Doom9's Forum - View Single Post - Compression of black bars in AVC, does it take a lot of space?

Sagekilla · 18th October 2009, 23:48

If you're using crf mode, the fact that the encode with black bars came out is normal and expected. Black bars = very flat, easy to encode. Because of how much space they take up in the frame, they decrease the overall complexity of the scene and x264 lowers the quantizer used for the frames. That's why you get a larger file size.

Otherwise, if you encoded using identical bitrates (using 2-pass, for example), there should be little to no difference since black bars consume VERY few bits.

18th October 2009, 23:48	#4 \| Link
Sagekilla x264aholic Join Date: Jul 2007 Location: New York Posts: 1,752	If you're using crf mode, the fact that the encode with black bars came out is normal and expected. Black bars = very flat, easy to encode. Because of how much space they take up in the frame, they decrease the overall complexity of the scene and x264 lowers the quantizer used for the frames. That's why you get a larger file size. Otherwise, if you encoded using identical bitrates (using 2-pass, for example), there should be little to no difference since black bars consume VERY few bits. __________________ You can't call your encoding speed slow until you start measuring in seconds per frame.