Mux/Demux Bug

cefn · Member Joined: 30 May 2008 Location: United Kingdom

I used FFMpeg to demux a VOB file into m2v and ac3 components (the DVD came from one of these cameras which records to DVD directly).

However, the inverse operation of muxing the same files (to a file which I'm hoping iMovie or iDVD will accept without having to reencode from the original MPEG2) doesn't work.

It throws loads of errors like...
INFO: [mplex] Video e0: buf= 0 frame=000000 sector=00000000
INFO: [mplex] Audio bd: buf= 0 frame=000000 sector=00000000
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=75694 required(DTS)=75600
...and then gives up.

The full output is below. Surely FFMpegX should be able to mux something it's just demuxed without throwing errors. However, if anyone has any ideas how I can use FFMpegX to export VOBs to something which can be edited and reburned to DVD without re-encoding the MPEG2, I would be very grateful. This seems like the most promising avenue from many tens of pathways I've tried through different video muxing and encoding programs and I can't get it to work.

>>>>>>>>>>>>>

INFO: [mplex] mplex version 1.9.0 (2.2.7 $Date: 2006/02/01 22:23:01 $)
INFO: [mplex] File /Users/cefn/Movies/passion_paragliding/Day3/VIDEO_TS/VTS_01_1.VOB.m2v looks like an MPEG Video stream.
INFO: [mplex] File /Users/cefn/Movies/passion_paragliding/Day3/VIDEO_TS/VTS_01_1.VOB.#0.ac3 looks like an AC3 Audio stream.
INFO: [mplex] Found 1 audio streams and 1 video streams
INFO: [mplex] Selecting generic MPEG2 output profile
INFO: [mplex] Multiplexing video program stream!
INFO: [mplex] Scanning for header info: Video stream e0 (/Users/cefn/Movies/passion_paragliding/Day3/VIDEO_TS/VTS_01_1.VOB.m2v)
INFO: [mplex] VIDEO STREAM: e0
INFO: [mplex] Frame width : 720
INFO: [mplex] Frame height : 576
INFO: [mplex] Aspect ratio : 4:3 display
INFO: [mplex] Picture rate : 25.000 frames/sec
INFO: [mplex] Bit rate : 9100000 bits/sec
INFO: [mplex] Vbv buffer size : 229376 bytes
INFO: [mplex] CSPF : 0
INFO: [mplex] Scanning for header info: AC3 Audio stream 00 (/Users/cefn/Movies/passion_paragliding/Day3/VIDEO_TS/VTS_01_1.VOB.#0.ac3)
INFO: [mplex] AC3 frame size = 1024
INFO: [mplex] AC3 AUDIO STREAM:
INFO: [mplex] Bit rate : 32768 bytes/sec (256 kbit/sec)
INFO: [mplex] Frequency : 48000 Hz
INFO: [mplex] SYSTEMS/PROGRAM stream:
INFO: [mplex] rough-guess multiplexed stream data rate : 9555296
INFO: [mplex] target data-rate specified : 3000000
++ 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 delay = 32400 Video delay = 32400 Audio delay = 43200
INFO: [mplex] New sequence commences...
INFO: [mplex] Video e0: buf= 0 frame=000000 sector=00000000
INFO: [mplex] Audio bd: buf= 0 frame=000000 sector=00000000
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=75694 required(DTS)=75600
++ WARN: [mplex] Video e0: buf= 16427 frame=000012 sector=00000147
++ WARN: [mplex] Audio bd: buf= 1803 frame=000013 sector=00000007
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=223150 required(DTS)=162000
++ WARN: [mplex] Video e0: buf= 2025 frame=000036 sector=00000432
++ WARN: [mplex] Audio bd: buf= 0 frame=000043 sector=00000022
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=370606 required(DTS)=252000
++ WARN: [mplex] Video e0: buf= 2025 frame=000061 sector=00000716
++ WARN: [mplex] Audio bd: buf= 0 frame=000074 sector=00000038
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=518062 required(DTS)=338400
++ WARN: [mplex] Video e0: buf= 2020 frame=000086 sector=00001001
++ WARN: [mplex] Audio bd: buf= 0 frame=000104 sector=00000053
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=665518 required(DTS)=428400
++ WARN: [mplex] Video e0: buf= 2025 frame=000110 sector=00001285
++ WARN: [mplex] Audio bd: buf= 0 frame=000135 sector=00000069
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=812974 required(DTS)=518400
++ WARN: [mplex] Video e0: buf= 2025 frame=000135 sector=00001570
++ WARN: [mplex] Audio bd: buf= 0 frame=000165 sector=00000084
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=960430 required(DTS)=604800
++ WARN: [mplex] Video e0: buf= 2020 frame=000160 sector=00001854
++ WARN: [mplex] Audio bd: buf= 0 frame=000196 sector=00000100
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=1107886 required(DTS)=694800
++ WARN: [mplex] Video e0: buf= 2025 frame=000184 sector=00002138
++ WARN: [mplex] Audio bd: buf= 0 frame=000228 sector=00000116
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=1255342 required(DTS)=784800
++ WARN: [mplex] Video e0: buf= 2015 frame=000210 sector=00002422
++ WARN: [mplex] Audio bd: buf= 0 frame=000259 sector=00000132
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=1402798 required(DTS)=874800
++ WARN: [mplex] Video e0: buf= 2025 frame=000234 sector=00002706
++ WARN: [mplex] Audio bd: buf= 0 frame=000290 sector=00000148
++ WARN: [mplex] Stream e0: data will arrive too late sent(SCR)=1550254 required(DTS)=964800
++ WARN: [mplex] Video e0: buf= 2020 frame=000260 sector=00002991
++ WARN: [mplex] Audio bd: buf= 0 frame=000320 sector=00000163
**ERROR: [mplex] Too many frame drops -exiting

45tripp · Dolphin Blue Joined: 21 Dec 2004 Location: Triptonia

ask to be moved to the mac forum.

have no idea what imovie or idvd take as input.

looks like mplex needs -r to be raised,
don't know how you'd do that with ffmpegx. or what ffmpegx is doing,
if you have high bitrate spikes,

a sample might be useful.

given mpeg streamclip a try to see what it can do for you?

tripp

cefn · Member Joined: 30 May 2008 Location: United Kingdom

At this stage, though, iMovie and iDVD haven't really come into the mix.

Even demuxing the video and re-muxing it into a standalone MPEG2 file with audio seems to be impossible with FFMpegX (mplex), even though it's the same tool which is doing the demux from the DVD VOB in the first place.

For now, I'm assuming iMovie/iDVD will handle a playable video file in MPEG2 format, and if not I'll look at using different editing packages instead once I've got the MPEG2 out.

The first objective is to start with a VOB and be able to get the Mpeg2 and audio streams out of the VOB and into a self-contained video file without re-encoding - suitable for some or other editor. A self-contained video file suitable for a player would be my first diagnostic step - if it won't play then I doubt I can import it to an editor.

So far I haven't managed to extract a combined video+audio file from the VOB which is playable.

Even better would be to get video clips out from a VOB based on the chapter markers, but I'll probably have to do this manually from what I can work out.

I've had a go demuxing with Mpeg Streamclip before and it generates m2v files which throw errors from Quicktime 'this is not a movie clip', along with all the normal 'you don't have an Mpeg2 codec installed' complaints. Hence I was trying to have it remuxed with a different tool to see if mplex would write decent headers which a player could handle.

It could be that FFMpegX is hiding options which I need to invoke on mplex, which might be a better issue to raise on a Mac forum. I'll have a look at that.

45tripp · Dolphin Blue Joined: 21 Dec 2004 Location: Triptonia