[FFmpeg-devel] [PATCH] frame: Simplify the video allocation

[Maxym Dmytrychenko]

On Mon, Sep 3, 2018 at 10:17 AM Michael Niedermayer <michael at niedermayer.cc>
wrote:

> On Sun, Sep 02, 2018 at 09:34:23PM -0300, James Almer wrote:
> > From: Luca Barbato <lu_zero at gentoo.org>
> >
> > Merged-by: James Almer <jamrial at gmail.com>
> > ---
> > This is the next merge in the queue. It's a critical part of the AVFrame
> API,
> > so even if FATE passes I'd rather have others look at it and test in case
> > something breaks.
> >
> > The only difference compared to the libav commit is the "32 - 1" padding
> per
> > plane when allocating the buffer, which was only in our tree.
>
> why is the STRIDE_ALIGN (which is a thing in units of bytes along the
> horizontal axis) added to padded_height which is vertical axis ?
> This is not done prior to the change
>
> Also if this changes how buffers are structured or sized it requires a more
> detailed commit message than "frame: Simplify the video allocation"
>
>
If can help:
Use of av_image_fill_pointers() helps to allocate planes continuously
instead of separate allocation for each plane,
which can end up in very different start locations of the allocated memory.

Continuous allocation can be better for performance and/or functional sides
of the operations,
example of Intel's HW - QSV,
which is assuming Y/UV planes to be continuously allocated.




> thanks
>
> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> I have often repented speaking, but never of holding my tongue.
> -- Xenocrates
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thank you - James, Michael.

regards
Maxym