Generated PSS file will freeze during playback when using NTSC video

[MarkusMaal]

If you try to generate a .PSS file from a .INT and .IPU with NTSC mode (i.e. 59.94fps or 29.97fps), it'll eventually freeze during playback.

Steps to reproduce:

1. Split your video into audio/video
2. Convert audio into RAW - Compressed Sony ADPCM (16 bits, interleave 0x400)
3. Convert video to PlayStation 2 friendly format (FFmpeg command: ffmpeg -i <source video> -c:v mpeg2video -profile:v main -level:v 8 -b:v 4.531M -maxrate 5M -minrate 4.531M -bufsize 1835k -pix_fmt yuv420p -g 1 -bf 0 -flags +ildct+ilme -top 1 -r 29.94 -s 512x448 <output video>)
4. Convert the created M2V file to IPU (IPU conversion tab in ps2strw)
5. You may need to manually patch the generated IPU to add correct header (69 70 75 6D <file size as u32 excluding last 8 bytes you'll add> <video width as u16> <video height as u16> <frame count as u32>) and append these bytes to the end: 00 00 01 B0 00 00 01 B1 (frame delimiter and end code)
6. Combine IPU and INT using FlipnicFileTools CLI: FlipnicFileTool --generate-pss <INT file> --input <IPU file> --output <PSS file>
7. Add the generated video to TUTO.BIN: FlipnicFileTool --replace-file CHAP01.PSS --input <PSS file> --output TUTO.BIN
8. Add the modified TUTO.BIN to a game ISO: FlipnicFileTool --replace-iso TUTO.BIN --input TUTO.BIN --output <ISO file>
9. Launch the game and go to HELP/EXPLAIN menu and play the first chapter
10. You'll now see the video you've inserted. It'll play back successfully until a certain point where it freezes

Testing done so far:

• Tried adding bad apple mv to NTSC-J version of the game, various attempted fixes are documented in the code