[FFmpeg-devel] avfilter/vf_ssim: align temp size

Submitted by Muhammad Faiz on Aug. 1, 2017, 3:01 p.m.

Details

Message ID 20170801150137.8844-1-mfcc64@gmail.com
State New
Headers show

Commit Message

Muhammad Faiz Aug. 1, 2017, 3:01 p.m.
Fix Ticket6519.

Signed-off-by: Muhammad Faiz <mfcc64@gmail.com>
---
 libavfilter/vf_ssim.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Tobias Rapp Aug. 2, 2017, 7:10 a.m.
On 01.08.2017 17:01, Muhammad Faiz wrote:
> Fix Ticket6519.
>
> Signed-off-by: Muhammad Faiz <mfcc64@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?

Regards,
Tobias
Muhammad Faiz Aug. 2, 2017, 10:31 a.m.
On Wed, Aug 2, 2017 at 2:10 PM, Tobias Rapp <t.rapp@noa-archive.com> wrote:
> On 01.08.2017 17:01, Muhammad Faiz wrote:
>>
>> Fix Ticket6519.
>>
>> Signed-off-by: Muhammad Faiz <mfcc64@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?

Changed locally with av_mallocz_array.

Thank's.
Tobias Rapp Aug. 2, 2017, 11:48 a.m.
On 02.08.2017 12:31, Muhammad Faiz wrote:
> On Wed, Aug 2, 2017 at 2:10 PM, Tobias Rapp <t.rapp@noa-archive.com> wrote:
>> On 01.08.2017 17:01, Muhammad Faiz wrote:
>>>
>>> Fix Ticket6519.
>>>
>>> Signed-off-by: Muhammad Faiz <mfcc64@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?
>
> Changed locally with av_mallocz_array.

LGTM then. Thanks for the fix.

Regards,
Tobias
Ronald S. Bultje Aug. 2, 2017, 12:04 p.m.
Hi,

On Wed, Aug 2, 2017 at 3:10 AM, Tobias Rapp <t.rapp@noa-archive.com> wrote:

> On 01.08.2017 17:01, Muhammad Faiz wrote:
>
>> Fix Ticket6519.
>>
>> Signed-off-by: Muhammad Faiz <mfcc64@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?

Ronald
Tobias Rapp Aug. 2, 2017, 12:45 p.m.
On 02.08.2017 14:04, Ronald S. Bultje wrote:
> Hi,
>
> On Wed, Aug 2, 2017 at 3:10 AM, Tobias Rapp <t.rapp@noa-archive.com> wrote:
>
>> On 01.08.2017 17:01, Muhammad Faiz wrote:
>>
>>> Fix Ticket6519.
>>>
>>> Signed-off-by: Muhammad Faiz <mfcc64@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.

Regards,
Tobias
Ronald S. Bultje Aug. 2, 2017, 1:57 p.m.
Hi,

On Wed, Aug 2, 2017 at 8:45 AM, Tobias Rapp <t.rapp@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.rapp@noa-archive.com>
>> wrote:
>>
>>> On 01.08.2017 17:01, Muhammad Faiz wrote:
>>>
>>>> Fix Ticket6519.
>>>>
>>>> Signed-off-by: Muhammad Faiz <mfcc64@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.

Ronald
Muhammad Faiz Aug. 3, 2017, 12:39 a.m.
On Wed, Aug 2, 2017 at 6:48 PM, Tobias Rapp <t.rapp@noa-archive.com> wrote:
> On 02.08.2017 12:31, Muhammad Faiz wrote:
>>
>> On Wed, Aug 2, 2017 at 2:10 PM, Tobias Rapp <t.rapp@noa-archive.com>
>> wrote:
>>>
>>> On 01.08.2017 17:01, Muhammad Faiz wrote:
>>>>
>>>>
>>>> Fix Ticket6519.
>>>>
>>>> Signed-off-by: Muhammad Faiz <mfcc64@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?
>>
>>
>> Changed locally with av_mallocz_array.
>
>
> LGTM then. Thanks for the fix.

Seems that this doesn't fix all cases. It fails with width=344.
Will post new patch.

Thank's.
Muhammad Faiz Aug. 3, 2017, 12:57 a.m.
On Wed, Aug 2, 2017 at 8:57 PM, Ronald S. Bultje <rsbultje@gmail.com> wrote:
> Hi,
>
> On Wed, Aug 2, 2017 at 8:45 AM, Tobias Rapp <t.rapp@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.rapp@noa-archive.com>
>>> wrote:
>>>
>>>> On 01.08.2017 17:01, Muhammad Faiz wrote:
>>>>
>>>>> Fix Ticket6519.
>>>>>
>>>>> Signed-off-by: Muhammad Faiz <mfcc64@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

Patch hide | download patch | download mbox

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;