Video streaming issues are notoriously hard to diagnose and resolve. Aside from the streaming speed, there are possibly transcoding issues at the source or target device due to resolution, format (Container, Codec, NTSC/PAL, etc.), caching and video buffering, decoding video, and then sometimes problems just seem to be compatibility issues.
The MPW can stream in two ways as well; Just stream files as any hard disk would, or stream media using the MPW Media Server, which is a DLNA Server.
If you are just streaming files, which means you are just treating the MPW as a dumb hard disk, theoretically only the transfer speed from the MPW to the target device and the caching occuring will effect whether playback is smooth or not. Well, from the perspective of the MPW anyway. There are still all the target device issues as well. If you are using this method:
1. The first thing I would try is to turn off "Streaming (DLNA)" in the My Cloud App [swipe left on your MyPassport, tap Gear to get to Settings, tap More, tap Media, turn off Streaming (DLNA). With that off, you know you, and any Apps you use, can only use simple file streaming.
2. Now tap the Menu icon (top left of screen in home page), tap Settings, and check the Cache Size setting. That is the cache size the My Cloud App uses. I have it set to 2GB.
3. Now go back to you My Passport file tree, tap into "Sample Media" if you still have it, tap into videos, and play the videos. How did they go? Any pauses?
I tested this on my old iPhone 4 16GB. On first play I can see the video buffer stays ahead of the play position, and the whole video plays without pauses. I can pause the video and restart it, and the video still plays normally. However, if I play the same video again after it is finished, I can see that the My Cloud App can’t keep the video buffer as far ahead of the play position, which eventually catches up, and I get a long pause of the video while it reads or decodes more of the file. These pauses continue to the end of the video. I get mulitple pauses.
My tentative conclusion there is that the caching in the My Cloud App on my iPhone 4 isn’t as good as it should be, but the speed of transfer is fine for playing those videos. Increasing the cache to 4GB and then 8GB did help a little bit, but I still got pauses when replaying those short videos 50% of the time. On replay I could see the video buffer, or the download bar for the video, just stopped loading most times that I replayed the video, even though it had loaded properly on the first play. I have no idea why it does that. It could be my iPhone 4, iOS, or it could be the App. It could be that the cache isn’t feeding the file to the video decoder, or the the decoder itself is pausing for some unrelated reason. The caching of the My Cloud App on your devices may be fine though.
By the way, if you are wondering how a 60MB or so video file can fill a 2, 4, or 8GB cache, it is possible that the cache is storing uncompressed video rather than the original encoded video file. Uncompressed video files are very large compared to their source files. But if the cache is storing uncompressed video, then on replay of the video the video buffer should fill instantly. Unless there is something wrong with the caching.
If you do the above test and see the same results, you either need to always watch a video from the start and watch it completely through, which probably isn’t practical, or you need to find an App that handles caching and/or video decoding much better. As you have Android device I can’t advise on that, but when you test Apps, look for cache settings and test playback as above
4. If the above test shows that the video buffer never fills enough to prevent video pauses, then maybe your transfer speed is too slow. If you have or can find an App that checks the speed of a file copy from the MPW to your devices, and that speed is fast enough to play the video, then you will need to look further at the decoder you are using. In other words, try more players, or try to find out what your devices are capable of playing smoothly. A simple test to see if your devices are capable of playing the videos would be to copy the files to your device, and play them from there. You could use the My Cloud "Download" capability to test that.
Hint: If you get a copy of MediaInfo https://sourceforge.net/projects/mediainfo/ and look at the average and peak Bitrates of your video, that is the minimum transfer rate required to play the video without pauses.
All of the above probably hasn’t helped a lot, as it still leaves question about which part of the process is stalling the video. Well, I said video streaming issues were notoriously hard to diagnose and resolve. However there is a whole other section to cover.
If you turn on the “Streaming (DLNA)” in the My Cloud App you then have a DLNA Media Server to work with. Then you need an App that is both a DLNA Controller and DLNA Renderer. I’m not going into details of that, but using DLNA may help with all of the above potential problems, as long as your device hardware and operating system is capable of playing the videos. But DLNA can also make things worse sometimes than simply streaming a file.