Saturday 27 August 2022

Chapter 9th (Audio and Video Editing)


 Chapter 9th (Audio and Video Editing)




We all listen to audio or music on computers. Sometimes we listen to music from audio CDs or play audio files like mp3, wav, flac, m4a, aac, ogg, wma using any media player software. The computer requires separate audic codecs to play these audio files. Some software

installs these audio codecs on the computer along with them, but sometimes, We face problems because some media players are unable to play a particular audio file format. This is usually

due to the codec not being available on the computer for that file type in player.Codecs are files that enable a software to play different types of audio formats or assist in the compression and decompression of a digital audio data stream, i.e. Audio file.



There are many audio file formats that can be played on a computer or other devices. Each format can be somehow better than the other. As we all know that mp3 (MPEG AUDIO LAYER 3) format is a common audio format that is widely played on electronic devices

including mp3 players, mobiles, tablets and more.


A software that is used to convert one audio file format to another is called audio converter. This software requires codec to complete this conversion. If audio file cannot be played on the computer then one of the 3rd party codec packs, which are available free of

charge on the internet, can be used.


One such codec pack is K-Lite Codec Pack which is the most popular free codec pack that can be downloaded from the internet and easily installed on the windows operating system. It comes in four versions basic, standard, full and mega. This pack also installs a player known as the Media Player Classic (MPC) with it. With this player we can play almost any kind of audio or video file on the computer. Other software may also automatically use codecs installed with

this codec pack, for this setting in this codec-pack can also be changed.


Some of the most popular audio converter software are: Xilisoft Audio Converter, Switch Audio Converter, Ashampoo Music Studio, Format Factory, Freemake Audio Converter And Fre:Ac


9.2.1 Codec

Codec is a file or program used to compress & decompress a digital media file. The codecs can be divided into two parts: the encoder and the decoder. Encoder performs the compression

(encoding) function and the decoder performs the decompression (decoding). Some codecs contain both of these components, and some codecs include only one of them. For example,when a song is ripped from an audio CD to our computer, Windows Media Player uses the

audio codec to compress the song by default to .wma (Windows Media Audio) file and when -wmna file is played, Windows Media Player uses the audio codec to decompress the file so that

audio can be played correctly.


9.2.2 CD ripping:

Songs on audio CDs are stored in Compact Disc Audio (.CDA) format in tracks, and these tracks are used when playing the audio CD and play audio of very good quality. The audio CD can be played directly to the HiFi audio systems, in-car audio players, home theatres, and

more. Usually only 5 to 10 tracks are stored on the audio CD and cannot be saved on the computer simply via copy / paste manner. Specialized software are required to accomplish this task.


The process of copying(extract) audio tracks from andio CDs to computer and storing them in commonly used and playable file formats (such as mp3, wav, etc.) is called CD Ripping. This process is done using specialized software that facilitates CD Ripping.


If the audio files in the CD are stored in .mp3 format, then this CD is called mp3 CD not an audio CD.


9.2.3 Encoder Settings

Audio encoder is a program or file that helps to play an audio file format correctly and converting to another format. It compresses digital audio data according to audio format. It is

usually used to reduce the file size and to keep the quality according to file size. The encoder is the part of codec, The encoder uses algorithm in a special way to encode.

There are generally two types of audio encoders:

(a) That uses Lossy Compression

(b) That uses Lossless Compression. Lossy Audio : This is a compression technique which is irreversible and does not

decompress audio files according to the amount of their original data, but it compresses large amounts of audio data, resulting in smaller file size. In this technique, some of the sound elements are removed, which affects the sound quality in an audio file and in result the audio quality ig reduced.


Lossy Audio Codecs:Audio codecs which use lossy compression include:

1. AAC

2. AC3



5. DTS

6. MP3


8. WMA Lossless Audio : This is a compression technique which is reversible and preserves original data amount. This technique compresses large amounts of audio data but does not

reduce file size or sound quality. This technique is used by professionals for audio files.Lossless Audio Codecs:Audio codecs which use lossless compression include:

1. Free Lossless Audio Codec (FLAC)

2. Apple LosslessAudio Codec (ALAC)

3. Direct Stream Transfer (DST)


5. WMA Lossless

6. Lossless Transform Audio Compression

7, RealAudio Lossless

8. WavPack Lossless

9. Lossless Predictive Audio Compression (LPAC) Uncompressed Audio : This technique does not apply any compression to the audio file and is only of the quality in which the audio was recorded. Examples: pcm, aiff, and way formats.


We usually use .mp3 audio files to play audio. Mp3 compression uses perceptual coding,a technique based on psychological models that remove audio components (elements) from audio files that humans are unable to hear but that results in low audio quality output and small size. Usually the mp3 file is made at 128 / bps or 192 / bps. (bps: bits per second)



Fre:ac is a free audio converter and CD ripper that supports various popular audio formats and encoders. It can convert between mp3, mp4 / m4a, wma, ogg (vorbis), flac, aac, wav formats. With Fre:ac we can easily rip and convert our audio CDs to mp3 or wma files. This

software can be downloaded from


9.3.1 Features Fre:ac

This is a portable application that can be copied to a pen drive and we can run it from there.


It is easy to learn and use.


Multi-core optimized encoders are used to speed up conversion.


It has the convenience of cd ripping.


It also has full UNICODE support for tags and file names.


It can convert mp3, mp4 / m4a, wma, ogg vorbis, flac, aac, wav formats.


Itis completely free and open source software.


9.3.2 Add Files to Software

To convert the files, we first need to add the files to the software. There are the following common ways to do so:

1. File menu — Add — Audio files or Cul + A

2. Add — Audio file (s) —» From folder

3. From toolbar, using Add audio files button


9.3.3 Removing Files

Sometimes we need to delete some files that we accidentally added into the software to convert. To delete files, first select the files we want to delete then use File menu — Remove or the shortcut key Ctrl + Shift + R.



Video editing is the process of joining video clips, photos, and audio files to make a movie. This is usually done on a computer with video editing software known as non-linear editors or NLE, which means we watch & edit the video without having to play the entire



Generally, the task of making a movie is divided into three stages:

Pre-Production : This is the initial stage where the script is written, the working people are organized, and then the shots are planned.


Production : This includes video shooting.


Post-Production : This is where video editing, audio editing and special effects are put on video in video editing software.


9.4.1 Popular Video Editing Software

Here are some popular video editing software that can be used to edit videos (on computers and mobile):


For Windows OS : Filmora Pro, Virtualdub, Pinnacle Video Spin, Sony Vegas Movie Studio, Windows Movie Maker, OpenShot, Adobe Premiere Pro Cc, Cyberlink PowerDirector


Android OS : Adobe Premiere Pro, PowerDirector Video Editor, KineMaster, Viva Video, Funimate, FilmoraGO


OS : LumaPusion. InShot, Adobe Premiere Rush, Splice, Magisto, iMovie



Almost all video editors work in the same way, so if we learn to use any one of them, we can easily use any other video editor software. Therefore, this chapter discusses the general

information about video editors.


9.5.1 Project

Whenever we want to make a movie in video editing software, we should create a file and save all settings, location of imported files, so that whenever we open the movie in the video editing software,we can resume the work where it was left off. The file in which all these settings are saved is called Project File.This project file can usually be saved using File >Save. Every video editing software saves a project file with its own separate file extension. The project file contains all information about the media files used, the story board/timeline settings, and other important settings for special editing environment.


9.5.2 Import Files (Andio/Video/Images)

It is useful to import all required audio, video and image files into the video editing software so that they can be accessed from within the software. We can import new media files and remove the imported files as needed at any time. Different software provides placeholders (specific places) to display such imported files, and these placeholders are given a specific

name such as collection panes, media files, project files, etc. From here, these files can be dragged-and-dropped on the tracks and timeline for video editing. Normally, we can import

files by clicking on import/add using the toolbar or the file menu in the software.



9.5.3 Video Transitions

Video transition controls how a video clip will get displayed after a video clip or picture has been played. This effect is implemented between two objects. We may apply transitions

between two pictures, video clips or titles that have been added in the story board or timeline.Transition runs after the end of one clip and before the beginning of next clip, but many

transition effects can also be overlapped. We have to apply transition effects on the media files added in the tracks. Transition time can also be set as required.


9.5.4 Video Effects

In video editing, video effects allow us to add a special effect to our movie. A video effect determines how pictures, video clips, and titles are displayed in our project and in the final movie. A video effect applies to the complete duration of pictures, video clips, or titles, (means as long as the object is playing). Some editing software also facilitates us to set duration of this



9.5.5 Titles

Titles help us to make our movie better by adding text-based captions to the movie. We can include titles in the movie to indicate any type of information, such as the movie name,

release date, actor names, etc. We can also apply animation effects on titles to make a movie more attractive.


9.5.6 Storyboard and Timeline

Generally, in video editing, there are two methods used in project to illustrate the layout of video clips. These are known as storyboard and timeline:


Storyboard : It is a panel of pictures or other video-clips to make a story of movie.It shows the sequence of photos and video clips that will be shown in the movie. We can also rearrange the pictures or videos by dragging them in the story board.Transition effects also do appear on it but storyboard is not very useful when timeline is available.


Timeline : it is used to edit the timing of clips in our project. Audio clips that we added to our movie project are not displayed on the storyboard. They can be displayed in the timeline panel. In the timeline view, we can also trim clips and add effects,titles, transitions and audio. It has been noted that timeline offers a more accurate

view of the project, displaying clips and events over time. It includes tracks as needed.

9.5.7 Video Preview (Monitor)

This is the place where we can watch video clips and our movie with all the effects,changes and more with audio, we applied using software. This allows us to see how the movie will play after the final step of export/produce. This allows us to view that whatever effects are put into the movie, how and for how long they will show up while playing the movie. There are also some basic buttons on the monitor such as play, pause, stop, forward, rewind or to take

screenshot (capture current frame)


9.5.8 Tracks

When we import / add the video on tracks in any video editing software, the video is splitted into 2 parts:

a. Visual

b. Audio


The visual part has only video (without audio) and audio part has only sound/voice. These video and audio parts are put on different video and audio tracks where we can edit them. We

can use different tracks for different audio and video parts. All video editing software provides separate tracks for audio and video, and we can add as many tracks as we need. Tracks can be

very useful when we need to edit audio / video for a particular part. It is not possible to put two clips on the same track in one place. If we want to include audio in our video as well, we need to use more than one track. Multi-track editing is used for organizational reasons. When working with many types of media, for example, audio, voice-over and videos from different sources, it is a useful, efficient and easy way to use different tracks for all types of media. The number of tracks depends on the video editing software. The best video editing software allows the use of unlimited tracks.


9.5.9 Export Video

The last step is to make the final movie file when we have finished editing i.e. after applying effects, transitions, animation, titles etc. and after we have finished arranging all media files as needed on the timeline / storyboard and already have set their playing duration.

Each editing software provides the export facility to either export or produce and this option is generally available in the File menu of the software.


In Export settings, we can select video resolution, quality, format and encoder settings.There are also other advanced settings that we can adjust as required.

We can also select output location and file name before exporting our final video file. After doing export, we can save our movie in PC, mobile, websites and formats like.

MP4 : MPEG Layer 4

AVI : Audio Video Interleave

FLV . Flash Video

WMV =- Windows Media Video


In the simple words, we can say that meaning of Export or Produce is to create a playable file, which is the last step in video editing.


9.5.10 Saving & Opening Projects

Saving a project is different from Export. We should save our project after a short period of time while working. It is best practice to save the project before starting the process of

exporting the video file. We can easily open a saved project file later. We can start editing right where we left off. When we open our saved project, all the media files, storyboard / timeline

settings are restored for us to edit. Usually, options for saving and opening projects can be found in the "File" menu of the software.


9.5.11 Video File Formats

Different file formats are generally used for different tasks. We can choose the file format for video file as per our requirement. The file format can be changed either when exporting the

video in the video editing software or later by using the video converter software.A common video file in digital format is made up of two parts, codec and container.


Video Codec is a video file used to compress and decompress. Examples of video codecs are ffmpeg, divx, xvid, and x264.


Containers on the other hand, are a set of files that store information about digital files. It's a combination of both audio and video data in a single file that allows us to play the same video track with audio playback at the same time. Some popular types of containers are avi, fly, wmv, mkv, mp4, and mov.


Video File Formats used by various Platforms:


For Social Media : mp4 is used by Facebook, Twitter, Instagram, IgTv, and Youtube.


For TVs and Computers : avi, mov, and mky are the best video quality formats that make them great option for big screen streaming.


For Websites : The webm and HTMLS video formats are used on personal and

private websites.


9.5.12 Video Cutting

Video cutting means adjusting the video to desired length as needed. Sometimes the unwanted video needs to be removed from the beginning or from the end of the video, or sometimes only a section of the video is required, or some part of video is to be removed, the

process of removing all such parts of video is called video cutting. Following are some of the terms related with the video cutting:


Trim : When we trim our video, we remove some part of the clip's head (start) or tail (end).


Cut: This means cutting off a portion of the video clip.


Split ; When splitting longer videos into smaller sections, this is called splitting the video.


Most video editing software includes features for trim, cut, split, and these features can be used while making a movie in the software.


9.5.13 Video Joining (Merge)

When we combine two or more videos or clips together, this is called video merge or join.The video can be joined with the second video's head (start) or tail (end). Files of different

video formats can be merged if the required codecs are installed on the computer. We should take cate of resolution when joining so that the video remains of the same display size after joining.



There are several software available to cut / join videos such as Free Video Cutter Joiner,mp4tools, Format factory, Bandicut, Avidemux, Vidcutter. Among these, Free Video Cutter Joiner is a commonly used and free software that can be downloaded using the internet from

the web site and can be installed on a windows based computer. We can cut and join video files easily with the help of this software.


9.6.1 Cutting / Splitting Video Files Using Free Video Cutter Joiner

Step 1 : Add Files : Use the Add Video File button to add files to the software. After adding video files using the Add Video File button, the preview of the added file can be seen within the application.


Step 2 : Set Start Point and End Point : Drag the button on the progress bar to set the start and end point of the

video for cutting. For setting these points, click on the [ (Square Left Bracket) button to set starting point and click on the ] (Square Right Bracket) button to set the end point for cutting video.


Tip : We can also enter "start point" and "end point" values directly into time boxes as shown below, its format is hh:mm:ss:fif


Step 3 : Cutting Video File : After Setting the Start and End Point for cutting the video, click on the “cut"

button.Following dialog box will appear and select appropriate option. If video file is not playing properly by using option "1 Direct Cut", then use the option "2. Indirect Cut".As shown in the below figures, we can select different

video formats and then adjust their audio/video parameter settings as per our requirement i.e. video file farmat, video size (resolution), audio quality etc.


9.6.2 Join/Merge Video Files Using Free Video Cutter Joiner:To join/merge videos using Free Video Cutter Joiner,first of all select the "Video Joiner"tab by clicking on it, as shown in the figure 9.14,


Step 1: Add or Remove Files : Several Files can be imported at once by clicking on the Add File button If a file has been added by mistake, select that file first and then click on Remove Button. The selected file will be removed.


Step 2 : Join Video Files : Select the files that we want to combine and Click on the “Join"button.A dialog box,as shown in the figure 9.16, will appear on the screen in which we can select settings as required.Now, Click on Start Join Button to join/merge selected videos.


Output File Setting:Click the browse button, set the output folder and then type the name of the file that we

want to set. The file, after joining the videos, will be saved at the selected output folde/location.


Sto Rementoar

1, Codecs are files that enable software to play different audio file formats.


2. Mp3 (Mpeg Audio Layer 3) format is a common audio format that is widely played on electronic devices including mp3 players, mobiles, tablets and more.


3. Audio files stored on the audio CD are in .CDA format. This audio format is a standard format for compact discs.


4. The process of copying audio files from an audio CD to a computer is called CD ripping.


5. Audio encoder is a program that compresses and decodes digital audio data.


6. The main purpose of audio encoder is to provide the best possible audio output with a minimum number of bits.


7. Video editing is the process of adding clips, photos, and audio altogether to make a movie,


8. There are three stages for making a movie: pre-production, production, post-production


9. By splitting we can divide the video clip into several parts.


10, By merging we can join multiple video clips into one big video file.



1. Multiple Choice Questions:


1. In order for the computer to play audio files, different_.....__ are required.

a. Video codecs

b. Audio Codecs

c. Botha& b

d. None


2 format is a common audio format that is played extensively on electronic devices.

a wmv

b avi

c. mp3

d. = cda


3. Audio files are stored on the Audio CD in ___ format.

a. flv

b. aac

c mov

d. eda


4. The effect applied between two video-clips is called

a sound

b. video

c. video transition

d. photo


5. The process of dividing the video into sections is called =

a. merging

b. splitting

c. compressing

d. decompressing


2. Write True or False:

1. The process of making a movie is divided into five stages.

2 Video editing works with only one video clip.

3. Merging a video means splitting the clip into several parts.

4. _Itis advisable to save the project before starting the process of exporting a video file.

5. MPEG-4 video format uses different compression for audio and video tracks.


3. Write the Full Forms of the Following:

1 mp4

2 mp3

3. wmv

4. flv

5. avi



4. Short Answer Type Questions. (Write the answers in 4-5 lines)

1. Write the names of the three stages of making a movie.

2 Write down the names of three video editing software.

3. What is CD ripping?

4. What are codecs?

5. What is video split?



5. Long Answer Type Questions. (Write the answers in 10-15 lines)

1. How export video is different from the save project.

2 What are tracks?

3. Explain the video transitions.

4. Write about the audic converter in detail.

5. Write in detail: Storyboard, Timeline, Titles.LAS ACTA?


Perform Audio and Video Editing Operation using any Audio and Video Editing Softwares of your choice.