Add support for higher QP values in h264.

In high bit depth, the QP values may now be up to (51 + 6*(bit_depth-8)).

Preparatory patch for high bit depth h264 decoding support.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/libavcodec/h264_cavlc.c b/libavcodec/h264_cavlc.c
index 61b057176b..2e5ea54679 100644
--- a/libavcodec/h264_cavlc.c
+++ b/libavcodec/h264_cavlc.c
@@ -922,6 +922,7 @@ decode_intra_mb:
         int dquant;
         GetBitContext *gb= IS_INTRA(mb_type) ? h->intra_gb_ptr : h->inter_gb_ptr;
         const uint8_t *scan, *scan8x8;
+        const int max_qp = 51 + 6*(h->sps.bit_depth_luma-8);
 
         if(IS_INTERLACED(mb_type)){
             scan8x8= s->qscale ? h->field_scan8x8_cavlc : h->field_scan8x8_cavlc_q0;
@@ -935,10 +936,10 @@ decode_intra_mb:
 
         s->qscale += dquant;
 
-        if(((unsigned)s->qscale) > 51){
-            if(s->qscale<0) s->qscale+= 52;
-            else            s->qscale-= 52;
-            if(((unsigned)s->qscale) > 51){
+        if(((unsigned)s->qscale) > max_qp){
+            if(s->qscale<0) s->qscale+= max_qp+1;
+            else            s->qscale-= max_qp+1;
+            if(((unsigned)s->qscale) > max_qp){
                 av_log(h->s.avctx, AV_LOG_ERROR, "dquant out of range (%d) at %d %d\n", dquant, s->mb_x, s->mb_y);
                 return -1;
             }