Implement the multimedia in the VC + + in automatic continuous play

Content Summary

Visual animation control ActiveMovie is an ActiveX control developed by Microsoft, and has been greatly improved in functionality from the initial version 1.0, version 1.2, and now 2.0. Because the control is embedded with a Microsoft MPEG Audio decoder and a Microsoft MPEG video decoder, it is good to support audio files and video files, and the VCD that is played with it is good. In addition, when playing with the right mouse click screen, you can directly to the screen playback, pause, stop, etc. to control, the reader can also own in the "Properties" of the movie Play control settings, it is very convenient to use. Version 2.0 of the ActiveMovie control is already included in the Microsoft vc++6.0, and this article describes the use of this control to automate the continuous playback of multimedia under vc++6.0.

Key words: VC + + ActiveMovie Multimedia continuous playback

With the development of computer technology, people not only use a single text as the carrier of information, but also through a variety of media to transmit and store information. What we usually call "media" includes two points of meaning. One refers to the physical carrier of information (that is, the entity that stores and transmits information), such as books, wall charts, disk, CD-ROM, tape and related playback equipment, and other meaning refers to the form of information (or communication form), such as text, sound, image, animation and so on. Multimedia computer refers to the media, which means that the computer can not only deal with the text, the value of information, but also to deal with sound, graphics, television images and other different forms of information.

The "processing" of all kinds of information media means that the computer can acquire, edit, store, retrieve, display and transmit all kinds of operation. In general, computers that have the ability to handle multiple media can be called multimedia computers.

The English word of multimedia is multimedia, it is composed of media and multi two parts. Generally understood as a combination of multiple media. Multimedia technology is not a simple compound of various information media, it is a kind of text, graphics (Graphics), image (Images), animation (Animation) and Sound (Sound) and other forms of information together, and through the computer for integrated processing and control, Information technology that can support the completion of a series of interactive operations. The development of multimedia technology has changed the use of computer, so that the computer from the Office, the special products in the laboratory into the general tools of the information society, widely used in industrial production management, school education, public Information consulting, commercial advertising, military command and training, and even family life and entertainment and other fields.

We can use the MCI control to develop this project, but now we're going to introduce a simpler way to implement with the ActiveMovie control object controls.

One, Common multimedia format

Visual animation Controls ActiveMovie control Object is a Microsoft-developed ActiveX controls that provide programmers with the ability to control the interface of media devices at that level. It contains a set of high-level commands that are independent of the device. Can control the audio and video peripherals, we do not have to care about the specific equipment can be CD, video disc, waveform audio equipment, audio-visual equipment and MIDI devices such as the control of media equipment, can also be understood as a row of buttons on the device panel, By selecting a different button (sending different commands) to enable the device to complete a variety of functions, without concern for the internal implementation of the device, it is a major way to achieve audio playback.

1, waveform audio

Waveform audio is an electronic digital sound, is a computer playing an important form of audio, it stored sound waveform information, characterized by: when playing broadcast audio, no matter what type of device to play the file, will get a similar sound. Waveform audio files typically have a. wav file name extension. Because the use of waveform audio storage electronics requires a lot of storage space, so it is generally used only for short time sound playback.

2, MIDI Music

MIDI (musical instrument Digital Interface) occupies an important place in multimedia audio and is an international standard for playing and recording music, which determines the cabling, hardware, and communication protocols that connect music devices. The multimedia computer only has the MIDI interface sound card and the MIDI synthesizer, has the function which handles the MIDI.

MIDI in the processing of music is the MIDI music device generated by the activity code recorded, the data passed to the MIDI synthesizer can be the original performance. There are two types of MIDI messages: state bytes and numeric bytes. The status byte describes the categories (actions and functions) that are sent, and the numeric byte is always followed by the status byte, representing the actual value of the message being sent. The number of numeric bytes depends on the message type represented by the state byte. MIDI distinguishes between these two types by the highest bit of channel byte. A maximum bit of 1 indicates a state byte, and a maximum of 0 indicates a numeric byte.

3, CD Audio

CD Audio uses the Red Book standard to play CD audio through the CD-ROM drive. CD audio requires a large amount of storage, a CD can store about 10 songs, 70 minutes audio around.

In general, the entire disc is used to store CD audio data, divided into multiple tracks, the length of the track can be indefinite, usually a track corresponding to a track. The length of the CD audio is measured in minutes, seconds, and frames, with the smallest units being frames, each frame being 1/75 seconds, and one point equal to 60 seconds.

4, digital video

Digital Video (Digital) uses data information to animate on a computer, it is the use of visual retention of human eyes to form, so that people need to continue the image effect of the minimum playback speed is 24/sec, the faster the playback speed, digital video gives people the visual continuity effect better. Storage of video images requires huge disk space, generally speaking, 1 seconds full screen video signal needs about 28MB of space. In order to achieve continuous video playback, not only need to have enough space to store video audio information, but also need to ensure that the hard drive has a 28mb/second transmission speed.

The audio_video_interleaved (AVI) file format is the standard that Microsoft proposes to store video information under Windows. AVI file in a series of bitmaps to store video information, and at the same time in the file if a digital form to store digital video information, it is actually composed of a set of information flow files.