+// FRAME_SIZE is the default frame size, in bytes. FFmpeg inputs (video files and SRT streams)
+// can allocate larger frames as needed; USB and DeckLink outputs always use FRAME_SIZE.
+// We should eventually add support for at least DeckLink outputs, allowing us to capture
+// 2160p frames. Also, it would allow us to lower the default frame size to the maximum
+// bmusb supports (2 MB just about covers 1080i 4:2:2, then add some for 10-bit?) to waste
+// less memory.
+//
+// As a general sanity check, we also have a MAX_FRAME_SIZE that even dynamic allocation
+// will not go past.
+#define FRAME_SIZE (8 << 20) // 8 MB (just enough for 1080p RGBA).
+#define MAX_FRAME_SIZE (140 << 20) // 140 MB; enough for 8192*4320 RGBA and then some.
+