Cropping

Video codecs perform best when the frame width and height use multiples of 16. While you can use any width and height in your encoding settings, non-optimal dimensions can result in poor image quality and reduced frame rate. For the best image quality and playback, you should always use width and height dimensions that use a multiple of 16 (best), 8 (better), or 4 (good). We would recommend that you refrain from using 4 or 8 multiples unless it is absolutely necessary. 

Note: Both the native encoding dimensions and the playback dimensions should be a multiple of 16. For example, if you encode your FLV file to use a frame dimension of 320 x 240, you should scale to a size such as 512 x 384. 

Refer to the following tables to pick dimensions for your layout.

4:3 aspect ratio sizes: Best (16) Better (8) Good (4) 640 x 480 608 x 456 624 x 468 576 x 432 544 x 408 592 x 444 512 x 384 480 x 360 560 x 420 448 x 336 416 x 312 528 x 396 384 x 288 352 x 264 496 x 372 320 x 240 288 x 216 464 x 348 256 x 192 224 x 168 432 x 324 192 x 144 160 x 120 400 x 300 128 x 96   368 x 276     336 x 252     304 x 228     272 x 204     240 x 180     208 x 156     176 x 132     144 x 108     112 x 84

16:9 aspect ratio sizes: Best (16) Better (8) Good (4) 1280 x 720 1152 x 648 1216 x 684 1024 x 576 896 x 504 1088 x 612 768 x 432 640 x 360 960 x 540 512 x 288 384 x 216 832 x 468 256 x 144 128 x 72 704 x 396     576 x 324     448 x 252     320 x 180     192 x 108

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To crop, you simple specify how many pixels will be cut from each side (left, top, right, bottom) of the original frame size. Once cropped, the resulting frame size will be resized and centered to fit output size (if necessary), as usual. Example: the source file size is 704x576, and we want to crop 10 pixels from each size. Just set 10 for top, left, right and bottom. So, after cropping the frame size is 684x556. Assume we set the result size to 640x480. Then, the frame will be resized to 590x480 and 25-pixels pads will be added to the left and to the right of the frame. <-- Hide