DVD playback distortion

[Bopsie]

I'm having distorted playback on some retail DVDs and could use some suggestions on where to start looking. (I don't play much with video, but I'm experienced in other parts of PCs.) I'm using the VLC 1.1.11 to run things.

The 3 DVDs that I'm testing with run perfectly on the built-in DVD players in my 2 desktops and 2 laptops.

The problem only occurs with 2 external DVD players that I connect to my laptop using USB connections. (The videos play fine on the laptop's built-in player.) When I connect the same 2 external players to my son's laptop (identical model laptop), all DVDs play perfectly. And when I move his hard drive to my laptop (easy to do since it's the same model laptop and same level OS), now the DVDs play perfectly in my laptop! So it seems like the problem is in the software in my laptop.

My assumptions so far:
- the disks are good since they play fine on other players / computers
- the USB-attached drives are good since they play fine when attached to other computers AND on my computer when my son's hard drive is installed and booted. (I'm going to mount one of the USB-attached drives in place of my built-in drive, but I bet it will work fine there....)
- VLC is good since it plays the DVDs fine on other computers with the same USB drives AND on my computer when my son's hard drive is installed and booted.

Someone at MYcE.com suggested that I try Media Player Classic - Home Cinema. MPC-HC played all videos fine, including on my laptop with the USB drives. So the problems shows up in VLC; but VLC plays the DVDs fine on the built-in player in my laptop. So I'm wondering if the actual problem could be in the USB driver or processing on my computer. (I don't think it's in the USB hardware since it works fine when my son's hard drive is installed and booted.)

Here are the symptoms:
1) one video shows a solid green window in VLC for about 30 seconds of the Intro, then switches to a very garbled version of one of the frames of the intro. This garbled picture remains frozen for the rest of the Intro time.
2) another video is trying to show the Intro (things keep flashing by), but the display is very garbled. Things are rendered in distorted blocks of colors in vaguely familiar placements, with some recognizable elements of the video in scattered places of the window. It's like a digital lava-lamp: blocks of color in roughly recognizable patterns moving around where there ought to be images. It's almost as if an 8x8 block of pixels is rendered using only 1 of the colors in that block; but it's more variable than that.
3) The 3rd video plays perfectly all the time on all the hardware, everywhere.

MPC-CH plays some stuff that VLC doesn't play: intro FBI warning, the Columbia Pictures "statue" intro and other intro ads. VLC doesn't play any of that stuff....

Some info: the laptops are both Dell Latitude D830 running XP Pro SP3 with all Windows fixes, updated Dell drivers, and latest BIOS. Region code is set to US. The external USB drives are:
1) Matshita DVD-RAM UJ8A0AS (bought from Newegg as a Rosewill ROD-EX002)
2) NEC DVD+-RW ND-6500A (mounted in an aftermarket case made by AGPTEK.)
The DVDs are basically new: one is brand-new, the other has fewer than 5 plays; no scratches are seen. All purchased in the US.

I don't know if the problem is in the driver that gets the data from the device on the USB port, some piece of software that converts the data stream to a video stream (VLC?), or perhaps a utility (codec?) that is another part of the system. As I said, I don't really know what happens behind the video curtain. Any suggestions would be appreciated!

[VLC_help]

Open Tools -> Messages (set Verbosity to 2) then start playback. Message log will complain when problems happen.

[Bopsie]

I installed one of the USB-attached DVD drives directly in my laptop, and it played all DVDs without any problems. So it seems VLC, the DVDs, and the device hardware are OK; the problem only happens when the DVD is played on a USB-attached device.

Thanks for the message logging suggestion. I ran VLC twice: once on a USB-attached device (with problems) and once with the internal DVD device (no problems.) Most of the beginnings of the 2 logs were the same with some minor differences:
- some entries were in a slightly different order: I assume this can be ignored.
- Most of the "main debug: TIMER module-need()" entries were slower in the bad output than in the good output; but I assume this is due to reading from the USB-attached device rather than the directly attached device

Near the end is where it got interesting. After the "End of audio preroll" and "Decoder buffering done" entries, the bad log has lots of warnings:
a52 debug: emulated sync word (no sync on following frame)
main warning: buffer is 96000 in advance, triggering downsampling
a52 debug: emulated sync word (no sync on following frame)
main warning: audio drift is too big (-192000), clearing out
main warning: timing screwed, stopping resampling
main warning: mixer start isn't output start (-76032)
main debug: audio output is starving (217262), playing silence
a52 debug: emulated sync word (no sync on following frame)
main warning: buffer is 96000 in advance, triggering downsampling
a52 debug: emulated sync word (no sync on following frame)
main warning: audio drift is too big (-192000), clearing out
main warning: timing screwed, stopping resampling
main warning: mixer start isn't output start (-92160)
main debug: audio output is starving (257200), playing silence
a52 debug: emulated sync word (no sync on following frame)
main warning: audio drift is too big (-160000), clearing out
main warning: mixer start isn't output start (-72192)
main warning: late picture skipped (13002 > -1113)
a52 debug: emulated sync word (no sync on following frame)
main warning: late picture skipped (7636 > -1113)
main warning: late picture skipped (-730 > -1084)
main warning: late picture skipped (904 > -1084)
main warning: buffer is 96000 in advance, triggering downsampling
main warning: late picture skipped (110538 > -1234)
a52 debug: emulated sync word (no sync on following frame)
main warning: output date isn't PTS date, requesting resampling (-45179)
main warning: late picture skipped (99172 > -1175)
main warning: late picture skipped (101806 > -1131)
main warning: audio drift is too big (-237179), clearing out
main warning: timing screwed, stopping resampling
main warning: mixer start isn't output start (-94916)
main warning: late picture skipped (134440 > -1098)
main debug: audio output is starving (247179), playing silence
a52 debug: emulated sync word (no sync on following frame)
main warning: buffer is 96000 in advance, triggering downsampling
main warning: output date isn't PTS date, requesting resampling (-46721)
a52 debug: emulated sync word (no sync on following frame)
a52 debug: emulated sync word (no sync on following frame)
main debug: auto hidding mouse

In the good log, there are some (minor?) entries: "ES_OUT_SET_(GROUP)_PCR is called too late"
and "spudec: invalid starting packet", but basically it buffers the stream. I assume these entries are no big deal since the DVD plays fine on that device.

Any comments on the warnings from the bad log? Certainly seems like something is wrong to me, but what do I know.... Any idea whether the errors might be caused by my system, especially the USB device processing? I'm going to use USBDeview from NirSoft to see if I can see anything odd....

Thanks for any help (including pointing me off to another area.)
Bopsie

[VLC_help]

DId you try high dvd-caching values?
http://wiki.videolan.org/WindowsFAQ-1.1 ... 2C_etc..29

[Bopsie]

Increasing the caching values didn't make a difference, even up to 20000.

However, the previous entry in the FAQ did help. It suggests to Open Folder to the VIDEO_TS folder, or Open File to the VIDEO_TS.IFO file. (BTW: is there an explanation of those folders, files, and filetypes for newbies?...) When using either Open Folder or File, I was able to see the Intro just fine. However, I couldn't do much more:
- Play All on the menu just hung: nothing displayed
- Scene Selection usually allowed me to navigate through some scene choices. (Sometimes it just went back to the VLC main menu.) But when I finally selected a scene to play, it would hang. The message window showed only "spudec debug: invalid starting packet": is that a fatal error?

How are Open Folder/Open File different from Open Disc? And what does it mean that Open Folder can display the Intro correctly?

Thanks for any info
Bopsie

[VLC_help]

They launch dvdnav with different folder which sometimes helps, since dvdnav is quite buggy (so dvdnav might work with e.g. d:\VIDEO_TS , but it might not work with d:\). Specially with discs that have added copy protection stuff.

[Bopsie]

Is there a way to tell if any of the DVDs have copy protection? They play fine on several DVD devices, including one that does not have a region set. I would assume that if the DVD had copy protection, it would not play on a device with no region set. And that a DVD without copy protection would play on any device, including one with no region set....

Any comments on the Message Output that I posted earlier? Especially things like:
main warning: buffer is 96000 in advance, triggering downsampling
main warning: audio drift is too big (-192000), clearing out
main warning: timing screwed, stopping resampling
main warning: mixer start isn't output start (-76032)
main warning: late picture skipped (13002 > -1113)
These feel like the data stream from the USB port has problems....

I'm going to play some more with VLC with Message Logging on: should I look only for Warnings (i.e. ignore the debug output)

Any suggestions for what to try next or where to look next?

Thanks for any help
Bopsie

[VLC_help]

Usually only dvdnav related errors, warnings or debugs reveal the actual cause if it is DVD related.