> -----Original Message----- > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of Fu, > Linjie > Sent: Tuesday, February 18, 2020 23:06 > To: FFmpeg development discussions and patches <ffmpeg- > de...@ffmpeg.org> > Subject: Re: [FFmpeg-devel] [PATCH, v2 2/4] avc/avcodec: add > AV_CODEC_CAP_VARIABLE_DIMENSIONS flag > > > -----Original Message----- > > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of > > Anton Khirnov > > Sent: Tuesday, February 18, 2020 21:32 > > To: FFmpeg development discussions and patches <ffmpeg- > > de...@ffmpeg.org> > > Subject: Re: [FFmpeg-devel] [PATCH, v2 2/4] avc/avcodec: add > > AV_CODEC_CAP_VARIABLE_DIMENSIONS flag > > > > Quoting Michael Niedermayer (2020-02-17 23:38:31) > > > On Mon, Feb 17, 2020 at 06:28:23PM +0000, Fu, Linjie wrote: > > > > > > > > > > https://patchwork.ffmpeg.org/patch/14122/ > > > > > > iam hesitating because it feeds encoders with changing resolution > resulting > > > in potentially undefined behavior ... > > > > > Any suggestions? > > > > > > > > https://patchwork.ffmpeg.org/patch/14139/ > > > > > > long discussion here its not immedeatly clear if anyone was against it > > Please help to give some inputs if this would leads to some unexpected > results from your point of view. > > > > Also there is the question about the API, is there anything in the API > > > documentation that restricts the user app from changing the encoder > > > input frame dimensions? > > > This should be documented somewhere if its not ... > > > > > > If a flag is added that affects this, it would have to > > > be documented so someone writing a user app using the encoders > > > would know if they are allowed to change the resolution. > > > With just the flag and its documentation a developer could miss > > > the flag entirely > > Since I didn't find the descriptions in doxygen: > https://ffmpeg.org/doxygen/trunk/group__lavc__encoding.html#ga4fde50 > e2cad4cf3d66d882a7078aeab4 > > The things should be done seem to be: > > [1]. Documentation in API, to declare that encoders require input frame to > be in constant dimensions, unless the encoders have the capability of > dynamic resolution encoding [2]. > > [2]. Documentation in API, to declare this codec flag would affect the > restrict > in [1]. > > If it's ok, I'll update the patch with the documentations added. >
Update the patch with API documentations added. And add checks to make sure it won't result into undefined behavior. As to the support for more encoders, flush/destroy/reinit the encoder would work, will investigate more to do this inside specific encoder or in more general ways. Please help to review, thanks. - Linjie _______________________________________________ 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".