@clement5

Hi

. . . . test file 1 is from a DVD which has been detelecined.  The aspect ratio is 4:3 . . . .

Assuming you are referring to the first video IVTC 1, the video on playback looks like the AR is 3:2, MediaInfo confirms this.

and in a 4:3 project you can see the letterboxing - I added the yellow background to differentiate the video from the actual screen AR.

Most of the problems, you are having are a result of this mismatch

Other points:

• . . . .  23976/1000 frame rate NOT 24000/1001 . . . .
  
  They are the same - note the different divisor.
   
• Item 4a - 23.976 fps is not supported in MMS for export, nor can it be set - NTSC by definition is 29.97 fps for colour TV, originally it was 30 fps for b/w TV.

John EB
Forum Moderator

@browj2

Hi john.

Before going into this any deeper, NTSC is 29.97, not 23.97.

Not for video taken for NTSC broadcast of old films that were to be seen on a colour TV set with no artifacts. Then the 24fps was made to become 23.976 fps to insert the colour signal and broadcast at the correct time length. At least as far as I understand it.

If I look up that frame rate on the net I get this.

23.976p. Some 24p productions, especially those made only for NTSC TV and video distribution (e.g., in Canada or the USA), actually have a frame rate of 24000 ÷ 1001, or 23. 976023 frames per second. Many use the term "24p" as a shorthand for this frame rate, since "23.976" does not roll off the tongue as easily.

So I guess these files are either from DVD or Blu-ray rips.

Ray.

The original file 1 is from a DVD which is most probably from a TV broadcast recorded on tape. It has been processed by Virtual Dub filters to remove a lot of the jitter, noise, and spots. There was much frame by frame processing and the final assembled from various processed segments using Movie studio 2023. Now 2024 works differently. I had ouput 2 minute avi segments for frame by frame processing because my version of Photoshop extended cannot handly anything longer. Yes, I looked up the current US standards which bless 24000/1001 frame rate. I have not checked to see if MS 2024 handles 30000/1001 old standard NTSC created for the early color era. VirtualDub handles 24000/1001 frame rate properly. One would think that 24976/1000 frame rate would line up properly in MS 2004, but it doesn't, so they have some really bad code, and this problem has been around through several iterations of the program, but it is now worse. All other codecs line up and have correct frame rate. The use of AVI is so that there is no loss in quality due successive iterations of processing from previous outputs.

In regards to the letterboxing. ---IVTC 1 is the original file which includes a black border of unknown origin. Early movies on TV were poorly broadcast with bad framing, usually cutting off parts of the scenes. This one looks like including more than the actual frame. This sloppiness seemed to continue for decades after the early B&W era. One station even continued to run the film during the commercials so when it came back you had no idea what had happened during the commercial. ...IVTC 2 has exactly the same black border, but the other outputs have letterboxing. There is an option to set the aspect ratio of the input file and I verified it was set to 4:3, the output aspect ratio was also set to 4:3 so there should have been no letterboxing. Yes I am a physicist as well as computer programmer and know how to calculate 23.976 from either of the ratios. Of course there are extra digits after the 6 for 24000/1001. Both of these ratios are close enough that the 2 videos should line up perfectly for a 1 hour movie, but not for longer ones. The 9 second mismatch at the end should not happen. AVI does not have an aspect ratio spec. so it has to be set by the program.

@clement5

The imported file does not have the correct displayed aspect ratio.  This is a new error in 2023/2024 versions of MS.  Since an AVI does not have aspect ratio information MS should assume the same aspect ratio as the movie project NOT the aspect ratio from the fame size.  If I right click on the track and look at the object properties it shows aspect ratio 4:3.  Since file 2 is not letterboxed using a display program, this may be problem with the display which was not in the 2023 version.

I can confirm this. With an AVI that doesn't have ratio information eg an analogue capture or an AVI from Virtual Dub, Movie Studio 2023 and 2024 do not import it "correctly". That is, the project ratio is not applied to it so that it remains at 720x576 5:4 (or, I assume, 720x480 3:2) aka square pixels.

Worse, when 4:3 or 5:4 (for PAL) is video properties is chosen, nothing changes.

MEP 2021 does not exhibit this error: importing one of these files results in the correct 4:3 ratio being displayed in the monitor.

While the videos can be manually stretched with SPR, as soon as the Section effect is applied, the stretch is ignored and the video becomes a mess.

For this reason, I have to import any AVI at the square-pixel shape for the video: 768x576 for PAL, 720x540 for NTSC.

This issue basically prevents use of analogue AVIs in the Magix editors.

I'll soon be making up a bug report.

Incidentally US Blu-Ray movies use 24000/1001 frame rate, but PAL areas use 24000/1000.

According to what I have read the AVI standard does not include an aspect ratio field however other containers or codecs do have embedded aspect ratio. MS assumed 4:3 and dutifully created a copy of the original with the same frames, but obviously duplicates of some which stretched it 9 seconds more. However, for other codecs it letterboxed the frames while preserving the original 24000/1001 frame rate. None of these are correct results. Curiously it even created output with the correct frame rate for other codecs in an AVI container. I used the default AVI output because it was the only lossless one that worked properly. I used to use Lagarith, but MS broke it. Maybe I should try it again.

I submitted a support request on Jan 15 and got a support ticket number, but have not heard back. The problem with AVI has been long standing through a number of different versions, so I think they don't know how to fix it. As a result I have gone back to the 2023 version which at least handled aspect ratio correctly, but not the frame rate correctly.

As to the frame rate 24000/1001, this is the same rate used on every US Blu-Ray from a movie I have in my possession, so it is a commonly used standard. To find out the actual frame rate you need a specialized program as it is normally quoted as 23.976 which could be either 24000/1001 or 23976/1000 and should not be a problem with a short video.

They still haven't fixed the AVI export in the 2025 version. When the frame rate 23.976 (24000/1001) standard NTSC, the AVI output is 23976/1000 and the time is shortened so that the audio and video get out of sync. It is possible to use VirtualDub by selecting output FPS 23.976 with no audio resync and use all frames to create a new AVI file which is correct. Since the AVI container does not support aspect ratio, the 4:3 export from a 720:480 file is squashed with black bars on top and bottom. This happens for both AVI and MP4 export. The workaround is to select 3:2 aspect ratio, but then the MP4 file has the wrong display aspect ratio.

Curiously both VirtualDub and MS agree as to the incorrect time for the video with the wrong FPS. This is curious because 23976/1000 is so close to 24000/1001 that there should be no difference in total time for a movie a couple of hours long.

Lossless compression is only possible with AVI export. This is desirable if multiple stages of editing are necessary, especially when different editing programs are needed.

@clement5

Hi

. . . . This is curious because 23976/1000 is so close to 24000/1001 that there should be no difference in total time for a movie a couple of hours long . . . .

The difference would appear to be 'insignicant', however, for every hour of the video run time you are losing approx 86 frames, approx 3.6 secs per hour, which is more than sufficient to throw audio out of sync.

Are the test videos you posted back in in January still avaialble, I have had a look and the Test1 and 2 video files appear to be empty, I also see that all files appear to have been modified within the last 24 hours.

John EB

I have created a new set of test videos, and they are very slooooow uploading! Try again later.

I did the calculations as (24000/1001 - 23.976)x3600 and got 0.086 frames difference, so it is strange that either frame rate would make a difference. since there are 60 s/min and 60 min/hr there are 2300 s/hr. 24000/1000=23.976 so subtracting it from 24000/1000 gives the number of extra frames/sec. The image of the end of the video with the Test videos lined up shows just a handful of frames difference. So I think that they have a roundoff error somewhere. The end of the the video for Test 2 is 6 frames from the end of test 1. I have tried various numbers and have not come up with a 6 frame difference. Mediainfo doesn't show fractions of seconds but it shows a different video time for Test 1 and Test 2. I wonder if Magix and VirtualDub are using the same library function that is misbehaving. VirtualDub2 has no current developer, and one wonders if Magix has a good developer. Magix is a German firm so they are probably tending to ignore the American standards for video.

As of this post Test 1.AVI is now available.

I just had the thought that the math error between the two frame rates can easily generate a 5 frame difference if there is a roundoff in the binary frame rate.

@clement5

Hi

My apologies, for some unknown reason I ended up comparing 24 fps to 24000/1001.

Thanks for the video update.

John EB