Playing DVD with USB DVD device

Li-Lun Wang (Leland Wang) llwang at
Thu Jun 10 13:07:04 GMT 2004

Hash: SHA1

Now I think that the bad performance results from something related to
mplayer rather than FreeBSD.

I noticed that the rate 1.000MB/s is hard-coded into umass.c. It seems
that this rate does not really mean the actual speed and is only some
information for cam_xpt.c to show in xpt_announce_periph().

When I use xine instead of mplayer, my DVD plays perfactly well. I
suspected that this is caused by the difference between libdvdread and
mplayer's internal dvd-read routine, but the performance is equally bad
after I rebuild mplayer with -DWITH_LIBDVDREAD.

One problem of using xine is that it is less stable than mplayer, but
I think I will be using xine to play DVDs for now.

I provide some details here in case someone is interested in improving
mplayer. When data are present in mplayer's cache, the video and audio
keep freezing as if I am playing from a very slow source. When mplayer
finally runs out of data in the cache (or when the video and audio run
out of sync? I don't know the actual case), I lose the audio, but the
video plays much better.

On Fri, Jun 04, 2004 at 12:39:55AM +0800, Li-Lun Wang (Leland Wang) wrote:
> I am playing DVD with a USB DVD-ROM using mplayer. If I use
> # mplayer dvd://1
> it does work but it is so slow that it is unacceptable. The transfer
> rate is only a little more than 1MB/sec, and this does not seem to
> be right for I am using USB 2.0. I found the following in the dmesg
> when I plug the DVD device:
> umass0: Prolific Technology Inc. Mass Storage Device, rev 2.00/1.00, addr 2
> cd0 at umass-sim0 bus 0 target 0 lun 0
> cd0: <NU CDRW/DVD SBW242U U301> Removable CD-ROM SCSI-0 device 
> cd0: 1.000MB/s transfers
> I don't know why the system says cd0 is only 1.000MB/s, and I don't
> konw whether this is the cause of the bad performance in playing DVD.
> If I mount the DVD and use
> $ mplayer /cdrom/video_ts/*.vob
> the performance is dramatically better. I don't know whether the
> improvement results from the use of system cache or from some real
> improvement in the transfer rate or from both. However, this does not
> work for region-code protected DVDs. I tried to use
> # mplayer -dvdauth /dev/cd0 /cdrom/video_ts/*.vob
> as suggested by the manual page of mplayer but failed. I kept getting
> DVD: opening as ...
> DVD: dlopen: Shared object "" not found
> Error in DVD auth...
> Exiting... (Fatal error)
> Since libcss seem to be no longer available, does anyone know how to
> solve this? Can't libdvdcss be used instead? Any suggestions?
> Sincerely,
> Leland Wang
Version: GnuPG v1.2.3 (FreeBSD)


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