Working with media often requires changing the characteristics of media files, such as bitrate or resolution. Finding a straightforward way to get started can be pretty intimidating. On this page, you will learn about the tools used and how to install them quickly.
First, we describe the basic usage for two common command-line media utilities: Shaka Packager and FFmpeg and then we help you quickly get the tools installed. Why cover two applications? While both are powerful and useful by themselves, neither does everything needed to prepare media for the web. We also created the Media conversion and Media encryption pages which show many more common operations with these two applications.
These applications aren't the only options available for file manipulation tasks, but they are two of the most common and powerful. Other options include the GUI applications Miro, HandBrake, and VLC. There are also encoding/transcoding services such as Zencoder, Amazon Elastic Encoder, and Google Transcoder API.
Shaka Packager
Shaka Packager is a free media packaging SDK. If you were using a media player on your site, Shaka Packager is what you would use to prepare the files. It supports conversion for the two most common video streaming protocols: Dynamic Adaptive Streaming over HTTP (DASH) or HTTP Live Streaming (HLS). Shaka Packager supports key security features: common encryption and Widevine digital rights management (DRM). It can also handle live-streaming, and video-on-demand.
Despite what it says on the package, this utility is for more than C++ developers. You can use it as both a library for building media software and as a command-line utility for preparing media files for web playback. It's the latter capacity that's useful for us here. In fact, for web media creators, Shaka Packager is the only way to do some tasks without spending money on expensive commercial applications.
Here's the basic pattern for a Shaka Packager command:
packager stream_descriptor [stream_descriptor-2 [stream_descriptor-n]] [flags]
This isn't quite what you get if you type packager -help. This example is
easier to reason about, and this reflects the examples in the
Shaka Packager documentation. Note that there are multiple stream_descriptor
items in the pattern. Though we don't show it, you could manipulate the video
and audio streams of a file separately in a single command.
Compare this basic pattern with a simple use that displays file characteristics. In the example, We've lined up equivalent parts.
packager stream_descriptor [stream_descriptor-n] [flags]
packager input=glocken.mp4 --dump_stream_info
The command outputs this:
File "glocken.mp4":
Found 2 stream(s).
Stream [0] type: Video
codec_string: avc1.640028
time_scale: 30000
duration: 300300 (10.0 seconds)
is_encrypted: false
codec: H264
width: 1920