 pm

  I’m trying to convert a prores 422 MOV to h.264 aac MOV, but it always results in no video, only black with aac audio.
  Haven’t found anything useful in trying to DEcode prores from google searching.

  Stephen Ratkovich replied 7 years, 5 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Gyan Doshi

  October 14, 2018 at 12:21 pm

  I’m fairly sure this isn’t an issue on the decoder side.

  FFmpeg will select the ‘best’ pixel format supported by the encoder, which loses the least amount of information relative to the source. Since your input is YUV 4:2:2 and libx264 (default MOV encoder) supports that, that’s what FFmpeg will choose. But most players (and editors) only support 4:2:0 H264, so instead of their decoder registering an error, the s/w will decode only the audio, and display a blank canvas.

  The solution is to encode as YUV 4:2:0. Add `-pix_fmt yuv420p` anywhere before the output filename and after the input filename.
• 

  Stephen Ratkovich

  November 26, 2018 at 5:13 pm

  Thanks, this worked.

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