Add Chroma subsampling options to jpeg writer.

Change-Id: I247a261bb96b0c437a43922070777892cdcbc1f6

vcl/source/filter/jpeg/jpeg.cxx

@@ -562,6 +562,7 @@ JPEGWriter::JPEGWriter( SvStream& rStm, const uno::Sequence< beans::PropertyValu
     FilterConfigItem aConfigItem( (uno::Sequence< beans::PropertyValue >*)pFilterData );
     bGreys = aConfigItem.ReadInt32( "ColorMode", 0 ) != 0;
     nQuality = aConfigItem.ReadInt32( "Quality", 75 );
+    aChromaSubsampling = aConfigItem.ReadInt32( "ChromaSubsamplingMode", 0 );
 
     if ( pFilterData )
     {
@@ -676,7 +677,7 @@ sal_Bool JPEGWriter::Write( const Graphic& rGraphic )
 
         JPEGCallbackStruct aCallbackData;
         aCallbackData.xStatusIndicator = xStatusIndicator;
-        bRet = (sal_Bool) WriteJPEG( this, &rOStm, pAcc->Width(), pAcc->Height(), bGreys, nQuality, &aCallbackData );
+        bRet = (sal_Bool) WriteJPEG( this, &rOStm, pAcc->Width(), pAcc->Height(), bGreys, nQuality, aChromaSubsampling, &aCallbackData );
 
         delete[] pBuffer;
         pBuffer = NULL;

vcl/source/filter/jpeg/jpeg.h

@@ -49,7 +49,7 @@ void    JPEGFree( void *ptr );
 long    JPEGCallback( void* pCallbackData, long nPercent );
 
 long    WriteJPEG( void* pJPEGWriter, void* pOStm, long nWidth, long nHeight, long bGreyScale,
-                   long nQualityPercent, void* pCallbackData );
+                   long nQualityPercent, long aChromaSubsampling, void* pCallbackData );
 void*   GetScanline( void* pJPEGWriter, long nY );
 
 void    ReadJPEG( void* pJPEGReader, void* pIStm, long* pLines );

vcl/source/filter/jpeg/jpeg.hxx

@@ -71,11 +71,12 @@ class JPEGWriter
     SvStream&           rOStm;
     Bitmap              aBmp;
     BitmapReadAccess*   pAcc;
-    sal_uInt8*              pBuffer;
-    sal_Bool                bNative;
+    sal_uInt8*          pBuffer;
+    sal_Bool            bNative;
 
     sal_Bool            bGreys;
     sal_Int32           nQuality;
+    sal_Int32           aChromaSubsampling;
 
     bool*               pExpWasGrey;
 

vcl/source/filter/jpeg/jpegc.c

@@ -91,7 +91,7 @@ void ReadJPEG( void* pJPEGReader, void* pIStm, long* pLines )
 
     jpeg_create_decompress( &cinfo );
     bDecompCreated = 1;
-        jpeg_svstream_src( &cinfo, pIStm );
+    jpeg_svstream_src( &cinfo, pIStm );
     jpeg_read_header( &cinfo, sal_True );
 
     cinfo.scale_num = 1;
@@ -215,7 +215,7 @@ Exit:
 
 long WriteJPEG( void* pJPEGWriter, void* pOStm,
                 long nWidth, long nHeight, long bGreys,
-                long nQualityPercent, void* pCallbackData )
+                long nQualityPercent, long aChromaSubsampling, void* pCallbackData )
 {
     struct jpeg_compress_struct cinfo;
     struct my_error_mgr         jerr;
@@ -257,6 +257,22 @@ long WriteJPEG( void* pJPEGWriter, void* pOStm,
     if ( ( nWidth > 128 ) || ( nHeight > 128 ) )
         jpeg_simple_progression( &cinfo );
 
+    if (aChromaSubsampling == 1) // YUV 4:4:4
+    {
+        cinfo.comp_info[0].h_samp_factor = 1;
+        cinfo.comp_info[0].v_samp_factor = 1;
+    }
+    else if (aChromaSubsampling == 2) // YUV 4:2:2
+    {
+        cinfo.comp_info[0].h_samp_factor = 2;
+        cinfo.comp_info[0].v_samp_factor = 1;
+    }
+    else if (aChromaSubsampling == 3) // YUV 4:2:0
+    {
+        cinfo.comp_info[0].h_samp_factor = 2;
+        cinfo.comp_info[0].v_samp_factor = 2;
+    }
+
     jpeg_start_compress( &cinfo, sal_True );
 
     for( nY = 0; nY < nHeight; nY++ )