[Mp4-tech] [H.264] "pumping" effet

Stéphane Péchard stephane.pechard univ-nantes.fr
Thu Jul 6 11:52:27 EDT 2006


Hello everyone,
I don't know the english term for this effect actually. At low bitrates, I 
images have smaller QP than P and B images (difference is around 5), except 
for the first image. This results in regular sudden changes in quality which 
is particularly visible and disturbing. I'm using the JM reference codec. I 
provide an example of output at the end of this message.
I would like to smooth this effect in equalising the QP. The best way I found 
until now is to disable the rate control, but of course, this is not a very 
realistic way of coding.
Does anyone have any tips to try to reduce this effect ?
Thanks in advance
Best regards,
stéphane
example of output file:
-----------------------------------------------------------------
  Frame  Bit/pic WP QP   SnrY    SnrU    SnrV    Time(ms) MET(ms)
-----------------------------------------------------------------
0000(NVB)     192
0000(IDR) 1951648 0 28  36.431  37.779  40.940    281000       0
0002(P)    280056 0 28  35.765  37.310  40.804    397312  129702
0001(B)    253496 0 29  34.769  36.931  40.650    581532  275651
0004(P)    377104 0 28  35.751  37.192  40.719    486438  208110
0003(B)    116504 0 30  34.944  36.783  40.580    596750  284346
0006(P)    198120 0 30  35.033  36.864  40.624    555547  222617
0005(B)     77456 0 31  34.993  36.639  40.560    582063  281179
0008(P)     69064 0 32  35.160  37.004  40.666    515516  203918
0007(B)     28816 0 33  35.046  36.877  40.604    512344  259499
0010(P)     44208 0 34  34.787  36.796  40.597    466453  205344
0009(B)     22136 0 35  34.247  36.761  40.594    538047  277340
0012(I)   1455976 0 30  35.257  36.959  40.355    331187       0
0011(B)      1320 0 35  35.018  37.110  40.708    533047  289951
0014(P)    147920 0 30  35.378  36.962  40.592    443172  187343
0013(B)     19888 0 34  35.242  36.994  40.572    494797  253137
0016(P)    119680 0 30  35.406  36.966  40.563    448390  192747
0015(B)     22280 0 32  34.939  36.857  40.519    500094  251564
0018(P)     41168 0 32  35.015  36.837  40.531    423578  184273
0017(B)     23704 0 33  34.676  36.781  40.532    485891  252617
0020(P)     26920 0 34  34.862  36.787  40.526    410703  190300
0019(B)     15328 0 35  34.751  36.739  40.484    432000  224236
0022(P)     22376 0 36  34.668  36.767  40.531    379546  180654
0021(B)      5824 0 37  34.901  36.763  40.528    462750  243328
0024(I)   1160024 0 32  33.987  36.379  39.849    260438       0
0023(B)      1184 0 37  34.652  36.868  40.393    468282  246717
0026(P)     59072 0 32  34.919  36.711  40.485    470563  195465
0025(B)      9336 0 36  34.517  36.686  40.448    468828  246436
0028(P)     64544 0 32  34.797  36.682  40.444    451047  183652
0027(B)     10544 0 34  34.684  36.695  40.477    511610  259890
0030(P)     23400 0 34  34.649  36.675  40.483    431938  167907
0029(B)     16096 0 35  34.398  36.627  40.452    473859  247254
0032(P)     15896 0 36  34.535  36.639  40.451    447390  179212
0031(B)     18008 0 37  34.388  36.630  40.459    434719  225364
0034(P)      9280 0 38  34.428  36.609  40.459    426594  190322
0033(B)      2928 0 39  33.796  36.577  40.456    462188  243720
0036(I)    921176 0 34  32.744  35.604  39.278    184125       0
0035(B)       496 0 39  34.257  36.383  40.160    474125  258449
0038(P)     42424 0 34  34.294  36.503  40.414    437391  188126
0037(B)     13936 0 38  33.901  36.459  40.398    421578  227120
0040(P)     39528 0 34  34.325  36.410  40.352    397453  167986
0039(B)      6008 0 36  33.825  36.383  40.374    471344  247505
0042(P)     28520 0 36  34.062  36.194  40.313    407297  176215
0041(B)     14048 0 37  33.664  36.333  40.339    440891  228799
0044(P)     27776 0 38  33.594  36.182  40.229    312078  137110
0043(B)     11432 0 39  33.692  36.024  40.204    392547  203899
0046(P)     13624 0 40  33.569  35.935  40.077    297625  141879
0045(B)     11256 0 41  32.882  36.120  40.171    323687  169649
0048(I)    741440 0 36  31.186  35.218  38.772    141281       0
0047(B)     13648 0 41  31.344  35.757  39.746    313078  163381
0050(P)     56704 0 36  33.191  35.840  39.970    269218  120526
0049(B)     21592 0 40  32.187  35.611  39.776    312234  166060
0052(P)     35104 0 36  32.987  35.791  39.955    282094  129723
0051(B)     13072 0 38  32.847  35.670  39.826    326812  169203
0054(P)     14656 0 38  32.668  35.964  40.078    270735  124553
0053(B)      7024 0 39  31.538  35.562  39.778    326906  169251
0056(P)     23464 0 40  32.146  35.869  40.047    273328  130073
0055(B)      9944 0 41  31.819  35.820  39.937    329672  174715
0058(P)     13784 0 42  31.498  35.510  39.654    266687  129179
0057(B)      3520 0 43  31.234  35.491  39.667    324734  169956
0060(I)    569336 0 38  29.761  35.042  38.521    130485       0
0059(B)     12160 0 43  30.653  35.474  39.634    324953  170913
0062(P)     43160 0 38  32.109  35.585  39.670    275110  125133
0061(B)     10304 0 44  31.592  35.277  39.414    311844  169654
0064(P)     29872 0 38  31.793  35.474  39.686    270610  125847
0063(B)      5120 0 42  31.137  35.334  39.519    320500  168668
0066(P)     26272 0 40  31.394  35.489  39.705    266797  126383
0065(B)      9384 0 41  30.958  35.265  39.559    333093  173950
0068(P)     19056 0 42  30.801  35.335  39.567    260593  125534
0067(B)      5104 0 43  30.730  35.289  39.527    321813  169715
0070(P)     11504 0 44  30.472  35.279  39.504    262938  127473
0069(B)      1576 0 45  29.988  35.102  39.352    315781  168440
0072(I)    433568 0 40  28.481  35.184  38.393    127172       0
0071(B)     16240 0 45  29.833  35.403  39.585    324047  171167
0074(P)     38520 0 40  31.496  35.709  39.799    271234  128563
0073(B)     12272 0 46  30.561  35.766  39.715    312141  169613
0076(P)     24104 0 40  30.978  35.409  39.616    272828  130351
0075(B)      2320 0 44  30.453  35.467  39.636    326938  173462
0078(P)     18592 0 42  30.596  35.227  39.385    268141  129334
0077(B)      3544 0 43  30.166  35.114  39.342    326516  171266
0080(P)     15224 0 44  30.414  35.372  39.516    265000  129265
0079(B)      1904 0 45  30.044  35.134  39.315    323219  172529
0082(P)     12648 0 46  29.893  35.436  39.503    254578  123417
0081(B)      1672 0 47  30.060  35.345  39.436    317610  169820
0084(I)    312784 0 42  27.229  35.384  38.538    121375       0
0083(B)     15016 0 47  28.016  35.345  39.528    323281  171839
0086(P)     37616 0 42  30.711  35.498  39.671    259953  125124
0085(B)     12232 0 48  28.586  35.354  39.082    313641  172134
0088(P)     22304 0 42  30.560  35.450  39.634    267735  131012
0087(B)      3160 0 46  30.156  35.452  39.642    311781  166272
0090(P)     15240 0 44  29.793  35.081  39.335    271406  129910
0089(B)      2048 0 45  29.487  35.159  39.405    314562  167913
0092(P)     10144 0 46  29.464  35.011  39.306    252297  122935
0091(B)       840 0 47  29.546  34.992  39.299    317812  169407
0094(P)     10424 0 48  29.164  35.068  39.400    220172  106218
0093(B)      1176 0 49  29.235  34.823  39.227    267531  140459
0096(I)    198328 0 44  26.388  35.172  38.395    106484       0
0095(B)     12192 0 49  25.962  35.157  39.338    270125  142453
0098(P)     34080 0 44  30.151  35.131  39.544    226656  110007
0097(B)     12000 0 50  28.749  35.236  39.471    260578  140567
0100(P)     18480 0 44  29.585  34.984  39.237    225359  109278
0099(B)      1224 0 48  29.240  34.856  39.240    268922  141985
0102(P)     14920 0 46  29.181  34.890  39.225    222360  107987
0101(B)      2024 0 47  29.254  34.808  39.177    270610  143456
-- 
~ stéphane péchard
~ phd student | irccyn-ivc | france
~ http://www.irccyn.ec-nantes.fr/~pechard
~~~~~~ pgp : hkp://subkeys.pgp.net ~~~~~~
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