[FFmpeg-devel] [PATCH 1/2] Revert "avcodec/qtrle: Do not output duplicated frames on insufficient input"

[Kieran Kunhya]

>
> if you dont return 3 fields you break the normative specification. This
> speaks
> about the "output of the decoding process" not how to interpret the output.
>
> I bring MPEG2 up here because we dont do what the normative spec says
> because it doesnt make sense for us. It does make sense if you output on a
> analoge interlaced PAL/NTSC screen. It is fundamentally the same as the
> CFR case, on one side a interlaced display as factor on the other a output
> only capable to handle fixed duration (CFR) frames.
>
> About CFR codecs, the cases this is about are generally input packets that
> code the equivalent of "nothing changed". In frameworks that allow only CFR
> an implementation would produce a duplicated frame. In frameworks that
> allow
> VFR an implementation can omit the duplicated frame.
>

I don't really care about qtrle here but this is not comparable.
If you are a cfr output device, you *know* that you have to duplicate a
field because of the flag that's exported and this duration is clearly
defined.
But with the qtrle patch, you don't know how long the duration of the frame
just returned is.

Kieran