diff --git a/src/wavewriter.rs b/src/wavewriter.rs index 80d5513..5e824fb 100644 --- a/src/wavewriter.rs +++ b/src/wavewriter.rs @@ -13,5 +13,81 @@ use byteorder::WriteBytesExt; /// This isn't working yet, do not use. pub struct WaveWriter where W: Write + Seek { - inner : W + inner : W, + form_size : u64 +} + +impl WaveWriter { + fn create(path: &str, format: WaveFmt) -> Result { + let f = File::create(path)?; + Self::new(f, format) + } +} + +impl WaveWriter { + /// Wrap a `Write` struct with a wavewriter. + fn new(inner : W, format: WaveFmt) -> Result { + let mut retval = Self { inner, form_size : 0 }; + retval.inner.seek(SeekFrom::Start(0))?; + retval.inner.write_fourcc(RIFF_SIG)?; + retval.inner.write_u32::(0)?; + retval.inner.write_fourcc(WAVE_SIG)?; + retval.update_form_size(4)?; + retval.write_ds64_reservation()?; + retval.write_format(format)?; + Ok( retval ) + } + + /// Unwrap the inner writer. + fn into_inner(self) -> W { + return self.inner; + } + + /// Append data as a new chunk to the wave file. + fn append_chunk(&mut self, ident: FourCC, data: &[u8]) -> Result<(),Error> { + assert!(data.len() < (u32::MAX as usize), + "append_chunk() can only be used for chunks sized less than u32::MAX"); + + let chunk_length = data.len() as u32; + let total_chunk_size : u64 = (8 + chunk_length + (chunk_length % 2)) as u64; + self.inner.seek(SeekFrom::End(0))?; + self.inner.write_fourcc(ident)?; + self.inner.write_u32::(chunk_length)?; + self.inner.write(data)?; + if chunk_length % 2 > 0 { self.inner.write_u8(0)?; } + self.update_form_size(total_chunk_size)?; + Ok( () ) + } +} + + +impl WaveWriter { /* Private implementation */ + + fn write_ds64_reservation(&mut self) -> Result<(), Error> { + let ds64_reservation_data = vec![0u8; 92]; + self.append_chunk(JUNK_SIG, &ds64_reservation_data) + } + + fn write_format(&mut self, format: WaveFmt) -> Result<(), Error> { + let mut buf : Vec = vec![]; + let mut cursor = Cursor::new(&mut buf); + cursor.write_wave_fmt(&format)?; + self.append_chunk(FMT__SIG, &buf) + } + + fn update_form_size(&mut self, added_size: u64) -> Result<(),Error> { + self.inner.seek(SeekFrom::Start(4))?; + let new_size = added_size + self.form_size; + if new_size < (u32::MAX as u64) { + self.inner.write_u32::(new_size as u32)?; + } else { + self.update_form_size_ds64(new_size)?; + } + self.form_size = new_size; + Ok( () ) + } + + fn update_form_size_ds64(&mut self, new_size: u64) -> Result<(), Error> { + todo!() + } }