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
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160

use std::ffi::CStr;
use std::fmt::{self, Debug, Display};
use std::marker::Send;
use std::mem::MaybeUninit;
use std::ptr;
use std::slice;
use std::str;

use faad2_sys::{self, NeAACDecHandle, c_char, c_uchar, c_ulong};

unsafe fn static_cstr(ptr: *const c_char) -> &'static str {
    str::from_utf8_unchecked(CStr::from_ptr(ptr).to_bytes())
}

pub fn version() -> (&'static str, &'static str) {
    unsafe {
        let mut id: *const c_char = ptr::null();
        let mut copyright: *const c_char = ptr::null();

        faad2_sys::NeAACDecGetVersion(&mut id as *mut _, &mut copyright as *mut _);

        (static_cstr(id), static_cstr(copyright))
    }
}

pub struct Error(c_uchar);

impl Error {
    pub fn message(&self) -> &'static str {
        unsafe {
            static_cstr(faad2_sys::NeAACDecGetErrorMessage(self.0))
        }
    }
}

impl Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", self.message())
    }
}

impl Debug for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "Error {{ code: {:?}, message: {:?} }}", self.0, self.message())
    }
}

struct DecoderHandle {
    handle: NeAACDecHandle,
}

unsafe impl Send for DecoderHandle {}

impl DecoderHandle {
    fn alloc() -> Self {
        let handle = unsafe { faad2_sys::NeAACDecOpen() };

        if handle == ptr::null_mut() {
            panic!("NeAACDecOpen failed")
        } else {
            DecoderHandle { handle }
        }
    }
}

impl Drop for DecoderHandle {
    fn drop(&mut self) {
        unsafe {
            faad2_sys::NeAACDecClose(self.handle);
        }
    }
}

pub struct Decoder {
    decoder: DecoderHandle,
    sample_rate: usize,
    channels: usize,
}

#[derive(Debug)]
pub struct DecodeResult<'a> {
    pub samples: &'a [f32],
    pub bytes_consumed: usize,
    pub channels: usize,
    pub sample_rate: usize,
}

impl Decoder {
    pub fn new(audio_specific_config: &[u8]) -> Result<Self, ()> {
        unsafe {
            let decoder = DecoderHandle::alloc();

            let mut config = faad2_sys::NeAACDecGetCurrentConfiguration(decoder.handle);
            (*config).outputFormat = faad2_sys::FAAD_FMT_FLOAT;
            if faad2_sys::NeAACDecSetConfiguration(decoder.handle, config) != 1 {
                return Err(());
            }

            let mut sample_rate: c_ulong = 0;
            let mut channels: c_uchar = 0;

            let err = faad2_sys::NeAACDecInit2(
                decoder.handle,
                audio_specific_config.as_ptr(),
                audio_specific_config.len() as c_ulong,
                &mut sample_rate as *mut _,
                &mut channels as *mut _,
            );

            if err != 0 {
                return Err(());
            }

            Ok(Decoder {
                decoder,
                sample_rate: sample_rate as usize,
                channels: channels as usize,
            })
        }
    }

    pub fn sample_rate(&self) -> usize {
        self.sample_rate
    }

    pub fn channels(&self) -> usize {
        self.channels
    }

    pub fn decode(&mut self, data: &[u8]) -> Result<DecodeResult<'_>, Error> {
        unsafe {
            let mut frame_info = MaybeUninit::zeroed();

            let samples = faad2_sys::NeAACDecDecode(
                self.decoder.handle,
                frame_info.as_mut_ptr(),
                data.as_ptr(),
                data.len() as c_ulong,
            );

            let frame_info = frame_info.assume_init();

            if samples == ptr::null_mut() {
                return Err(Error(frame_info.error));
            }

            let info = DecodeResult {
                samples: slice::from_raw_parts::<f32>(samples as *const f32, frame_info.samples as usize),
                bytes_consumed: frame_info.bytesconsumed as usize,
                channels: frame_info.channels as usize,
                sample_rate: frame_info.samplerate as usize,
            };

            self.channels = info.channels;
            self.sample_rate = info.sample_rate;

            Ok(info)
        }
    }
}