[FFmpeg-devel] [PATCH 4/7] Adds gray floating-point pixel formats.

[Martin Vignali]

>
> +static int uint_y_to_float_y_wrapper(SwsContext *c, const uint8_t *src[],
> +                                     int srcStride[], int srcSliceY,
> +                                     int srcSliceH, uint8_t *dst[], int
> dstStride[])
> +{
> +    int y, x;
> +    int dstStrideFloat = dstStride[0] >> 2;;
> +    const uint8_t *srcPtr = src[0];
> +    float *dstPtr = (float *)(dst[0] + dstStride[0] * srcSliceY);
> +
> +    for (y = 0; y < srcSliceH; ++y){
> +        for (x = 0; x < c->srcW; ++x){
> +            dstPtr[x] = (float)srcPtr[x] / 255.0f;
> +        }
> +        srcPtr += srcStride[0];
> +        dstPtr += dstStrideFloat;
> +    }
> +
> +    return srcSliceH;
> +}
> +
> +static int float_y_to_uint_y_wrapper(SwsContext *c, const uint8_t* src[],
> +                                     int srcStride[], int srcSliceY,
> +                                     int srcSliceH, uint8_t* dst[], int
> dstStride[])
> +{
> +    int y, x;
> +    int srcStrideFloat = srcStride[0] >> 2;
> +    const float *srcPtr = (const float *)src[0];
> +    uint8_t *dstPtr = dst[0] + dstStride[0] * srcSliceY;
> +
> +    for (y = 0; y < srcSliceH; ++y){
> +        for (x = 0; x < c->srcW; ++x){
> +            dstPtr[x] = (uint8_t)(255.0f * FFMIN(FFMAX(srcPtr[x], 0.0f),
> 1.0f));
> +        }
> +        srcPtr += srcStrideFloat;
> +        dstPtr += dstStride[0];
> +    }
> +
> +    return srcSliceH;
> +}
>


Maybe you can avoid to use float for these conversions
like in libavcodec/exr.c, where there is a float to uint16 conversion

Martin