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)
The only online resolution calculator that generates a list of possible combinations based on a fixed ratio. (May have seen another some time ago but is lost in the search results now)
Handy tool, kudos.