[FFmpeg-devel] [PATCH] matroskadec, matroskadec, srtenc: Read/Write duration for subtitles. (v2)

Hendrik Leppkes h.leppkes at gmail.com
Sun Aug 5 09:07:25 CEST 2012

On Sun, Aug 5, 2012 at 6:25 AM, Philip Langdale <philipl at overt.org> wrote:
> The original claim was that convergence_duration was needed to avoid
> overflow on long duration subtitles. This claim seems questionable.
> If we consider the typical timebase of 1/1000, that still allows
> for a duration of 8 years. For a 1/1000000 timebase, you still get
> a 71 minute maximum duration, so I'm not sure where this claim
> originated from. Only if you go down to a 1ns timebase do you end
> up with a short max duration of ~4 seconds. Am I missing something?
There are files with such a timebase. It may not be common, but they do
exist and they are valid according to the MKV spec.
So, yes, it is needed for such files, until such a day when the real
duration is converted to int64 (if ever)

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