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 No artefacts

  • 2
    The source is interlaced. Deinterlace it by adding -vf yadif
    – Gyan
    Jan 23, 2023 at 4:04
  • That was it! Thanks @Gyan!
    – beneix
    Jan 24, 2023 at 6:22


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