Add tutorial to use NVDEC with Stream API (pytorch#2393)

Summary:
This commit adds tutorial to enable/use NVDEC with Stream API.

https://output.circle-artifacts.com/output/job/19e66a4b-1819-4804-8834-d38e6c80c4fd/artifacts/0/docs/hw_acceleration_tutorial.html

Because the use of NVDEC requires build / install FFmpeg from source,
this tutorial was authored on Google Colab, tailored to its environment.

The tutorial here is the result of the notebook execution, with
the link to the publicly accessible Google Colab notebook.

Pull Request resolved: pytorch#2393

Reviewed By: hwangjeff

Differential Revision: D36404408

Pulled By: mthrok

fbshipit-source-id: 9c820d3db4d06c5b343ecad0708489125ca06948

Author: mthrok

.circleci/config.yml

@@ -834,7 +834,7 @@ jobs:
             apt update && apt-get -qq install -y git make
             source /usr/local/etc/profile.d/conda.sh && conda activate python${PYTHON_VERSION}
             pip install -r requirements.txt -r requirements-tutorials.txt
-            conda install -y 'ffmpeg<5'
+            conda install -y pandoc 'ffmpeg<5'
             make 'SPHINXOPTS=-W' html
           environment:
             BUILD_GALLERY: 1
@@ -866,6 +866,7 @@ jobs:
             DONE
       - run:
           name: Upload docs
+          no_output_timeout: 30m
           command: |
             # Don't use "checkout" step since it uses ssh, which cannot git push
             # https://circleci.com/docs/2.0/configuration-reference/#checkout

.circleci/config.yml.in

@@ -5,3 +5,5 @@ pandas
 librosa
 numpy<=1.20
 sentencepiece
+nbsphinx
+pandoc

docs/requirements-tutorials.txt

@@ -51,6 +51,7 @@
     "sphinxcontrib.katex",
     "sphinxcontrib.bibtex",
     "sphinx_gallery.gen_gallery",
+    "nbsphinx",
 ]
 
 autodoc_member_order = "bysource"
@@ -169,7 +170,12 @@ def _get_pattern():
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This patterns also effect to html_static_path and html_extra_path
-exclude_patterns = ["*/index.rst"]
+exclude_patterns = [
+    "*/index.rst",
+    "tutorials/*.md5",
+    "tutorials/*.py",
+    "tutorials/*.ipynb",
+]
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = "sphinx"