> -----Original Message----- > From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On Behalf Of > Hendrik Leppkes > Sent: Monday, April 8, 2019 5:27 PM > To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> > Subject: Re: [FFmpeg-devel] [PATCH RFC v2 2/3] libavcodec: Add thumbnail > output to vaapi_h264 decoder > > On Mon, Apr 8, 2019 at 10:54 AM Zachary Zhou <zachary.z...@intel.com> > wrote: > > > > This is sample code for reference > > > > HW support for decode+scaling in a single HW command (VDBOX+SFC). > > The primary target usage is video analytics, but can be used playback, > > transcoding, etc. > > > > For VAAPI - > > https://github.com/intel/libva > > basically, it allows multiple outputs (in different resolutions) using the > decode context in a single call (you can search for “additional_outputs” in > va.h). > > > > VAAPI sample code - > > https://github.com/intel/libva-utils/commit/957a269f02b00760b7e807643c > > 821ee26abc529b > > --- > > libavcodec/avcodec.h | 8 +++ > > libavcodec/decode.c | 16 +++++ > > libavcodec/options_table.h | 4 ++ > > libavcodec/vaapi_decode.c | 122 > > ++++++++++++++++++++++++++++++++++--- > > libavcodec/vaapi_decode.h | 30 +++++++++ > > libavcodec/vaapi_h264.c | 13 ++++ > > 6 files changed, 185 insertions(+), 8 deletions(-) > > > > diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h index > > 0ce22ec4fa..36db21c0a5 100644 > > --- a/libavcodec/avcodec.h > > +++ b/libavcodec/avcodec.h > > @@ -3357,6 +3357,14 @@ typedef struct AVCodecContext { > > * - encoding: unused > > */ > > int discard_damaged_percentage; > > + > > + /* > > + * Thumbnail options > > + */ > > + int thumbnail_flags; > > + int thumbnail_format; > > + int thumbnail_width; > > + int thumbnail_height; > > } AVCodecContext; > > > > Global fields for such a purpose seem not appropriate. We try to get away > from fields that only serve a single purpose with a single decoder. Nevermind > that they aren't even documented. > > In general I must say I'm not sure I like this entire patchset. We have > component seperation for a reason, so trying to add magic features like that > is > generally a bad idea. > > - Hendrik
Thanks Hendrik for the comments. currently I didn't find any good places to set input parameters for decoder, in this feature I think the end user may want to set the scaling size and out format. And I don't know if ffmpeg will add better decoder input parameters control in future. This feature will also save the scaling filter code writing for the end user. -Zach > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org > with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".