1 files changed, 14 insertions, 0 deletions
diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c
index 47db1edd91..9b4dad49ef 100644
--- a/libavcodec/mpegvideo_enc.c
+++ b/libavcodec/mpegvideo_enc.c
@@ -146,6 +146,20 @@ void ff_write_quant_matrix(PutBitContext *pb, uint16_t *matrix){
         put_bits(pb, 1, 0);
 }
 
+/**
+ * init s->current_picture.qscale_table from s->lambda_table
+ */
+void ff_init_qscale_tab(MpegEncContext *s){
+    int8_t * const qscale_table= s->current_picture.qscale_table;
+    int i;
+
+    for(i=0; i<s->mb_num; i++){
+        unsigned int lam= s->lambda_table[ s->mb_index2xy[i] ];
+        int qp= (lam*139 + FF_LAMBDA_SCALE*64) >> (FF_LAMBDA_SHIFT + 7);
+        qscale_table[ s->mb_index2xy[i] ]= av_clip(qp, s->avctx->qmin, s->avctx->qmax);
+    }
+}
+
 static void copy_picture_attributes(MpegEncContext *s, AVFrame *dst, AVFrame *src){
     int i;