On Fri, 27 Oct 2023 23:42:41 +0200 Michael Niedermayer <mich...@niedermayer.cc> wrote: > On Fri, Oct 27, 2023 at 07:04:39PM +0200, Niklas Haas wrote: > > From: Niklas Haas <g...@haasn.dev> > > > > More commonly, this fixes the case of sws_setColorspaceDetails after > > sws_getContext, since the latter implies sws_init_context. > > > > The problem here is that sws_init_context sets up the range conversion > > and fast path tables based on the values of srcRange/dstRange at init > > time. This may result in locking in a "wrong" path (either using > > unscaled fast path when range conversion later required, or using > > scaled slow path when range conversion becomes no longer required). > > > > There are two way outs: > > > > 1. Always initialize range conversion and unscaled converters, even if > > they will be unused, and extend the runtime check. > > 2. Re-do initialization if the values change after > > sws_setColorspaceDetails. > > > > I opted for approach 1 because it was simpler and easier to reason > > about. > > --- > > libswscale/swscale.c | 2 +- > > libswscale/utils.c | 5 +---- > > 2 files changed, 2 insertions(+), 5 deletions(-) > > > > diff --git a/libswscale/swscale.c b/libswscale/swscale.c > > index 90e5b299ab..46ba68fe6a 100644 > > --- a/libswscale/swscale.c > > +++ b/libswscale/swscale.c > > @@ -1016,7 +1016,7 @@ static int scale_internal(SwsContext *c, > > reset_ptr(src2, c->srcFormat); > > reset_ptr((void*)dst2, c->dstFormat); > > > > - if (c->convert_unscaled) { > > + if (c->convert_unscaled && !c->lumConvertRange && !c->chrConvertRange) > > { > > int offset = srcSliceY_internal; > > int slice_h = srcSliceH; > > > > diff --git a/libswscale/utils.c b/libswscale/utils.c > > index e1ad685972..455955e907 100644 > > --- a/libswscale/utils.c > > +++ b/libswscale/utils.c > > @@ -1728,9 +1728,7 @@ static av_cold int sws_init_single_context(SwsContext > > *c, SwsFilter *srcFilter, > > } > > > > /* unscaled special cases */ > > - if (unscaled && !usesHFilter && !usesVFilter && > > - (c->srcRange == c->dstRange || isAnyRGB(dstFormat) || > > - isFloat(srcFormat) || isFloat(dstFormat))){ > > + if (unscaled && !usesHFilter && !usesVFilter) { > > ff_get_unscaled_swscale(c); > > > > if (c->convert_unscaled) { > > @@ -1738,7 +1736,6 @@ static av_cold int sws_init_single_context(SwsContext > > *c, SwsFilter *srcFilter, > > av_log(c, AV_LOG_INFO, > > "using unscaled %s -> %s special converter\n", > > av_get_pix_fmt_name(srcFormat), > > av_get_pix_fmt_name(dstFormat)); > > - return 0; > > } > > } > > the av_log() message will be wrong if this path is unused
Indeed. Perhaps the only way to fix that would be to instead try approach 2 and go through full reinit if any params change after setColorspaceDetails. > also this ties convert_unscaled to never do range conversion, if thats > intended, i guess thats ok. Otherwise that maybe is a restriction > we dont want to add. In the original code, c->convert_unscaled is set behind a `c->srcRange == c->dstRange` check, so how is that a change in behavior? _______________________________________________ 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".