Answers.Body: <p>If you're using x264 directly, it's <code>--rc-lookahead 20</code> for 20 frames. If it's via ffmpeg, it's <code>-x264-params rc_lookahead=10</code>.</p>
  
  <p>Although I would suggest to use faster <a href="http://dev.beandog.org/x264_preset_reference.html" rel="nofollow noreferrer">presets</a>. Default is medum.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-05-31T20:03:20.720Z
Answers.Text: So I'm using OpenCVs videowrite() function. I know that it uses x264 encoding in the back end. Is there a way to set `--rc-lookahead 20` as a parameter through OpenCV?
Answers.UserDisplayName: newuser
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-01T05:40:27.347Z
Answers.Text: From what I can see, this is not possible. OpenCV does not accept private parameters for x264. You can raise an issue at https://github.com/opencv/opencv/issues
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-04T15:57:58.117Z
Answers.Text: Would it be possible to change encoder parameters in the OpenCV sourcecode? Or do I have to into the x264 encoder source code?
Answers.UserDisplayName: newuser
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-04T16:16:41.420Z
Answers.Text: Not familiar with the OpenCV source but search for the x264 API calls initializing the encoder parameters and change those.
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-04T16:43:24.013Z
Answers.Text: OpenCV does not seem to use x264, See https://github.com/opencv/opencv/blob/master/3rdparty/ffmpeg/readme.txt.
Answers.UserDisplayName: Gyan
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Answers.CreationDate: 2018-05-31T18:00:17.870Z
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Answers.UserDisplayName: Gyan
Body: <p>I want minimize encoding latency per frame. Right now, there is a high increase in encoding latency on the 46th frame. I think lowering the lookahead value might help with this. How do I do this? 
  Capture Resolution is 1080p. </p>
  
Tags: <h.264><x264><latency>
Title: I'm using H264 encoding to encode video capture from a webcam. How do I turn of rc lookahead?
UserDisplayName: newuser
ThreadText: # I'm using H264 encoding to encode video capture from a webcam. How do I turn of rc lookahead?
  
  (Asked by: username_0 on 2018-05-31)
  
  I want minimize encoding latency per frame. Right now, there is a high increase in encoding latency on the 46th frame. I think lowering the lookahead value might help with this. How do I do this?
  Capture Resolution is 1080p.
  
  **Tags:** h.264, x264, latency
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2018-05-31. Score: 0 | Accepted answer
  
  If you're using x264 directly, it's `--rc-lookahead 20` for 20 frames. If it's via ffmpeg, it's `-x264-params rc_lookahead=10`.
  
  Although I would suggest to use faster [presets](http://dev.beandog.org/x264_preset_reference.html). Default is medum.
  
  > **Comments:**
  > **username_0**: So I'm using OpenCVs videowrite() function. I know that it uses x264 encoding in the back end. Is there a way to set `--rc-lookahead 20` as a parameter through OpenCV?  
  > **username_1**: From what I can see, this is not possible. OpenCV does not accept private parameters for x264. You can raise an issue at https://github.com/opencv/opencv/issues  
  > **username_0**: Would it be possible to change encoder parameters in the OpenCV sourcecode? Or do I have to into the x264 encoder source code?  
  > **username_1**: Not familiar with the OpenCV source but search for the x264 API calls initializing the encoder parameters and change those.  
  > **username_1**: OpenCV does not seem to use x264, See https://github.com/opencv/opencv/blob/master/3rdparty/ffmpeg/readme.txt.  
  
  ---
  
  