Hello,

While backing-up certain DVDs, I get a "broken bit-stream" error (see below) from mplex (part of mjpegtools) when I try to multiplex the audio/video tracks back together. I've done this successfully several times recently w/ other DVDs, however, I've gotten this error on at least two DVDs now, and I don't know what's causing it, or how to fix. The procedure I'm using (all command line) was taken from a tutorial I found here, and usually works like a charm. It goes something like this:

1) vobcopy -l (rip the original DVD)
2) tcextract -i $FILE.vob -t vob -x mpeg2 > video.m2v (extract the video)
3) tcextract -i $FILE.vob -t vob -x ac3 -a 0 > audio.ac3 (extract the audio track)
(video compression not necessary for this particular movie, so that step is skipped)
4) mplex -f 8 -o ""$FILE"%d.mpg" video.m2v audio.ac3 (multiplex the audio and video back together)

Is something going wrong during step 3, the audio extraction? Is there another tool I could try besides tcextract, or are there other parameters I could pass to it that might fix this? Or is the problem w/ mplex?

Any suggestions would be greatly appreciated!

Here is the output from mplex (step #4 above)

INFO: [mplex] mplex version 1.6.2 (2.2.3 $Date: 2004/01/13 20:45:26 $)
INFO: [mplex] File video.m2v looks like an MPEG Video stream.
INFO: [mplex] File audio.ac3 looks like an AC3 Audio stream.
INFO: [mplex] Video stream 0: profile 8 selected - ignoring non-standard options!
INFO: [mplex] Found 1 audio streams and 1 video streams
INFO: [mplex] Selecting dvdauthor DVD output profile
INFO: [mplex] Multiplexing video program stream!
INFO: [mplex] Scanning for header info: Video stream e0 (video.m2v)
INFO: [mplex] VIDEO STREAM: e0
INFO: [mplex] Frame width : 720
INFO: [mplex] Frame height : 480
INFO: [mplex] Aspect ratio : 16:9 display
INFO: [mplex] Picture rate : 29.970 frames/sec
INFO: [mplex] Bit rate : 9800000 bits/sec
INFO: [mplex] Vbv buffer size : 229376 bytes
INFO: [mplex] CSPF : 0
INFO: [mplex] Scanning for header info: AC3 Audio stream 00 (audio.ac3)
INFO: [mplex] AC3 frame size = 1536

INFO: [mplex] AC3 AUDIO STREAM:
INFO: [mplex] Bit rate : 49152 bytes/sec (384 kbit/sec)
INFO: [mplex] Frequency : 48000 Hz
INFO: [mplex] SYSTEMS/PROGRAM stream:
INFO: [mplex] rough-guess multiplexed stream data rate : 10403400
INFO: [mplex] target data-rate specified : 10080000
++ WARN: [mplex] Target data rate lower than computed requirement!
++ WARN: [mplex] N.b. a 20% or so discrepancy in variable bit-rate
++ WARN: [mplex] streams is common and harmless provided no time-outs will occur
INFO: [mplex] Run-in Sectors = 89 Video delay = 13019 Audio delay = 16022
INFO: [mplex] New sequence commences...
INFO: [mplex] Video e0: buf= 237568 frame=000000 sector=00000000
INFO: [mplex] Audio bd: buf= 16384 frame=000000 sector=00000000
**ERROR: [mplex] Can't find next AC3 frame: @ 1532928 we have bd28 - broken bit-stream?

**ERROR: [mplex] Can't find next AC3 frame: @ 1532928 we have bd28 - broken bit-stream?

Were you able to figure this problem out?
I'm having the same.

dlw

> Were you able to figure this problem out?

Negative. But I haven't really spent any time on it. I've downloaded a couple other tools that (I think) do the same thing (dvdbackup & acidrip), but I've been so busy, I haven't had a chance to install them and try. When I do, perhaps later this week or weekend, I'll post results. If you solve this, pls do likewise.

In case you're interested in the alternatives mentioned above:

dvdbackup
acidrip (sourceforge)
acidrip (homepage)

I am putting together a script to dupe DVD movies and nameing it 'stf' - Start To Finish.
You insert the original DVD in one DVD-rw -/dev/hdc,and a blank DVD in the second, -/dev/hdd.
Go to bed, go play or whatever. It goes from 'stf' without any input.
The script works now except when it runs into this problem about the '*.ac3' file.
One person told me to 'chmod +r' the '*.ac3' file.
I did and that worked on that particular movie but not on others.
I'm going to try 'chmod +rwxrwxrwx' and see what happens.
This will give 'root, group and user' permission to 'read, write and execute' the file.
I'll do this to all files. It may or may not help.

The second problem is the movie plays most of the way and stops.
Looking at the back of the DVD you can see a difference in the emulsion.
It looks as if the emulsion was 'burnt deeper' with a darker color, -purpleish, most of the way.
Then it looks as if something changed and did not 'burn' as deep.

The movie plays great from 'stf' as '*.vob' on the computer.
I'm wondering if using the computer while the script is running has anything to do with it.
It appears the problem happens in the 'burning' process.

Oh well, one day at a time.

dlw