QARC (video Quality Aware Rate Control)

Introduction

Real-time video streaming is now one of the main applications in all network environments. Due to the fluctuation of throughput under various network conditions, how to choose a proper bitrate adaptively has become an upcoming and interesting issue. To tackle this problem, most proposed rate control methods work for providing high video bitrates instead of video qualities. Nevertheless, we notice that there exists a trade-off between sending bitrate and video quality, which motivates us to focus on how to reach a balance between them. We then propose QARC (video Quality Aware Rate Control), a rate control algorithm that aims to obtain a higher perceptual video quality with possible lower sending rate and transmission latency. In detail, QARC uses deep reinforcement learning(DRL) algorithm to train a neural network to select future bitrates based on previously observed network status and past video frames. To overcome the state explosion problem, we design a neural network to predict future perceptual video quality as a vector for taking the place of the raw picture in the DRL's inputs.

Install Requirements

The current codebase runs on Python 2.7. This work requires tensorflow, tflearn, scipy, matplotlib, opencv2 and tensorboard. Please install these package before using QARC.

pip install tensorflow==1.15 tflearn==0.3.2 scipy==1.2.2 matplotlib opencv-python tensorboard

Video datasets

In videodatasets/, we describe how to generate video datasets.

1. Clone the vmaf git repository

   git clone https://github.com/Netflix/vmaf
   

   and checkout version 1.3.9 (available on the v1.3.9 tag).

2. Copy the videodatasets/ folder to the vmaf/ folder.

3. Download several video clips into videodatasets/mov/ folders, and the video MUST be encoded in h.264 format.

4. Run trans.py for transcoding mp4 video format to flv.

5. Run main.py for generating video datasets including logs and video frames.

   Note: To avoid any potential errors, make sure to install ffmpeg, find your path to ffmpeg by running which ffmpeg in the command line, and set FFMPEG_PATH in vmaf/python/src/vmaf/externals.py, e.g. add a line like

   FFMPEG_PATH="[path to exec]/ffmpeg"
   

6. Run process-vmaf.py to generate a h5py file for training.

   Note: This script expects frame image files from the previous step to be in a subdirectory named img/<original_video_filename>/, e.g., if the original file was 1.mp4, then its frame image files would be under img/1.mp4/.

QARC-basic

The traditional QARC method is composed of two modules: VQPN and VQRL.

VQPN (Video Quality Prediction Network)

To run and evaluate VQPN, you should follow these steps.

1. Copy the *.h5 training dataset and test dataset from videodatasets/ to QARC/VQPN

2. There are two nerual network architecture candidates, GRU model (as shown in the paper) and CNN model (also reaches a high performance but a little bit lower than the GRU model performs), in different folders. Type cd gru/ & python main.py for training GRU model or cd cnn/ & python main.py for training CNN model. We use early stopping method that automaticlly tear down the training process if overfitting occurs.

3. We provide several baselines for evaluating the performance of VQPN in baseline/ folder.

VQRL (Video Quality Reinforcement Learning)

To run and test VQRL, one should follow these steps:

1. Copy the pretrain VQPN model to QARC/VQRL/model/, we recommend GRU model for higher performances.

2. Collect network traces and copy the traces to QARC/VQRL/train_sim_traces/, the format of network traces is described like this: timestamp\tbandwidth\n, and you can also use cooked_traces from Pensieve as network trace dataset.

3. Run the training process via python main.py

The usage of advanced-QARC is quite the same as QARC.

Cite

If you find this work useful to you, please cite

@inproceedings{huang2018qarc,
  title={Qarc: Video quality aware rate control for real-time video streaming based on deep reinforcement learning},
  author={Huang, Tianchi and Zhang, Rui-Xiao and Zhou, Chao and Sun, Lifeng},
  booktitle={Proceedings of the 26th ACM international conference on Multimedia},
  pages={1208--1216},
  year={2018}
}