[FFmpeg-devel] [PATCH] avutil: Move av_rint64_clip_* to internal.h

[Ganesh Ajjanagadde]

On Sat, Nov 14, 2015 at 9:01 PM, James Almer <jamrial at gmail.com> wrote:
> On 11/14/2015 10:48 PM, Michael Niedermayer wrote:
>> From: Michael Niedermayer <michael at niedermayer.cc>
>>
>> This should avoid build failures on VS2012
>> Feel free to changes this to a different solution
>>
>> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>> ---
>>  libavutil/common.h   |   39 ---------------------------------------
>>  libavutil/internal.h |   40 ++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 40 insertions(+), 39 deletions(-)
>>
>> diff --git a/libavutil/common.h b/libavutil/common.h
>> index 813fb37..6f0f582 100644
>> --- a/libavutil/common.h
>> +++ b/libavutil/common.h
>> @@ -298,42 +298,6 @@ static av_always_inline av_const double av_clipd_c(double a, double amin, double
>>      else               return a;
>>  }
>>
>> -/**
>> - * Clip and convert a double value into the long long amin-amax range.
>> - * This function is needed because conversion of floating point to integers when
>> - * it does not fit in the integer's representation does not necessarily saturate
>> - * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
>> - * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
>> - * behavior, allowing this sort of mathematically bogus conversions. This provides
>> - * a safe alternative that is slower obviously but assures safety and better
>> - * mathematical behavior.
>> - * @param a value to clip
>> - * @param amin minimum value of the clip range
>> - * @param amax maximum value of the clip range
>> - * @return clipped value
>> - */
>> -static av_always_inline av_const int64_t av_rint64_clip_c(double a, int64_t amin, int64_t amax)
>> -{
>> -    int64_t res;
>> -#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
>> -    if (amin > amax) abort();
>> -#endif
>> -    // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
>> -    // do range checks first
>> -    if (a >=  9223372036854775808.0)
>> -        return amax;
>> -    if (a <= -9223372036854775808.0)
>> -       return amin;
>> -
>> -    // safe to call llrint and clip accordingly
>> -    res = llrint(a);
>> -    if (res > amax)
>> -        return amax;
>> -    if (res < amin)
>> -        return amin;
>> -    return res;
>> -}
>> -
>>  /** Compute ceil(log2(x)).
>>   * @param x value used to compute ceil(log2(x))
>>   * @return computed ceiling of log2(x)
>> @@ -547,9 +511,6 @@ static av_always_inline av_const int av_popcount64_c(uint64_t x)
>>  #ifndef av_clipd
>>  #   define av_clipd         av_clipd_c
>>  #endif
>> -#ifndef av_rint64_clip
>> -#   define av_rint64_clip   av_rint64_clip_c
>> -#endif
>>  #ifndef av_popcount
>>  #   define av_popcount      av_popcount_c
>>  #endif
>> diff --git a/libavutil/internal.h b/libavutil/internal.h
>> index 5c2cd99..cb0c8cd 100644
>> --- a/libavutil/internal.h
>> +++ b/libavutil/internal.h
>> @@ -257,6 +257,46 @@ void avpriv_request_sample(void *avc,
>>  #endif
>>
>>  /**
>> + * Clip and convert a double value into the long long amin-amax range.
>> + * This function is needed because conversion of floating point to integers when
>> + * it does not fit in the integer's representation does not necessarily saturate
>> + * correctly (usually converted to a cvttsd2si on x86) which saturates numbers
>> + * > INT64_MAX to INT64_MIN. The standard marks such conversions as undefined
>> + * behavior, allowing this sort of mathematically bogus conversions. This provides
>> + * a safe alternative that is slower obviously but assures safety and better
>> + * mathematical behavior.
>> + * @param a value to clip
>> + * @param amin minimum value of the clip range
>> + * @param amax maximum value of the clip range
>> + * @return clipped value
>> + */
>> +static av_always_inline av_const int64_t av_rint64_clip_c(double a, int64_t amin, int64_t amax)
>
> IMO rename it to avpriv_rint64_clip() or even ff_rint64_clip() since it's inlined
> and not public/exported.

Just noticed an issue: Ronald mentioned to me that ffserver and other
such programs should not use internal API. This therefore needs to be
exported somehow.

>
>> +{
>> +    int64_t res;
>> +#if defined(HAVE_AV_CONFIG_H) && defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
>> +    if (amin > amax) abort();
>> +#endif
>> +    // INT64_MAX+1,INT64_MIN are exactly representable as IEEE doubles
>> +    // do range checks first
>> +    if (a >=  9223372036854775808.0)
>> +        return amax;
>> +    if (a <= -9223372036854775808.0)
>> +       return amin;
>> +
>> +    // safe to call llrint and clip accordingly
>> +    res = llrint(a);
>> +    if (res > amax)
>> +        return amax;
>> +    if (res < amin)
>> +        return amin;
>> +    return res;
>> +}
>> +
>> +#ifndef av_rint64_clip
>> +#   define av_rint64_clip   av_rint64_clip_c
>> +#endif
>
> No need for this chunk.
>
>> +
>> +/**
>>   * A wrapper for open() setting O_CLOEXEC.
>>   */
>>  av_warn_unused_result
>>
>
>
> In any case should be ok.
>
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