[opus] [PATCH] Fix memory issue in Projection API

Drew Allen bitllama at google.com
Tue Nov 28 17:24:31 UTC 2017


Done!

On Tue, Nov 28, 2017 at 12:12 AM Jean-Marc Valin <jmvalin at jmvalin.ca> wrote:

> I only had a quick look, but your patch looks good except for the:
>   output[output_rows * i] = (1/(32768.f*128.f))*tmp;
>
> For floating point, you shouldn't do the >>7 either. Just remove the >>8
> from the floating-point calculation of tmp so that all the scaling is
> done in float.
>
> Cheers,
>
>         Jean-Marc
>
> On 11/27/2017 04:01 PM, Drew Allen wrote:
> > Hi Jean-Marc,
> >
> > Attached is an updated patch with your suggestions + additional
> > corrections I caught over the weekend.
> >
> > Cheers,
> > Drew
> >
> > On Fri, Nov 24, 2017 at 10:08 AM Drew Allen <bitllama at google.com
> > <mailto:bitllama at google.com>> wrote:
> >
> >     Aha good point! Im travelling this weekend but will submit another
> >     patch Monday morning.
> >
> >     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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> >         <mailto:opus at xiph.org <mailto:opus at xiph.org>>>
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> >         <mailto:opus at xiph.org <mailto:opus at xiph.org>>
> >         >     <mailto:opus at xiph.org <mailto:opus at xiph.org>
> >         <mailto:opus at xiph.org <mailto:opus at xiph.org>>>>
> >         <mailto:opus at xiph.org <mailto:opus at xiph.org>
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> >         >     >     <mailto:opus at xiph.org <mailto:opus at xiph.org>
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> >         <mailto:opus at xiph.org <mailto:opus at xiph.org>>
> >         >     <mailto:opus at xiph.org <mailto:opus at xiph.org>
> >         <mailto:opus at xiph.org <mailto:opus at xiph.org>>>>>
> >         >     >     >     >     >
> >         http://lists.xiph.org/mailman/listinfo/opus
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> >         >     >     >
> >         >     >
> >         >
> >
>
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