transcode_file/
transcode_file.rs

1use std::{env, path::PathBuf, time::Instant};
2
3use lumen_ffmpeg::{
4    DecodeMode, InputContext, MuxedEncoder, VideoCodec, VideoDecoder, VideoDecoderConfig,
5    VideoEncoderConfig,
6};
7
8fn main() -> Result<(), Box<dyn std::error::Error>> {
9    let mut args = env::args().skip(1);
10    let input_path = args
11        .next()
12        .map(PathBuf::from)
13        .ok_or("usage: transcode_file <input> <output> [max_frames] [encoder]")?;
14    let output_path = args
15        .next()
16        .map(PathBuf::from)
17        .ok_or("missing output path")?;
18    let max_frames = args.next().and_then(|value| value.parse::<usize>().ok());
19    let encoder_name = args.next();
20
21    let started = Instant::now();
22    let mut input = InputContext::open(input_path.to_string_lossy().to_string())?;
23    let stream = input.best_video_stream()?;
24    let mut decoder = VideoDecoder::open(
25        &input,
26        VideoDecoderConfig {
27            stream_index: stream.stream_index,
28            mode: DecodeMode::Cpu,
29        },
30    )?;
31    let fps = stream
32        .avg_frame_rate
33        .as_f64()
34        .filter(|fps| *fps > 0.0)
35        .unwrap_or(60.0)
36        .round()
37        .clamp(1.0, u32::MAX as f64) as u32;
38    let mut config =
39        VideoEncoderConfig::cpu_rgba(stream.width, stream.height, fps, VideoCodec::H264);
40    if let Some(encoder_name) = encoder_name {
41        config.encoder_name = Some(encoder_name);
42    }
43    let mut encoder = MuxedEncoder::create(output_path.to_string_lossy().to_string(), config)?;
44
45    let mut frames = 0_usize;
46    'decode: while let Some(packet) = input.read_packet()? {
47        decoder.send_packet(&packet)?;
48        while let Some(frame) = decoder.receive_cpu_frame()? {
49            encoder.write_video_frame(&frame)?;
50            frames = frames.saturating_add(1);
51            if max_frames.is_some_and(|limit| frames >= limit) {
52                break 'decode;
53            }
54        }
55    }
56
57    if max_frames.is_none_or(|limit| frames < limit) {
58        decoder.send_eof()?;
59        while let Some(frame) = decoder.receive_cpu_frame()? {
60            encoder.write_video_frame(&frame)?;
61            frames = frames.saturating_add(1);
62            if max_frames.is_some_and(|limit| frames >= limit) {
63                break;
64            }
65        }
66    }
67
68    encoder.finish()?;
69    println!("input={}", input_path.display());
70    println!("output={}", output_path.display());
71    println!("frames={frames}");
72    println!("elapsed_ms={}", started.elapsed().as_millis());
73    println!(
74        "fps={:.2}",
75        frames as f64 / started.elapsed().as_secs_f64().max(1e-9)
76    );
77    Ok(())
78}
transcode_file/transcode_file.rs

transcode_file/
transcode_file.rs
