Answers.Body: <p>From <a href="http://x264.nl/x264/10bit_02-ateme-why_does_10bit_save_bandwidth.pdf" rel="nofollow noreferrer">Why does 10-bit save bandwidth (even when content is 8-bit)?</a></p>
  
  <blockquote>
    <p>When encoding with the 10-bit tool, the compression process is
    performed with at least 10-bit accuracy compared to only 8-bit
    otherwise. So there is less truncation errors, especially in the
    motion compensation  stage, increasing the efficiency of compression 
    tools. As a consequence, there is less need to quantize to achieve a
    given bit-rate.</p>
    
    <p>The net result is a better quality for the same bit-rate or conversely
    less bit-rate for the same quality: between 5% and 20% on typical
    sources.</p>
  </blockquote>
  
  <p>See the link for additional info.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-01-08T18:46:41.177Z
Answers.LastActivityDate: 2019-01-08T18:46:41.177Z
Answers.UserDisplayName: llogan
Body: <p>Our workflow involves huge 8K clips(i.e., 8192x8192). The inputs are mostly very high bitrates 264/265 clips, though we are using ProRes or  DNxHD for post-production within the process, we do not want to archive such huge files as the "master" copies(easily over 100GB for 1 minute).</p>
  
  <p>My current approach is, using FFMPEG to compress the ProRes/DHxHD clips into H.265 clips using a very high-quality setting (crf=12, slow profile).</p>
  
  <p>Another quality related setting is the pixel format config. Then my question comes up:</p>
  
  <p>Targeting the same clips(5 of them), using the same compress settings, one with yuv420 8-bit, one with yuv444 10-bit, yuv444 outputs are constantly smaller than yuv420 outputs(5%-10%), i.e, lower bitrates.</p>
  
  <p>If yuv444 10-bit needs to store more information, how could this be possible?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-01-08T23:00:00.847Z
Comments.Text: I can't answer your question, but may I ask which camers you are using? As not even RED's r3d codec at 8k uses so much storage. Thanks.
Comments.UserDisplayName: Timothy Lukas H.
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-01-09T02:39:10.957Z
Comments.Text: Yes, this is not from a single camera, they are VR content, a multiple camera setup.
Comments.UserDisplayName: Jerry Tian
Tags: <ffmpeg><h.265>
Title: H.265(libx265) codec for 8K videos, using same compress settings, why yuv444 10-bit is saving bitrates than yuv420 8-bit?
UserDisplayName: Jerry Tian
ThreadText: # H.265(libx265) codec for 8K videos, using same compress settings, why yuv444 10-bit is saving bitrates than yuv420 8-bit?
  
  (Asked by: username_0 on 2019-01-08)
  
  Our workflow involves huge 8K clips(i.e., 8192x8192). The inputs are mostly very high bitrates 264/265 clips, though we are using ProRes or DNxHD for post-production within the process, we do not want to archive such huge files as the "master" copies(easily over 100GB for 1 minute).
  
  My current approach is, using FFMPEG to compress the ProRes/DHxHD clips into H.265 clips using a very high-quality setting (crf=12, slow profile).
  
  Another quality related setting is the pixel format config. Then my question comes up:
  
  Targeting the same clips(5 of them), using the same compress settings, one with yuv420 8-bit, one with yuv444 10-bit, yuv444 outputs are constantly smaller than yuv420 outputs(5%-10%), i.e, lower bitrates.
  
  If yuv444 10-bit needs to store more information, how could this be possible?
  
  **Tags:** ffmpeg, h.265
  
  > **Comments:**
  > **username_1**: I can't answer your question, but may I ask which camers you are using? As not even RED's r3d codec at 8k uses so much storage. Thanks.  
  > **username_0**: Yes, this is not from a single camera, they are VR content, a multiple camera setup.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2019-01-08. Score: 1 | Accepted answer
  
  From [Why does 10-bit save bandwidth (even when content is 8-bit)?](http://x264.nl/x264/10bit_02-ateme-why_does_10bit_save_bandwidth.pdf)
  
  > When encoding with the 10-bit tool, the compression process is
  > performed with at least 10-bit accuracy compared to only 8-bit
  > otherwise. So there is less truncation errors, especially in the
  > motion compensation stage, increasing the efficiency of compression
  > tools. As a consequence, there is less need to quantize to achieve a
  > given bit-rate.
  >
  > The net result is a better quality for the same bit-rate or conversely
  > less bit-rate for the same quality: between 5% and 20% on typical
  > sources.
  
  See the link for additional info.
  
  
  ---
  
  