Revise transcode_aac example and various updates
#395
| Job | Run time |
|---|---|
| 28m 41s | |
| 14s | |
| 49s | |
| 6m 3s | |
| 5m 42s | |
| 1m 10s | |
| 6s | |
| 5m 58s | |
| 5m 6s | |
| 1h 3m 39s | |
| 6m 11s | |
| 5m 47s | |
| 2m 4s | |
| 2m 13s | |
| 2h 13m 43s |