[FFmpeg-user] DV playback rate issues, timecode is invalid

Dragan Randjelovic logicomyu at gmail.com
Thu Jan 19 12:37:23 EET 2023


>From my experience with dv and dvcam tapes I would recommend capturing DV
with  Enosoft DV Processor  in a raw dv stream (extension *.dv)
and then process it with ffmpeg or ffmbc.

However, the problem that you are experiencing might be related to the
audio resampling, since video goes normally as far as I can see.

Mind that DV cam specification supports 4 channels at 32Khz and 12 bits, or
2 channels at 48Khz 16bit.

therefore when you map streams from avi or .dv file put something like
this: ffmpeg -i "file.dv" -map 0 -c:v copy -c:a pcm_s16le outputfile.mov
(or outputfile.mxf)
(resampling will be invoked automatically or you may specify it with -ar
48000 or using sox library)

You may transcode outputfile  to whatever format you like or keep it like
that as intermediate format suitable for editing.

It looks to me that audio resampling was not done correctly prior to muxing.

Regards.
Dragan

On Thu, Jan 19, 2023 at 10:05 AM Stuart Robinson <Stuart.Robinson at ed.ac.uk>
wrote:

>  I am having terrible trouble with a long play DV I have captured that I
> am trying to transcode. It seems to be playing back slowly regardless of
> what I've tried. The original also plays back strangely, it was captured
> with ffmpeg from a dv camcorder.
>
>
>
> https://drive.google.com/file/d/1ya2C6JmbBQuRUJ_U-fJT8XODYVw0U1kr/view?usp=sharing
> [
> https://lh3.googleusercontent.com/2Z8CVgH_AoIH1LrOrsKKyOeyPmv6bNovZD9akGxW3FD_b0aqhfwUxCGUHIzzrcPW1Tg=w1200-h630-p
> ]<
> https://drive.google.com/file/d/1ya2C6JmbBQuRUJ_U-fJT8XODYVw0U1kr/view?usp=sharing
> >
> Test1.dv<
> https://drive.google.com/file/d/1ya2C6JmbBQuRUJ_U-fJT8XODYVw0U1kr/view?usp=sharing
> >
> drive.google.com
> Can someone take a look and let me know what might help? Are the first few
> frames throwing it off somehow?
>
> Thanks for any help.
>
> Stuart
>
> --
>
> Thanks,
>
>         Stuart Robinson,
>
>         AV Technician,
>
>         Sound Lab,
>
>         School of Scottish Studies,
>
>         University of Edinburgh,
>
>         29 George Square,
>
>         Edinburgh,
>
>         EH8 9LD
>
>
>
>         0131 651 5001
>
>
>
>
>
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>
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