diff --git a/png.c b/png.c
index d99e2643b8..4849ffba6f 100644
--- a/png.c
+++ b/png.c
@@ -1150,7 +1150,7 @@ png_colorspace_sync_info(png_const_structrp png_ptr, png_inforp info_ptr)
    {
       /* Everything is invalid */
       info_ptr->valid &= ~(PNG_INFO_gAMA|PNG_INFO_cHRM|PNG_INFO_sRGB|
-         PNG_INFO_iCCP);
+        PNG_INFO_iCCP|PNG_INFO_cLLi|PNG_INFO_mDCv);
 
 #     ifdef PNG_COLORSPACE_SUPPORTED
       /* Clean up the iCCP profile now if it won't be used. */
diff --git a/png.h b/png.h
index f5aa4c313d..37243b6c57 100644
--- a/png.h
+++ b/png.h
@@ -608,6 +608,25 @@ typedef png_time * png_timep;
 typedef const png_time * png_const_timep;
 typedef png_time * * png_timepp;
 
+#ifdef PNG_mDCv_SUPPORTED
+typedef struct png_mdcv_struct
+{
+   png_uint_16 chromaticity_redx;   /* for use in display primaries */
+   png_uint_16 chromaticity_redy ;
+   png_uint_16 chromaticity_greenx;
+   png_uint_16 chromaticity_greeny;
+   png_uint_16 chromaticity_bluex;
+   png_uint_16 chromaticity_bluey;
+   png_uint_16 chromaticity_whitex;  /* for use white point */
+   png_uint_16 chromaticity_whitey;
+   png_uint_32 max_Lum; /* max, min master display luminance */
+   png_uint_32 min_Lum;
+} png_mdcv;
+typedef png_mdcv * png_mdcvp;
+typedef const png_mdcv * png_const_mdcvp;
+typedef png_mdcv * * png_mdcvpp;
+#endif
+
 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
    defined(PNG_USER_CHUNKS_SUPPORTED)
 /* png_unknown_chunk is a structure to hold queued chunks for which there is
@@ -744,6 +763,8 @@ typedef png_unknown_chunk * * png_unknown_chunkpp;
 #define PNG_INFO_sCAL 0x4000U  /* ESR, 1.0.6 */
 #define PNG_INFO_IDAT 0x8000U  /* ESR, 1.0.6 */
 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
+#define PNG_INFO_mDCv 0x40000U /* mDCv chunk */
+#define PNG_INFO_cLLi 0x80000U /* cLLi chunk */
 
 /* This is used for the transformation routines, as some of them
  * change these values for the row.  It also should enable using
@@ -2093,6 +2114,20 @@ PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
     png_const_bytep profile, png_uint_32 proflen));
 #endif
 
+#ifdef PNG_mDCv_SUPPORTED
+PNG_EXPORT(250, png_uint_32, png_get_mDCv, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_mdcvp *mastering_display_color_volume));
+PNG_EXPORT(251, void, png_set_mDCv, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_const_mdcvp mastering_display_color_volume));
+#endif
+
+#ifdef PNG_cLLi_SUPPORTED
+PNG_EXPORT(252, png_uint_32, png_get_cLLi, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 *max_cll, png_uint_32 *max_fall));
+PNG_EXPORT(253, void, png_set_cLLi, (png_const_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 max_cll, png_uint_32 max_fall));
+#endif
+
 #ifdef PNG_sPLT_SUPPORTED
 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_sPLT_tpp entries));
@@ -3237,7 +3272,7 @@ PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
  * one to use is one more than this.)
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(249);
+  PNG_EXPORT_LAST_ORDINAL(253);
 #endif
 
 #ifdef __cplusplus
diff --git a/pngget.c b/pngget.c
index fac370d044..b5882cb894 100644
--- a/pngget.c
+++ b/pngget.c
@@ -767,6 +767,48 @@ png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
 }
 #endif
 
+#ifdef PNG_mDCv_SUPPORTED
+png_uint_32 PNGAPI
+png_get_mDCv(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_mdcvp *mastering_display_color_volume)
+{
+   png_debug1(1, "in %s retrieval function", "mDCv");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_mDCv) != 0 && mastering_display_color_volume != NULL)
+   {
+      *mastering_display_color_volume = &(info_ptr->mastering_display_color_volume);
+      return (PNG_INFO_mDCv);
+   }
+
+   return (0);
+}
+#endif /* mDCv */
+
+#ifdef PNG_cLLi_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cLLi(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_uint_32 *max_cll, png_uint_32 *max_fall)
+{
+   png_debug1(1, "in %s retrieval function", "cLLi");
+
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_cLLi) != 0)
+   {
+       if (max_cll != NULL)
+           *max_cll = info_ptr->maximum_content_light_level;
+
+       if (max_fall != NULL)
+           *max_fall = info_ptr->maximum_frame_average_light_level ;
+
+      return (PNG_INFO_cLLi);
+   }
+
+   return (0);
+
+}
+#endif /* cLLi */
+
 #ifdef PNG_sPLT_SUPPORTED
 int PNGAPI
 png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
diff --git a/pnginfo.h b/pnginfo.h
index ea4f115003..d18626ea7f 100644
--- a/pnginfo.h
+++ b/pnginfo.h
@@ -106,6 +106,20 @@ struct png_info_def
    png_bytep iccp_profile;  /* International Color Consortium profile data */
    png_uint_32 iccp_proflen;  /* ICC profile data length */
 #endif
+    
+#ifdef PNG_mDCv_SUPPORTED
+   /* The mDCv chunk characterizes the Mastering Display Color Volume (mDCv)
+    * used at the point of content creation holds the last time the displayed image
+    * data was modified. See the png_mdcv struct for the contents of this struct.
+    */
+    png_mdcv mastering_display_color_volume;
+#endif
+
+#ifdef PNG_cLLi_SUPPORTED
+   /* cLLi chunk data. */
+    png_uint_32 maximum_content_light_level;
+    png_uint_32 maximum_frame_average_light_level;
+#endif
 
 #ifdef PNG_TEXT_SUPPORTED
    /* The tEXt, and zTXt chunks contain human-readable textual data in
diff --git a/pngpread.c b/pngpread.c
index 322b0cf9f1..74d51b2c61 100644
--- a/pngpread.c
+++ b/pngpread.c
@@ -332,6 +332,22 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
       png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
    }
 
+#endif
+#ifdef PNG_READ_mDCv_SUPPORTED
+   else if (png_ptr->chunk_name == png_mDCv)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_mDCv(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
+#endif
+#ifdef PNG_READ_cLLi_SUPPORTED
+   else if (png_ptr->chunk_name == png_cLLi)
+   {
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
+      png_handle_cLLi(png_ptr, info_ptr, png_ptr->push_length);
+   }
+
 #endif
 #ifdef PNG_READ_sPLT_SUPPORTED
    else if (chunk_name == png_sPLT)
diff --git a/pngpriv.h b/pngpriv.h
index 62615bee88..dd575de05f 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -842,6 +842,8 @@
 #define png_gIFx PNG_U32(103,  73,  70, 120)
 #define png_hIST PNG_U32(104,  73,  83,  84)
 #define png_iCCP PNG_U32(105,  67,  67,  80)
+#define png_mDCv PNG_U32(109,  68,  67, 118) /* mDCv */
+#define png_cLLi PNG_U32( 99,  76,  76, 105) /* cLLi */
 #define png_iTXt PNG_U32(105,  84,  88, 116)
 #define png_oFFs PNG_U32(111,  70,  70, 115)
 #define png_pCAL PNG_U32(112,  67,  65,  76)
@@ -1149,6 +1151,16 @@ PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
     */
 #endif
 
+#ifdef PNG_WRITE_mDCv_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_mDCv,(png_structrp png_ptr,
+    png_const_mdcvp mastering_display_color_volume), PNG_EMPTY);
+#endif
+
+#ifdef PNG_WRITE_cLLi_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_cLLi,(png_structrp png_ptr,
+    png_uint_32 maximum_content_light_level, png_uint_32 maximum_frame_average_light_level), PNG_EMPTY);
+#endif
+
 #ifdef PNG_WRITE_sPLT_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_write_sPLT,(png_structrp png_ptr,
     png_const_sPLT_tp palette),PNG_EMPTY);
@@ -1493,6 +1505,16 @@ PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif /* READ_iCCP */
 
+#ifdef PNG_READ_mDCv_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_mDCv,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif /* READ_mDCv */
+
+#ifdef PNG_READ_cLLi_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_handle_cLLi,(png_structrp png_ptr,
+    png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
+#endif /* READ_cLLi */
+
 #ifdef PNG_READ_iTXt_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
diff --git a/pngread.c b/pngread.c
index b10b426519..3a182f47b3 100644
--- a/pngread.c
+++ b/pngread.c
@@ -224,6 +224,16 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 
+#ifdef PNG_READ_mDCv_SUPPORTED
+      else if (chunk_name == png_mDCv)
+          png_handle_mDCv(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_cLLi_SUPPORTED
+      else if (chunk_name == png_cLLi)
+         png_handle_cLLi(png_ptr, info_ptr, length);
+#endif
+       
 #ifdef PNG_READ_sPLT_SUPPORTED
       else if (chunk_name == png_sPLT)
          png_handle_sPLT(png_ptr, info_ptr, length);
@@ -900,6 +910,16 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
       else if (chunk_name == png_iCCP)
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
+    
+#ifdef PNG_READ_mDCv_SUPPORTED
+      else if (chunk_name == png_mDCv)
+          png_handle_mDCv(png_ptr, info_ptr, length);
+#endif
+
+#ifdef PNG_READ_cLLi_SUPPORTED
+      else if (chunk_name == png_cLLi)
+         png_handle_cLLi(png_ptr, info_ptr, length);
+#endif
 
 #ifdef PNG_READ_sPLT_SUPPORTED
       else if (chunk_name == png_sPLT)
@@ -1638,6 +1658,12 @@ png_image_skip_unused_chunks(png_structrp png_ptr)
            103,  65,  77,  65, '\0',  /* gAMA */
 #        ifdef PNG_READ_iCCP_SUPPORTED
            105,  67,  67,  80, '\0',  /* iCCP */
+#        endif
+#        ifdef PNG_READ_mDCv_SUPPORTED
+           109,  68,  67, 118, '\0',  /* mDCv */
+#        endif
+#        ifdef PNG_READ_cLLi_SUPPORTED
+            99,  76,  76, 105, '\0',  /* cLLi */
 #        endif
            115,  66,  73,  84, '\0',  /* sBIT */
            115,  82,  71,  66, '\0',  /* sRGB */
diff --git a/pngrutil.c b/pngrutil.c
index 44b3a68693..4cc6487465 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -301,6 +301,7 @@ png_crc_error(png_structrp png_ptr)
 #if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\
     defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\
     defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\
+    defined(PNG_READ_mDCv_SUPPORTED) || defined(PNG_READ_cLLi_SUPPORTED) ||\
     defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED)
 /* Manage the read buffer; this simply reallocates the buffer if it is not small
  * enough (or if it is not allocated).  The routine returns a pointer to the
@@ -1647,6 +1648,94 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
 }
 #endif /* READ_iCCP */
 
+#ifdef PNG_READ_mDCv_SUPPORTED
+void /* PRIVATE */
+png_handle_mDCv(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+    png_byte buf[24];
+    png_mdcv mastering_display_color_volume;
+
+    png_debug(1, "in png_handle_mDCv");
+
+    if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+        png_chunk_error(png_ptr, "missing IHDR");
+
+    else if ((png_ptr->mode & (PNG_HAVE_IDAT | PNG_HAVE_PLTE)) != 0)
+    {
+        png_crc_finish(png_ptr, length);
+        png_chunk_benign_error(png_ptr, "out of place");
+        return;
+    }
+
+    if (length != 24)
+    {
+        png_crc_finish(png_ptr, length);
+        png_chunk_benign_error(png_ptr, "invalid length");
+        return;
+    }
+
+    png_crc_read(png_ptr, buf, 24);
+
+    if (png_crc_finish(png_ptr, 0) != 0)
+        return;
+
+    // Extract the information
+    mastering_display_color_volume.chromaticity_redx = png_get_uint_16(buf);
+    mastering_display_color_volume.chromaticity_redy = png_get_uint_16(buf + 2);
+    mastering_display_color_volume.chromaticity_greenx = png_get_uint_16(buf + 4);
+    mastering_display_color_volume.chromaticity_greeny = png_get_uint_16(buf + 6);
+    mastering_display_color_volume.chromaticity_bluex = png_get_uint_16(buf + 8);
+    mastering_display_color_volume.chromaticity_bluey = png_get_uint_16(buf + 10);
+    mastering_display_color_volume.chromaticity_whitex = png_get_uint_16(buf + 12);
+    mastering_display_color_volume.chromaticity_whitey = png_get_uint_16(buf + 14);
+    mastering_display_color_volume.max_Lum = png_get_uint_32(buf + 16);
+    mastering_display_color_volume.min_Lum = png_get_uint_32(buf + 20);
+
+    png_set_mDCv(png_ptr, info_ptr, &mastering_display_color_volume);
+
+}
+#endif /* READ_mDCv */
+
+#ifdef PNG_READ_cLLi_SUPPORTED
+void /* PRIVATE */
+png_handle_cLLi(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
+{
+    png_byte buf[8];
+    png_uint_32 max_cll, max_fall;
+
+    png_debug(1, "in png_handle_cLLi");
+
+    if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
+        png_chunk_error(png_ptr, "missing IHDR");
+
+    else if ((png_ptr->mode & (PNG_HAVE_IDAT | PNG_HAVE_PLTE)) != 0)
+    {
+        png_crc_finish(png_ptr, length);
+        png_chunk_benign_error(png_ptr, "out of place");
+        return;
+    }
+
+    if (length != 8)
+    {
+        png_crc_finish(png_ptr, length);
+        png_chunk_benign_error(png_ptr, "invalid length");
+        return;
+    }
+
+    png_crc_read(png_ptr, buf, 8);
+
+    if (png_crc_finish(png_ptr, 0) != 0)
+        return;
+
+    // Extract the information
+    max_cll = png_get_uint_32(buf);
+    max_fall = png_get_uint_32(buf + 4);
+
+    png_set_cLLi(png_ptr, info_ptr, max_cll, max_fall);
+
+}
+#endif /* READ_cLLi */
+
 #ifdef PNG_READ_sPLT_SUPPORTED
 void /* PRIVATE */
 png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
diff --git a/pngset.c b/pngset.c
index b530f65d1e..6361dcecd9 100644
--- a/pngset.c
+++ b/pngset.c
@@ -744,6 +744,46 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
 }
 #endif
 
+#ifdef PNG_mDCv_SUPPORTED
+void PNGAPI
+png_set_mDCv(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_const_mdcvp mastering_display_color_volume)
+{
+   png_debug1(1, "in %s storage function", "mDCv");
+
+   if (png_ptr == NULL || info_ptr == NULL || mastering_display_color_volume == NULL)
+      return;
+
+   if (mastering_display_color_volume->chromaticity_redx < 0 || mastering_display_color_volume->chromaticity_redy < 0 ||
+       mastering_display_color_volume->chromaticity_greenx < 0 || mastering_display_color_volume->chromaticity_greeny < 0 ||
+       mastering_display_color_volume->chromaticity_bluex < 0 || mastering_display_color_volume->chromaticity_bluey < 0 ||
+       mastering_display_color_volume->chromaticity_whitex < 0 || mastering_display_color_volume->chromaticity_whitey < 0 ||
+       mastering_display_color_volume->max_Lum < 0 || mastering_display_color_volume->min_Lum < 0)
+   {
+      png_warning(png_ptr, "Invalid value");
+      return;
+   }
+
+   info_ptr->mastering_display_color_volume = *mastering_display_color_volume;
+   info_ptr->valid |= PNG_INFO_mDCv;
+}
+#endif
+
+#ifdef PNG_cLLi_SUPPORTED
+void PNGAPI
+png_set_cLLi(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 max_cll, png_uint_32 max_fall)
+{
+    png_debug1(1, "in %s storage function", "cLLi");
+
+    if (png_ptr == NULL || info_ptr == NULL)
+       return;
+
+    info_ptr->maximum_content_light_level = max_cll;
+    info_ptr->maximum_frame_average_light_level = max_fall;
+    info_ptr->valid |= PNG_INFO_cLLi;
+ }
+#endif
+
 #ifdef PNG_TEXT_SUPPORTED
 void PNGAPI
 png_set_text(png_const_structrp png_ptr, png_inforp info_ptr,
@@ -1398,6 +1438,8 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
         103,  65,  77,  65, '\0',  /* gAMA */
         104,  73,  83,  84, '\0',  /* hIST */
         105,  67,  67,  80, '\0',  /* iCCP */
+        109,  68,  67, 118, '\0',  /* mDCv */
+         99,  76,  76, 105, '\0',  /* cLLi */
         105,  84,  88, 116, '\0',  /* iTXt */
         111,  70,  70, 115, '\0',  /* oFFs */
         112,  67,  65,  76, '\0',  /* pCAL */
diff --git a/pngstruct.h b/pngstruct.h
index 7e919d0a37..2e62d13074 100644
--- a/pngstruct.h
+++ b/pngstruct.h
@@ -315,6 +315,11 @@ struct png_struct_def
    png_color_16 trans_color;  /* transparent color for non-paletted files */
 #endif
 
+#if defined(PNG_READ_cLLi_SUPPORTED)
+    png_uint_32 maximum_content_light_level;
+    png_uint_32 maximum_frame_average_light_level;
+#endif /* cLLi */
+    
    png_read_status_ptr read_row_fn;   /* called after each row is decoded */
    png_write_status_ptr write_row_fn; /* called after each row is encoded */
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
diff --git a/pngtest.c b/pngtest.c
index bcf0f30b5b..d3e25f4151 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1182,6 +1182,26 @@ test_one_file(const char *inname, const char *outname)
       }
    }
 #endif
+#ifdef PNG_mDCv_SUPPORTED
+   {
+      png_mdcv mastering_display_color_volume;
+
+      if (png_get_mDCv(read_ptr, read_info_ptr, &mastering_display_color_volume) != 0)
+#ifdef PNG_WRITE_mDCv_SUPPORTED
+         png_set_mDCv(write_ptr, write_info_ptr, &mastering_display_color_volume);
+#endif
+   }
+#endif
+#ifdef PNG_cLLi_SUPPORTED
+   {
+      png_uint_32 max_cll, max_fall;
+
+      if (png_get_cLLi(read_ptr, read_info_ptr, &max_cll, &max_fall) != 0)
+#ifdef PNG_WRITE_cLLi_SUPPORTED
+         png_set_cLLi(write_ptr, write_info_ptr, max_cll, max_fall);
+#endif
+   }
+#endif
 #ifdef PNG_sRGB_SUPPORTED
    {
       int intent;
diff --git a/pngwrite.c b/pngwrite.c
index 0ed6a551a4..d1e2bb48c5 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -164,6 +164,16 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
             png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent);
 #  endif /* WRITE_sRGB */
 #endif /* COLORSPACE */
+       
+#ifdef PNG_WRITE_mDCv_SUPPORTED
+        if ((info_ptr->valid & PNG_INFO_mDCv) != 0)
+            png_write_mDCv(png_ptr, &(info_ptr->mastering_display_color_volume));
+#endif
+
+#ifdef PNG_WRITE_cLLi_SUPPORTED
+        if ((info_ptr->valid & PNG_INFO_cLLi) != 0)
+            png_write_cLLi(png_ptr, info_ptr->maximum_content_light_level, info_ptr->maximum_frame_average_light_level);
+#endif
 
 #ifdef PNG_WRITE_sBIT_SUPPORTED
          if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
diff --git a/pngwutil.c b/pngwutil.c
index abe7b07f96..cf589e3f93 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -1190,6 +1190,55 @@ png_write_iCCP(png_structrp png_ptr, png_const_charp name,
 }
 #endif
 
+#ifdef PNG_WRITE_mDCv_SUPPORTED
+/* Write the mDCv chunk */
+void /* PRIVATE */
+png_write_mDCv(png_structrp png_ptr, png_const_mdcvp mastering_display_color_volume)
+{
+    png_byte buf[24];
+
+    png_debug(1, "in png_write_mDCv");
+
+    if (mastering_display_color_volume == NULL)
+        png_error(png_ptr, "Null mastering display color volume");
+
+    png_save_uint_16(buf + 0, mastering_display_color_volume->chromaticity_redx);
+    png_save_uint_16(buf + 2, mastering_display_color_volume->chromaticity_redy);
+    png_save_uint_16(buf + 4, mastering_display_color_volume->chromaticity_greenx);
+    png_save_uint_16(buf + 6, mastering_display_color_volume->chromaticity_greeny);
+    png_save_uint_16(buf + 8, mastering_display_color_volume->chromaticity_bluex);
+    png_save_uint_16(buf + 10, mastering_display_color_volume->chromaticity_bluey);
+    png_save_uint_16(buf + 12, mastering_display_color_volume->chromaticity_whitex);
+    png_save_uint_16(buf + 14, mastering_display_color_volume->chromaticity_whitey);
+    png_save_uint_32(buf + 16, mastering_display_color_volume->max_Lum);
+    png_save_uint_32(buf + 20, mastering_display_color_volume->min_Lum);
+
+    png_write_complete_chunk(png_ptr, png_mDCv, buf, 24);
+
+}
+#endif
+
+#ifdef PNG_WRITE_cLLi_SUPPORTED
+/* Write the cLLi chunk */
+void /* PRIVATE */
+png_write_cLLi(png_structrp png_ptr, png_uint_32 max_cll, png_uint_32 max_fall)
+{
+    png_byte buf[8];
+
+    png_debug(1, "in png_write_cLLi");
+
+    /* Check that we have valid input data from the application info */
+    if (max_cll < 0 || max_fall < 0)
+       png_error(png_ptr, "Invalid value");
+
+    png_save_int_32(buf, max_cll);
+    png_save_int_32(buf + 4, max_fall);
+
+    png_write_complete_chunk(png_ptr, png_cLLi, buf, 8);
+
+}
+#endif
+
 #ifdef PNG_WRITE_sPLT_SUPPORTED
 /* Write a sPLT chunk */
 void /* PRIVATE */
diff --git a/scripts/pnglibconf.dfa b/scripts/pnglibconf.dfa
index fe8e481238..90aaea76fd 100644
--- a/scripts/pnglibconf.dfa
+++ b/scripts/pnglibconf.dfa
@@ -850,6 +850,8 @@ chunk eXIf
 chunk gAMA enables GAMMA
 chunk hIST
 chunk iCCP enables COLORSPACE, GAMMA
+chunk mDCv
+chunk cLLi
 chunk iTXt enables TEXT
 chunk oFFs
 chunk pCAL
diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index c46f7c4035..e05dc50fd3 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -92,6 +92,8 @@
 #define PNG_READ_gAMA_SUPPORTED
 #define PNG_READ_hIST_SUPPORTED
 #define PNG_READ_iCCP_SUPPORTED
+#define PNG_READ_mdCv_SUPPORTED
+#define PNG_READ_cLLi_SUPPORTED
 #define PNG_READ_iTXt_SUPPORTED
 #define PNG_READ_oFFs_SUPPORTED
 #define PNG_READ_pCAL_SUPPORTED
@@ -162,6 +164,8 @@
 #define PNG_WRITE_gAMA_SUPPORTED
 #define PNG_WRITE_hIST_SUPPORTED
 #define PNG_WRITE_iCCP_SUPPORTED
+#define PNG_WRITE_mdCv_SUPPORTED
+#define PNG_WRITE_cLLi_SUPPORTED
 #define PNG_WRITE_iTXt_SUPPORTED
 #define PNG_WRITE_oFFs_SUPPORTED
 #define PNG_WRITE_pCAL_SUPPORTED
@@ -180,6 +184,8 @@
 #define PNG_gAMA_SUPPORTED
 #define PNG_hIST_SUPPORTED
 #define PNG_iCCP_SUPPORTED
+#define PNG_mdCv_SUPPORTED
+#define PNG_cLLi_SUPPORTED
 #define PNG_iTXt_SUPPORTED
 #define PNG_oFFs_SUPPORTED
 #define PNG_pCAL_SUPPORTED
diff --git a/scripts/symbols.def b/scripts/symbols.def
index 82494bbf94..2731c6049d 100644
--- a/scripts/symbols.def
+++ b/scripts/symbols.def
@@ -253,3 +253,7 @@ EXPORTS
  png_set_eXIf @247
  png_get_eXIf_1 @248
  png_set_eXIf_1 @249
+ png_get_mDCv @250
+ png_set_mDCv @251
+ png_get_cLLi @252
+ png_set_cLLi @253