Once a recording has been made, it will almost certainly need to be edited. The basic sound editing operations that most multimedia procedures needed are described in the paragraphs that follow
Multiple Tasks: Able to edit and combine multiple tracks and then merge the tracks and export them in a final mix to a single audio file.
Trimming: Removing dead air or blank space from the front of a recording and an unnecessary extra time off the end is your first sound editing task.
Splicing and Assembly: Using the same tools mentioned for trimming, you will probably want to remove the extraneous noises that inevitably creep into recording.
Volume Adjustments: If you are trying to assemble ten different recordings into a single track there is a little chance that all the segments have the same volume.
Format Conversion: In some cases your digital audio editing software might read a format different from that read by your presentation or authoring program.
Resampling or downsampling: If you have recorded and edited your sounds at 16 bit sampling rates but are using lower rates you must resample or down sample the file.
Equalization: Some programs offer digital equalization capabilities that allow you to modify a recording frequency content so that it sounds brighter or darker.
Digital Signal Processing: Some programs allow you to process the signal with reverberation, multitap delay, and other special effects using DSP routines.
Reversing Sounds: Another simple manipulation is to reverse all or a portion of a digital audio recording. Sounds can produce a surreal, other wordly effect when played backward.
Time Stretching: Advanced programs let you alter the length of a sound file without changing its pitch. This feature can be very useful but watch out: most time stretching algorithms will severely degrade the audio quality.
Midi Audio: Requirements To make MIDI score, we need:
Midi keyboard / Midi keyboard software : MIDI keyboard is used to simplify the creation of music scores (MIDI information) MIDI information is transmitted in "MIDI messages", which can be thought of as instructions which tell a music synthesizer how to play a piece of music. The synthesizer receiving the MIDI data must generate the actual sounds.
Sequencer software A MIDI sequencer software lets us to record and edit MIDI data like a word processor cut and paste and Insert / delete
Sound synthesizer (built-in in to sound card)
Midi Audio Facts
Since they are small, MIDI files embedded in web pages load and play. Length of a MIDI file can be changed without affecting the pitch of the music or degrading audio quality. Working with MIDI requires knowledge of music theory.
Recording MIDI Files: MIDI files can be generated by recording the MIDI data from a MIDI instrument (electronic keyboard) as it is played by using a MIDI sequencer software application
MIDI versus Digital Audio Advantages of MIDI over digital audio:
MIDI files smaller that digital audio file.
Because small file, MIDI files embedded in web pages load and play more quickly.
If MIDI sound source are high quality – sound better.
Can change the length of MIDI files without changing the pitch of the music or degrading the audio quality.
Disadvantages of MIDI over digital audio:
Because MIDI data does not represent the sound but musical instruments, playback will be accurate only if the MIDI playback (instrument) is identical to the device used in the production.
Higher cost and requires skill to edit.
Cannot emulate voice, other effects.
Factors considered before adding Sound to MM Project:
File formats compatible with multimedia authoring software being used along with delivery mediums, must be determined.
Sound playback capabilities offered by end user’s system must be studied.
The type of sound, whether background music, special sound effects, or spoken dialog, must be decided.
Digital audio or MIDI data should be selected on the basis of the location and time of use.
Last modified: Thursday, 24 November 2011, 12:40 PM
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