Some devices (like older Apple TVs) may require the NAS to transcode MP4 files if the audio codec (like 6-channel AC3) isn't supported.

was never natively designed to be a powerhouse media player, but the homebrew community found ways to make it the "ultimate media player" of the mid-2000s.

For the best compatibility across mobile and TV apps, many users recommend converting files to an MP4 container with 2-channel AAC audio using tools like Handbrake. Community Experiences

If you are looking for information regarding the app, the focus is usually on streaming performance and compatibility:

—I have also included a brief section on Synology troubleshooting below. 🎥 Watching Movies on a Nintendo DS Nintendo DS

While I am focusing on the most likely intent—the nostalgic and technical hobby of getting video to run on a Nintendo DS Go to product viewer dialog for this item.

Users often compare DS Video to Plex, noting that Plex sometimes offers smoother playback for high-resolution files.