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Handle 2448-byte sectors

Handle images that have 2448-byte sectors, i.e. 2352 audio bytes + 96
sub-channel bytes.
master
Matteo Cypriani 4 years ago
parent
commit
e801140625
2 changed files with 65 additions and 9 deletions
  1. +15
    -0
      src/metadata/metadata.rs
  2. +50
    -9
      src/raw_audio.rs

+ 15
- 0
src/metadata/metadata.rs View File

@ -84,6 +84,21 @@ impl NrgMetadata {
}
self.chunk_offset
}
/// Returns the sector size of this image.
///
/// This information is retrieved from the first DAOX track only; it is
/// assumed that every track has the same sector size.
///
/// Returns 0 if there are no DAOX tracks.
pub fn sector_size(&self) -> u16 {
if let Some(daox_chunk) = self.daox_chunk.as_ref() {
if let Some(first_track) = daox_chunk.tracks.first() {
return first_track.sector_size;
}
}
0
}
}
impl fmt::Display for NrgMetadata {


+ 50
- 9
src/raw_audio.rs View File

@ -29,6 +29,9 @@ use std::path::PathBuf;
use ::error::NrgError;
use ::metadata::metadata::NrgMetadata;
const RAW_SEC_SIZE: u16 = 2352;
const RAW96_SEC_SIZE: u16 = 2448;
/// Extracts the raw audio data from an NRG image.
///
@ -45,18 +48,19 @@ pub fn extract_nrg_raw_audio(in_fd: &mut File,
let first_audio_byte = metadata.first_audio_byte();
try!(in_fd.seek(SeekFrom::Start(first_audio_byte)));
// Get the last audio byte
let last_audio_byte = metadata.last_audio_byte();
// Open output file
let audio_name = try!(make_output_file_name(img_path));
let mut out_fd = try!(File::create(audio_name));
// Copy the audio data
let count = last_audio_byte - first_audio_byte;
let bytes_copied = try!(copy_raw_audio(in_fd, &mut out_fd, count));
assert_eq!(count, bytes_copied);
let count = metadata.last_audio_byte() - first_audio_byte;
let bytes_read = match metadata.sector_size() {
RAW96_SEC_SIZE => try!(copy_raw96_audio(in_fd, &mut out_fd, count)),
0 => return Err(NrgError::AudioReadError),
_ => try!(copy_raw_audio(in_fd, &mut out_fd, count)),
};
assert_eq!(count, bytes_read);
Ok(())
}
@ -66,12 +70,12 @@ pub fn extract_nrg_raw_audio(in_fd: &mut File,
/// The offsets of `in_fd` and `out_fd` are not reset prior to reading and
/// writing.
///
/// Returns the number of bytes copied.
/// Returns the number of bytes read/written.
fn copy_raw_audio(in_fd: &mut File, out_fd: &mut File, count: u64)
-> Result<u64, NrgError> {
// The buffer size (~4,6 MiB) is a multiple of the standard audio CD sector
// size, i.e. 2352 bytes (it doesn't have to be, though).
const BUF_SIZE: usize = 2352 * 1024 * 2;
const BUF_SIZE: usize = RAW_SEC_SIZE as usize * 1024 * 2;
// Read/write audio data
let mut bytes_read = 0;
@ -107,6 +111,43 @@ fn copy_raw_audio(in_fd: &mut File, out_fd: &mut File, count: u64)
}
/// Reads `count` bytes from `in_fd` and write them to `out_fd` after stripping
/// the sub-channel bytes.
///
/// `in_fd` is read by chunks of 2448 bytes, then the first 2352 bytes are
/// written to `out_fd`, leaving out the 96 sub-channel bytes.
///
/// The offsets of `in_fd` and `out_fd` are not reset prior to reading and
/// writing.
///
/// Returns the number of bytes read (not written).
fn copy_raw96_audio(in_fd: &mut File, out_fd: &mut File, count: u64)
-> Result<u64, NrgError> {
const IN_BUF_SIZE: usize = RAW96_SEC_SIZE as usize;
const OUT_BUF_SIZE: usize = RAW_SEC_SIZE as usize;
// Read/write audio data
let mut bytes_read = 0;
while bytes_read < count {
let mut audio_buf = vec![0u8; IN_BUF_SIZE];
let mut nbytes = try!(in_fd.read(&mut audio_buf));
if nbytes != IN_BUF_SIZE {
return Err(NrgError::AudioReadError);
}
bytes_read += nbytes as u64;
audio_buf.truncate(OUT_BUF_SIZE);
nbytes = try!(out_fd.write(&audio_buf));
if nbytes != OUT_BUF_SIZE {
return Err(NrgError::AudioWriteError);
}
}
Ok(bytes_read)
}
/// Generates the output file's name from the NRG image's name.
///
/// The output file's name will be `img_path`'s base name stripped for its


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