int slice_count
number of slices in the current picture
unsigned mb_width
width of the current picture in mb
int frame_type
0 = progressive, 1 = tff, 2 = bff
static void unpack_alpha(GetBitContext *gb, uint16_t *dst, int num_coeffs, const int num_bits, const int decode_precision)
unsigned mb_height
height of the current picture in mb