docs: update README with extra dev info

This commit ensure that developers are aware of the extra build flags
they have to run when installing ffmpeg for the tests to be succesfull.
It also cleans up the README a bit.

README.md

@@ -3,12 +3,13 @@
 # LPMS - Livepeer Media Server
 
 LPMS is a media server that can run independently, or on top of the [Livepeer](https://livepeer.org)
-network.  It allows you to manipulate / broadcast a live video stream.  Currently, LPMS supports RTMP
+network. It allows you to manipulate / broadcast a live video stream. Currently, LPMS supports RTMP
 as input format and RTMP/HLS as output formats.
 
-LPMS can be integrated into another service, or run as a standalone service.  To try LPMS as a
+LPMS can be integrated into another service, or run as a standalone service. To try LPMS as a
 standalone service, simply get the package:
-```
+
+```sh
 go get -d github.com/livepeer/lpms/cmd/example
 ```
 
@@ -23,36 +24,39 @@ go build cmd/example/main.go
 
 LPMS requires libavcodec (ffmpeg) and friends. See `install_ffmpeg.sh` . Running this script will install everything in `~/compiled`. In order to build LPMS, the dependent libraries need to be discoverable by pkg-config and golang. If you installed everything with `install_ffmpeg.sh` , then run `export PKG_CONFIG_PATH=~/compiled/lib/pkgconfig:$PKG_CONFIG_PATH` so the deps are picked up.
 
-Running golang unit tests (`test.sh`) requires the `ffmpeg` and `ffprobe` executables in addition to the libraries. However, none of these are run-time requirements; the executables are not used outside of testing, and the libraries are statically linked by default. Note that dynamic linking may substantially speed up rebuilds if doing heavy development.
+Running golang unit tests (`test.sh`) requires the `ffmpeg` and `ffprobe` executables in addition to the libraries. Additionally it requires ffmpeg to be build with additional codecs and formats enabled. To build `ffmpeg` with all codecs and formats enabled, ensure `clang` is installed and then run `BUILD_TAGS=debug-video ./install_ffmpeg.sh`. However, none of these are run-time requirements; the executables are not used outside of testing, and the libraries are statically linked by default. Note that dynamic linking may substantially speed up rebuilds if doing heavy development.
 
 ### Testing out LPMS
 
 The test LPMS server exposes a few different endpoints:
+
 1. `rtmp://localhost:1935/stream/test` for uploading/viewing RTMP video stream.
 2. `http://localhost:7935/stream/test_hls.m3u8` for consuming the HLS video stream.
 
 Do the following steps to view a live stream video:
-1. Start LPMS by running `go run cmd/example/main.go`
 
-2. Upload an RTMP video stream to `rtmp://localhost:1935/stream/test`.  We recommend using ffmpeg or [OBS](https://obsproject.com/download).
+1. Start LPMS by running `go run cmd/example/main.go`
+2. Upload an RTMP video stream to `rtmp://localhost:1935/stream/test`. We recommend using ffmpeg or [OBS](https://obsproject.com/download).
 
-For ffmpeg on osx, run: `ffmpeg -f avfoundation -framerate 30 -pixel_format uyvy422 -i "0:0" -c:v libx264 -tune zerolatency -b:v 900k -x264-params keyint=60:min-keyint=60 -c:a aac -ac 2 -ar 44100 -f flv rtmp://localhost:1935/stream/test`
+   For ffmpeg on osx, run: `ffmpeg -f avfoundation -framerate 30 -pixel_format uyvy422 -i "0:0" -c:v libx264 -tune zerolatency -b:v 900k -x264-params keyint=60:min-keyint=60 -c:a aac -ac 2 -ar 44100 -f flv rtmp://localhost:1935/stream/test`
 
-For OBS, fill in Settings->Stream->URL to be rtmp://localhost:1935
+   For OBS, fill in Settings->Stream->URL to be rtmp://localhost:1935
 
 3. If you have successfully uploaded the stream, you should see something like this in the LPMS output
-```
-I0324 09:44:14.639405   80673 listener.go:28] RTMP server got upstream
-I0324 09:44:14.639429   80673 listener.go:42] Got RTMP Stream: test
-```
-4. Now you have a RTMP video stream running, we can view it from the server.  Simply run `ffplay http://localhost:7935/stream/test.m3u8`, you should see the hls video playback.
 
+   ```bash
+   I0324 09:44:14.639405   80673 listener.go:28] RTMP server got upstream
+   I0324 09:44:14.639429   80673 listener.go:42] Got RTMP Stream: test
+   ```
+
+4. Now you have a RTMP video stream running, we can view it from the server. Simply run `ffplay http://localhost:7935/stream/test.m3u8`, you should see the hls video playback.
 
 ### Integrating LPMS
 
 LPMS exposes a few different methods for customization. As an example, take a look at `cmd/main.go`.
 
 To create a new LPMS server:
+
 ```go
 // Specify ports you want the server to run on, and the working directory for
 // temporary files. See `core/lpms.go` for a full list of LPMSOpts
@@ -65,6 +69,7 @@ lpms := lpms.New(&opts)
 ```
 
 To handle RTMP publish:
+
 ```go
 lpms.HandleRTMPPublish(
 	//getStreamID
@@ -168,19 +173,25 @@ go run cmd/transcoding/transcoding.go transcoder/test.ts P144p30fps16x9,P240p30f
 ```
 
 ### Testing GPU transcoding with failed segments from Livepeer production environment
+
 To test transcoding of segments failed on production in Nvidia environment:
+
 1. Install Livepeer from sources by following the [installation guide](https://docs.livepeer.org/guides/orchestrating/install-go-livepeer#build-from-source)
 2. Install [Google Cloud SDK](https://cloud.google.com/sdk/docs/install-sdk)
 3. Make sure you have access to the bucket with the segments
 4. Download the segments:
-    ```sh
-    gsutil cp -r gs://livepeer-production-failed-transcodes /home/livepeer-production-failed-transcodes
-    ```
+
+   ```sh
+   gsutil cp -r gs://livepeer-production-failed-transcodes /home/livepeer-production-failed-transcodes
+   ```
+
 5. Run the test
-    ```sh
-    cd transcoder
-    FAILCASE_PATH="/home/livepeer-production-failed-transcodes" go test --tags=nvidia -timeout 6h -run TestNvidia_CheckFailCase
-    ```
+
+   ```sh
+   cd transcoder
+   FAILCASE_PATH="/home/livepeer-production-failed-transcodes" go test --tags=nvidia -timeout 6h -run TestNvidia_CheckFailCase
+   ```
+
 6. After the test has finished, it will display transcoding stats. Per-file results are logged to `results.csv` in the same directory
 
 ### Contribute