[MPlayer-users] 30fps->25fps works, 23->25 doesn't

[Sascha Schumann]

    Hi,

    I'm trying to convert some avi/mpegs into DV format using
    mencoder (current CVS) and libdv (0.9.5 and 0.99).

    The cmdline for DV conversion:

        mencoder $in -o $out -ovc libdv -oac pcm \
            -vop scale=720:576 -ofps 25 -srate 32000

    This works marvelously for movies which already have more fps
    than PAL requires (25fps), e.g. avis with 30fps.  I can
    successfully send the raw DV stream to the DV cam using
    "dvavi tmp.avi > /dev/../PAL/out".

    The latter step fails though when the movie has less than
    25fps.  The cam displays some real frames followed by white
    frames, real frames, and so on.

    I've tried increasing the fps of the source movie:

        mencoder some.avi -o n.avi -ovc lavc \
            -lavcopts vcodec=mpeg4 -oac mp3lame -ofps 30

    This however had no effect when sending the DV stream to the
    cam.  The pattern of real/white frames does not change.

    mplayer plays the generated DV-encoded avi correctly.
    However, after creating a raw DV stream using dvavi, neither
    mplayer or playdv display proper output.  In mplayer,
    the screen "moves up" block-wise.  E.g. after the first
    iteration:

        http://schumann.cx/enc1.png

    playdv shows some intermediate flicker, but otherwise
    continues to play.

    Please let me know if you need more information.

    Thanks
    - Sascha