[FFmpeg-user] Muxing audio-only MXF

[Robert Krüger]

Hi Erik,

On Fri, Dec 1, 2017 at 12:25 PM, Erik Dobberkau <erik.dobberkau at gmail.com>
wrote:

> Am Freitag, 1. Dezember 2017 schrieb Robert Krüger :
>
> > Hi Kieran,
> >
> > On Thu, Nov 30, 2017 at 5:39 PM, Kieran O Leary <
> kieran.o.leary at gmail.com
> > <javascript:;>>
> > wrote:
> >
> > > On Thu, Nov 30, 2017 at 4:38 PM, Kieran O Leary
> > > <kieran.o.leary at gmail.com <javascript:;>> wrote:
> > > > Hi,
> > > >
> > > > On Thu, Nov 30, 2017 at 3:46 PM, Robert Krüger
> > > > <krueger at lesspain.software> wrote:
> > > >> Hi,
> > > >>
> > > >> is there a way to mux an mxf file only containing a pcm audio
> stream?
> > > When
> > > >
> > > > You could try using the op-atom muxer as it looks like your command
> is
> > > > defaulting to op1a. Add -f  mxf_opatom to your command line.
> > > > ffmpeg -i
> > > > /Users/krueger/lesspain/samples/software/compressor/
> > > compressor4_1080_25p_apple_devices_best_compat_2s.m4v
> > > > -vn -c:a pcm_s16le -f mxf_opatom ~/tmp/ffmpeg_pcm16_rewrap.mxf
> > > >
> > > > [...]
> > > >
> > > >>
> > > >> Is this a conscious limitation of the muxer or am I missing a
> command
> > > line
> > > >> option?
> > > >>
> > > >
> > > > It looks like it. The reasons why I suggested trying OP-Atom is that
> > > > this seems to be performing a specific check for OP1a.
> >
> >
> Which is wrong, btw. There is a spec for MXF_OP1a_AES3 to wrap the
> respective audio without a picture essence. I would guess MCA labels will
> have to be provided though, and also the audio samples would have to be
> formatted to AES, which ffmpeg afaik currently doesn't do.
>
> Best,
> Erik
>
>
tanks a lot for the additional info! In my case, it's fine for my limited
scope of application where I need to generate audio-only MXF files that
just need to be decodable by ffmpeg for internal testing purposes, so I'm
still OK with what it does now but I will keep that in mind for later when
we might want to do more with it.

Best,
Robert