Export: Field Order is always Bottom Field First

[radadad]

Hi Forum!

Version 19.04.30

I’m trying to export to the following broadcast standard:
FRAME RATE: 29.97
MPEG TYPE: MPEG-2 HD
FIELD ENCODING: TOP FIELD FIRST
DEINTERLACING: USE TOP FIELD
BITRATE TYPE: CONSTANT
RATE CONTROL MODE: MODE 1
MAX. BITRATE: 20Mb/s Constant
GOP STRUCTURE: IBBP

The source video is Interlaced, TFF.

I’ve selected the Stock MPEG-2 export preset, and changed the following in Advanced:
Scan mode: Interlaced
Field order: Top Field First

After export, the video is Bottom Frame First, regardless of how field order is set.

The mighty question: How can I export to these standards with Top Frame First?

Thanks,
Rick

[radadad]

Bump!

Please forgive the bump, but this is a blocking issue for us. Shotcut works great for us in so many ways - I really want to get past this issue.

Thanks,
Rick

[Hudson555x]

I am not experienced with your issue.
I do see that you’re using an outdated version of Shotcut.
You can download the latest version here.
Does the issue still exist with the current version?
Shotcut is updated quite frequently with many changes each version. You can read all of the changes here.

[Namna]

@radadad

I’ve selected the Stock MPEG-2 export preset, and changed the following in Advanced:
Scan mode: Interlaced
Field order: Top Field First

After export, the video is Bottom Frame First, regardless of how field order is set.

The mighty question: How can I export to these standards with Top Frame First?

Have you try this preset?
It works for me

[brian]

@radadad

After export, the video is Bottom Frame First, regardless of how field order is set.

Do you mean “Bottom field first”?

How do you know this? What are you using to determine the field order of the exported file?

If you open the exported file in Shotcut, what does the properties panels show?

[shotcut]

I made a quick test, and it worked for me with v19.04.30 on macOS. From mediainfo

Scan type                                : Interlaced
Scan order                               : Top Field First

I did not have an interlaced clip on this machine while out of town, and I used a progressive source, but it encoded with signaling as expecting.

[radadad]

Thank you Brian, Shotcut, for testing through this.

I was able to narrow down steps to reproduce, which I illustrate here:

Shotcut - Bottom field first - Steps to reproduce

Basically (for the benefit of search terms), if I add an video to the timeline, with a png below it on the timeline, and then export the MPEG-2 preset interlaced, a bottom-field-first video is created regardless of the field order setting. But if the png is above the video on the timeline, the video is top field first.

Now that I have a workaround I am no longer blocked. This is a low priority bug for the queue.

Oh - I did install the latest version. I haven’t seen much yet, but the new Size & Position filter is quite intuitive, and the rendering progress much improved. I really appreciate your work - thank you!!

Rick