[FFmpeg-user] How to set FLAC --no-padding equivalent switch in FFMPEG?

Барт Гопник bart.gopnik at gmail.com
Sun Dec 29 14:20:18 CET 2013

It is strange that FFMPEG don't show any warnings when user use greater
than 8 value of -compression_level switch in flac codec (if FFMPEG with
these values REALLY produces "non-subset files").

> When I said ID3 I meant ID3, specifically ID3v2 and an equivalent of lame's
--pad-id3v2-size option.
Sorry for my inattention. :-[

FFMPEG's FLAC encoder support variable block size encoding?

I've found this awesame document (
It would be nice if somebody add it to FFMPEG documentation.

2013/12/29 James Darnley <james.darnley at gmail.com>

> On 2013-12-29 08:42, Барт Гопник wrote:
> > I know that FFMPEG doesn't use LibFLAC and has its own FLAC codec based
> on
> > source code of Flake (http://flake-enc.sourceforge.net/). But it's a
> pain
> > in the ass to find any info on Flake encoder options.
> For specific options for flac you can see them by running:
> ffmpeg -h encoder=flac
> You can see other options for other components in a similar way.
> -compression_level is a common option so it doesn't shiow under these
> and then you have to guess what it might control or just read it from
> the source.
> > "equivalent options" = options produced equivalent (not bit-by-bit
> > identical streams, but have comparable compress ratio) output.
> >
> > Maximum value of -compression_level option in LibFLAC is 8, maximum value
> > of -compression_level option in Flake and FFMPEG is 12.
> >
> > Is FLAC files compressed by FFMPEG with -compression_level 12 compatible
> > with reference FLAC decoders and hardware implimentation?
> > Should I use -compression_level 8 instead of -compression_level 12 for
> > saving compatibility (is -compression_level 8 in FFMPEG equivalent to
> > -compression_level in LibFLAC in this regard)?
> If I remember using flake correctly I think that using anything greater
> than 8 (the max in libflac) produces what the flac project calls
> "non-subset files".  The flac project gives lots of warning about these
> files.  I don't know if they actually present any problems for hardware
> decoders.
> 12 doesn't compress much more than 8 so if you are worried about this
> then stick with 8.
> If you really want to know ask somewhere more dedicated than ffmpeg's
> support list.  Perhaps try Hydrogenaudio.
> >> It should be simple(ish) to add a control for the padding.  I can do it
> > if people want it.
> >
> > It would be nice! Could you please add a control for the padding in FLAC
> > (equivalent to --no-padding swith in LibFLAC)? ;)
> I shall get my environment set up again
> >> I have also considered padding for ID3 tags on mp3 files.
> >
> > Did you mean MP3 Header (http://gabriel.mp3-tech.org/mp3infotag.html)
> > instead of leading padding (silence to the beginning of each song)?
> > MP3 header is very useful thing. It must be enabled for VBR (VBR MP3
> files
> > without Xing tag are unusable) and should be (very recommended) for CBR
> MP3
> > files. But I think users should still be able to control (enable/disable)
> > MP3 header. Could you please add a control MP3 header (equivalent to -t
> > swith in LAME)?
> When I said ID3 I meant ID3, specifically ID3v2 and an equivalent of
> lame's --pad-id3v2-size option.
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