[MPlayer-users] lavc b_frames bug ?

[Mihai RUSU]

Hi

I was most happy hearing the new rc4 doesnt crash anymore with b_frames
and some other options. But now I have another problem. Although PSNR
shown a better cality, and visually I can say it looks a LOT nicer with
b_frames, I have a very motion scene of like 2 minutes, where after the
first 1:30 minute shows very good, the next 30 seconds show only squares
of colors.  Like the image is made of squares. Very low quality. Then
after the moving scene ends it gets back to normal high quality.

This is my info:
- system: linux slack 8.0 based, 2.4.20 kernel, libc 2.2.3, no X windows
(on the encoder machine), gcc 2.95.3, ld 2.11.90.0.19, binutils
2.11.90.0.19
- hardware info:

$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Pentium(R) 4 CPU 2.00GHz
stepping        : 4
cpu MHz         : 2040.409
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
bogomips        : 4063.23

I used ./configure --disable-vidix to compile mplayer/mencoder

Here are the options I used for encoding: cat source.vob | mencoder -ofps
23.976 -ovc lavc -lavcopts
vcodec=mpeg4:vpass=1:vbitrate=970:vme=4:vhq:v4mv:precmp=2:cmp=2:subcmp=2:trell:vmax_b_frames=1:psnr
-oac copy -o menc/movie.avi -

And the same for pass2 (with vpass=2 of course).

I have tried vb_strategy=1 too but with this one it seems there is no B
frame at all in the movie (according to the psnr_* file). And at least at
the beginning of the movie there are lots of almost static scenes. Not
much motion. And of course it doesnt show the problem (but has lesser
quality).

What can I do to not have the problem with the motion scene and still have
the quality of the b_frames (not necesary in the motion scenes) ?

Thanks

----------------------------
Mihai RUSU

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