Update requirements.txt

requirements.txt

@@ -1,4 +1,17 @@
-gradio
+# official PPA comes with ffmpeg 2.8, which lacks tons of features, we use ffmpeg 4.0 here
+sudo add-apt-repository ppa:jonathonf/ffmpeg-4 # for ubuntu20.04 official PPA is already version 4.2, you may skip this step
+sudo apt-get update
+sudo apt-get install -y build-essential python3-dev python3-setuptools make cmake
+sudo apt-get install -y ffmpeg libavcodec-dev libavfilter-dev libavformat-dev libavutil-dev
+# note: make sure you have cmake 3.8 or later, you can install from cmake official website if it's too old
+git clone --recursive https://github.com/dmlc/decord
+cd decord
+mkdir build && cd build
+cmake .. -DUSE_CUDA=0 -DCMAKE_BUILD_TYPE=Release
+make
+cmake .. -DUSE_CUDA=ON -DCMAKE_BUILD_TYPE=Release
+
+
 opencv-python-headless
 --extra-index-url https://download.pytorch.org/whl/cu113
 torch