Introduction

The clip output channel allows capturing of the rendered video and audio as it appears on the output of the video card into one or more files. Creation of interleaved and atomic files is possible. Depending on the resolution/container/codec combination video, as fill and key, audio, VBI, and time code information can be saved.

The generation of a proxy clip with video and optional audio is also supported. It is similar to the post-render plug-ins, except that does realtime capturing of audio, video and VBI of the actual output as it appears on the video screen. The clip out channel is available on Matrox X.mio hardware or DSX Core systems.
Before it can be used it needs to be enabled in the configuration (Config/Matrox/ClipOut1/Capture Enable). Once this is done it may be configured and controlled via the external command interface. The basic command structure is:

RENDERER*VIDEO*CLIPOUT*n*command

where n is the index of the clip channel, starting at one and command is a placeholder for the various commands. The configuration is state aware (the possible next configuration command depends on the current state of the clip out channel). For example, the codec that can be set depends on the container that is configured and so on. Hence, a certain sequence of the commands must be obeyed.

Available File Types

The first step is to configure the type of file to create. It is a multiple choice of the following types:

• Video

• Key

• Audio

• VBI

• Proxy

Video File

This file contains video, as fill and key, or fill only. If supported by the container and codec, it may be interleaved with audio and VBI. It can carry time code. For some container/codec combinations, audio and VBI are required (whereas for others they may be optional).

Enable or disable creation of the video file with the following command:

RENDERER*VIDEO*CLIPOUT*n*CREATE VIDEO_SET arg

where arg is a boolean argument and can be enabled with On or 1 or disabled with Off or 0.

Key File

This file contains only the alpha component of the video signal. This is beneficial if the requested codec does not support an alpha channel. If enabled then the video signal is split into fill and key. The fill part is written into the video file and the key part into this file. Enable or disable creation of the key file with the following command:

RENDERER*VIDEO*CLIPOUT*n*CREATE KEY_SET 1

Audio File

This file contains only the audio signal. This is beneficial if the container/codec combination does not allow audio or does not utilize the current audio configuration. Enable or disable creation of the audio file with the following command:

RENDERER*VIDEO*CLIPOUT*n*CREATE AUDIO_SET 1

VBI File

This file contains only the VBI signal. A separate VBI file is useful when the container/codec does not allow interleaved VBI or does not utilize the current VBI configuration. Enable or disable creation of the .vbi file with the following commands:
RENDERER*VIDEO*CLIPOUT*n*CREATE VBI_SET 1

Proxy File

If enabled, a proxy clip is created along the full resolution clip. The proxy clip also supports interleaved audio. Enable or disable creation of the audio file with the following command:
RENDERER*VIDEO*CLIPOUT*1*CREATE PROXY_SET 1