[FFmpeg-devel] Patch: add AVOption for extra video descriptors in MPEGTS PMT

[Michael Niedermayer]

On Thu, May 24, 2012 at 08:02:06PM -0400, Jason Livingston wrote:
> On Wed, May 23, 2012 at 03:19:13PM +0200, Michael Niedermayer wrote:
> > this looks like a buffer overflow to me
> > theres nothing checking that q is large enough for the user specified
> > data that is put into it
> 
> Good point, thanks Michael.  Fixed in the attached revision.
> 
> > also do you have a testcase for this feature ?
> 
> I can probably put together some sample ATSC streams that contain the
> extra descriptors that I'd like to insert.
> 
> I'm trying to implement some of the required descriptors for ATSC or
> SCTE spec transport streams.
> E.g.: http://www.etherguidesystems.com/Help/SDOs/atsc/semantics/descriptors/Default.aspx
> 
> This won't make the MPEGTS muxer fully ATSC/SCTE spec compliant yet
> but maybe a small step in the right direction.  If it's a problem, I
> can wrap the changes in ifdef, but if the option is not used it will
> have zero effect on the output.
> 
> Perhaps a more robust solution would be to implement each
> ATSC/SCTE/DVB optional/required descriptor as a separate option in the
> MPEGTS muxer, but there are quite a few of them and this will add a
> lot of options. :)

I think required descriptors should be generated automatically
for example when the muxer would be set to a ATSC compliant mode it
should generate all stuff that is needed to be ATSC compliant.
Well or at least try to as far as its implemented ...

specifying stuff via base64 encoded options is more for free form
user data or stuff for which no existing means/API exists

[...]

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