[FFmpeg-user] Piping output of ffmpeg into ffmbc

[Keith Reilly]

Erik,
      This is a major step for me in that i got Avid to fast import media
that could be played back when created from ffmpeg. With your command minus
line 5, [-rc_max_vbv_use 1 -rc_min_vbv_use 1 -rc_buf_aggressivity 0.25], I
was able to do this. I do however have a few issues.  FYI with line 5 I get
an error from the output of ffmpeg:
[NULL @ 0x7ff76100d200] Unable to find a suitable output format for
'[-rc_max_vbv_use'
[-rc_max_vbv_use: Invalid argument
I'm not concerned by this since it works fine omitting this as it did for
you.
       The issue i have now is with the padding, the image needs to be
manipulated by the editors to get it centered creating extra steps we'd
rather do without. I thought this would be simple enough to fix but now i'm
getting an education on imx video and how Avid handles them. I'm still not
%100 clear on how things are working so let me go over the steps with you
on what i did and you can tell me if I got the right conclusion.
        With your video filters line, "scale=720:576:interl=0:in_
color_matrix=bt709:out_color_matrix=bt601,pad=720:608:0:32,
tinterlace=4:flags=vlpf,setdar=16/9", i changed scale=720:576 to 720:486
since when i looked up what the NTSC standard for IMX was i read it was
720X486. This worked find with your padding but when i take that out Avid
will fast import but not playback. After comparing this output from ffmpeg
(720x486 with no padding) to the ffmbc counterpart i saw that the
resolution of ffmbc was actually 720x512. So when I changed this in ffmpeg,
scale=720:512, i can fast import and playback just fine. The problem there
is that the aspect ratio is slightly off and the very top of the image is
cut off. Also i took note that Avid reports this file with a raster of
720x486 even though it is clearly 720x512.
        My conclusion is that with Avid, when using the IMX format, it will
ignore the top 24 lines of resolution. So I need to create a video that
has, at least for NTSC, 24 lines of padding at the top since Avid will
treat the video as 720:486 by cutting off the top. This seems insane but
that is what i'm looking at. I can clearly see the top of the video in VLC
but in Avid it is gone.  And I think the reason why the image is not
centered with your command is because i change the scale for NTSC but not
the padding and it threw everything off. Is this correct? It looks like it
is to me from all the testing i did but it seems so strange that things
would behave this way. I tried to google this but it did not clear anything
up.
       Again thanks for all your help. I know this was a lengthy response.
Thanks for reading

Keith

On Tue, Aug 23, 2016 at 4:13 PM, Erik Dobberkau <erik.dobberkau at gmail.com>
wrote:

> > 2016-08-23 9:45 GMT+02:00 Erik Dobberkau <erik.dobberkau at gmail.com
> > <javascript:;>>:
> >
> > > With the (as of testing a few days ago) latest ffmpeg Win build (3.0.2)
> >
> > 3.0.2 is six months old.
> >
> > Please consider cutting your quotes, Carl Eugen
> >
>
> Sure.
> Last downloaded on Aug 8, 2016 --- whatever this (zeranoe) build's version
> no. is...should be 3.1.x I guess.
>
> Erik
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