> From: Rogozhkin, Dmitry V > Sent: Wednesday, October 31, 2018 2:07 AM > To: Li, Zhong <zhong...@intel.com>; ffmpeg-devel@ffmpeg.org > Subject: Re: [FFmpeg-devel] [PATCH 1/5] lavc/qsvenc: add forced_idr opiton > > On Tue, 2018-10-30 at 18:05 +0800, Li, Zhong wrote: > > > > + } else > > > > + enc_ctrl->FrameType = > MFX_FRAMETYPE_UNKNOWN; > > > > > > "else" block don't make much sense to me. You eventually already had > > > enc_ctrl structure passed to the encoder. Thus, it should be > > > initialized to default (already). And you don't make anything > > > specific/new in the "else". > > > From my perspective "else" just obscures the code and should be > > > dropped. > > > > This was a case I had concern. I doubt the default initialization is > > always zero (you know MFX_FRAMETYPE_UNKNOWN is zero). Isn't it > > possible? > > Please check the regression case I fixed: https://patchwork.ffmpeg.or > > g/patch/10517/ > > Patch 10517 deals with unitialized variable on a compilation level. As for the > enc_ctrl I very much hope that ffmpeg-qsv code takes care to memset the > mfcEncodeCtrl (as well as all other mediasdk structures) _before_ usage. I.e. > there should be a code somewhere similar to: > memset(enc_ctrl, 0, sizeof(mfxEncodeCtrl)); If this is missing, there is a > VERY big problem in the QSV code since indeed compiler may initialize > structures to everything it wants and there will be very bad consequences. > > As for the usage of mfxEncodeCtrl, the idea is the following. User allocates > this control and memsets it to 0. If this will be passed in that way mediasdk > will change nothing to encode the frame. If user wants to change some > parameter, it can do this changing only the parameter it wants to take effect. > So, the "else" should really not be needed. > > Dmitry.
Yup, we are on the same page now to avoid uninitialized value. Memset is a good idea, will update. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
