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smplayer-dev / smplayer

Free Media Player for Windows, Linux and Mac OS with YouTube support.
https://smplayer.info
GNU General Public License v2.0
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Can a recording of 1080i video that was broadcast as 720p be fixed during playback? #1026

Open SteegHobland opened 1 month ago

SteegHobland commented 1 month ago

Describe the bug Some videos, recorded from broadcasts of a particular station, appear to have visible effects that seem to be due to interlacing, despite the video being 720p. None of the five deinterlacing options seem able to help much, nor the options in video filters.

To Reproduce Steps to reproduce the behavior:

  1. I record shows from WFTS sometimes, using one of those cheap DTV converter/DVR boxes with a USB thumbdrive stuck into it.
  2. I then put that stick in my computer.
  3. I watch the video I recorded.
  4. I sometimes notice this shuddering lines effect that looks like improper deinterlacing, even though the video's 720p.

Expected behavior Some option in video>deinterlace, or video>filters, should eliminate the effect.

Screenshots I don't think a still will convey the effect properly, and I don't know how to capture a sequence of frames that would.

Your Enviroment

Logs An error log isn't applicable, as far as I know.

Additional context It was especially noticeable during Jeopardy! Masters, when text or player rankings were shown on screen. I'm guessing the station is, at least some of the time, using a source that is 1080i, and broadcasting it as 720p, without doing a deinterlacing step somewhere in that process? If that's the case, what can be done to fix it during playback?

Raza-0007 commented 1 month ago

Whether a deinterlacing filter will kick-in depends on the video. If the video file indicates that it is interlaced, a deinterlacing filter, if enabled, will automatically kick in and deinterlace the video. If the video file is broken, and does not indicate if it is interlaced then sometimes force enabling a deinterlacing filter will fix the problem. If the interlacing is hard encoded into the video file then I am afraid a deinterlacing filter will not be able to correct the problem.

Did your mpv log indicate if deinterlacing was attempted?

smplayer's deinterlacing or video filters do not work if hardware decoding, other than the copy-back type, is enabled.

Check your file in VLC, it has deinterlacing enabled by default. If VLC is able to deinterlace your video then smplayer will also be able to do it, otherwise the video file is broken.

~Raza