brew install ffmpeg
go get github.com/fzakaria/transcoding
go install github.com/fzakaria/transcoding
#Assumes $GOPATH/bin is on your $PATH 
transcoding --config ./configs/prod-us-east-1.toml

A basic server implementation is included that offers the facility to transcode uploaded multipart files and some additional admin urls.

GET /transcode                               
POST /transcode 
#Some admin routes
GET /admin 
GET /admin/ping                                 
GET /admin/pprof/                            
GET /admin/pprof/heap                        
GET /admin/pprof/goroutine                   
GET /admin/pprof/block                       
GET /admin/pprof/threadcreate                
GET /admin/pprof/cmdline                     
GET /admin/pprof/profile                     
GET /admin/pprof/symbol                      
GET /admin/stats    
GET /admin/config

###Transcoding A useful route is the [POST|GET] /transcode one, which provided a file and conversion type will return the resulting MP4 file. A sample form is provided at the GET route, however you can also make use of CLI tools.

brew install http 
http -f POST http://localhost:8080/transcode input@~/Downloads/sample.mp4 type=480p  > output.mp4

###AWS The server has a tighter integration with performing Transcoding from files saved in S3 and writting them back out to S3. The route available is POST /api/transcode

You can specify a samlpe request based on the following schema:

{
		"input": {
			"bucket": "slinger-test",
			"key": "input.mp4"
		},
		"output": {
			"bucket": "slinger-test",
			"key": "output.mp4"
		},
		"type" : "320p"
}

THE SERVER MUST HAVE ACCESS TO THE INPUT & OUTPUT BUCKET - SEE AWS BUCKET POLICIES

To make bootstrapping easier for variety of platforms. A Dockerfile is provided which will run the server in a docker container.

#The following commands assumes you are in the package
docker build -t transcode-server .
docker run -p 8080:8080 transcode-server   
#You can now access the server at localhost:8080
#or if you ar on mac osx `docker-machine ip default`

A common scenario is re-encoding a video for streaming over the web. In such a scenario you generally want to transcode to a lower resolution and bitrate.

Resolution is the "sharpness" of the video in question. Filesize is not determined by resolution

filesize (in MB) = (bitrate in Mbit/s * 8) * (video length in seconds) But a larger resolution will require more bitrate for it to keep the same level of "quality"

According to this post here are some general resolution/bitrate guidelines.