Mpeg Mode 3 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
 4851/3996/3735
 4h13m/4h4m/4h7m
 47.79/47.41/47.79
 very fast
0:2:2 0/1/2
 7500 4847/4061/3734
 5h33m/5h59m/6h12m
 48.21/48.06/48.11
 fast, turbo
0:3:2 0/1/2
 7500 3668/3131/2929
 9h50m/9h29m/9h28m
 47.33/46.85/46.90
 high compression, turbo
0:4:2 0/1/2
 7500 4723/4221/3946
 11h2m/13h55m/14h34m
 47.83/48.06/48.18
 high PSNR, turbo

Video 2
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
0:1:2
 0/1/2
 9000
 4854/4188/3918
 3h21m/3h32m/3h42m
 47.19/46.43/46.54
 very fast
0:2:2 0/1/2
 9000 4857/4209/3940
 4h38m/5h28m/5h43m
 47.33/46.66/46.78
 fast, turbo
0:3:2 0/1/2
 9000 3824/3385/3132
 9h15m/9h19m/9h28m
 46.11/45.47/45.33
 high compression, turbo
0:4:2 0/1/2
 9000 4771/4306/4095
 10h32m/13h54m/14h54m
 47.32/46.77/46.95
 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 but has a lower PSNR
-encode n:4:1 has higher PSNR
For m = 1, 2 and 4, 3 pass encoding produces a bigger file and a higher PSNR than 1 pass encoding.
For m = 3, 3 pass encoding produces a smaller file and a lower 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 2159/1924/1831
 3h25m/3h26m/3h21m
 45.36/45.24/45.06
 faster
4:2:2 0/1/2 2500 2156/1952/1867
 4h8m/4h37m/4h50m
 45.46/45.40/45.26
 fast, good PSNR, turbo
4:3:2 0/1/2 2500 1837/1665/1596
 6h19m/6h16m/6h25m
 45.46/45.26/45.04
 better compression, good PSNR, turbo
4:4:2 0/1/2 2500 2120/1993/1924
 7h36m/9h21m/9h55m
 45.37/45.15/44.99
 do not use

Video 2
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
4:1:2 0/1/2
 2500 2135/2046/1988
 3h1m/3h9m/3h13m
 43.18/42.74/42.36
 faster
4:2:2 0/1/2 2500 2135/2052/1994
 3h36m/4h14m/4h31m
 43.24/42.83/42.49
 fast, good PSNR, turbo
4:3:2 0/1/2 2500 1964/1860/1792
 6h10m/6h28m/6h45m
 43.55/43.26/42.94
 better compression, good PSNR, turbo
4:4:2 0/1/2 2500 2118/2064/2016
 7h15m/9h19m/10h5m
 43.21/42.60/42.08
 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 AND has high PSNR
-encode n:3:1 compress better AND has a high PSNR
-encode n:4:1 does not show any advantage
For m = 1, 2 and 4, 3 pass encoding produces a smaller file than 1 pass encoding.
For m = 3, 3 pass encoding produces a smaller file than 1 pass encoding.
In all the cases 3 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 2h10m/2h15m/2h1m
44.56/44.53/44.12
4:2:2 0/1/2 1152 1320/1320/1320 2h28m/2h36m/2h43m
44.62/44.63/44.14
 turbo
4:3:2 0/1/2 1152 1320/1320/1320 3h14m/3h19m/3h23m
 44.08/44.57/44.01
 turbo
4:4:2 0/1/2 1152 1320/1320/1320 3h33m/4h15m/4h31m
 43.73/43.93/43.22
 turbo

Video 2
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
4:1:2 0/1/2 1152 1127/1127/1127 1h56m/1h59m/2h4m
42.03/41.82/40.99
4:2:2 0/1/2 1152 1127/1127/1127 2h7m/2h21m/2h26m
 42.13/41.86/41.05
 turbo
4:3:2 0/1/2 1152 1127/1127/1127 3h6m/3h20m/3h29m
 41.92/42.73/42.09
 turbo
4:4:2 0/1/2 1152 1127/1127/1127 3h22m/4h7m/4h22m
 42.23/41.57/40.59
 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 3 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 1005/915/883
 2h8m/2h9m/2h2m
 44.93/44.67/44.43
4:2:2 0/1/2 1152 1001/922/893
 2h24m/2h33m/2h38m
 45.00/44.78/44.57
 turbo
4:3:2 0/1/2 1152 888/822/798
 3h10m/3h14m/3h16m
 44.81/44.61/44.28
 turbo
4:4:2 0/1/2 1152 988/932/915
 3h40m/4h22m/4h32m
 44.96/44.64/44.45
 turbo

Video 2
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
4:1:2 0/1/2 1152 1036/968/949
 1h55m/1h58m/1h58m
 43.11/42.73/42.39
4:2:2 0/1/2 1152 1035/970/952
 2h7m/2h19m/2h26m
 43.16/42.81/42.51
 turbo
4:3:2 0/1/2 1152 934/876/849
 3h10m/3h19m/3h23m
 43.16/42.94/42.62
 turbo
4:4:2 0/1/2 1152 1030/973/962
 3h27m/4h18m/4h30m
 43.15/42.65/42.24
 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, 3 pass encoding produces a bigger file than 1 pass encoding.
For m = 3, 3 pass encoding produces a smaller file than 1 pass encoding.
For every m, 3 pass encoding produces a smaller PSNR than 1 pass encoding.

SVCD (352x288)

Video 1
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
4:1:2 0/1/2 1152 1083/986/951
 2h11m/2h11m/1h59m
 44.88/44.84/44.68
 -svcd 2
4:2:2 0/1/2 1152 1078/1002/968
 2h25m/2h34m/2h40m
 44.97/45.09/44.96
 -svcd 2, turbo
4:3:2 0/1/2 1152 960/892/863
 3h14m/3h14m/3h16m
 44.89/44.83/44.54
 -svcd 2, turbo
4:4:2 0/1/2 1152 1057/1021/991
 3h41m/4h25m/4h38m
 44.89/45.02/44.85
 -svcd 2, turbo

Video 2
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
4:1:2 0/1/2 1152 1089/1039/1007 1h57m/1h57m/1h58m 42.98/42.99/42.75 -svcd 2
4:2:2 0/1/2 1152 1088/1045/1020
 2h9m/2h21m/2h25m
 43.03/43.14/43.13
 -svcd 2, turbo
4:3:2 0/1/2 1152 999/945/911
 3h12m/3h13m/3h16m
 43.35/43.36/43.11
 -svcd 2, turbo
4:4:2 0/1/2 1152 1079/1053/1032
 3h28m/4h18m/4h34m
 43.02/43.02/42.89
 -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, 3 pass produces worst results than 1 pass. For m=3 the file size is smaller than 1 pass.

DVD (720x576)

Video 1
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
0:1:2
 0/1/2
 7500
 3670/3137/2933
 4h1m/3h52m/3h50m
 46.65/46.36/46.43
 -usesbr 3668/3131/2929
0:2:2 0/1/2
 7500 3670/3137/2933
 5h8m/5h43m/6h2m
 46.81/46.51/46.57
 -usesbr 3668/3131/2929
0:3:2 0/1/2
 7500 3668/3131/2929 9h50m/9h29m/9h28m 47.33/46.85/46.90  
0:4:2 0/1/2
 7500 3684/3151/2947
 10h24m/13h0m/13h52m
 46.88/46.32/46.24
 -usesbr 3668/3131/2929
0:3:2 0/1/2 7500 3414/2996/2834
 8h42m/8h21m/8h23m
 46.85/46.51/46.63
 -qmatrix tmpgenc
0:3:2 0/1/2 7500 3379/3027/2824
 9h24m/9h21m/9h15m
 46.89/46.68/46.69
 -usesbr 3414/2996/2834
0:3:2 0/1/2 7500 3159/2773/2622
 8h18m/8h4m/8h6m
 46.26/45.92/46.00
 -qmatrix kvcd
0:3:2 0/1/2 7500 3162/2779/2625
 8h56m/8h53m/8h56m
 46.64/46.26/46.27
 -usesbr 3159/2773/2622

Video 2
-encode
 B frames
 -vbr
 size (MB)
 job time PSNR note
0:1:2
 0/1/2
 9000
 3819/3383/3127
 3h35m/3h27m/3h28m
 45.80/45.14/45.01
 -usesbr 3824/3385/3132
0:2:2 0/1/2
 9000 3819/3383/3127
 4h24m/5h9m/5h29m
 45.88/45.25/45.12
 -usesbr 3824/3385/3132
0:3:2 0/1/2
 9000 3824/3385/3132 9h15m/9h19m/9h28m 46.11/45.47/45.33
0:4:2 0/1/2
 9000 3820/3386/3130
 10h0m/13h4m/14h12m
 46.02/45.20/44.99
 -usesbr 3824/3385/3132
0:3:2 0/1/2 9000 3625/3261/3054
 7h41m/7h54m/8h8m
 45.77/45.22/45.17
 -qmatrix tmpgenc
0:3:2 0/1/2 9000 3620/3259/3049
 8h54m/9h11m/9h28m
 45.81/45.22/45.16
 -usesbr 3625/3261/3054
0:3:2 0/1/2 9000 3376/3021/2821
 7h37m/7h43m/7h58m
 45.05/44.44/44.38
 -qmatrix kvcd
0:3:2 0/1/2 9000 3372/3019/2816
 8h31m/8h55m/9h11m
 45.42/44.78/44.66
 -usesbr 3376/3021/2821

If you need to reduce the size of the mpeg video always use -encode n:3:i or B frames. 3 PASS encoding produces a smaller file than 1 PASS.
If you use -qmatrix tmpgenc or kvcd, 2 PASS gives a smaller file than 3 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 3 PASS encoding, the final file size is the one specified with -usesbr.