How audio and video are digitized in Intro to Computing - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to represent the process of converting sound waves into digital data by sampling.

Intro to Computing

digital_audio = sample(sound_wave, [1])

Drag options to blanks, or click blank then click option'

Afrequency

Bamplitude

Cduration

Dspeed

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing amplitude instead of frequency

Confusing duration with sampling rate

Sampling frequency is how often the sound wave is measured per second to convert it into digital data.

2fill in blank

medium

Complete the code to show how video frames are captured at a certain rate for digitization.

Intro to Computing

digital_video = capture_frames(video_source, [1])

Drag options to blanks, or click blank then click option'

Aresolution

Bcolor_depth

Cbit_rate

Dframe_rate

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing resolution instead of frame rate

Confusing bit rate with frame rate

Frame rate is the number of video frames captured per second to create smooth motion in digital video.

3fill in blank

hard

Fix the error in the code that converts analog audio to digital by quantizing the amplitude values.

Intro to Computing

digital_audio = quantize(analog_audio, [1])

Drag options to blanks, or click blank then click option'

Asample_rate

Bbit_depth

Cframe_rate

Dresolution

Attempts:

3 left

💡 Hint

Common Mistakes

Using sample rate instead of bit depth

Confusing frame rate with bit depth

Bit depth determines how many levels of amplitude can be represented digitally, affecting audio quality.

4fill in blank

hard

Fill both blanks to complete the dictionary comprehension that maps video frames to their timestamps in seconds.

Intro to Computing

frame_timestamps = {frame: frame[1] frame_rate for frame in range(1, 6) if frame [2] 2 == 0}

Drag options to blanks, or click blank then click option'

A/

B%

C*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using multiplication instead of division for timestamp

Using subtraction instead of modulo for condition

Each frame's timestamp is calculated by dividing the frame number by the frame rate. The condition checks if the frame number is even using modulo (%).

5fill in blank

hard

Fill all three blanks to create a dictionary of audio samples with their quantized values filtered by bit depth.

Intro to Computing

quantized_samples = {sample[1] bit_depth: value for sample, value in audio_data.items() if value [2] max_value and sample[3] 2 == 0}

Drag options to blanks, or click blank then click option'

A**

B<

C%

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' instead of '**' for power

Using '>' instead of '<' for filtering

Using '-' instead of '%' for modulo

Sample keys are raised to a power (bit depth) using '**'. Values less than max_value are filtered with '<'. The modulo operator '%' checks if sample number is even.