ff-decode

Decode video and audio frames without managing codec contexts, packet queues, or timestamp conversions. Open a file, call decode_frame in a loop, and receive VideoFrame objects with their position already expressed as a Duration.

Installation

[dependencies]

ff-decode = "0.3"

ff-format = "0.3"

Video Decoding

use ff_decode::VideoDecoder;
use ff_format::PixelFormat;

let mut decoder = VideoDecoder::open("video.mp4")?
    .output_format(PixelFormat::Rgba)
    .build()?;

while let Some(frame) = decoder.decode_frame()? {
    // frame.data()      — raw pixel bytes in RGBA order
    // frame.width()     — frame width in pixels
    // frame.height()    — frame height in pixels
    // frame.timestamp() — position as std::time::Duration
    process(&frame);
}

Audio Decoding

use ff_decode::AudioDecoder;
use ff_format::{SampleFormat, ChannelLayout};

let mut decoder = AudioDecoder::open("audio.flac")?
    .output_format(SampleFormat::Fltp)
    .output_sample_rate(44_100)
    .output_channel_layout(ChannelLayout::Stereo)
    .build()?;

while let Some(frame) = decoder.decode_frame()? {
    // frame.data()        — interleaved or planar sample bytes
    // frame.sample_rate() — samples per second
    // frame.timestamp()   — position as std::time::Duration
    process(&frame);
}

Seeking

use ff_decode::{VideoDecoder, SeekMode};
use std::time::Duration;

let mut decoder = VideoDecoder::open("video.mp4")?.build()?;

// Jump to the nearest keyframe at or before 30 seconds.
decoder.seek(Duration::from_secs(30), SeekMode::Keyframe)?;

// Jump to the exact position (may decode additional frames internally).
decoder.seek(Duration::from_secs(30), SeekMode::Exact)?;

Seeking does not re-open the file. The existing codec context is flushed and reused.

Hardware Acceleration

use ff_decode::{VideoDecoder, HardwareAccel};

let mut decoder = VideoDecoder::open("video.mp4")?
    .hardware_accel(HardwareAccel::Auto)
    .build()?;

HardwareAccel::Auto probes for NVDEC, DXVA2, VideoToolbox, and VAAPI in that order, and falls back to software decoding if none is available.

Error Handling

Variant	When it occurs
`DecodeError::FileNotFound`	The input path does not exist
`DecodeError::CannotOpen`	FFmpeg could not open the container or codec
`DecodeError::UnsupportedCodec`	No decoder available for the stream's codec
`DecodeError::InvalidConfig`	Builder options are inconsistent or unsupported
`DecodeError::Io`	Read error on the underlying file

What the Crate Handles for You

Codec context allocation and lifetime
PTS-to-Duration conversion using the stream's time base
Packet queue management and buffering
EOF signalled as Ok(None) rather than a special error variant
Pixel format and sample format negotiation via swscale / swresample

MSRV

Rust 1.93.0 (edition 2024).

License

MIT OR Apache-2.0

ff-decode 0.5.0