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

[James Almer]

On 11/15/2015 12:20 PM, Ganesh Ajjanagadde wrote:
> 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.

This is an inline function in a header. ffprobe already includes a few
internal headers.
What it should ideally not use is exported but not public API.