fix the bug of h.264 bit stream demux.

@@ -876,6 +876,13 @@ int SrsAvcAacCodec::avc_demux_sps()
         
         // XX 00 00 03 XX, the 03 byte should be drop.
         if (nb_rbsp > 2 && rbsp[nb_rbsp - 2] == 0 && rbsp[nb_rbsp - 1] == 0 && rbsp[nb_rbsp] == 3) {
+            // read 1byte more.
+            if (stream.empty()) {
+                break;
+            }
+            rbsp[nb_rbsp] = stream.read_1bytes();
+            nb_rbsp++;
+            
             continue;
         }
         

@@ -73,7 +73,7 @@ int srs_avc_nalu_read_uev(SrsBitStream* stream, int32_t& v)
     
     v = (1 << leadingZeroBits) - 1;
     for (int i = 0; i < leadingZeroBits; i++) {
-        int64_t b = stream->read_bit();
+        int32_t b = stream->read_bit();
         v += b << (leadingZeroBits - 1);
     }