Lately I have experimented with PAL DV to DVD rendering, both using ffmpeg/DeVeDE, and now using CinGG mpeg2enc/FFMPEG

I hope someone can help to clarify the following questions and debug possible issues regarding DVD Rendering with CinGG:

1. dvd.m2v and dvd.mpg
Why are there two video files created, dvd.m2v w/o Audio and dvd.mpg w/Audio, and which one is used for what?

tree -sh dvd_20230528-115747
dvd_20230528-115747
├── [ 16M] dvd.ac3
├── [3.4K] dvd.jobs
├── [562M] dvd.m2v
├── [588M] dvd.mpg
├── [ 733] dvd.sh
├── [6.5K] dvd.xml
└── [4.0K] iso
    ├── [4.0K] AUDIO_TS
    └── [4.0K] VIDEO_TS
        ├── [6.0K] VIDEO_TS.BUP
        ├── [6.0K] VIDEO_TS.IFO
        ├── [ 18K] VTS_01_0.BUP
        ├── [ 18K] VTS_01_0.IFO
        └── [588M] VTS_01_1.VOB

2. Deinterlacing:

The input PAL DV source file is Interlaced, Bottom Field First

ffprobe:
Stream #0:0: Video: dvvideo, none, 25000 kb/s, SAR 16:15 DAR 0:0, 25 fps, 25 tbr, 25 tbn
Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
Unsupported codec with id 24 for input stream 0

mediainfo:
Width                                    : 720 pixels
Height                                   : 576 pixels
Color space                              : YUV
Scan type                                : Interlaced
Scan order                               : Bottom Field First

Why does deinterlacing with dvd default rendering (mpeg2enc) still come out as Interlaced, but Top Field first?

ffprobe -hide_banner dvd.m2v
Input #0, mpegvideo, from 'dvd.m2v':
Duration: N/A, bitrate: N/A
Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, bt470bg, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 1200k tbn
    Side data:
      cpb: bitrate max/min/avg: 8000000/0/0 buffer size: 1835008 vbv_delay: N/A

ffprobe -hide_banner dvd.mpg
[mpeg @ 0x55a756c7af00] start time for stream 0 is not set in estimate_timings_from_pts
Input #0, mpeg, from 'dvd.mpg':
Duration: 00:09:56.44, start: 0.160000, bitrate: 8305 kb/s
Stream #0:0[0x1bf]: Data: dvd_nav_packet
Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn
    Side data:
      cpb: bitrate max/min/avg: 8000000/0/0 buffer size: 1835008 vbv_delay: N/A
Stream #0:2[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 224 kb/s
Unsupported codec with id 98312 for input stream 0

mediainfo dvd.m2v | egrep "Color|pixels|Scan"
Width                                    : 720 pixels
Height                                   : 576 pixels
Color space                              : YUV
Scan type                                : Interlaced
Scan order                               : Top Field First
Color primaries                          : BT.601 PAL

mediainfo dvd.mpg | egrep "Color|pixels|Scan"
Width                                    : 720 pixels
Height                                   : 576 pixels
Color space                              : YUV
Scan type                                : Interlaced
Scan order                               : Top Field First
Color primaries                          : BT.601 PAL

While corresponding deinterlacing with the optional FFMPEG DVD Rendering comes out as Progressive?

ffprobe -hide_banner dvd.m2v
Input #0, mpegvideo, from 'dvd.m2v':
Duration: N/A, bitrate: N/A
Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, bt470bg/unknown/unknown, progressive), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 1200k tbn
    Side data:
      cpb: bitrate max/min/avg: 9000000/0/0 buffer size: 1835008 vbv_delay: N/A

ffprobe -hide_banner dvd.mpg
[mpeg @ 0x561effba3f00] start time for stream 0 is not set in estimate_timings_from_pts
Input #0, mpeg, from 'dvd.mpg':
Duration: 00:09:56.42, start: 0.160000, bitrate: 8266 kb/s
Stream #0:0[0x1bf]: Data: dvd_nav_packet
Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg/unknown/unknown, progressive), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn
    Side data:
      cpb: bitrate max/min/avg: 9000000/0/0 buffer size: 1835008 vbv_delay: N/A
Stream #0:2[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 224 kb/s

mediainfo dvd.m2v | egrep "Color|pixels|Scan"
Width                                    : 720 pixels
Height                                   : 576 pixels
Color space                              : YUV
Scan type                                : Progressive

mediainfo dvd.mpg | egrep "Color|pixels|Scan"
Width                                    : 720 pixels
Height                                   : 576 pixels
Color space                              : YUV
Scan type                                : Progressive

3. Dvd Interlaced Chroma

With reference to the CinGG manual
https://cinelerra-gg.org/download/CinelerraGG_Manual/Dvd_Interlaced_Chroma.html

Now you can use the YUV420P DVD Interlace Mode when rendering DV directly to mpeg2 through a yuv4mpeg stream and when using video effects on HDV video.
With this option enabled, improved chroma results will be obtained from your DV or HDV source. Editing DV or HDV and rendering it back to the same format does not require any special handling. In order to perform colorspace conversions correctly in CINELERRA-GG and avoid Chroma errors for interlaced 4:2:0 video, check the box as follows:

Settings → Performance → YUV420P DVD Interlace Mode

I can't find this option and is it relevant for DVD rendering?

4. Missing FFMPEG output

According to the manual:
https://cinelerra-gg.org/download/CinelerraGG_Manual/DVD_Bluray_Creation.html

It is also highly recommended to run the CINELERRA-GG startup from a terminal window, instead of the icon, in order to see informative messages of how to actually write the output (at prompt: keyin <install_directory_path/bin/cin).

For the default mpeg2enc DVD rendering there is output like

mpeg2enc -v 0 -b 8000 -q 1 -a 3 -F 3 -H -I 1 -M 8 -z t -f 8 -g 15 -G 15 -R 0 -o '/home/terje/Videoklipp/DVD/dvd_mpeg2enc_20230527-184531/dvd.m2v'

For the optional FFMEG DVD Rendering it would be nice to also get the actual "ffmpeg code line" as terminal output, both for learning, customizing and debugging.
Is that possible ?