Task: Text to Code
Input (English): SQL: SELECT Avg ( T1.duration ) FROM files AS T1 JOIN song AS T2 ON T1.f_id = T2.f_id WHERE T2.resolution < 800
Feedback: ( And)It should also satisfy one more condition in step 2 where formats equals mp 3.
Output (English): SELECT avg(T1.duration) FROM files AS T1 JOIN song AS T2 ON T1.f_id  =  T2.f_id WHERE T1.formats  =  "mp3" AND T2.resolution   <  800