JPEG/R Optimization: remove repeating log2() calculation

Bug: 264715926
Test: jpegr_test.cpp recoverymapmath_test.cpp
Change-Id: If135b1003b7835c9c59418f61842c26724eb6e80

3 files changed, 15 insertions, 4 deletions

diff --git a/libs/jpegrecoverymap/include/jpegrecoverymap/recoverymapmath.h b/libs/jpegrecoverymap/include/jpegrecoverymap/recoverymapmath.h
index 67d2a6a0be..bd5ca8b9f0 100644
--- a/libs/jpegrecoverymap/include/jpegrecoverymap/recoverymapmath.h
+++ b/libs/jpegrecoverymap/include/jpegrecoverymap/recoverymapmath.h
@@ -361,6 +361,8 @@ ColorTransformFn getHdrConversionFn(jpegr_color_gamut sdr_gamut, jpegr_color_gam
  * luminances in linear space, and the hdr ratio to encode against.
  */
 uint8_t encodeRecovery(float y_sdr, float y_hdr, jr_metadata_ptr metadata);
+uint8_t encodeRecovery(float y_sdr, float y_hdr, jr_metadata_ptr metadata,
+                       float log2MinContentBoost, float log2MaxContentBoost);
 
 /*
  * Calculates the linear luminance in nits after applying the given recovery
diff --git a/libs/jpegrecoverymap/jpegr.cpp b/libs/jpegrecoverymap/jpegr.cpp
index e395d51a26..559ca3564a 100644
--- a/libs/jpegrecoverymap/jpegr.cpp
+++ b/libs/jpegrecoverymap/jpegr.cpp
@@ -586,6 +586,8 @@ status_t JpegR::generateRecoveryMap(jr_uncompressed_ptr uncompressed_yuv_420_ima
 
   metadata->maxContentBoost = hdr_white_nits / kSdrWhiteNits;
   metadata->minContentBoost = 1.0f;
+  float log2MinBoost = log2(metadata->minContentBoost);
+  float log2MaxBoost = log2(metadata->maxContentBoost);
 
   ColorTransformFn hdrGamutConversionFn = getHdrConversionFn(
       uncompressed_yuv_420_image->colorGamut, uncompressed_p010_image->colorGamut);
@@ -613,7 +615,8 @@ status_t JpegR::generateRecoveryMap(jr_uncompressed_ptr uncompressed_yuv_420_ima
 
   std::function<void()> generateMap = [uncompressed_yuv_420_image, uncompressed_p010_image,
                                        metadata, dest, hdrInvOetf, hdrGamutConversionFn,
-                                       luminanceFn, hdr_white_nits, &jobQueue]() -> void {
+                                       luminanceFn, hdr_white_nits, log2MinBoost, log2MaxBoost,
+                                       &jobQueue]() -> void {
     size_t rowStart, rowEnd;
     size_t dest_map_width = uncompressed_yuv_420_image->width / kMapDimensionScaleFactor;
     size_t dest_map_stride = dest->width;
@@ -638,7 +641,7 @@ status_t JpegR::generateRecoveryMap(jr_uncompressed_ptr uncompressed_yuv_420_ima
 
           size_t pixel_idx = x + y * dest_map_stride;
           reinterpret_cast<uint8_t*>(dest->data)[pixel_idx] =
-              encodeRecovery(sdr_y_nits, hdr_y_nits, metadata);
+              encodeRecovery(sdr_y_nits, hdr_y_nits, metadata, log2MinBoost, log2MaxBoost);
         }
       }
     }
diff --git a/libs/jpegrecoverymap/recoverymapmath.cpp b/libs/jpegrecoverymap/recoverymapmath.cpp
index 2cffde3c54..8808b55b0c 100644
--- a/libs/jpegrecoverymap/recoverymapmath.cpp
+++ b/libs/jpegrecoverymap/recoverymapmath.cpp
@@ -443,6 +443,12 @@ ColorTransformFn getHdrConversionFn(jpegr_color_gamut sdr_gamut, jpegr_color_gam
 ////////////////////////////////////////////////////////////////////////////////
 // Recovery map calculations
 uint8_t encodeRecovery(float y_sdr, float y_hdr, jr_metadata_ptr metadata) {
+  return encodeRecovery(y_sdr, y_hdr, metadata,
+                        log2(metadata->minContentBoost), log2(metadata->maxContentBoost));
+}
+
+uint8_t encodeRecovery(float y_sdr, float y_hdr, jr_metadata_ptr metadata,
+                       float log2MinContentBoost, float log2MaxContentBoost) {
   float gain = 1.0f;
   if (y_sdr > 0.0f) {
     gain = y_hdr / y_sdr;
@@ -451,8 +457,8 @@ uint8_t encodeRecovery(float y_sdr, float y_hdr, jr_metadata_ptr metadata) {
   if (gain < metadata->minContentBoost) gain = metadata->minContentBoost;
   if (gain > metadata->maxContentBoost) gain = metadata->maxContentBoost;
 
-  return static_cast<uint8_t>((log2(gain) - log2(metadata->minContentBoost))
-                            / (log2(metadata->maxContentBoost) - log2(metadata->minContentBoost))
+  return static_cast<uint8_t>((log2(gain) - log2MinContentBoost)
+                            / (log2MaxContentBoost - log2MinContentBoost)
                             * 255.0f);
 }