Digital Communication – Assignment 4 – Video and Audio Editing

Evidence for K/600/8297 3.3.3.4

Importing Video/Audio Files

The following screenshots show how a user imports a file into Adobe Premiere Pro. The process is by navigating ‘File’ and by clicking on ‘Import…’. This then takes the user to a window that allows them to view all of their files. The last step is to select the file(s) to be imported by navigating them using the window.

Screen Shot 2017-06-16 at 11.20.52Screen Shot 2017-06-16 at 11.21.37

The same process can be used to import audio. Below is a screenshot of a timeline with audio imported separately from the video file.Importing audio

 

However, a video’s own audio can be removed. This can be achieved by right-clicking on the image and then ‘Unlink’. This seperates the video file and the audio file from the timeline. This then allows for separate editing and enables the user to remove one of the components without effecting the other.Unlink audio from video.png

The screenshot below shows how a user cuts a component on the timeline. The screenshot shows that the razor tool has been selected on the toolbar on the left hand side of the page. The next step would be to click on the component with the tool where the clip is set to be cut. There will then be a small grey line where the audio clip has been cut. This creates two sections to the file and allows for separate editing.

Cut image

 

This screenshot shows how a user trims a clip. The user should use the select tool in the toolbar and then hover over the end of a clip. The user may have to cut the clip first to be able to achieve this effectively. Once the user hovers over the end of a clip there will be a red bracket that appears. This can be seen at the end of the audio clip on the screenshot below. This then allows the user to trim the clip by dragging the bracket. This screenshot also shows how the footage is assembled with fading effects at the start and end of the video and audio clips.

Trim

Users can also add titles to their videos in Adobe Premiere. The screenshot on the left shows the first stage of the process by clicking ‘Title’ > ‘Default Still’. Default Roll and Default Crawl can also be used depending on the type of title the user is looking for. The second screenshot shows how the user changes the setting of the title in the video such as the size, timebase, aspect ratio and the text.

There are also some colour correction effects (e.g. brightness and contrast) that a user can implement into their footage. The two screenshots below show how a user changes the colour correction settings in their footage. First, the user should click on their preferred colour correction setting under the ‘Effects’ tab. After this, they can then change the levels of the setting by clicking on ‘Effect Controls’, as seen on the second screenshot below.

Effects.. brightness and contrast

Levels of Brightness and Contrast

Once the footage is edited to a level where the user can finalise the project, the user can choose to save the project. This can be achieved by clicking ‘File’ > ‘Save As…’. This then takes the user to the ‘Save Project’ window and the user can then modify the file name, format and location before saving the project. The two screenshots below demonstrate the process of saving the project.

 

After using all the techniques of Adobe Premiere, as seen in the screenshots, I have produced a video edited on the program which can be seen below. It involves fading effects to both the video and audio, volume control modification, brightness and contrast modification, two titles over the visuals of the video and trimming and cutting to the video and audio.

 

Video and Audio Settings (K/600/8297 – 2.2 & 2.3)

The frame rate of a video is the frequency of consecutive images (or frames) being displayed. The higher the frame rate, the smoother and clearer the video will look. Frame rate is measured in frames per second (fps). Recommended settings for a HD video is 25 or 30fps, however, some videos are 60 fps. If I were to upload a video to the web, I would use the recommended frame rate settings – 30 fps would be appropriate because it will display a clear display. The viewer will not notice each still frame and it will appear more of a video than a group of still images. A higher frame rate setting can cause a slightly larger video size because each frame uses a few bytes of information.

Bitrate, or bits per second, is the number of bits that are processed in the duration of a video or audio file. 1 byte consists of 8 bits. A byte is a measurement for video and audio file size. Therefore, the higher the bitrate, the higher the size of the video (in bytes). Standard bitrate settings for videos range from 1mbps (HD web video) to 20mbps (HD blu-ray). Typically, the higher the bitrate of a file, the better the quality of the file.

There are different frame dimensions that are used for videos. In pixels, there is 1920×1080, 1280×720 and 854×480. The latter number of the resolution is often used as a measurement of quality of a video, for example 1080p – which is of high-definition. Frame dimensions have increased since the introduction of widescreen monitors, with square shaped monitors often displaying only up to 854×480. The most common frame dimensions for a video is 1920×1080. However, the recommened setting is 1280×720. The higher the resolution often means the higher the quality of the file and this then causes a larger file size. Choosing smaller frame dimensions when encoding a video can produce a smaller file size. Smaller frame dimensions can also produce quicker and more consistent streaming rates. When streaming higher resolution videos from the internet, buffering may occur. This involves pre-loading data into an area of memory for the data to be accessed.

Sample rate is the number of samples of audio carried per second, measured in Hz or kHz (one kHz = 1,000 Hz). (Ref 1 – wiki.audacityteam.org/wiki_Sample_Rates) A common sampling frequency is 44,100 Hz (or 44.1kHz). Audio is recorded by sampling 44,100 times per second. It is used the most because it is the sampling rate used in compact discs. The higher the sampling rate, the higher the quality of the audio. Sampling rates and bitrates affect data transfer rates due to both rates having an impact on the file size. The larger the file size of a video or audio file, the smaller the data transfer rate. This is the rate at which data is transmitted from one device to another. It is measured in megabytes per second (mbps).
It is important to use the correct compression settings when exporting video and audio files for websites. Changing compression settings can decrease the size of a video or audio file. Different video and audio rates such as frame rate, frame dimensions, sampling rate and bitrate determine the size and quality of a file. These settings are chosen before encoding a file to customise it to the user’s needs. If a user has limited disk space left or they want a file to be streamed easily, they may consider decreasing the frame rate to decrease the size of the file. These settings cannot be effectively increased and can only reach a higher rate by re-recording visuals or audio. The best settings for exporting files for web use include mp4 or avi format, the same frame rate that was used for recording is recommended, 12 mbps bitrate for high quality video that streams effectively and finally 44.1 kHz sampling rate.
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