[FFmpeg-devel] [PATCH] movenc: Fix muxing of Apple Quicktime chapters.

Philip Langdale philipl at overt.org
Thu May 17 02:46:19 CEST 2012

On Thu, 17 May 2012 02:28:11 +0200
Michael Niedermayer <michaelni at gmx.at> wrote:

> On Sun, May 13, 2012 at 05:51:27PM -0700, Philip Langdale wrote:
> > On Mon, 14 May 2012 09:48:06 +0900
> > Yusuke Nakamura <muken.the.vfrmaniac at gmail.com> wrote:
> > 
> > > 
> > > For 3GPP timed text, atom type tag of the sample description is
> > > 'tx3g', not 'text'.
> > 
> > Your statement is correct in isolation, but in the context of
> > Apple's chapter format, they use and expect 'text'. This isn't a
> > real subtitle track.
> The check for extradata to determine if its a subtitle or chapter
> track seems fragile. 

My rationale here is that if there's no extradata, the track is not
valid - as it needs this data, regardless of whether it is a subtitle
or chapter track. In practice it's a flat out bug if a subtitle track
is fed in without the extradata. ie: It's not a check for subtitle
vs chapter

> have you tested this with a few different players to make sure it
> has no negative sideeffects ?

Yes, I've tested with the usual suspects (but let's be honest, the
open-source players are extremely tolerant - and already worked fine
with the old broken chapters). The apple players work correctly after
the patch.
> but in the absence of further comments iam in favor of applying this

Thanks. I'll do some more testing and push once that's verified.


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