2019-01-14 9:03 GMT+01:00, Fu, Linjie <[email protected]>: >> -----Original Message----- >> From: ffmpeg-devel [mailto:[email protected]] On Behalf >> Of Li, Zhong >> Sent: Friday, January 11, 2019 11:43 >> To: FFmpeg development discussions and patches <ffmpeg- >> [email protected]> >> Subject: Re: [FFmpeg-devel] [FFmpeg-cvslog] lavc/qsvenc: add VDENC >> support for H264 >> >> > From: ffmpeg-devel [mailto:[email protected]] On >> Behalf >> > Of Carl Eugen Hoyos >> > Sent: Friday, January 11, 2019 10:39 AM >> > To: FFmpeg development discussions and patches >> > <[email protected]> >> > Subject: Re: [FFmpeg-devel] [FFmpeg-cvslog] lavc/qsvenc: add VDENC >> > support for H264 >> > >> > 2019-01-11 3:28 GMT+01:00, Li, Zhong <[email protected]>: >> > >> From: ffmpeg-devel [mailto:[email protected]] On >> > Behalf >> > >> Of Carl Eugen Hoyos >> > >> Sent: Friday, January 11, 2019 1:06 AM >> > >> To: [email protected] >> > >> Subject: Re: [FFmpeg-devel] [FFmpeg-cvslog] lavc/qsvenc: add VDENC >> > >> support for H264 >> > >> >> > >> 2019-01-10 14:51 GMT+01:00, Linjie Fu <[email protected]>: >> > >> >> > >> > +#if QSV_HAVE_VDENC >> > >> > + { "low_power", "enable low power mode(experimental: many >> > >> > +limitations by >> > >> > mfx version, BRC modes, etc.)", OFFSET(qsv.low_power), >> > >> > AV_OPT_TYPE_BOOL, { >> > >> > .i64 = 0 }, 0, 1, VE}, >> > >> > +#endif >> > >> >> > >> This seems wrong to me: The visibility of an option should probably >> > >> not depend on configuration details (the effect can of course depend >> > >> on many details). >> > >> >> > >> Carl Eugen >> > > >> > > That's is just a remind that this feature has some limitations. The >> > > configures are just to make driver to support this feature. >> > > In ffmpeg level, the only thing we should do IMHO is to query >> > > MSDK/Driver capability and report an error message if not supported. >> > > And it was done: >> > > >> > https://github.com/FFmpeg/FFmpeg/blob/395e8a53fa0266f26581f3e9752b >> > 0dbc >> > > 93998a90/libavcodec/qsvenc.c#L376 >> > >> > That is probably helpful, but the issue I try to explain is unrelated to >> > the >> > brokenness of the option: >> > Now, in some cases FFmpeg shows the option and in other cases it does >> not. >> > I believe that instead, the option should always be shown, even if it >> > does >> not >> > work. >> >> That is a big topic since I see many components are doing this. E.g; we >> can >> find some options of libx264 and nvenc are hided too. >> Personally speaking I like current way: if the implementation of an option >> is >> not built-in, it is not necessary to show the option, else it is really >> confusing >> that this option can't work at any case. >> But I am open to your suggestion, and looking forward more comments from >> you and others. (If we get alignment, we need to clear up many options, >> not >> only this one). > > Is it a possible way to show "not supported" info and set the option to > default off instead of just hiding the option? > > Like: > #if QSV_HAVE_VDENC > { "low_power", "enable low power mode (experimental, many limitations by > mfx version, HW platform, BRC modes, etc.)", OFFSET(qsv.low_power), > AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE}, > # else > { "low_power", "not supported", OFFSET(qsv.low_power), AV_OPT_TYPE_BOOL, > { .i64 = 0 }, 0, 0, VE}, > #endif
This is also an option but I wonder if a failure message wouldn't help users even more. Carl Eugen _______________________________________________ ffmpeg-devel mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
