Server: Unpredictive playout when using interlaced

[dotarmin]

Expected behaviour

Predictive output when playing progressive/interlaced media files in interlaced mode.

Current behaviour

When setting a channel to 1080i50 and playing media files that are progressive or interlaced the output becomes unpredictive. For example, when playing a progressive file and then starting an interlaced file results sometimes in wrong upper and lower field order and sometimes the order is right.

Verified by using decklink output.

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Steps to reproduce

1. Set channel to 1080i50
2. Play a progressive file
3. Play an interlaced file
4. Toggle between those two files
5. Results in unpredictive output for interlaced media

Environment

• Commit: 727542f
• Server version: v2.2

[dotarmin]

ping @ronag @Julusian

[ronag]

What does unpredictive mean?

[ronag]

Can you record and post?

[dotarmin]

ping @5opr4ni

[ronag]

Is seeking involved? e.g. START

[5opr4ni]

Hi
No there is no seek involved. Made a phonerecording to clearer show the issue. I have one 50p 720 file, that plays flawlessly and then I have a 50i file that the first couple of times has the wrong field order but when I restart it several times, it jumps to the correct field order. I hope you can se it in the video here. (Sadly this makes it impossible for us to test more in production, we mix these two formats in some productions, I know now ;) )
https://youtu.be/jDS4LmuPFc8

/olle

[ronag]

Can you provide me with the exact files used? The interlaced clip should be de-interlaced... so this issue should not be possible unless the meta in the interlaced file doesn't properly indicate it is interlaced.

[5opr4ni]

Large one, uploading it to wetransfer, you will have a gmaIl soon.

[ronag]

We changed somewhere in between betas to go from always deinterlace, to only deinterlace if meta says the file is interlaced... due to performance considerations...

Maybe we should make this configurable?

[5opr4ni]

AE discovers the interlacing on this file, haven't checked it with probe. Will do that.

[5opr4ni]

MediaInfo shows
ScanType: Interlaced
Scan order: Top Field First

[ronag]

Does this happen on the screen consumer as well? Or only decklink consumer?

[5opr4ni]

You cant see the wrong fieldorder in the screenconsumer it shows both fields all the time.

[ronag]

@5opr4ni yes, screen consumer shows the de-interlaced output. If that is correct then this is an issue in the decklink consumer (which performs the interlacing of the output you see in the screen consumer) somewhere.

[5opr4ni]

No, I see the complete frame with the fields.

<channel> <video-mode>720p5000</video-mode> <consumers> <screen> <device>1</device> <aspect-ratio>16:9</aspect-ratio> <windowed>true</windowed> <key-only>false</key-only> <vsync>true</vsync> <borderless>false</borderless> <interactive>true</interactive> </screen> <system-audio> <channel-layout>stereo</channel-layout> <latency>0</latency> </system-audio> </consumers> </channel>

[ronag]

@5opr4ni that is totally wrong, it's something with the de-interlacer then. I will take a look.

[ronag]

The default config was to never deinterlace. Fixed in master.