Skip to main content

decode_frame/
decode_frame.rs

1use std::io::Write;
2
3use libav_ng::{
4    avcodec::CodecContext, avformat::FormatContext, avframe::Frame, avpacket::Packet, sws::Sws,
5};
6use libav_sys_ng::{
7    sws_freeContext, sws_getContext, sws_scale, AVPixelFormat_AV_PIX_FMT_RGB24, SwsContext,
8    SWS_BILINEAR,
9};
10
11fn main() {
12    let url = if let Some(url) = std::env::args().skip(1).next() {
13        url
14    } else {
15        eprintln!("No input file!");
16        std::process::exit(1);
17    };
18
19    let mut format_context = FormatContext::open_input(&url).expect("Failed to open file!");
20
21    format_context.find_stream_info();
22
23    for i in format_context.streams() {
24        println!("{i:#?}");
25    }
26
27    let video_stream = format_context
28        .streams()
29        .filter(|x| x.codec_parameters().is_video())
30        .next()
31        .expect("Failed to find a video stream");
32
33    println!("CodecParams idx: {}", video_stream.index());
34    println!(
35        "CodecParams format: {}",
36        video_stream.codec_parameters().format()
37    );
38
39    let mut codec = CodecContext::from_decoder_id(video_stream.codec_parameters().codec_id())
40        .expect("Failed to create CodecContext");
41
42    codec.fill_from_parameters(&video_stream.codec_parameters());
43
44    codec.open(None).unwrap();
45
46    println!("Pixel format: {}", codec.get_pixel_format());
47
48    format_context.seek_msec(video_stream.index(), 4 * 60 * 1000);
49
50    let mut packet = Packet::new();
51
52    while format_context.read_frame(&mut packet) >= 0 {
53        println!("{}", packet.stream_index());
54
55        if packet.stream_index() == video_stream.index() {
56            codec.send_packet(&packet);
57
58            let mut frame = Frame::empty().expect("Failed to allocate a frame");
59
60            while codec.receive_frame(&mut frame) >= 0 {
61                println!("{}", frame.format());
62                {
63                    let (width, height) = video_stream.codec_parameters().size();
64                    println!("{width} x {height}");
65
66                    let mut new_frame =
67                        Frame::from_size_and_pixfmt(width, height, AVPixelFormat_AV_PIX_FMT_RGB24)
68                            .unwrap();
69
70                    let sws = Sws::new(
71                        width,
72                        height,
73                        video_stream.codec_parameters().format(),
74                        width,
75                        height,
76                        AVPixelFormat_AV_PIX_FMT_RGB24,
77                        SWS_BILINEAR as _,
78                    );
79
80                    println!("{:?} {:?}", frame.linesize(), new_frame.linesize());
81
82                    sws.scale(&frame, &mut new_frame);
83
84                    let mut file = std::fs::OpenOptions::new()
85                        .create(true)
86                        .truncate(true)
87                        .write(true)
88                        .open("data.bin")
89                        .unwrap();
90
91                    file.write(new_frame.data_plane(0).unwrap()).unwrap();
92                }
93            }
94
95            break;
96        }
97    }
98
99    println!("Exit!");
100}