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yadif 2x deinterlace filter ignores field order

Posted: 27 Feb 2023 03:08
by sprucejuice
I encoded interlaced content with x264 with the interlaced flag set in an mkv container. mediainfo confirms this.

Code: Select all

Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High 4:2:2@L3 Format settings : CABAC / 5 Ref Frames Format settings, CABAC : Yes Format settings, Reference frames : 5 frames Codec ID : V_MPEG4/ISO/AVC Duration : 2 s 169 ms Bit rate : 2 024 kb/s Width : 720 pixels Height : 480 pixels Display aspect ratio : 4:3 Frame rate mode : Constant Frame rate : 29.970 (30000/1001) FPS Standard : NTSC Color space : YUV Chroma subsampling : 4:2:2 Bit depth : 8 bits Scan type : MBAFF Scan type, store method : Interleaved fields Scan order : Top Field First Bits/(Pixel*Frame) : 0.195 Stream size : 536 KiB (97%) Title : Video Writing library : x264 core 164 Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=tff / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=0 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00 Language : English Default : Yes Forced : No
If I open it in Virtualdub2, add a deinterlace filter with yadif, double frame rate, and top field first (matching the x264 stream), it works as expected. If I open it in VLC, force deinterlace, use Yadif 2x, the image jumps back and forth. It's like the deinterlace filter is ignoring the field order in the stream. Maybe it's because it's NTSC, but TFF? I also tried encoding with bff=1 in case Virtualdub2 mixed up its interface, but it was still jittery in VLC.

Here's a small part of the video:

https://web.archive.org/web/20230227015 ... d-demo.mkv

This might be related to a decade-old issue/feature request: https://forum.videolan.org/viewtopic.php?f=7&t=3101

I'm using VLC 3.0.18 on Windows 10.

Re: yadif 2x deinterlace filter ignores field order

Posted: 27 Feb 2023 10:23
by Lotesdelere
Looks like the corresponding ticket is still open:
https://code.videolan.org/videolan/vlc/-/issues/10191

You should add your report and your sample file to it.

Re: yadif 2x deinterlace filter ignores field order

Posted: 27 Feb 2023 18:43
by sprucejuice
I will, but they seem to be about adding an option. I shouldn't even need the option because I think the stream is tagged correctly.