Add support for non standard resolutions

[arturjpv]

When using recordings from mobile phones with vertical aspect ratios, the dimensions of the video can be encoded in a non standard resolution, adding additional information in a SAR / DAR section.

For example:

Stream #0:0[0x1](und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 1080x720 [SAR 3:8 DAR 9:16], 1743 kb/s, 29.92 fps, 29.92 tbr, 90k tbn (default)

or with rotation information

Stream #0:2[0x3](eng): Video: hevc (Main) (hvc1 / 0x31637668), yuvj420p(pc, bt709), 1920x1080, 20286 kb/s, SAR 1:1 DAR 16:9, 29.99 fps, 30 tbr, 90k tbn (default)
...
  displaymatrix: rotation of -90.00 degrees

Use SAR information to calculate the size of the output images. In the first example, 1080x1920.
Swap width and height if we find rotation information of -90 or 90 degrees.

The testing of this code has not been exhaustive, I have only tested it with vertical/horizontal recordings of a couple of Android phones, but videos with no SAR/DAR information encoded should not be affected.