second try fixing time code in gxf

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@16839 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/gxfenc.c

@@ -362,8 +362,8 @@ static int gxf_write_umf_material_description(ByteIOContext *pb, GXFContext *ctx
 {
     // XXX drop frame
     uint32_t timecode =
-        ctx->nb_frames / ctx->sample_rate * 3600 % 24 << 27 | // hours
-        ctx->nb_frames / ctx->sample_rate * 60 % 60   << 16 | // minutes
+        ctx->nb_frames / (ctx->sample_rate * 3600) % 24 << 24 | // hours
+        ctx->nb_frames / (ctx->sample_rate * 60) % 60   << 16 | // minutes
         ctx->nb_frames / ctx->sample_rate % 60          <<  8 | // seconds
         ctx->nb_frames % ctx->sample_rate;                    // fields