Stuff

(from libavcodec/mpeg12data.h)

const AVRational ff_frame_rate_tab[] = {
    {    0,    0},
    {24000, 1001},
    {   24,    1},
    {   25,    1},
    {30000, 1001},
    {   30,    1},
    {   50,    1},
    {60000, 1001},
    {   60,    1},
  // Xing's 15fps: (9)
    {   15,    1},
  // libmpeg3's "Unofficial economy rates": (10-13)
    {    5,    1},
    {   10,    1},
    {   12,    1},
    {   15,    1},
    {    0,    0},
};