void ff_set_qscale ( MpegEncContext * s , int qscale ) {
 if ( qscale < 1 ) qscale = 1 ;
 else if ( qscale > 31 ) qscale = 31 ;
 s -> qscale = qscale ;
 s -> chroma_qscale = s -> chroma_qscale_table [ qscale ] ;
 s -> y_dc_scale = s -> y_dc_scale_table [ qscale ] ;
 s -> c_dc_scale = s -> c_dc_scale_table [ s -> chroma_qscale ] ;
 }
void ff_set_qscale ( MpegEncContext * s , int qscale ) {
 if ( qscale < 1 ) qscale = 1 ;
 else if ( qscale > 31 ) qscale = 31 ;
 s -> qscale = qscale ;
 s -> chroma_qscale = s -> chroma_qscale_table [ qscale ] ;
 s -> y_dc_scale = s -> y_dc_scale_table [ qscale ] ;
 s -> c_dc_scale = s -> c_dc_scale_table [ s -> chroma_qscale ] ;
 }