Program Usage

Commandline options

Unified Capture is a command-line driven program. It's generic format is:

unified_capture -o output_file [options] <input_url>

Supported input

The input_url is a fully qualified URL.

In addition to fetching content from a HTTP webserver running the USP origin, it is also possible to use local files.

This in effect is comparable to a file copy.

All options available to HTTP based access are available for file based access as well.

Important

When accessing local files, it is required that the software versions of the Origin and Capture are identical.

The input URL specified on the command-line to the Manifest on disk is partly a virtual path. The full path always begins with the server manifest file (in the example below that is /var/www/live/chan1/chan1.isml) that is stored on disk. The second part is /Manifest, this is the virtual part. The time range is specified after that using t as a query parameter.

Example:
#!/bin/bash
unified_capture -o video.ismv
  "file:///var/www/live/channel01/channel01.isml/Manifest?t=2013-03-31T12:00:00.000-2013-03-31T12:30:00.000"

Options for Capturing

--license-key

The license key

--copy_ts

Copy the timestamp from the source (default is to start at 0).

--key

The 128 bits Key ID (KID) and 128 bits Content Encryption Key (CEK) are passed with the --key option to Decrypt the stream.

--frame_accurate

Enable frame accurate mode.

-v

Verbosity level.

Frame accurate

The Windows version of Unified Capture uses the Intel Media SDK to create frame accurate clips.

Prerequisites:

  1. A computer or VM running Windows version 8,10 or Server 2012. It must be 64-bit.
  2. The Intel Media Server Studio SDK (Software Development Kit).
  3. Unified Capture.

It is possible to make use of the hardware acceleration afforded by the SDK on a very specific Intel hardware set up, please see the Intel Media Server Studio website for a list of prerequisites for that use case. The example below will use a software implementation and therefore no specific hardware is necessary and it can also be virtualised.

First download the free community edition of Intel Media Server Studio. Install it on a 64-bit version of either Windows 8, 10, or Server 2012.

../../_images/intel.png

When installing, only the SDK (Software Development Kit) component is necessary, so please uncheck any other options as shown below:

../../_images/intel-install.png

The installer will prompt you to reboot, please do so. Once up and running again you may install the 64-bit Windows version of Unified Capture. Using the --frame_accurate parameter on your command line will produce frame accurate clips when specifying the begin and ending times with the t= parameter e.g.

#!/bin/bash

unified_capture -o clip1.ismv --frame_accurate \
  "http://demo.unified-streaming.com/video/oceans/oceans.ism/Manifest?t=00:00:00.000-00:04:00.000"

By default the begin and ending times are aligned to video key frames. When --frame-accurate is specified Unified Capture decodes and encodes the beginning and ending fragments to allow for sample accurate timing.

Note

When referring to Intel Media Server Studio SDK any names, terms, version numbers or asset links are subject to change.

Decrypt

When the presentation is encrypted, then you can decrypt and store an unencrypted stream.

To do so the KID and CEK used for encryption/DRM must be passed to capture using the --key option, separating KID and CEK by a colon, e.g. --key=KID:CEK.

The KID identifier uniquely identifies the content. The CEK is the Content Encryption Key.

In case the encryption/DRM does not use a KID the CEK may be passed as --key=:CEK, omitting the KID.

Example:

#!/bin/bash

KID=000102030405060708090a0b0c0d0e0f
CEK=000102030405060708090a0b0c0d0e0f

unified_capture -o clip1.ismv \
  --key=${KID}:${CEK} \
  "http://example.com/video1/video1.ism/Manifest"

This option is available for both VOD and Live streams.

Decrypting clips can be useful for instance for QoS purposes (to monitor normally encrypted/DRMed streams) or to maintain a clear archive for catch-up services.

Clips produced by capture may be post-processed with the Unified Packager to create other formats.

Filtering may be applied make a selection of tracks or just one track to be captured.