The util module provides utility functions for common media file operations.
get_duration
Extract the duration of a media file using ffprobe.
Runs ffprobe in quiet mode and parses the format=duration entry from the output. Returns the duration as a std::time::Duration.
pub async fn get_duration<P: AsRef<Path>>(
input: P,
cancellation_token: CancellationToken,
) -> Result<Duration, DurationError>
Parameters
The path to the media file. Can be any type that implements AsRef<Path>, such as &str, String, Path, or PathBuf.
cancellation_token
CancellationToken
required
A token to cancel the ffprobe operation. When cancelled, the process is killed immediately.
Returns
Returns Result<Duration, DurationError>:
Ok(Duration) - The duration of the media file as a std::time::DurationErr(DurationError) - An error occurred during execution or parsing
Error Cases
The underlying ffprobe execution failed (e.g., binary not found).
DurationError::IncompleteSubprocess
The process returned but no exit status was present. This indicates an unexpected termination.
DurationError::ExitedUnsuccessfully
{ exit_code: CommandExitCode }
ffprobe exited with a non-zero exit code, indicating the operation failed.
DurationError::ExpectedLine
Expected ffprobe to output a line with the duration, but no output was received.
DurationError::Parse
{ inner_error: AnyError }
Failed to parse the duration string provided by ffprobe into a valid f64 number.
Implementation Details
The function executes ffprobe with the following arguments:
-threads 4 - Use 4 threads for processing-v quiet - Suppress all output except errors-show_entries format=duration - Only show the duration field from the format section-of default=noprint_wrappers=1:nokey=1 - Output only the value without key names or wrappers
The output is parsed as a floating-point number representing seconds, which is then converted to a std::time::Duration.
Example
use libffmpeg::util::get_duration;
use tokio_util::sync::CancellationToken;
use std::time::Duration;
let token = CancellationToken::new();
let duration = get_duration("video.mp4", token).await?;
println!("Duration: {:?}", duration);
println!("Duration in seconds: {}", duration.as_secs());
println!("Duration in milliseconds: {}", duration.as_millis());
Example with Path Types
use libffmpeg::util::get_duration;
use tokio_util::sync::CancellationToken;
use std::path::{Path, PathBuf};
let token = CancellationToken::new();
// Works with &str
let duration = get_duration("video.mp4", token.clone()).await?;
// Works with String
let path = String::from("video.mp4");
let duration = get_duration(path, token.clone()).await?;
// Works with Path
let path = Path::new("video.mp4");
let duration = get_duration(path, token.clone()).await?;
// Works with PathBuf
let path = PathBuf::from("video.mp4");
let duration = get_duration(path, token.clone()).await?;
Example with Error Handling
use libffmpeg::util::{get_duration, DurationError};
use tokio_util::sync::CancellationToken;
let token = CancellationToken::new();
match get_duration("video.mp4", token).await {
Ok(duration) => {
println!("Video duration: {:.2} seconds", duration.as_secs_f64());
}
Err(DurationError::Ffprobe { inner_error }) => {
eprintln!("ffprobe error: {}", inner_error);
}
Err(DurationError::ExitedUnsuccessfully { exit_code }) => {
eprintln!("ffprobe failed with exit code: {:?}", exit_code);
}
Err(DurationError::Parse { inner_error }) => {
eprintln!("Failed to parse duration: {}", inner_error);
}
Err(e) => {
eprintln!("Unexpected error: {}", e);
}
}
Example with Cancellation
use libffmpeg::util::get_duration;
use tokio_util::sync::CancellationToken;
use tokio::time::{timeout, Duration};
let token = CancellationToken::new();
// Clone the token for the timeout handler
let token_clone = token.clone();
// Cancel after 5 seconds
tokio::spawn(async move {
tokio::time::sleep(Duration::from_secs(5)).await;
token_clone.cancel();
});
// This will be cancelled if it takes more than 5 seconds
match get_duration("very_large_video.mp4", token).await {
Ok(duration) => println!("Duration: {:?}", duration),
Err(e) => eprintln!("Operation cancelled or failed: {}", e),
}