Rust MediaCodec

此库提供了对Android MediaCodec API的Rust绑定。它还添加了一些非常实用的工具，以简化在Android上使用缓冲区的工作。

已实现的功能

• MediaCodec
• MediaExtractor
• MediaMuxer
• MediaFormat
• 安全的编解码器缓冲区抽象
• 一些额外的实用工具，以简化使用库的工作

一些解码示例

use log::debug;
use mediacodec::{Frame, MediaCodec, MediaExtractor, SampleFormat, VideoFrame};

#[no_mangle]
extern "C" fn process() {
    let mut extractor = MediaExtractor::from_url("/path/to/a/resource").unwrap();

    debug!("Track count: {}", extractor.track_count());

    let mut decoders = vec![];

    for i in 0..extractor.track_count() {
        let format = extractor.track_format(i).unwrap();
        debug!("{}", format.to_string());
        let mime_type = format.get_string("mime").unwrap();
        let mut codec = MediaCodec::create_decoder(&mime_type).unwrap();

        codec.init(&format, None, 0).unwrap();

        codec.start().unwrap();
        decoders.push(codec);
        extractor.select_track(i);
    }

    while extractor.has_next() {
        // 1. Get the track index
        let index = extractor.track_index();

        if index < 0 {
            break;
        }

        let codec = &mut decoders[index as usize];

        // Fetch the codec's input buffer
        while let Ok(mut buffer) = codec.dequeue_input() {
            if !extractor.read_next(&mut buffer) {
                debug!(
                    "MediaExtractor.read_next() returned false! has_next(): {}",
                    extractor.has_next()
                );
                break; // VERY IMPORTANT, there's nothing else to DO, so break!!!
            }

            // When the buffer gets dropped (here), the buffer will be queued back to MediaCodec
            // And we don't have to do anything else
        }

        // Check for output
        let output_fmt = codec.output_format().unwrap();
        while let Ok(mut buffer) = codec.dequeue_output() {
            if let Some(ref frame) = buffer.frame() {
                match frame {
                    Frame::Audio(value) => match value.format() {
                        SampleFormat::S16(_) => {
                            // Do something with the audio frame
                        }
                        SampleFormat::F32(_) => {
                            // Do something with the audio frame
                        }
                    },
                    Frame::Video(value) => match value {
                        VideoFrame::Hardware => {
                            // Nothing TODO. The frame will be rendered
                        }
                        VideoFrame::RawFrame(_) => {
                            // Read out the raw buffers or something
                        }
                    },
                }
            }

            // Set the buffer to render when dropped. Only applicable to video codecs that have a hardware buffer (i.e, attached to a native window)
            buffer.set_render(true);
        }
    }
}

你可以在examples目录中找到更多示例。