return v4l2_fwht_pixfmts + idx;
 }
 
-unsigned int v4l2_fwht_encode(struct v4l2_fwht_state *state,
-                             u8 *p_in, u8 *p_out)
+int v4l2_fwht_encode(struct v4l2_fwht_state *state, u8 *p_in, u8 *p_out)
 {
        unsigned int size = state->width * state->height;
        const struct v4l2_fwht_pixfmt_info *info = state->info;
        u32 encoding;
        u32 flags = 0;
 
+       if (!info)
+               return -EINVAL;
        rf.width = state->width;
        rf.height = state->height;
        rf.luma = p_in;
                rf.cr = rf.cb + 2;
                rf.luma++;
                break;
+       default:
+               return -EINVAL;
        }
 
        cf.width = state->width;
        return cf.size + sizeof(*p_hdr);
 }
 
-int v4l2_fwht_decode(struct v4l2_fwht_state *state,
-                    u8 *p_in, u8 *p_out)
+int v4l2_fwht_decode(struct v4l2_fwht_state *state, u8 *p_in, u8 *p_out)
 {
        unsigned int size = state->width * state->height;
        unsigned int chroma_size = size;
        struct fwht_cframe cf;
        u8 *p;
 
+       if (!state->info)
+               return -EINVAL;
+
        p_hdr = (struct fwht_cframe_hdr *)p_in;
        cf.width = ntohl(p_hdr->width);
        cf.height = ntohl(p_hdr->height);
                        *p++ = 0;
                }
                break;
+       default:
+               return -EINVAL;
        }
        return 0;
 }
 
 const struct v4l2_fwht_pixfmt_info *v4l2_fwht_find_pixfmt(u32 pixelformat);
 const struct v4l2_fwht_pixfmt_info *v4l2_fwht_get_pixfmt(u32 idx);
 
-unsigned int v4l2_fwht_encode(struct v4l2_fwht_state *state,
-                             u8 *p_in, u8 *p_out);
-
-int v4l2_fwht_decode(struct v4l2_fwht_state *state,
-                    u8 *p_in, u8 *p_out);
+int v4l2_fwht_encode(struct v4l2_fwht_state *state, u8 *p_in, u8 *p_out);
+int v4l2_fwht_decode(struct v4l2_fwht_state *state, u8 *p_in, u8 *p_out);
 
 #endif