Struct FfmpegChild

pub struct FfmpegChild { /* private fields */ }

A wrapper around tokio::process::Child containing a spawned Ffmpeg command. Provides interfaces for reading parsed metadata, progress updates, warnings and errors and piped output frames if applicable.

Implementations

impl FfmpegChild

pub fn stream(&mut self) -> Result<FfmpegEventStream>

Crates a stream over events emitted by Ffmpeg. Functions similarly to Lines from tokio::io::BufReader, but providing a variety of parsed events:

• Log messages
• Parsed metadata
• Progress updates
• Errors and warnings
• Raw output frames

Examples found in repository

examples/test_exit.rs (line 13)

async fn main() {
  let mut child = FfmpegCommand::new()
    .arg("-report")
    .testsrc()
    .rawvideo()
    .print_command()
    .spawn()
    .unwrap();
  let count = child.stream().unwrap().filter_progress().count().await;

  assert!(count <= 1);
}

pub fn take_stdout(&mut self) -> Option<ChildStdout>

Escape hatch to manually control the process’ stdout channel. Calling this method takes ownership of the stdout channel, so the iterator will no longer include output frames in the stream of events.

pub fn take_stderr(&mut self) -> Option<ChildStderr>

Escape hatch to manually control the process’ stderr channel. This method is mutually exclusive with events_iter, which relies on the stderr channel to parse events.

pub fn take_stdin(&mut self) -> Option<ChildStdin>

Escape hatch to manually control the process’ stdin channel. This method is mutually exclusive with send_stdin_command and quit, which use the stdin channel to send commands to ffmpeg.

pub async fn send_stdin_command(&mut self, command: &[u8]) -> Result<()>

Send a command to ffmpeg over stdin, used during interactive mode.

This method does not validate that the command is expected or handled correctly by ffmpeg. The returned io::Result indicates only whether the command was successfully sent or not.

In a typical ffmpeg build, these are the supported commands:

?      show this help
+      increase verbosity
-      decrease verbosity
c      Send command to first matching filter supporting it
C      Send/Queue command to all matching filters
D      cycle through available debug modes
h      dump packets/hex press to cycle through the 3 states
q      quit
s      Show QP histogram

pub async fn quit(&mut self) -> Result<()>

Send a q command to ffmpeg over stdin, requesting a graceful shutdown as soon as possible.

This method returns after the command has been sent; the actual shut down may take a few more frames as ffmpeg flushes its buffers and writes the trailer, if applicable.

pub async fn kill(&mut self) -> Result<()>

Forcibly terminate the inner child process.

Alternatively, you may choose to gracefully stop the child process by sending a command over stdin, using the quit method.

Identical to kill in std::process::Child.

pub async fn wait(&mut self) -> Result<ExitStatus>

Waits for the inner child process to finish execution.

Identical to wait in std::process::Child.

pub fn as_inner(&mut self) -> &Child

Escape hatch to access the inner Child.

pub fn as_inner_mut(&mut self) -> &mut Child

Escape hatch to mutably access the inner Child.