[FFmpeg-user] can't reorder streams and concatenate vob's

[sean darcy]

On 11/8/18 5:34 PM, Nicolas George wrote:
> sean darcy (2018-11-08):
>> Ok. So is it possible to concatenate 2 vob's where the audio and video don't
>> have the same stream numbers ?
> 
> VOB do not have stream numbers (FFmpeg is inventing them on the fly), so
> the question does not make any sense.
> 
>> for input in *.VOB ; do
>>    ffmpeg -i $input -c copy  $(basename $input .VOB).[???]
>>    echo $(basename $input .VOB).[???] >> concat.txt
>> done
>> ffmpeg -f concat -i concat.txt ..........    out.mp4
>>
>> Bigger question : is the concatenation problem here the stream numbers ?
> 
> In this instance, if the files are the ones you have shown earlier,
> yes, the order in which FFmpeg detects the streams is the problem.
> 
> I suggest you read the documentation of the concat demuxer to the end,
> the answer to your question is there.
> 
> Note that VOB files are also concatenable at the container level,
> provided they do not contain extra junk at the beginning or the end (if
> you got them directly from a DVD Video filesystem, they do and you
> should NOT be using them directly).
> 
> Regards,
> 

On 11/8/18 5:34 PM, Nicolas George wrote:
 > sean darcy (2018-11-08):
 >> Ok. So is it possible to concatenate 2 vob's where the audio and 
video don't
 >> have the same stream numbers ?
 >
 > VOB do not have stream numbers (FFmpeg is inventing them on the fly), so
 > the question does not make any sense.
 >
 >> for input in *.VOB ; do
 >>    ffmpeg -i $input -c copy  $(basename $input .VOB).[???]
 >>    echo $(basename $input .VOB).[???] >> concat.txt
 >> done
 >> ffmpeg -f concat -i concat.txt ..........    out.mp4
 >>
 >> Bigger question : is the concatenation problem here the stream numbers ?
 >
 > In this instance, if the files are the ones you have shown earlier,
 > yes, the order in which FFmpeg detects the streams is the problem.
 >
 > I suggest you read the documentation of the concat demuxer to the end,
 > the answer to your question is there.
 >
 > Note that VOB files are also concatenable at the container level,
 > provided they do not contain extra junk at the beginning or the end (if
 > you got them directly from a DVD Video filesystem, they do and you
 > should NOT be using them directly).
 >
 > Regards,
 >

Thanks for the help. I've set up a complex filter. That works.

But following up on:

 > if you got them directly from a DVD Video filesystem ... you
 > should NOT be using them directly

So for vob's from a video dvd :

cat VTS* | ffmpeg -i - ........... out.mp4

or

ffmpeg -f concat -i list.of.vobs  ...... out.mp4

is not a good idea ? Even though it does not generate any errors.

I should be using a complex filter for any vob's from a video dvd ? Who 
knew ?