On Wed, Aug 2, 2017 at 8:57 PM, Ronald S. Bultje <rsbul...@gmail.com> wrote: > Hi, > > On Wed, Aug 2, 2017 at 8:45 AM, Tobias Rapp <t.r...@noa-archive.com> wrote: > >> On 02.08.2017 14:04, Ronald S. Bultje wrote: >> >>> On Wed, Aug 2, 2017 at 3:10 AM, Tobias Rapp <t.r...@noa-archive.com> >>> wrote: >>> >>>> On 01.08.2017 17:01, Muhammad Faiz wrote: >>>> >>>>> Fix Ticket6519. >>>>> >>>>> Signed-off-by: Muhammad Faiz <mfc...@gmail.com> >>>>> --- >>>>> libavfilter/vf_ssim.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/libavfilter/vf_ssim.c b/libavfilter/vf_ssim.c >>>>> index c3c204268f..dfd276e015 100644 >>>>> --- a/libavfilter/vf_ssim.c >>>>> +++ b/libavfilter/vf_ssim.c >>>>> @@ -402,7 +402,7 @@ static int config_input_ref(AVFilterLink *inlink) >>>>> for (i = 0; i < s->nb_components; i++) >>>>> s->coefs[i] = (double) s->planeheight[i] * s->planewidth[i] / >>>>> sum; >>>>> >>>>> - s->temp = av_malloc_array((2 * inlink->w + 12), sizeof(*s->temp) * >>>>> (1 + (desc->comp[0].depth > 8))); >>>>> + s->temp = av_malloc_array(FFALIGN(2 * inlink->w + 12, 64), >>>>> sizeof(*s->temp) * (1 + (desc->comp[0].depth > 8))); >>>>> if (!s->temp) >>>>> return AVERROR(ENOMEM); >>>>> s->max = (1 << desc->comp[0].depth) - 1; >>>>> >>>>> >>>>> I confirm that the command doesn't crash anymore and the reports of >>>> "invalid read/write" in Valgrind are gone. However there are still some >>>> "use of uninitialized value" reports remaining. Maybe use >>>> av_mallocz_array? >>>> >>> >>> >>> Wait wait, before we do that, which values are uninitialized and what are >>> they used for? >>> >> >> Reads into s->temp seem to use uninitialized values on x86-64 when >> vf_ssim.asm routines are used (-cpuflags all), see attached Valgrind >> report. When vf_ssim.asm is not used (-cpuflags 0) no "use of uninitialized >> value" is reported. >> >> The difference of the reported SSIM scores between my asm and non-asm test >> runs was <= 10^-6. > > > Which function is causing the warnings? Isit dsp->ssim_4x4_line() or > dsp->ssim_end_line()? (My gut feeling tells me it's ssim_4x4_line(), but I > don't understand why, since the result should be unused in > ssim_end_line().) It's really important to understand the source and > implication of these warnings before we silence them - they may be causing > actual inaccuracies in the result, which we don't want.
Because ssim_4x4_line never reads sums, I think the warnings are caused by ssim_end_line. Looking at the asm code: ssim_4x4_line writes to sums 32-bytes per loop, while ssim_end_line reads sum0/sum1 64-bytes per loop + 16-bytes overread Thank's _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
