[FFmpeg-devel] [PATCH 2/3] avcodec/aacenc_is: Assert that minthr is not 0.0, this would lead to division by 0 later

[Michael Niedermayer]

On Mon, May 16, 2016 at 01:33:37PM -0300, Claudio Freire wrote:
> On Mon, May 16, 2016 at 12:26 PM, Kieran Kunhya <kierank at obe.tv> wrote:
> >> Testcase is fate-aac-pred-encode
> >>
> >> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> >> ---
> >>  libavcodec/aacenc_is.c |    3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/libavcodec/aacenc_is.c b/libavcodec/aacenc_is.c
> >> index 473897b..e5cfa14 100644
> >> --- a/libavcodec/aacenc_is.c
> >> +++ b/libavcodec/aacenc_is.c
> >> @@ -64,6 +64,9 @@ struct AACISError ff_aac_is_encoding_err(AACEncContext
> >> *s, ChannelElement *cpe,
> >>          abs_pow34_v(I34, IS,                   sce0->ics.swb_sizes[g]);
> >>          maxval = find_max_val(1, sce0->ics.swb_sizes[g], I34);
> >>          is_band_type = find_min_book(maxval, is_sf_idx);
> >> +
> >> +        av_assert0(minthr != 0.0);
> >> +
> >>          dist1 += quantize_band_cost(s, &L[start + (w+w2)*128], L34,
> >>                                      sce0->ics.swb_sizes[g],
> >>                                      sce0->sf_idx[w*16+g],
> >> --
> >> 1.7.9.5
> >>
> >>
> >>
> > Does this assert on actual input data?

yes,

with the patch fate fails:

Test aac-pred-encode failed. Look at tests/data/fate/aac-pred-encode.err for details.
make: *** [fate-aac-pred-encode] Error 134


> 
> A threshold of 0 would in theory cause a zeroed band (zeroes[i] == 1),
> and those should be skipped.
> 
> I think the proper fix would be figuring out why those aren't being
> skipped, if that is the case.

i never meant this patch to be a proper fix, more a bug report ...


[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

He who knows, does not speak. He who speaks, does not know. -- Lao Tsu
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