Selur's Little Message Board
[HELP] Aspect ratio for DVD PAL 16:9 not preserved - Printable Version

+- Selur's Little Message Board (https://forum.selur.net)
+-- Forum: Hybrid - Support (https://forum.selur.net/forum-1.html)
+--- Forum: Problems & Questions (https://forum.selur.net/forum-3.html)
+--- Thread: [HELP] Aspect ratio for DVD PAL 16:9 not preserved (/thread-2083.html)

Aspect ratio for DVD PAL 16:9 not preserved - 4i4oVi40 - 28.09.2021

I try to de-interlace with QTGMC and encode a video sample from a DVD PAL 16:9 (720x576) to x265 (CRF 22).
Although the MediaInfo reports DAR 2.40 : 1 for both source and output file, the encoded video plays in VLC as if stretched, while the source plays fine.
When I select in VLC Video > Aspect Ratio > 16:9 the output file also plays fine.

What should I do so the output file plays by default at 16:9 as the source?
Here are the sample and the encoded file: https://filetransfer.io/data-package/R43v6woU

Thanks in advance.


Please, read the 'Infos needed to fix&reproduce bugs,..'-sticky before you post about a problem.Please, read the 'Infos needed to fix&reproduce bugs,..'-sticky before you post about a problem.

RE: Aspect ratio for DVD PAL 16:9 not preserved - shijan - 29.09.2021

Formally exported MKV is correct. It stretches to 2.40:1 and match to MediaInfo data.

Seems there is some mistake in source file metadata brutti1.mpg. Or maybe conflict between Container and stream metadata. Hybrid reads it as Input PAR: 256x135 (see in Crop/Resize tab)
To preserve 16:9 proportions from 720x576 source you need manually set Input PAR. I know that 16:9 720x480 DVDs use Input PAR 32x27. So you need somehow calculate proper 16:9 PAR for your 720x576 file.
For 16:9 720x576 use Input PAR: 64x45
https://en.wikipedia.org/wiki/Pixel_aspect_ratio#Pixel_aspect_ratios_of_common_video_formats

RE: Aspect ratio for DVD PAL 16:9 not preserved - 4i4oVi40 - 29.09.2021

(29.09.2021, 00:41)shijan Wrote: Formally exported MKV is correct. It stretches to 2.40:1 and match to MediaInfo data.

Seems there is some mistake in source file metadata brutti1.mpg. Or maybe conflict between Container and stream metadata. Hybrid reads it as Input PAR: 256x135 (see in Crop/Resize tab)
To preserve 16:9 proportions from 720x576 source you need manually set Input PAR. I know that 16:9 720x480 DVDs use Input PAR 32x27. So you need somehow calculate proper 16:9 PAR for your 720x576 file.
For 16:9 720x576 use Input PAR: 64x45
https://en.wikipedia.org/wiki/Pixel_aspect_ratio#Pixel_aspect_ratios_of_common_video_formats

Thanks, shijan! The workaround of manually setting Input PAR: 64x45 worked as a charm.

Still, since I'm new to Hybrid, I wonder why this workaround is needed, when I tested the same sample with HandBrake and the output's DAR came out correct.

Source Video: mpeg2video (Main), yuv420p(tv, bt470bg, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps

Hybrid Video: hevc (Main 10), yuv420p10le(tv, bt470bg/unknown/unknown), 720x576, SAR 64:45 DAR 16:9, 25 fps

HandBrake Video: hevc (Main 10), yuv420p10le(tv, bt470bg), 720x550 [SAR 64:45 DAR 512:275], 25 fps
(Some cropping was applied in this case but this is not the issue.)

RE: Aspect ratio for DVD PAL 16:9 not preserved - Selur - 29.09.2021

Mediainfo reports:
Width                                    : 720
Width                                    : 720 pixels
Height                                   : 576
Height                                   : 576 pixels
Sampled_Width                            : 720
Sampled_Height                           : 576
Pixel aspect ratio                       : 1.896
Display aspect ratio                     : 2.370
Display aspect ratio                     : 2.40:1
About the source, Hybrid uses the 'Pixel aspect ratio' info of 1.896 and converts it to a fractional (256/135).
FFmpeg on the other hand reports:
Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k
Since Handbrake like uses libav it will also detect the same as FFmpeg.
No clue whether it's a bug in MediaInfo or FFmpeg always overwrites the PAR in some cases.
You would have to ask the MediaInfo developer about the discrepancy.

Hybrid does use MediaInfo and ffmpeg for the source analysis, but it normally relies on MediaInfo for the aspect ratio.

Cu Selur

RE: Aspect ratio for DVD PAL 16:9 not preserved - 4i4oVi40 - 29.09.2021

(29.09.2021, 05:55)Selur Wrote: Mediainfo reports:
Width                                    : 720
Width                                    : 720 pixels
Height                                   : 576
Height                                   : 576 pixels
Sampled_Width                            : 720
Sampled_Height                           : 576
Pixel aspect ratio                       : 1.896
Display aspect ratio                     : 2.370
Display aspect ratio                     : 2.40:1
About the source, Hybrid uses the 'Pixel aspect ratio' info of 1.896 and converts it to a fractional (256/135).
FFmpeg on the other hand reports:
Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k
Since Handbrake like uses libav it will also detect the same as FFmpeg.
No clue whether it's a bug in MediaInfo or FFmpeg always overwrites the PAR in some cases.
You would have to ask the MediaInfo developer about the discrepancy.

Hybrid does use MediaInfo and ffmpeg for the source analysis, but it normally relies on MediaInfo for the aspect ratio.

Cu Selur

Thanks for the explanation. So it's a discrepancy between MediaInfo and ffmpeg.

Also, thanks for Hybrid. I have used HandBrake, VidCoder, Shutter, StaxRip, myFFmpeg, etc. However, it seems Hybrid will become my new favorite. It's very comprehensive, yet its default behavior delivers great results. Also, the hover over tool tips (CTRL+F10) are very helpful. 

I've just donated.