Interesting issue w/ EE4-encoded assets and bitrate aspect ratios

Jul 23, 2011 at 2:05 PM

Troubleshooting an interesting issue we have seen for a while now with assets encoded through Expression Encoder 4.

If you look at this video: http://play.nimbushd.com/lfm9 ... you will notice that when the player starts (at lowest bitrate), there is a black area on top and bottom that the video doesn't fill. As bitrates change, the video will change sizes slightly to fill the frame as expected. This creates a highly noticeable bitrate change that doesn't look good.

We only see this occuring on EE4-encoded videos; other encoders do not produce the same effect (see, for example: http://play.nimbushd.com/lfv518d )

Question is: anybody know of anything already built in to the player framework to compensate and hold size, or anyone figured out why EE4 does this?

Coordinator
Jul 23, 2011 at 4:51 PM

I'm not sure if this is the cause or not, but check the aspect ratio for all your video tracks to make sure they are the same. You can do this by looking at the manifest xml (http://cdn03.x9tech.com/Media/1/33/356/bigbuckbunny1080ph264.ism) and comparing width/height for each track.

Tim

Jul 23, 2011 at 6:04 PM

Yes, the aspect ratios are definitely different (the player is doing what it is told), from largest bitrate to smallest:

1.78
1.78
1.78
1.78
1.78
1.77
1.78
1.81

Any way to tell the player to just stretch it? I think I know the cause (the EE4 SDK calculates aspect ratios a little weird, and when you set height/width yourself, it throws an invalid size for anything over really small sizes - 320x240 or something close to it), but that's one to take up with the EE team...

1.78
1.78
1.78
1.78
1.78
1.77
1.78
1.81