Field Order - BFF on analog source

[harrypm]

All files are being encoded as BFF when souce is TFF there is no apparent overides for this?

Config

Source --> Analog to SDI Converter --> BMD Decklink SDI 4k --> Vrecord --> FFV1/FLAC/MKV

[dericed]

Hi @harrypm, with a digitized sample could you run ffmpeg -i your_sample_here.mkv -vf idet -f null - and paste back the lines that start with [Parsed_idet. I just want to make sure the video is actually analyzing as tff.

Vrecord takes the interlacement from the decklink devices, but I think here you're wishing to express something different than what decklink is. To do that, you can go to the Config / Player tab and change Force Interlacement from auto to something else, but I'm curious if decklink is actually wrong about your video and if idet is saying something else.

[harrypm]

I figured it out hooked up an PWM-EX3 & HackDAC and did NTSC/PAL though the chain looks like the defualts under vrecord are BFF for NTSC and TFF for PAL

Really I think it would make more logical sense for field order config to be a main page config option.

@dericed I did run that for you also.

[Parsed_idet_0 @ 0x55de8d8b12c0] Repeated Fields: Neither: 55851 Top: 26 Bottom: 25 [Parsed_idet_0 @ 0x55de8d8b12c0] Single frame detection: TFF: 45 BFF: 55696 Progressive: 5 Undetermined: 156 [Parsed_idet_0 @ 0x55de8d8b12c0] Multi frame detection: TFF: 6 BFF: 55772 Progressive: 0 Undetermined: 124

Media Info from the file:

Scan type, store method : Interleaved fields Scan order : Bottom Field First

[dericed]

Hi @harrypm, from your test I see:

[Parsed_idet_0 @ 0x55de8d8b12c0] Repeated Fields: Neither: 55851 Top:    26 Bottom:    25
[Parsed_idet_0 @ 0x55de8d8b12c0] Single frame detection: TFF:    45 BFF: 55696 Progressive:     5 Undetermined:   156
[Parsed_idet_0 @ 0x55de8d8b12c0] Multi frame detection: TFF:     6 BFF: 55772 Progressive:     0 Undetermined:   124

From this analysis, the decklink is sending in a bottom-field-first appearing video, then from mediainfo the file is noted as bottom field first, so the interlacement presentation and interlacement match, so it seems like your source is not TFF, but BFF.