[FFmpeg-devel] [PATCH 0/2]: allow hwaccel vda module to manage its buffers lifetime.

[Xidorn Quan]

On Fri, May 24, 2013 at 6:42 AM, Sebastien Zwickert <dilaroga at gmail.com>wrote:

>
> On May 23, 2013, at 9:21 AM, Xidorn Quan <quanxunzhen at gmail.com> wrote:
>
> > On Thu, May 23, 2013 at 3:19 PM, Hendrik Leppkes <h.leppkes at gmail.com
> >wrote:
> >
> >> On Thu, May 23, 2013 at 9:14 AM, Sebastien Zwickert <dilaroga at gmail.com
> >
> >> wrote:
> >>> On May 23, 2013, at 8:29 AM, Hendrik Leppkes <h.leppkes at gmail.com>
> >> wrote:
> >>>> On Wed, May 22, 2013 at 9:53 PM, Sebastien Zwickert <
> dilaroga at gmail.com>
> >> wrote:
> >>>>> This patchset fixes memory leaks of vda core video buffers while
> >> seeking.
> >>>>> It allows hwaccel modules to set a custom callback for freeing av
> >> buffers.
> >>>>> Then vda decoder can flush correctly dropped frames.
> >>>>>
> >>>>> Thanks to Xidorn Quan who gives me good feebacks about the patch I
> >> shared
> >>>>> with him in private.
> >>>>>
> >>>>> Sebastien Zwickert (2):
> >>>>> hwaccel: allow to set a user-defined callback for releasing private
> >>>>>   av buffer.
> >>>>> vda: use hwaccel custom callback for releasing private picture
> >>>>>   context.
> >>>>>
> >>>>> libavcodec/avcodec.h   |   12 ++++++++++++
> >>>>> libavcodec/h264.c      |    9 ++++++++-
> >>>>> libavcodec/mpegvideo.c |    9 ++++++++-
> >>>>> libavcodec/vda.h       |   12 +++++++++++-
> >>>>> libavcodec/vda_h264.c  |   18 ++++++++++++++++++
> >>>>> 5 files changed, 57 insertions(+), 3 deletions(-)
> >>>>>
> >>>>> --
> >>>>> 1.7.9.6 (Apple Git-31.1)
> >>>>>
> >>>>> _______________________________________________
> >>>>> ffmpeg-devel mailing list
> >>>>> ffmpeg-devel at ffmpeg.org
> >>>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >>>>
> >>>> You set frame->data[3] to the same buffer that needs freeing, why not
> >>>> simply also set frame->buf appropriately to a AVBufferRef you create,
> >>>> so that it gets free'ed with a callback there?
> >>>> No extra release buffer callback needed from where i stand.
> >>>
> >>> I'm not sure to understand correctly but the vda buffer is part of
> >>> Core Video SDK which is based on a ref counted memory management
> >>> and must be released with CVPixelBufferRelease().
> >>> So custom callback for freeing Core Video types is necessary.
> >>>
> >>
> >> You can do that if you just create a AVBufferRef around your buffer
> >> (you can specify a release callback for AVBufferRefs) and put it
> >> somewhere in frame->buf, it'll be free'ed with the frame then.
> >> I'm not really liking the new function in AVHWAccel, because its not
> >> really required with the new buffer management functions.
> Ok it makes sense.
>
> >>
> >> Considering frame->data[3] is set by the code, i think its safe to
> >> also set frame->buf[3] to the AVBufferRef managing this buffer without
> >> worrying about user-code.
> >>
> >
> > So you may like to have a look at my solution here:
> > http://ffmpeg.org/pipermail/ffmpeg-devel/2013-May/143988.html
>
> This patch applies what you explain here and works fine.
>

I have an idea: we can drop the first patch of your patchset and use
hwaccel_priv_buf directly like how I use frame->buf in my patch.
What do you think?

-- 
Xidorn Quan
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