1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101

use libc::malloc;
use minimp4_sys::{
    mp4_h26x_write_init, mp4_h26x_writer_t, MP4E_close, MP4E_mux_t, MP4E_open,
    MP4E_set_text_comment,
};
use std::convert::TryInto;
use std::ffi::CString;
use std::io::{Seek, SeekFrom, Write};
use std::mem::size_of;
use std::os::raw::{c_int, c_void};
use std::ptr::null_mut;
use std::slice::from_raw_parts;

extern "C" {
    fn write_mp4(
        mp4wr: *const mp4_h26x_writer_t,
        fps: c_int,
        data: *const c_void,
        data_size: c_int,
    );
}

pub struct Mp4Muxer<W> {
    writer: W,
    muxer: *mut MP4E_mux_t,
    muxer_writer: *mut mp4_h26x_writer_t,
    str_buffer: Vec<CString>,
}

impl<W: Write + Seek> Mp4Muxer<W> {
    pub fn new(writer: W) -> Self {
        unsafe {
            Self {
                writer,
                muxer: null_mut(),
                muxer_writer: malloc(size_of::<mp4_h26x_writer_t>()) as *mut mp4_h26x_writer_t,
                str_buffer: Vec::new(),
            }
        }
    }

    pub fn init_video(&mut self, width: i32, height: i32, is_hevc: bool, track_name: &str) {
        self.str_buffer.push(CString::new(track_name).unwrap());
        unsafe {
            if self.muxer.is_null() {
                let self_ptr = self as *mut Self as *mut c_void;
                self.muxer = MP4E_open(0, 0, self_ptr, Some(Self::write));
            }
            mp4_h26x_write_init(
                self.muxer_writer,
                self.muxer,
                width,
                height,
                if is_hevc { 1 } else { 0 },
                self.str_buffer.last().unwrap().as_ptr(),
            );
        }
    }

    pub fn write_video(&self, data: &[u8]) {
        unsafe {
            write_mp4(
                self.muxer_writer,
                60,
                data.as_ptr() as *const c_void,
                data.len().try_into().unwrap(),
            );
        }
    }

    pub fn write_comment(&mut self, comment: &str) {
        self.str_buffer.push(CString::new(comment).unwrap());
        unsafe {
            MP4E_set_text_comment(self.muxer, self.str_buffer.last().unwrap().as_ptr());
        }
    }
    pub fn close(&self) -> &W {
        unsafe {
            MP4E_close(self.muxer);
        }
        &self.writer
    }

    pub fn write_data(&mut self, offset: i64, buf: &[u8]) -> usize {
        self.writer.seek(SeekFrom::Start(offset as u64)).unwrap();
        self.writer.write(buf).unwrap_or(0)
    }

    extern "C" fn write(
        offset: i64,
        buffer: *const c_void,
        size: usize,
        token: *mut c_void,
    ) -> i32 {
        let p_self = token as *mut Self;
        unsafe {
            let buf = from_raw_parts(buffer as *const u8, size);
            ((&mut *p_self).write_data(offset, buf) != size) as i32
        }
    }
}