The video is telecined, not interlaced. On Fri, May 16, 2025 at 11:39 PM Richard Bartczak via ffmpeg-user < ffmpeg-user@ffmpeg.org> wrote:
> Am 17.05.25 um 06:03 schrieb Alex Xu: > > Hi everyone, > > > > I'm working to detelecine a video, attached here (12 MB, first 32 seconds > > truncated): > > https://www.mediafire.com/file/x4ly6moqb8ayfyy/detelecine_input.mkv/file > > > > I wasn't sure what was the right command to get the result I wanted so I > > looped over all possible combos like so: > > > > for i in 0 1 2 3 4; do > > for j in 23 2332; do > > ffmpeg -i detelecine_input.mkv -c:v libx264 -crf 18 -c:a aac -b:a 192k > > -pix_fmt yuv420p -vf "detelecine=start_frame=$i:pattern=$j" $i$j.mkv; > > done > > done > > > > It was very clear which option was correct, since the correct option > > encoded the best and had a significantly smaller file size. I visually > > verified it too. In the source, every set of 5 frames had 3 clear frames > > and 2 interleaved frames. In the final output, it preserved those 3 clear > > frames and combines the 2 interleaved frames into 1, going from 30i to > 24p. > > > > But I'm just not sure why the correct result was > start_frame=3:pattern=2332. > > > > Examining the video, it seems pretty clear to me the pattern should be > 23. > > Since it has two interleaved frames. I learned about 23 from > > https://en.wikipedia.org/wiki/Telecine#2:3_pulldown > > > > Could someone explain the gap in my knowledge? > > > > Alex > > _______________________________________________ > > ffmpeg-user mailing list > > ffmpeg-user@ffmpeg.org > > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > > > To unsubscribe, visit link above, or email > > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > > If you want to get the progressive mode : > > ffmpeg -i "interlacevideo.mkv" -vcodec libx264 -crf 18 -preset slow -vf > yadif -c:a copy "progressivevideo.mkv" > > Richard > > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
