[opus] [PATCH] Fix memory issue in Projection API
Jean-Marc Valin
jmvalin at jmvalin.ca
Thu Dec 7 18:06:40 UTC 2017
Made a few minor tweaks to your patch (attached). Can you confirm you're
OK with those and I haven't missed anything?
Cheers,
Jean-Marc
On 12/04/2017 06:34 PM, Drew Allen wrote:
> I've solely addressed this concern here.
>
> Cheers,
> Drew
>
> On Fri, Nov 24, 2017 at 9:15 AM Jean-Marc Valin <jmvalin at jmvalin.ca
> <mailto:jmvalin at jmvalin.ca>> wrote:
>
> Hi Drew,
>
> I noticed you reverted the
> output[output_rows * i] = (tmp + 16384) >> 15;
> from the previous patch. That's still good. What should have been
> changed is the float version:
> output[output_rows * i] = (1/32768.f) * ((tmp + 16384) >> 15);
> which should just be:
> output[output_rows * i] = (1/(32768.f*32768.f)) * tmp;
> since there's no point in doing integer rounding when you have float
> available.
>
> Cheers,
>
> Jean-Marc
>
> On 11/23/2017 10:35 PM, Drew Allen wrote:
> > Hi Jean-Marc,
> >
> > Attached is an updated patch. I had to include some of Mark's
> > suggestions in order to get the tests to work correctly. I will still
> > submit a separate patch for him for a few other concerns he had after
> > this one clears.
> >
> > Cheers,
> > Drew
> >
> > On Thu, Nov 23, 2017 at 10:42 AM Jean-Marc Valin
> <jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>> wrote:
> >
> > Actually, there's also something wrong with the in_short()
> function. For
> > floating point (#else case), you shouldn't need shifting since
> you're
> > already doing the scaling through a float multiply.
> >
> > Jean-Marc
> >
> > On 11/23/2017 01:39 PM, Drew Allen wrote:
> > > got it. actually that patch i sent you has something wrong
> with the
> > > mapping_matrix_multiply_short_out... let me fix that and
> will send you
> > > another patch soon.
> > >
> > > Cheers,
> > > Drew
> > >
> > > On Thu, Nov 23, 2017 at 10:34 AM Jean-Marc Valin
> > <jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>
> > > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>>> wrote:
> > >
> > > On 11/23/2017 01:28 PM, Drew Allen wrote:
> > > > To your first point, I was only trying to copy how
> > _multistream_'s c
> > > > files function in this way, possibly that's worth
> > refactoring as well
> > > > (as a separate patch).
> > >
> > > Well, the opus_multistream_decode_* calls were correct
> before your
> > > patch. It's only the encode ones that have the issues
> (should be
> > > addressed separately).
> > >
> > > Jean-Marc
> > >
> > > > On Thu, Nov 23, 2017 at 9:02 AM Jean-Marc Valin
> > > <jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>
> > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>>
> > > > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>
> > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>>>> wrote:
> > > >
> > > > On 11/22/2017 06:23 PM, Drew Allen wrote:
> > > > > 1) I didn't change how multistream_decode_float
> works
> > in the
> > > argument
> > > > > list... I noticed it changes it's arguments
> depending
> > on whether
> > > > > FIXED_POINT is used. I copied this style for the
> > projection
> > > API as
> > > > well.
> > > > > If this isn't desired, we should make those changes
> > separately.
> > > > >
> > > > > 2) See above.
> > > >
> > > > Just noticed the code will actually work because
> > opus_val16 is
> > > defined
> > > > to the right thing, but I still think it's a bad
> idea. For
> > > example, if
> > > > you look at the public header,
> opus_projection_decode()
> > has a pcm
> > > > argument of type opus_int16*, so it's a bit confusing
> > for the
> > > C file to
> > > > define pcm as opus_val16*, even if the two map to
> the same.
> > > >
> > > > > 3) I only zero out initially. For the
> matrix_multiply_out
> > > > functions, we
> > > > > need to be able to take a single decoded stream and
> > add weighted
> > > > > versions of it to each of the final output
> channels. This
> > > zero-ing out
> > > > > on stream 0 ensures the block is zero-set so we can
> > > incrementally add
> > > > > all the decoded streams to the output channels.
> > > >
> > > > OK, I see. In that case, you should replace the
> two for()
> > > loops with
> > > > just a single call to OPUS_COPY(). That should be both
> > faster and
> > > > simpler.
> > > >
> > > > > 4) See 3), short and float versions of
> multiply_out should
> > > > function the
> > > > > same.
> > > >
> > > > Again, I now see what that code is doing.
> Unfortunately,
> > it means
> > > > increased noise for fixed-point since we have to round
> > > multiple times. I
> > > > don't have a proposed fix for that, so I guess
> we'll have to
> > > deal with
> > > > it. However, instead of rounding tmp twice (>>8
> followed by
> > > +64>>7), you
> > > > should only round once. That means (tmp+16384)>>15
> > > >
> > > > Cheers,
> > > >
> > > > Jean-Marc
> > > >
> > > > > Let me know your thoughts.
> > > > >
> > > > > Cheers,
> > > > > Drew
> > > > >
> > > > > On Tue, Nov 21, 2017 at 7:39 PM Jean-Marc Valin
> > > > <jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>
> > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>>
> > > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>
> > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>>>
> > > > > <mailto:jmvalin at jmvalin.ca
> <mailto:jmvalin at jmvalin.ca> <mailto:jmvalin at jmvalin.ca
> <mailto:jmvalin at jmvalin.ca>>
> > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>>
> > > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>
> > <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>
> <mailto:jmvalin at jmvalin.ca <mailto:jmvalin at jmvalin.ca>>>>>> wrote:
> > > > >
> > > > > Hi Drew,
> > > > >
> > > > > Had a look at your patch. I think it's on the
> > right track --
> > > > there's no
> > > > > fundamental issue with it as far as I can tell.
> > There's
> > > a few
> > > > > implementation issues though.
> > > > >
> > > > > 1) In opus_multi_stream_decode_float(), you
> > changed the pcm
> > > > argument
> > > > > from float* to opus_val16*. That's a mistake
> and will
> > > fail for
> > > > > fixed-point. This should have shown up as an
> error
> > on a
> > > > fixed-point
> > > > > build. Make sure you test that.
> > > > >
> > > > > 2) In opus_projection_decode(), you also changed
> > the pcm
> > > > argument to an
> > > > > opus_val16*, which again will cause problems for
> > the same
> > > > reasons as 1).
> > > > > Please check you haven't made that same mistake
> > elsewhere.
> > > > >
> > > > > 3) In
> opus_projection_copy_channel_out_float() and
> > > > > opus_projection_copy_channel_out_short(), you're
> > zeroing the
> > > > values with
> > > > > this loop:
> > > > > for (i=0;i<frame_size;i++)
> > > > > {
> > > > > for (j=0;j<dst_stride;j++)
> > > > > {
> > > > > float_dst[i*dst_stride+j] = 0;
> > > > > }
> > > > > }
> > > > > That looks wrong, since you'll be
> overwriting all
> > channels
> > > > instead of
> > > > > just the one you're copying. That should
> have come
> > up in
> > > > testing, no?
> > > > >
> > > > > 4) You might want to have a look at
> > > > > mapping_matrix_multiply_channel_out_short(). I
> > can't quite
> > > > follow what
> > > > > it's doing, but it seems wrong since the whole
> > point of
> > > adding
> > > > the "tmp"
> > > > > is to avoid rounding multiple times.
> > > > >
> > > > > I haven't had time to thoroughly review the
> changes to
> > > > mapping_matrix.c,
> > > > > but I'll do that on your revised version.
> > > > >
> > > > > Cheers,
> > > > >
> > > > > Jean-Marc
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > On 11/20/2017 05:15 PM, Drew Allen wrote:
> > > > > > Hello,
> > > > > >
> > > > > > Attached is a patch to resolve a memory issue
> > using the
> > > > Projection API
> > > > > > when compiling using a psuedo-stack / limited
> > memory.
> > > > > >
> > > > > > Please let me any ?s you might have.
> > > > > >
> > > > > > Cheers,
> > > > > > Drew
> > > > > >
> > > > > >
> > > > > >
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