Ranking system
- 5. Hard/Unable to find any difference at 2X, ie: Perfect.
- 4. Differences are visible at 1X, but not too visible when watching the movie.
- 3. Defects visible when watching the movie, not too annoying.
- 2. Defects are annoying when watching.
- 1. Defects are overwhelming: Disturbs the viewing.
Overall results
| Frame # | Frame | 500kbps | 750kbps | 1000kbps | 1500kbps | 2000kbps | 3000kbps | 4000kbps |
|---|---|---|---|---|---|---|---|---|
| 19617 |  |
1 | 1 | 2 | 2 | 3 | 4 | 4 |
| 20237 |  |
3 | 3 | 3 | 4 | 4 | 4 | 4 |
| 22016 |  |
3 | 3 | 4 | 4 | 5 | 5 | 5 |
| 36120 |  |
2 | 3 | 4 | 4 | 5 | 5 | 5 |
| 50815 |  |
3 | 3 | 4 | 4 | 5 | 5 | 5 |
| 119047 |  |
2 | 3 | 4 | 5 | 5 | 4 | 4 |
| 126847 |  |
5 | 5 | 5 | 5 | 5 | 5 | 5 |
| Filesize (KB): | 714,008 | 864,958 | 1,016,722 | 1,104,406 | 1,472,690 | 2,239,160 | 2,850,628 | |
| Computed bitrate (kbps): | 946 | 1146 | 1348 | 1464 | 1952 | 2969 | 3780 | |
| Total: | 19/35 | 21/35 | 26/35 | 29/35 | 32/35 | 32/35 | 32/35 | |
Conclusion
To summarize this DVD backup review:
- XviD is like DivX: A frame with lots of small very contrasted details will look awesome whatever the bitrate. However a smooth shade between two colors will not look perfect even at 4000kbps. I am wondering if the bit allocation mechanism (the factor by which the codec judge the quality of a frame) if very useful here. Maybe a new algorithm should be chosen. It is weird (to say the least) that the same target bitrate generates stuff nearly perfect and stuff barely watchable...
- Above 1500kbps, increasing the bitrate did not change anything! I certainly didn't foresee such a strange result... Where are all these bits going? 1500kbps is even better looking than 4000kbps on some frames !!!!
- It would seem that XviD takes some liberty when it comes to bitrate target... That is the least one can say (although to be fair I got a warning when encoding the 500kbps file)
- I will keep my usual bitrate of 1250kbps unchanged for now.
What's Next?
Just come over and talk about what you want to see next in the forum! DivX, XviD, TMPGEnc and DVDShrink have already been tested to some extent on this site, but it is only the beginning. Let me know what you want to see next in the forum.