Mpeg Mode 2 pass (turbo)

Source video

The first video was filmed in 2.35:1 scope, therefore the DVD video contains horizontal black bars. Because of that, the video compress better and requires a lower video bit rate. The second video instead has a higher video bit rate requirement.

DVD (720x576)

Video 1
-encode
B frames
-vbr
size (MB)
job time PSNR note
0:1:2
0/1/2
7500
4675/3888/3633
2h54m/2h54m/2h49m
47.44/47.16/46.96
very fast
0:2:2 0/1/2
7500 4596/3812/3562
3h38m/4h3m/4h13m
47.60/47.26/47.03
fast, turbo
0:3:2 0/1/2
7500 4118/3424/3200
5h42m/5h41m/5h51m
48.04/47.29/46.92
high compression, turbo
0:4:2 0/1/2
7500 4633/3844/3590
6h28m/8h0m/8h19m
47.70/47.16/46.85
high PSNR, turbo

Video 2
-encode
B frames
-vbr
size (MB)
job time PSNR note
0:1:2
0/1/2
9000
4748/4129/3809
2h33m/2h38m/2h37m
46.97/46.30/46.21
very fast
0:2:2 0/1/2
9000 4696/4064/3745
3h11m/3h42m/3h54m
47.01/46.33/46.22
fast, turbo
0:3:2 0/1/2
9000 4289/3788/3484
5h23m/5h31m/5h42m
46.82/46.17/46.06
high compression, turbo
0:4:2 0/1/2
9000 4711/4080/3760
6h3m/7h51m/8h25m
47.19/46.30/46.07
high PSNR, turbo

When the video bit rate is high (like for dvd), you can assume that:
-encode n:1:1 is very fast
-encode n:2:1 is fast and has a good PSNR
-encode n:3:1 compress better and may have a good PSNR too
-encode n:4:1 has good PSNR
For m = 1, 2 and 4, 2 pass encoding produces a smaller file and a lower PSNR than 1 pass encoding.
For m = 3, 2 pass encoding produces a bigger file and a higher PSNR than 1 pass encoding.

SVCD (480x576)

Video 1
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2
2500 2152/1915/1819
2h21m/2h23m/2h14m
45.36/45.33/45.23
faster
4:2:2 0/1/2 2500 2139/1901/1808
2h49m/3h9m/3h21m
45.45/45.36/45.25
fast, turbo
4:3:2 0/1/2 2500 1969/1775/1692
3h51m/3h58m/4h5m
45.66/45.46/45.31
better compression and PSNR, turbo
4:4:2 0/1/2 2500 2146/1911/1818
4h38m/5h29m/5h49m
45.46/45.16/44.97
do not use

Video 2
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2
2500 2127/2037/1971
2h5m/2h9m/2h13m
43.16/42.87/42.57
faster
4:2:2 0/1/2 2500 2123/2028/1959
2h26m/2h54m/3h6m
43.21/42.92/42.65
fast, turbo
4:3:2 0/1/2 2500 2052/1953/1878
3h41m/3h58m/4h7m
43.59/43.40/43.18
better compression and PSNR, turbo
4:4:2 0/1/2 2500 2125/2032/1964
4h19m/5h27m/5h53m
43.22/42.79/42.40
do not use

In case of SVCD the standard vbr (2500) is close to the average vbr required to compress the video. As you can see:
-encode n:1:1 is still faster
-encode n:2:1 is fast
-encode n:3:1 compress better AND has a higher PSNR
-encode n:4:1 does not show any advantage
For m = 1, 2 and 4, 2 pass encoding produces a smaller file than 1 pass encoding.
For m = 3, 2 pass encoding produces a bigger file than 1 pass encoding.
In all the cases 2 pass encoding produces a lower PSNR than 1 pass encoding.

VCD (352x288)

Video 1
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2 1152 1320/1320/1320 1h31m/1h30m/1h27m
44.74/43.96/43.71

4:2:2 0/1/2 1152 1320/1320/1320 1h40m/1h48m/1h52m
44.78/44.01/43.65
turbo
4:3:2 0/1/2 1152 1320/1320/1320 2h3m/2h10m/2h11m
44.13/43.78/43.55
turbo
4:4:2 0/1/2 1152 1320/1320/1320 2h12m/2h34m/2h43m
43.34/43.20/42.68
turbo

Video 2
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2 1152 1127/1127/1127 1h23m/1h22m/1h21m
42.37/40.97/40.61

4:2:2 0/1/2 1152 1127/1127/1127 1h27m/1h37m/1h41m
42.62/41.00/40.66
turbo
4:3:2 0/1/2 1152 1127/1127/1127 1h58m/2h5m/2h9m
42.46/40.97/40.74
turbo
4:4:2 0/1/2 1152 1127/1127/1127 2h4m/2h28m/2h36m
42.46/40.65/39.84
turbo

VCD has constant video bit rate. The file size will be always the same, it doesn't matter which option you use.
-encode n:2:1 and -encode n:3:1 give the better PSNR and there is no big difference between them.
In all the cases 2 pass encoding produces a lower PSNR than 1 pass encoding.

VCD (352x288) variable bit rate

Video 1
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2 1152 997/908/874
1h26m/1h20m/1h18m
44.94/44.75/44.47

4:2:2 0/1/2 1152 994/908/875
1h36m/1h43m/1h47m
45.02/44.76/44.47
turbo
4:3:2 0/1/2 1152 947/871/840
2h0m/2h4m/2h5m
45.18/45.01/44.69
turbo
4:4:2 0/1/2 1152 995/910/877
2h13m/2h36m/2h42m
45.09/44.63/44.23
turbo

Video 2
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2 1152 1024/954/925
1h18m/1h19m/1h19m
43.02/42.69/42.19

4:2:2 0/1/2 1152 1023/954/922
1h25m/1h35m/1h38m
43.06/42.74/42.27
turbo
4:3:2 0/1/2 1152 980/915/881
1h56m/2h2m/2h8m
43.36/43.17/42.84
turbo
4:4:2 0/1/2 1152 1024/956/925
2h4m/2h29m/2h41m
43.09/42.65/42.04
turbo

In case your hardware player can play VCD with variable video bit rate add the option -mpeg1vbr.
-encode n:3:1 compress better AND has a higher PSNR
-encode n:2:1 is faster
For m = 1, 2 and 4, 2 pass encoding produces a smaller file and a lower PSNR than 1 pass encoding.
For m = 3, 2 pass encoding produces a bigger file than 1 pass encoding and the PSNR is usually higher.

SVCD (352x288)

Video 1
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2 1152 1065/965/926
1h29m/1h31m/1h25m
44.85/44.80/44.61
-svcd 2
4:2:2 0/1/2 1152 1061/964/925
1h39m/1h53m/1h50m
44.94/44.82/44.62
-svcd 2, turbo
4:3:2 0/1/2 1152 1006/925/891
2h3m/2h7m/2h7m
45.20/45.14/44.83
-svcd 2, turbo
4:4:2 0/1/2 1152 1065/969/931
2h18m/2h43m/2h47m
45.03/44.69/44.40
-svcd 2, turbo

Video 2
-encode
B frames
-vbr
size (MB)
job time PSNR note
4:1:2 0/1/2 1152 1081/1027/992
1h19m/1h21m/1h23m
42.91/42.96/42.72
-svcd 2
4:2:2 0/1/2 1152 1079/1024/988
1h27m/1h37m/1h49m
42.97/43.03/42.81
-svcd 2, turbo
4:3:2 0/1/2 1152 1041/990/954
2h0m/2h3m/2h4m
43.51/43.65/43.47
-svcd 2, turbo
4:4:2 0/1/2 1152 1080/1027/991
2h8m/2h34m/2h43m
43.01/42.94/42.62
-svcd 2, turbo

Instead of a VCD you can create a SVCD with VCD resolution.
It is very similar to a VCD with variable video bit rate, but mpeg2 should give better quality.
As before, 2 pass produces worst results than 1 pass, except for m=3 where it gives a higher PSNR.

DVD (720x576)

Video 1
-encode
B frames
-vbr
size (MB)
job time PSNR note
0:1:2
0/1/2
7500
4119/3429/3203
2h44m/2h40m/2h42m
46.99/46.73/46.43
-usesbr 4118/3424/3200
0:2:2 0/1/2
7500 4120/3430/3203
3h30m/3h59m/4h7m
47.18/46.91/46.59
-usesbr 4118/3424/3200
0:3:2 0/1/2
7500 4118/3424/3200 5h42m/5h41m/5h51m 48.04/47.29/46.92  
0:4:2 0/1/2
7500 4132/3443/3216
6h13m/7h48m/8h8m
47.24/46.79/46.40
-usesbr 4118/3424/3200
0:3:2 0/1/2 7500 3408/2945/2764
5h23m/5h28m/5h36m
46.83/46.45/46.52
-qmatrix tmpgenc
0:3:2 0/1/2 7500 3410/2951/2767
5h24m/5h30m/5h34m
46.88/46.38/46.41
-usesbr 3408/2945/2764
0:3:2 0/1/2 7500 3152/2770/2609
5h3m/5h8m/5h10m
46.23/45.85/45.89
-qmatrix kvcd
0:3:2 0/1/2 7500 3155/2776/2613
5h17m/5h23m/5h28m
46.45/46.02/46.05
-usesbr 3152/2770/2609

Video 2
-encode
B frames
-vbr
size (MB)
job time PSNR note
0:1:2
0/1/2
9000
4283/3785/3478
2h28m/2h29m/2h29m
46.37/45.75/45.60
-usesbr 4289/3788/3484
0:2:2 0/1/2
9000 4283/3785/3478
3h5m/3h38m/3h50m
46.46/45.88/45.73
-usesbr 4289/3788/3484
0:3:2 0/1/2
9000 4289/3788/3484 5h23m/5h31m/5h42m 46.82/46.17/46.06
0:4:2 0/1/2
9000 4284/3788/3481
5h56m/7h40m/8h16m
46.60/45.86/45.62
-usesbr 4289/3788/3484
0:3:2 0/1/2 9000 3578/3166/2931
4h47m/5h1m/5h6m
45.68/45.02/44.87
-qmatrix tmpgenc
0:3:2 0/1/2 9000 3572/3163/2926
5h23m/5h35m/5h38m
45.71/45.04/44.90
-usesbr 3578/3166/2931
0:3:2 0/1/2 9000 3218/2884/2679
4h40m/4h53m/4h59m
44.66/44.07/43.93
-qmatrix kvcd
0:3:2 0/1/2 9000 3212/2881/2674
4h49m/5h13m/5h24m
45.08/44.46/44.31
-usesbr 3218/2884/2679

If you need to reduce the size of the mpeg video always use -encode n:3:i or B frames, but keep in mind that 1 PASS encoding produces a smaller file than 2 PASS.
If you use -qmatrix tmpgenc or kvcd, 2 PASS gives a smaller file than 1 PASS. Better results are obtained using -usesbr instead.
The usage of -usesbr (and therefore a lower vbr) always has a bad impact on the PSNR.
With 2 PASS encoding, the final file size is the one specified with -usesbr.