> -----Original Message-----
> From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On Behalf
> Of Vittorio Giovara
> Sent: Wednesday, January 02, 2019 11:13 PM
> To: FFmpeg development discussions and patches <ffmpeg-
> de...@ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH V4 1/2] avutil: add ROI data struct and
> bump version
>
> On Fri, Dec 28, 2018 at 3:17 AM Guo, Yejun <yejun....@intel.com> wrote:
>
> > The encoders such as libx264 support different QPs offset for
> > different MBs, it makes possible for ROI-based encoding. It makes
> > sense to add support within ffmpeg to generate/accept ROI infos and
> > pass into encoders.
> >
> > Typical usage: After AVFrame is decoded, a ffmpeg filter or user's
> > code generates ROI info for that frame, and the encoder finally does
> > the ROI-based encoding.
> >
> > The ROI info is maintained as side data of AVFrame.
> >
> > Signed-off-by: Guo, Yejun <yejun....@intel.com>
> > ---
> > libavutil/frame.c | 1 +
> > libavutil/frame.h | 23 +++++++++++++++++++++++
> > libavutil/version.h | 2 +-
> > 3 files changed, 25 insertions(+), 1 deletion(-)
> >
> > diff --git a/libavutil/frame.c b/libavutil/frame.c index
> > 34a6210..bebc50e 100644
> > --- a/libavutil/frame.c
> > +++ b/libavutil/frame.c
> > @@ -841,6 +841,7 @@ const char *av_frame_side_data_name(enum
> > AVFrameSideDataType type)
> > case AV_FRAME_DATA_QP_TABLE_DATA: return "QP table
> > data";
> > #endif
> > case AV_FRAME_DATA_DYNAMIC_HDR_PLUS: return "HDR Dynamic
> Metadata
> > SMPTE2094-40 (HDR10+)";
> > + case AV_FRAME_DATA_ROIS: return "Regions Of Interest";
> > }
> > return NULL;
> > }
> > diff --git a/libavutil/frame.h b/libavutil/frame.h index
> > 582ac47..3460b01 100644
> > --- a/libavutil/frame.h
> > +++ b/libavutil/frame.h
> > @@ -173,6 +173,12 @@ enum AVFrameSideDataType {
> > * volume transform - application 4 of SMPTE 2094-40:2016 standard.
> > */
> > AV_FRAME_DATA_DYNAMIC_HDR_PLUS,
> > +
> > + /**
> > + * Regions Of Interest, the data is an array of AVROI type, the
> > + array
> > size
> > + * is implied by AVFrameSideData::size / sizeof(AVROI).
> > + */
> > + AV_FRAME_DATA_ROIS,
> >
>
> Any chance i could convince you of unfolding this acronym into
> AV_FRAME_REGIONS_OF_INTEREST (and AVRegionOfInterest)?
> When I first read it I thought you were talking about Return of Investments
> or Request of Invention, which were mildly confusing.
thanks, sure, will change to AV_FRAME_DATA_REGIONS_OF_INTEREST and
AVRegionOfInterest
>
> The "AVFrameSideData::size" is a C++-ism, could you please use
> "AVFrameSideData.size" like elsewhere in the header?
ok, will change it.
>
> You should probably document that sizeof() of this struct is part of the
> public
> ABI.
thanks for catching this issue, it is not ABI compatible if a new data member
is later added into
struct AVRegionOfInterest. will response in following emails.
>
>
> > };
> >
> > enum AVActiveFormatDescription {
> > @@ -201,6 +207,23 @@ typedef struct AVFrameSideData { }
> > AVFrameSideData;
> >
> > /**
> > + * Structure to hold Region Of Interest.
> > + *
> > + * top/bottom/left/right are coordinates at frame pixel level.
> >
>
> what does "pixel level" mean? May I suggest better wording?
>
> Number of pixels to discard from the the top/bottom/left/right border of
> the frame to obtain the region of interest of the frame.
thanks., much better than mine, will use it.
>
> + * They will be extended internally if the codec requires an alignment.
> > + * If the regions overlap, the last value in the list will be used.
> >
>
> Isn't this encoder dependent too?
yes, and will add to notes explicitly.
>
>
> > + *
> > + * qoffset is quant offset, it is encoder dependent.
>
> + */
> > +typedef struct AVROI {
> > + size_t top;
> > + size_t bottom;
> > + size_t left;
> > + size_t right;
> > + int qoffset;
> >
>
> so int instead of float?
I used float in very early version and got feedback to use int. I'm open to
both, I'll change to float since two comments till now ask for float.
>
> +} AVROI;
> > +
> > +/**
> > * This structure describes decoded (raw) audio or video data.
> > *
> > * AVFrame must be allocated using av_frame_alloc(). Note that this
> > only diff --git a/libavutil/version.h b/libavutil/version.h index
> > f997615..1fcdea9 100644
> > --- a/libavutil/version.h
> > +++ b/libavutil/version.h
> > @@ -79,7 +79,7 @@
> > */
> >
> --
> Vittorio
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