Trouble with DVD-Video compatible transcoding from 5:4 to 4:3

[pauleck]

Hi everybody,
I have trouble with transcoding a h264 file into a DVD-Video compatible mpeg2 file.

The h246 source file aspect ratio prefererences are as follows:

Display Aspect Ratio (DAR) = 5/4
Storage Aspect Ratio (SAR) = 1/1
Pixel Aspect Ratio (PAR) = 5/4

The transcoded mpeg2 file gives the following aspect ratio preferences:

Display Aspect Ratio (DAR) = 4/3
Storage Aspect Ratio (SAR) = 16/15
Pixel Aspect Ratio (PAR) = 5/4

As a result, the transcoding process leads to a horizontally stretched and blurred pictures. Please have a look on the screenshots I have made.
How can I overcome this problem? I just want to keep the movie file in the same shape but It should be compatible with the DVD-Video standard. Maybe it has something to do with the SAR value, right?

I am using a trial version of Adobe Media Encoder CC for the transcoding process. Besides, I own the macOS app called "ff-works", which is a GUI environment for the open source command line tool "ffmpeg".

Many thanks in advance and blessed holidays,
Paul


[Attachment 48761 - Click to enlarge]

[flashandpan007]

I think this issue is a bit more complex than mp4 to DVD compliant file.

What is your source? According to picture I think it might be VHS. What did you do to get the VHS video to your computer and post MediaInfo log (Text output) of your first file, the captured file.

[jagabo]

Your source is obviously a 720x576 ITU cap that's encoded improperly as 5:4 DAR. It should be 4:3 DAR. Even so, AME did the conversion "properly", the way a professional DVD would be made from an ITU cap. The wider picture is how the original video was supposed to look.

[pauleck]

Thanks for your replies!

@Flashandpan007
yes, This is digitised data from old VHS (PAL) tapes, by using a hardware h264 converter box (AverMedia Game Capture HDII).

Als follows, the data from MediaInfo:

1) from the h264 source file

Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 169 MiB
Duration                                 : 4mn 36s
Overall bit rate                         : 5 136 Kbps
Writing application                      : Lavf57.71.100

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.1
Format settings                          : CABAC / 2 Ref Frames
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 2 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 4mn 36s
Bit rate                                 : 4 998 Kbps
Width                                    : 720 pixels
Height                                   : 576 pixels
Display aspect ratio                     : 5:4
Frame rate mode                          : Constant
Frame rate                               : 50.000 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Interlaced
Scan type, store method                  : Separated fields
Scan order                               : Top Field First
Bits/(Pixel*Frame)                       : 0.241
Stream size                              : 165 MiB (97%)
Codec configuration box                  : avcC

Audio
ID                                       : 2
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 4mn 36s
Bit rate mode                            : Constant
Bit rate                                 : 128 Kbps
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 KHz
Frame rate                               : 46.875 fps (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 4.21 MiB (2%)
Default                                  : Yes
Alternate group                          : 1

2) from the transcoded mpeg2 DVD-Video file

Format                                  : MPEG-PS
File size                                : 141 MiB
Duration                                 : 4mn 36s
Overall bit rate mode                    : Variable
Overall bit rate                         : 4 274 Kbps

Video
ID                                       : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@Main
Format settings                          : BVOP
Format settings, BVOP                    : Yes
Format settings, Matrix                  : Default
Format settings, GOP                     : M=2, N=12
Format settings, picture structure       : Frame
Duration                                 : 4mn 36s
Bit rate mode                            : Variable
Bit rate                                 : 3 997 Kbps
Maximum bit rate                         : 9 000 Kbps
Width                                    : 720 pixels
Height                                   : 576 pixels
Display aspect ratio                     : 4:3
Frame rate                               : 25.000 fps
Standard                                 : PAL
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Interlaced
Scan order                               : Bottom Field First
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 0.386
Time code of first frame                 : 00:00:00:00
Time code source                         : Group of pictures header
GOP, Open/Closed                         : Open
GOP, Open/Closed of first frame          : Closed
Stream size                              : 132 MiB (94%)

Audio
ID                                       : 192 (0xC0)
Format                                   : MPEG Audio
Format version                           : Version 1
Format profile                           : Layer 2
Duration                                 : 4mn 36s
Bit rate mode                            : Constant
Bit rate                                 : 192 Kbps
Channel(s)                               : 2 channels
Sampling rate                            : 48.0 KHz
Frame rate                               : 41.667 fps (1152 SPF)
Compression mode                         : Lossy
Stream size                              : 6.32 MiB (4%)

@ jagabo
This was also my initial thought, but the more I look at the results (I digitised about 30 tapes), the more I am convinced they are unnaturally stretched. Is there any method to check it?


Cheers

[jagabo]

I am convinced they are unnaturally stretched. Is there any method to check it?

Find something of a known aspect ratio and measure it on screen. Like the tire of a car viewed directly from the side, a window of known dimensions, a photograph of a person in the video taken from the same angle, etc.

But given the size of the black borders on the left and right of the frame, the half black line at the top of the frame and the head switching noise at the bottom, it's almost certain that you have an cap that conforms to the ITU spec.

[pauleck]

I am convinced they are unnaturally stretched. Is there any method to check it?

Find something of a known aspect ratio and measure it on screen. Like the tire of a car viewed directly from the side, a window of known dimensions, a photograph of a person in the video taken from the same angle, etc.

Sounds logical
It should also be fine to compare the orginal tape footage on my TV with the captured one?

[jagabo]

It should also be fine to compare the orginal tape footage on my TV with the captured one?

Maybe. If you're using a modern fixed pixel display (LCD, plasma, OLED) it should be ok. But old CRTs are usually out of spec as far as aspect ratios are concerned.

[pauleck]

It should also be fine to compare the orginal tape footage on my TV with the captured one?

Maybe. If you're using a modern fixed pixel display (LCD, plasma, OLED) it should be ok. But old CRTs are usually out of spec as far as aspect ratios are concerned.

Should be fine, I own a 65" Panasonic TX-65DXW904 LCD TV from 2017

I will report the results later on..