Struct ProxyGenerator 

pub struct ProxyGenerator { /* private fields */ }

Generates a lower-resolution proxy file from an original media file.

Proxy files allow smooth real-time playback of high-resolution footage by substituting a lower-quality copy during editing. Uses ff_pipeline::Pipeline internally — no raw FFmpeg calls.

Usage

let output = ProxyGenerator::new(Path::new("4k_clip.mp4"))?
    .resolution(ProxyResolution::Half)
    .output_dir(Path::new("/tmp/proxies"))
    .generate()?;

Output path

{output_dir}/{stem}_proxy_{half|quarter|eighth}.mp4

Implementations

impl ProxyGenerator

pub fn new(input: &Path) -> Result<Self, PreviewError>

Open the input file and prepare for proxy generation.

Probes input to confirm it is a valid media file with a video stream.

Errors

Returns PreviewError if the file cannot be probed.

pub fn resolution(self, res: ProxyResolution) -> Self

Set the output resolution (default: ProxyResolution::Half).

pub fn codec(self, codec: VideoCodec) -> Self

Set the output video codec (default: VideoCodec::H264).

pub fn output_dir(self, dir: &Path) -> Self

Set the output directory (default: same directory as the input file).

pub fn generate(self) -> Result<PathBuf, PreviewError>

Generate the proxy file synchronously.

Returns the path of the generated proxy file on success.

Dimensions are source ÷ resolution factor, rounded down to the nearest even number. Default quality: H.264 CRF 23, AAC audio.

Errors

Returns PreviewError if probing, filtering, or encoding fails.

pub fn generate_async(self) -> ProxyJob

Start proxy generation on a background thread and return immediately.

The returned ProxyJob lets you poll progress with ProxyJob::progress or block until completion with ProxyJob::wait.

Progress is tracked via ff-pipeline’s progress callback: each encoded frame updates an AtomicU32 (thousandths of completion, 0–1000). When the source container does not report a total frame count, progress stays at 0.0 throughout the run.