This is a simple overview and a list of different aspect ratios that are 16:9, and some notes on encoding them with H.264.
H.264
The best results for H.264 encoding comes from using 16×16 blocks. This should allow the encoder to do a much better task at encoding. However, you don’t need to. Since you are starting out with a 16:9 resolution (likely 1920×1080 or 1280×720 (ie: 1080p and 720p)), there are not many which provide a width which is divisible by 16.
For my tests, I didn’t actually take this into account, and simply used my original HDV resolution (1440×1080 really, but I wanted to convert it to square pixels) .
In addition, I’ve found very few good encoders for H.264 which are, to me, easy to use. The one I have been using is StaxRip, since it has an excellent walkthrough from start to finish, although contains some issues; it can’t do anamorphic video, which HDV uses. Instead, square pixels are the name of the game. Also, when creating a queue (as internet video is prone to be in at least low and high quality) it sometimes goes odd. The audio encoding part of it also seems a bit unwieldy with very little information being available to change the AAC audio encoding. But it works fine still!
Recommended resolutions
If you are not cropping a 1920×1080 image, then the maximum resolution you’d really want to put on the internet is around 50% of the original, being 960×540. For medium (and very acceptable) size, I chose to half it again to 480×270. Then, for a tiny size, half again is 256×144.
Out of these, only 256×144 is able to make full use of H.264’s 16×16 encoding, but this didn’t worry me. To get the best encoding however, choosing a suitable scale from the tables below with both height and width in italics would be a good idea – then using around half, and around a quarter sizes of this initial resolution to produce lower quality versions.
For a better quality “High” – perhaps for release onto TV sets – scaling down 1920×1080 to 1280×720 (which is 66.67% of the size) is a good idea, and is also able to take advantage of 16×16 encoding. This is 720p scale.
For other resolutions then 16:9, try the aspect ratio calculator to find them.
1920×1080 resolutions
To find a perfect lower resolution here is a list of them. The bolded entries are ones in roughly 10% steps of the original size (so 90%, 80% etc. of the original size). The Italic numbers are divisible by 16, which of course means all the heights are.
Width | Height | % of original |
---|---|---|
16 | 9 | 0.83 |
32 | 18 | 1.67 |
48 | 27 | 2.5 |
64 | 36 | 3.33 |
80 | 45 | 4.17 |
96 | 54 | 5 |
112 | 63 | 5.83 |
128 | 72 | 6.67 |
144 | 81 | 7.5 |
160 | 90 | 8.33 |
176 | 99 | 9.17 |
192 | 108 | 10 |
208 | 117 | 10.83 |
224 | 126 | 11.67 |
240 | 135 | 12.5 |
256 | 144 | 13.33 |
272 | 153 | 14.17 |
288 | 162 | 15 |
304 | 171 | 15.83 |
320 | 180 | 16.67 |
336 | 189 | 17.5 |
352 | 198 | 18.33 |
368 | 207 | 19.17 |
384 | 216 | 20 |
400 | 225 | 20.83 |
416 | 234 | 21.67 |
432 | 243 | 22.5 |
448 | 252 | 23.33 |
464 | 261 | 24.17 |
480 | 270 | 25 |
496 | 279 | 25.83 |
512 | 288 | 26.67 |
528 | 297 | 27.5 |
544 | 306 | 28.33 |
560 | 315 | 29.17 |
576 | 324 | 30 |
592 | 333 | 30.83 |
608 | 342 | 31.67 |
624 | 351 | 32.5 |
640 | 360 | 33.33 |
656 | 369 | 34.17 |
672 | 378 | 35 |
688 | 387 | 35.83 |
704 | 396 | 36.67 |
720 | 405 | 37.5 |
736 | 414 | 38.33 |
752 | 423 | 39.17 |
768 | 432 | 40 |
784 | 441 | 40.83 |
800 | 450 | 41.67 |
816 | 459 | 42.5 |
832 | 468 | 43.33 |
848 | 477 | 44.17 |
864 | 486 | 45 |
880 | 495 | 45.83 |
896 | 504 | 46.67 |
912 | 513 | 47.5 |
928 | 522 | 48.33 |
944 | 531 | 49.17 |
960 | 540 | 50 |
976 | 549 | 50.83 |
992 | 558 | 51.67 |
1008 | 567 | 52.5 |
1024 | 576 | 53.33 |
1040 | 585 | 54.17 |
1056 | 594 | 55 |
1072 | 603 | 55.83 |
1088 | 612 | 56.67 |
1104 | 621 | 57.5 |
1120 | 630 | 58.33 |
1136 | 639 | 59.17 |
1152 | 648 | 60 |
1168 | 657 | 60.83 |
1184 | 666 | 61.67 |
1200 | 675 | 62.5 |
1216 | 684 | 63.33 |
1232 | 693 | 64.17 |
1248 | 702 | 65 |
1264 | 711 | 65.83 |
1280 | 720 | 66.67 |
1296 | 729 | 67.5 |
1312 | 738 | 68.33 |
1328 | 747 | 69.17 |
1344 | 756 | 70 |
1360 | 765 | 70.83 |
1376 | 774 | 71.67 |
1392 | 783 | 72.5 |
1408 | 792 | 73.33 |
1424 | 801 | 74.17 |
1440 | 810 | 75 |
1456 | 819 | 75.83 |
1472 | 828 | 76.67 |
1488 | 837 | 77.5 |
1504 | 846 | 78.33 |
1520 | 855 | 79.17 |
1536 | 864 | 80 |
1552 | 873 | 80.83 |
1568 | 882 | 81.67 |
1584 | 891 | 82.5 |
1600 | 900 | 83.33 |
1616 | 909 | 84.17 |
1632 | 918 | 85 |
1648 | 927 | 85.83 |
1664 | 936 | 86.67 |
1680 | 945 | 87.5 |
1696 | 954 | 88.33 |
1712 | 963 | 89.17 |
1728 | 972 | 90 |
1744 | 981 | 90.83 |
1760 | 990 | 91.67 |
1776 | 999 | 92.5 |
1792 | 1008 | 93.33 |
1808 | 1017 | 94.17 |
1824 | 1026 | 95 |
1840 | 1035 | 95.83 |
1856 | 1044 | 96.67 |
1872 | 1053 | 97.5 |
1888 | 1062 | 98.33 |
1904 | 1071 | 99.17 |
1920 | 1080 | 100 |
1280×720 resolutions
And here is 1280×720 resolutions, with the same key:
Width | Height | % of original |
---|---|---|
16 | 9 | 1.25 |
32 | 18 | 2.5 |
48 | 27 | 3.75 |
64 | 36 | 5 |
80 | 45 | 6.25 |
96 | 54 | 7.5 |
112 | 63 | 8.75 |
128 | 72 | 10 |
144 | 81 | 11.25 |
160 | 90 | 12.5 |
176 | 99 | 13.75 |
192 | 108 | 15 |
208 | 117 | 16.25 |
224 | 126 | 17.5 |
240 | 135 | 18.75 |
256 | 144 | 20 |
272 | 153 | 21.25 |
288 | 162 | 22.5 |
304 | 171 | 23.75 |
320 | 180 | 25 |
336 | 189 | 26.25 |
352 | 198 | 27.5 |
368 | 207 | 28.75 |
384 | 216 | 30 |
400 | 225 | 31.25 |
416 | 234 | 32.5 |
432 | 243 | 33.75 |
448 | 252 | 35 |
464 | 261 | 36.25 |
480 | 270 | 37.5 |
496 | 279 | 38.75 |
512 | 288 | 40 |
528 | 297 | 41.25 |
544 | 306 | 42.5 |
560 | 315 | 43.75 |
576 | 324 | 45 |
592 | 333 | 46.25 |
608 | 342 | 47.5 |
624 | 351 | 48.75 |
640 | 360 | 50 |
656 | 369 | 51.25 |
672 | 378 | 52.5 |
688 | 387 | 53.75 |
704 | 396 | 55 |
720 | 405 | 56.25 |
736 | 414 | 57.5 |
752 | 423 | 58.75 |
768 | 432 | 60 |
784 | 441 | 61.25 |
800 | 450 | 62.5 |
816 | 459 | 63.75 |
832 | 468 | 65 |
848 | 477 | 66.25 |
864 | 486 | 67.5 |
880 | 495 | 68.75 |
896 | 504 | 70 |
912 | 513 | 71.25 |
928 | 522 | 72.5 |
944 | 531 | 73.75 |
960 | 540 | 75 |
976 | 549 | 76.25 |
992 | 558 | 77.5 |
1008 | 567 | 78.75 |
1024 | 576 | 80 |
1040 | 585 | 81.25 |
1056 | 594 | 82.5 |
1072 | 603 | 83.75 |
1088 | 612 | 85 |
1104 | 621 | 86.25 |
1120 | 630 | 87.5 |
1136 | 639 | 88.75 |
1152 | 648 | 90 |
1168 | 657 | 91.25 |
1184 | 666 | 92.5 |
1200 | 675 | 93.75 |
1216 | 684 | 95 |
1232 | 693 | 96.25 |
1248 | 702 | 97.5 |
1264 | 711 | 98.75 |
1280 | 720 | 100 |
Other resolutions
You can calculate whatever resolutions you like on my aspect ratio calculator.
I have to drop a line to say thank-you! for this table, I for one appreciate it, and will find it extremely useful in the coming uni semester while gunning to finish my major work for my MDM (digital media)