The concept of "audio frame rate" is actually a misnomer; audio does not have a frame rate. Instead, audio utilizes sample rates.
Understanding Sample Rate vs. Frame Rate
It's crucial to distinguish between audio and video when talking about rates:
- Video: Uses frame rate (frames per second - fps), which determines how many individual still images are displayed per second to create the illusion of motion.
- Audio: Uses sample rate (samples per second), which determines how many times per second the audio waveform is measured and converted into digital data.
The Role of Sample Rate in Audio
Think of it this way:
- Analogue to Digital Conversion: Audio recording starts with an analogue sound wave.
- Sampling: The sample rate dictates how frequently this analogue signal is measured.
- Digital Representation: These measurements are then converted into digital samples, which are stored as data.
- Playback: During playback, these samples are reassembled back to a continuous analog signal.
The higher the sample rate, the more accurately the original sound is captured and reproduced. Common sample rates are 44.1 kHz (CD quality), 48 kHz, and 96 kHz.
How Audio Syncs with Video
According to the provided reference, as long as the frame rate of the video is the same, the audio will stay in sync, regardless of the audio's sample rate. The crucial element for synchronized audio and video is the matching of their time units. Because audio is not divided into frames the way video is, time is what keeps them synchronized.
Key Differences Summarized
| Feature | Video | Audio |
|---|---|---|
| Measurement | Frame Rate (fps) | Sample Rate (samples/sec) |
| Function | Captures motion | Captures sound |
| Data Structure | Frames | Samples |
In Conclusion
Therefore, when discussing audio, the correct term to use is sample rate, not frame rate. The sample rate defines the frequency at which audio is sampled, whereas video uses frame rate to capture and display motion. As long as both audio and video use a consistent measure of time, they can be synchronized.
