How to Use the Command 'pw-record' (with examples)

The pw-record command is an audio recording tool that uses PipeWire, a Linux multimedia server responsible for handling audio and video streams on your system. It serves as a shorthand for the pw-cat --record command, allowing users to efficiently capture audio input and save it to a file. This tool can be particularly useful for tasks such as recording lectures, meetings, voice memos, or even music.

Use Case 1: Record a Sample Recording Using the Default Target

Code:

pw-record path/to/file.wav

Motivation:

Recording audio with the default target is often the most straightforward approach. This default setup is beneficial for users who wish to quickly record without any configuration, securely capturing the audio input into a WAV file. This simplicity is ideal for everyday recording needs, such as voice memos or podcast episodes, where high quality and ease of use are required.

Explanation:

• pw-record: Initiates the recording process using PipeWire.
• path/to/file.wav: Specifies the output path and filename for the captured audio. The use of .wav indicates that the file format is WAV, which is a commonly used and high-quality audio format.

Example Output:

Upon running the command, the system will not give explicit output on the terminal. Instead, it will create a new file at the specified path, file.wav, containing the recorded audio data captured from the default audio input device. The size and content of the file will depend on the duration and input source of the recording.

Use Case 2: Record a Sample Recording at a Different Volume Level

Code:

pw-record --volume=0.1 path/to/file.wav

Motivation:

There are instances when controlling the volume of the output recording is crucial. Lowering the volume can be necessary in environments with high ambient noise or when the source audio is exceedingly loud. This feature is particularly useful for musicians or podcasters who need to balance different audio sources to achieve a harmonious output without distortion.

Explanation:

• --volume=0.1: This option sets the recording volume to 10% of the original input level. This argument is essential for managing audio dynamics, especially when audio input levels are not optimal.
• path/to/file.wav: Specifies the output path and filename. The recorded audio is saved in the same WAV format, preserving the quality of the audio at the adjusted volume level.

Example Output:

As the command executes, it will produce an audio file named file.wav at the specified path, recorded at a significantly reduced volume of 10%. There is no direct terminal output, but the resulting file will audibly reflect the adjusted volume, making it useful for playback in situations where lower volume is required.

Use Case 3: Record a Sample Recording Using a Different Sample Rate

Code:

pw-record --rate=6000 path/to/file.wav

Motivation:

Changing the sample rate of a recording is a common practice for specific applications, such as creating small file sizes or emulating lower quality to fit older technology standards. For instance, archival purposes or legacy system compatibility might require a lower sample rate, as seen in certain telecommunication applications.

Explanation:

• --rate=6000: Specifies the sample rate of the recording at 6000 Hz. A lower sample rate reduces the fidelity of the audio but simultaneously reduces the file size. This parameter is crucial for optimizing recordings for certain storage or bandwidth constraints.
• path/to/file.wav: The chosen file path and name where the recording is saved. Despite the lower sample rate, the format remains WAV, suitable for many audio processing applications.

Example Output:

Running this command will generate a file called file.wav at the input path. The resulting audio will have a noticeably diminished quality compared to standard sample rates (like 44100 Hz) but will occupy less storage space. This trade-off makes it suitable for specific technical or storage-related circumstances.

Conclusion:

Leveraging the pw-record command through PipeWire is a versatile solution for capturing audio in diverse scenarios. Whether you need simplicity, volume control, or sample rate adjustment, pw-record offers the customization needed to fulfill different recording requirements while maintaining a straightforward workflow. By understanding and applying these use cases, users can efficiently tailor audio recordings to suit their specific needs, ensuring quality and versatility in their audio projects.