AV_PIX_FMT_GRAYF32BE,///< IEEE-754 single precision Y, 32bpp, big-endian
AV_PIX_FMT_GRAYF32LE,///< IEEE-754 single precision Y, 32bpp, little-endian
AV_PIX_FMT_NB///< number of pixel formats, DO NOT USE THIS if you want to link with shared libav* because the number of formats might differ between versions