[FFmpeg-devel] [PATCH] aacenc: avoid double in quantize_bands.

[Rostislav Pehlivanov]

On 1 March 2016 at 21:55, Reimar Döffinger <Reimar.Doeffinger at gmx.de> wrote:

> I cannot see any point whatsoever to use
> double here instead of float.
> Using float allows for use of SIMD.
> ---
>  libavcodec/aacenc_utils.h | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/libavcodec/aacenc_utils.h b/libavcodec/aacenc_utils.h
> index cb5bc8d..571b1e6 100644
> --- a/libavcodec/aacenc_utils.h
> +++ b/libavcodec/aacenc_utils.h
> @@ -66,10 +66,9 @@ static inline void quantize_bands(int *out, const float
> *in, const float *scaled
>                                    const float rounding)
>  {
>      int i;
> -    double qc;
>      for (i = 0; i < size; i++) {
> -        qc = scaled[i] * Q34;
> -        out[i] = (int)FFMIN(qc + rounding, (double)maxval);
> +        float qc = scaled[i] * Q34;
> +        out[i] = (int)FFMIN(qc + rounding, (float)maxval);
>          if (is_signed && in[i] < 0.0f) {
>              out[i] = -out[i];
>          }
> --
>

You could just avoid the whole need for qc and just do "FFMIN((scaled[i] *
Q34) + rounding, (float)maxval));". We have plenty of space and I think it
would look neater.
But up to you to decide, either way it looks good to me, doesn't change
anything. Feel free to push if you can.

Thanks