RenderSoft CamStudio is a tool used for recording screen activity into standard AVI video files. If you move the cursor, launch a new program, type some text, click a few buttons, or select some menus -- anything that you see on your screen -- CamStudio will be able to record all these and allow you to play them back later on.

 

You can use CamStudio to develop videos to demonstrate features of a new software, for creating movies used in user training, for tracking the progress of a program that executes for a long time, or for recording the sequence of steps that cause the occurrence of bugs in faulty software.

 

 

Example Video

An example of a video recorded with CamStudio can be accessed here: example.avi

 

 

 

 

 

 

Getting Started

 

To start recording, click the red button. A rectangle will appear for you to select the area you want to record.

 

When you want to stop recording, click the blue stop button. A dialog will appear for you to name and save the file.

 

 

 

System Requirements

 

 

 

 

 

 

 

 

Introduction

 

 

Moving images impact our lives heavily nowadays. A changing image speaks much more than a stationary snapshot. Any one who has watched a movie understands how the power of animation can immensely enhance the process of communication. By capturing the moving action faithfully on your computer screen, CamStudio is essentially putting this power right onto your computer desktop.

The video files created by RenderSoft CamStudio are saved in the standard AVI (Audio Video Interleave) format, which is used pervasively in many Windows applications that support video, including MS Office.  (You can effectively paste an AVI file into an Office application just like pasting text.)


This ensures maximum compatibility with other software, and you can easily edit the output of CamStudio with a third party video editor.

 

 

Uses of RenderSoft CamStudio

 

 

 

 

 

 

Recording a Screen Movie

 

To start recording, click the red record button or choose File:Record from the menu.

 

When you want to stop recording, click the blue stop button or choose File:Stop from the menu. A dialog will appear for you to name and save the file.

 

To pause a recording to adjust your screen, click the pause button or choose File:Pause from the menu. You can resume recording by clicking on the record button again.

 

 

Halfway into the recording, you can cancel the capture operation by pressing the Escape key.

 

 

Video Basics

 

When you record a movie using CamStudio, you are actually saving a sequence of bitmaps (known as frames), that, when displayed in rapid succession, exhibit motion.

 

If more frames are recorded per second, the resultant animation will also be smoother. However, this will also cause the file size of the movie to be much larger.

 

In the process of recording, CamStudio allows you to specify two video rates: the input rate and output rate. The input rate tells your computer how many frames to record per second. The output rate tells your computer how fast to play them back. Usually, these two rates are equal, so that the time of playback is equal to the time used in the recording.

 

However, these two rates can also be different. Normally, you do this only if you want to create a time-lapse movie. For example, you can capture a frame once every hour and play the frames back at 20 frames per second.

 

The default value is set at 20 frames per second for the output (playback) rate and 20 frames per second  (corresponding to 50 milliseconds sleep time) for the input /capture rate.

 

There is also a third rate: known as the keyframe rate. When a frame is saved in an AVI file, they can either be saved as a full frame, or only as a difference to the previous frame. This keyframe rate specifies how often full frames are written to the AVI file. A high value means you can fast forward/rewind to a particular frame in your movie much faster. But it also means a higher file size.

 

 

 

 

Setting Video Options

(From the main menu, choose Options->Video Options)

 

 

 

Setting the video options allows you to optimize your video recordings by choosing between the file size, quality and frame rates of your video files.

 

 

 

 

Compressor

The Compressor select-box allows you to select the encoder for your AVI file. An encoder compresses your AVI files to make them smaller in size and cause them to play faster. The default setting is the MS Video 1 compressor.

 

 

Quality

The quality setting determines how nicely your picture is saved. A lower value means a lower picture quality but also a smaller file size. Only some compressors use this value.

 

 

Set Key Frames Every

This setting specifies the keyframe rate. When a frame is saved in an AVI file, they can either be saved as a full frame, or only partially as a difference to the previous frame. The keyframe rate specifies how often full frames are written to the AVI file. A high value means you can fast forward/rewind to a particular frame in your movie much faster. But it also means a higher file size.

 

 

Capture Frames Every

 This field determines the input frame rate. It dictates how long the CamStudio will ‘sleep’ after capturing each frame.  One millisecond is 1/1000 of a second.

 

If you set this to a large value (for example 1 hour, or 3,600,000 milliseconds), you practically create a time-lapse movie. CamStudio will actually ‘sit and watch’ for activities on the screen that takes a long time to occur and take a snapshot (say, only once every hour).

 

 

Playback Rate  

This field determines the output frame rate. It specifies how many frames are played back per second. A higher value means a smoother playback. Typical values of 20 – 30 frames per seconds are adequate for most purposes.

 

 

 

Setting Regions

(From the main menu, choose Regions->Region or Fixed Region or Full Screen)

 

 

 

You should set the Input Region before recording. This allows you to define the area and type of video capture.  From the main menu, choose Region

There are 3 types of regions you can choose:

 

 

Region

Before recording starts, you can define an arbitrary rectangular region with the mouse. The cursor turns into a pen on cross-hairs, which you use to define a rectangular region on your screen by click-dragging the left mouse button.

 

To cancel recording, you can press the Escape key.

 

 

Fixed Region…       

You can capture a fixed-size rectangular region. A dialog allows you to define the size of the region in pixels.  Before recording starts, you can move the fixed-size region around the screen to determine where you want the recording area to be.

 

To cancel recording, you can click the right mouse button or press the Escape key.

 

 

Screen          

The entire computer screen is captured.

 

 

 

 

Setting Cursor Options

(From the main menu, choose Options->Cursor Options)

 

 

Setting cursor options can help illustrate the action you are recording by drawing attention to the area where the action happens. The following cursor effects can be selected:

 

Hide Cursor

The cursor will be hidden during screen capture

 

Show Cursor

 

Use Actual Cursor – The actual shape and position of the cursor will be recorded during screen capture.

 

Use Custom Cursor – Replace the recorded cursor with a customized one.

 

Use Cursor From File - Replace the recorded cursor with a cursor that is loaded from file.

 

 

Highlight Cursor

When this option is selected, the recorded cursor will have a highlight area around it. This helps in calling attention to the movements of the cursor. You can set the shape, size and color of the highlight area.

 

 

Recording Audio

(From the main menu, choose Options->Record Audio)

 

 

You can add a soundtrack to your movie by selecting this option. When enabled, CamStudio will record your voice input from the microphone while it is capturing video.  You need a sound card with an attached microphone to use this option.

 

 

 

Setting Audio Options

(From the main menu, choose Options->Audio Options)

 

 

Use this dialog box to set the recording format and compressed format of your audio.

 

Recording Format  -- The recording format is the format your soundcard use to record your voice from the microphone.  Its main attributes are samples per second (measured in kHz), mono/stereo input, and bits per sample (usually 8 or 16 bit). Larger values for samples per second and bits per sample will result in better recording quality, but at the expense of the movie file size.

 

Compressed Format -- This is the format that will be saved with your movie file.  You can click on the “Choose Compressed Format” button to select another compressed format. After recording your movie, CamStudio will attempt to convert your audio from the recording format to the compressed one. 

 

Your choices for the compressed format are determined by the recording format. If you change your recording format, the compressed format will also change automatically.

 

Interleave Video and Audio – Interleave your audio and video for smoother playback on a slow device such as CD-ROM. This will also allow better synchronization of your video and sound content. The interleave factor determines the amount of interleaving in your movie.  The default is set to 1 frame for full interleave. Larger values will mean less interleaving.

 

Volume - Use this to adjust the input volume of your microphone if your recorded audio is barely audible. If CamStudio is unable to locate your volume control, you will need to adjust the volume manually through Start : Programs : Accessories: Entertainment : Volume Control.

 

 

Please note that some configurations of the Recording and Compressed format will result in the audio recording becoming choppy or inaudible.

 

Some sound card disallows your system to record while another application is playing sound. In this case CamStudio will issue an error when you attempt to record with the “Record Audio” option being enabled.

 

 

Enable Autopan

(From the main menu, choose Options->Enable Autopan)

 

If this option is selected, the capture area will follow the cursor to wherever it goes during recording. This has the effect of making the screen capture to occur at the region with the most action.

 

 

 

Autopan Speed

(From the main menu, choose Options->Autopan Speed)

 

 

Use this to control the maximum speed at which the capture area follows the mouse. The value is measured in screen pixels.

 

 

 

Program Options

(From the main menu, choose Options->Program Options)

 

Use the program options to customize the way the program behave when it starts/stops recording. A tick beside the menu items indicates that option is enabled.

 

P  Minimize program on start recording

P  Hide flashing rectangle during recording

P  Play AVI file when recording stops

 

 

 

Some Notes on the Quality and Performance of the Recording

 

            CamStudio creates a movie by sampling the screen on fixed-time intervals. If this sampling frequency is too slow, it may not be able to pick up some cursor movements if the mouse moves too fast. The result of this will be that the cursor will appear to jump, become jerky or even cannot be seen in the recorded movie. It is thus advisable to slow down your mouse movements during recording.

 

            This sampling problem can also happen when you are recording a fast animation. If CamStudio cannot record much faster than the changes in the animation, CamStudio will miss out on some important data and the playback will not be smooth.

 

 

 

Frame Rates

 

The speed of your computer will directly affect the performance of CamStudio. A slow CPU will unquestionably mean slower frame rates. For the best performance, use the fastest computer available for recording.

 

Apart from CPU speed, the following factors will also affect the performance of the recording:

 

 

 

 

 

 

File Size

 

An AVI file usually has a very large file size, especially for those lengthy and detailed videos. This is due to the fact that a video file has to pack hundreds and thousands of images into a single file. It is thus very common to have size exceeding one megabyte.

 

To reduce the size of the AVI file, you can do the following:

 

 

 

 

 

 

 

 

Website of CamStudio:

CamStudio is an Open Source product.  You may obtain its source code at:

 

http://www.atomixbuttons.com/vsc

 

 

 

Credits:

This product uses code from certain individuals. The authors of this product would like to express their heartfelt thanks to: