[FFmpeg-devel] [PATCH] mkv 0-byte integer parsing

Måns Rullgård mans
Tue Sep 7 21:19:28 CEST 2010

Reimar D?ffinger <Reimar.Doeffinger at gmx.de> writes:

> On Tue, Sep 07, 2010 at 08:12:49PM +0200, Sebastian Hagen wrote:
>> On 2010-09-05 16:22, Sebastian Hagen wrote:
>> >with a length of 0 bytes correctly, even though those are valid
>> >according to the Matroska specs[1] and mkv files containing them can be
>> My bad, that statement was incorrect. Such integers are valid
>> according to the EBML specs[1], but not the matroska ones[2], since
>> the latter gratuituously set a minimum uint size of 1 byte.
>> Nevertheless, while such elements are technically invalid, some
>> demuxers will happily accept them, and the robust thing to do would
>> be for ffmpeg to do the same.
> In that case it would actually be good to warn, it is preferable
> to warn about technically invalid files otherwise people will generate
> them without noticing and the format will over time become more and
> more painful to support.

This assumes people pay any heed whatsoever to warnings.  In actual
practice they do not.  It is thus in my opinion preferable to fail
with an error message for such files, optionally providing an
unwieldy, hard to find setting to reluctantly accept these files
regardless.  It is the only way to be sure.  Unless we nuke them from

M?ns Rullg?rd
mans at mansr.com

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