Body: <p>I am converting video taken with various personal cameras in .MTS format to mp4 in order to reduce the file size. I am getting some strange artefacts and I wonder what simple mistake I am making?</p>
  <p>ffmpeg finds this content in the infile:
  Program 1
  Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p(top first), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 50 tbr, 90k tbn, 50 tbc
  Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 256 kb/s
  Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090), 1920x1080</p>
  <p>I used:</p>
  <pre><code>ffmpeg -i infile.MTS -c:a copy -c:v libx264 -r 25 -b 8M outfile.mp4
  </code></pre>
  <p>I set the frame rate in order to keep the original frame rate, otherwise I get 50 fps, but even at 50 fps the artefacts are there.</p>
  <p>See attached screen grab (a small crop) for the artefacts, followed by the original.
  <a href="https://i.sstatic.net/CjlJD.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/CjlJD.png" alt="Artefacts:crop" /></a>
  <a href="https://i.sstatic.net/7SIo9.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/7SIo9.png" alt="No artefacts" /></a></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-01-23T04:04:25.103Z
Comments.Text: The source is interlaced. Deinterlace it by adding `-vf yadif`
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-01-24T06:22:38.047Z
Comments.Text: That was it! Thanks @Gyan!
Comments.UserDisplayName: beneix
Tags: <ffmpeg><mp4><conversion><h.264>
Title: Converting MTS to MP4 gives strange artefacts
UserDisplayName: beneix
ThreadText: # Converting MTS to MP4 gives strange artefacts
  
  (Asked by: username_0 on 2023-01-22)
  
  I am converting video taken with various personal cameras in .MTS format to mp4 in order to reduce the file size. I am getting some strange artefacts and I wonder what simple mistake I am making?
  
  ffmpeg finds this content in the infile:
  Program 1
  Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p(top first), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 50 tbr, 90k tbn, 50 tbc
  Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 256 kb/s
  Stream #0:2[0x1200]: Subtitle: hdmv\_pgs\_subtitle ([144][0][0][0] / 0x0090), 1920x1080
  
  I used:
  
  ```
  ffmpeg -i infile.MTS -c:a copy -c:v libx264 -r 25 -b 8M outfile.mp4
  
  ```
  
  I set the frame rate in order to keep the original frame rate, otherwise I get 50 fps, but even at 50 fps the artefacts are there.
  
  See attached screen grab (a small crop) for the artefacts, followed by the original.
  [![Artefacts:crop](https://i.sstatic.net/CjlJD.png)](https://i.sstatic.net/CjlJD.png)
  [![No artefacts](https://i.sstatic.net/7SIo9.png)](https://i.sstatic.net/7SIo9.png)
  
  **Tags:** ffmpeg, mp4, conversion, h.264
  
  > **Comments:**
  > **username_1**: The source is interlaced. Deinterlace it by adding `-vf yadif`  
  > **username_0**: That was it! Thanks @username_1!  
  
  ---
  
  ## 0 answers
  
  