Answers.Body: <p>Judge based on the quality rather than the bitrate value. Use CRF mode encoding and if the quality isn't what you can accept, decrease the CRF value.</p>
  
  <pre><code>ffmpeg -i "%%a" -s 3840x2610 -c:v libx264 -crf 18 -acodec copy D:\%%~na.mp4
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-11-01T16:02:42.197Z
Answers.Text: Is it possible to say which -crf gets me the same quality as the original?
Answers.UserDisplayName: screenfun2312
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-11-01T16:07:06.273Z
Answers.Text: CRF 18 is advertised as 'visually lossless', but isn't technically lossless. See http://slhck.info/articles/crf
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-11-01T21:02:55.090Z
Answers.Text: Alternatively you could use `-vf scale=3840:-1`.
Answers.UserDisplayName: llogan
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-11-01T15:45:35.690Z
Answers.LastActivityDate: 2015-11-01T15:45:35.690Z
Answers.UserDisplayName: Gyan
Body: <p>I have recently come into possession of a couple of 4k movies with a resolution of 4096x2304. Unfortunately my Samsung 4k TV wont play anything over 3840x2160.</p>
  
  <p>I have managed to re-encode the videos to 3840x2160, unfortunately the bitrate fell to 1/10th of what it was before.</p>
  
  <p>I used:</p>
  
  <pre><code>for %%a in ("*.mkv") do ffmpeg -i "%%a" -s 3840x2610 -q:v 0 -c:v libx264 -acodec copy D:\%%~na.mp4
  </code></pre>
  
  <p>Original file size was 27.8GB, the re-encoded one was under 8GB.</p>
  
  <p>Is there any way I can re-encode them so I can keep the original bitrate/quality?</p>
  
  <blockquote>
    <p>Rant: Even my 4 year old computer can play the movie, but that fcking
    new Samsung TV of course can't /rant-end</p>
  </blockquote>
  
Tags: <ffmpeg><encoding><conversion><4k>
Title: Convert resolution 4096x2304 to 3840x2160 keeping the quality the same
UserDisplayName: screenfun2312
ThreadText: # Convert resolution 4096x2304 to 3840x2160 keeping the quality the same
  
  (Asked by: username_0 on 2015-11-01)
  
  I have recently come into possession of a couple of 4k movies with a resolution of 4096x2304. Unfortunately my Samsung 4k TV wont play anything over 3840x2160.
  
  I have managed to re-encode the videos to 3840x2160, unfortunately the bitrate fell to 1/10th of what it was before.
  
  I used:
  
  ```
  for %%a in ("*.mkv") do ffmpeg -i "%%a" -s 3840x2610 -q:v 0 -c:v libx264 -acodec copy D:\%%~na.mp4
  
  ```
  
  Original file size was 27.8GB, the re-encoded one was under 8GB.
  
  Is there any way I can re-encode them so I can keep the original bitrate/quality?
  
  > Rant: Even my 4 year old computer can play the movie, but that fcking
  > new Samsung TV of course can't /rant-end
  
  **Tags:** ffmpeg, encoding, conversion, 4k
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2015-11-01. Score: 3 | Accepted answer
  
  Judge based on the quality rather than the bitrate value. Use CRF mode encoding and if the quality isn't what you can accept, decrease the CRF value.
  
  ```
  ffmpeg -i "%%a" -s 3840x2610 -c:v libx264 -crf 18 -acodec copy D:\%%~na.mp4
  
  ```
  
  > **Comments:**
  > **username_0**: Is it possible to say which -crf gets me the same quality as the original?  
  > **username_1**: CRF 18 is advertised as 'visually lossless', but isn't technically lossless. See http://slhck.info/articles/crf  
  > **username_2**: Alternatively you could use `-vf scale=3840:-1`.  
  
  ---
  
  