The emerging Long-Term-Evolution (LTE) network is widely used in video transmission and plays an important role in supporting different services with high data rates and strict quality requirements. In addition to the quantization induced encoder distortion, the network environment induced packet loss can also lead to great distortions during video transmission. The Quality of Experience (QoE) of mobile users is significantly influenced by both the encoder distortion and the transmission distortion. Accordingly, there is a deadly need to combine source and channel distortions to optimize the encoding and transmission scheme. In this paper, a new end-to-end distortion model of the video streaming is proposed. The goal of this model is to investigate how the encoding rate and user number influence video qualities when videos are delivered through LTE network. Experimental results verify the accuracy of the proposed model.