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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,183 @@ | ||
| //! PCE PRI format | ||
| //! Bitstream format | ||
| //! http://www.hampa.ch/pce/index.html | ||
| use std::collections::HashMap; | ||
| use std::io::{Seek, SeekFrom}; | ||
|
|
||
| use super::FloppyImageLoader; | ||
| use crate::{Floppy, FloppyImage, FloppyType, OriginalTrackType, TrackLength}; | ||
|
|
||
| use anyhow::{bail, Result}; | ||
| use binrw::io::Cursor; | ||
| use binrw::{binrw, BinRead}; | ||
| use log::*; | ||
|
|
||
| const CRC_PRI: crc::Algorithm<u32> = crc::Algorithm { | ||
| width: 32, | ||
| poly: 0x1edc6f41, | ||
| init: 0, | ||
| refin: false, | ||
| refout: false, | ||
| xorout: 0, | ||
| check: 0, | ||
| residue: 0, | ||
| }; | ||
|
|
||
| /// Standardized chunk header | ||
| #[binrw] | ||
| #[brw(big)] | ||
| #[derive(Debug)] | ||
| struct ChunkHeader { | ||
| /// ASCII chunk identifier | ||
| pub id: [u8; 4], | ||
|
|
||
| /// Chunk size in bytes | ||
| pub size: u32, | ||
| } | ||
|
|
||
| /// Standardized chunk tail | ||
| #[binrw] | ||
| #[brw(big)] | ||
| #[derive(Debug)] | ||
| struct ChunkTail { | ||
| pub crc: u32, | ||
| } | ||
|
|
||
| /// File header chunk payload | ||
| #[binrw] | ||
| #[brw(big)] | ||
| #[derive(Debug)] | ||
| struct PayloadHeader { | ||
| pub version: u8, | ||
| } | ||
|
|
||
| /// Track header | ||
| #[binrw] | ||
| #[brw(big)] | ||
| #[derive(Debug)] | ||
| struct PayloadTrack { | ||
| pub track: u32, | ||
| pub head: u32, | ||
| pub length: u32, | ||
| pub clock: u32, | ||
| } | ||
|
|
||
| /// PCE PRI image format loader | ||
| pub struct PRI {} | ||
|
|
||
| impl FloppyImageLoader for PRI { | ||
| fn load(data: &[u8], filename: Option<&str>) -> Result<FloppyImage> { | ||
| let mut cursor = Cursor::new(data); | ||
|
|
||
| let mut tracks: HashMap<(usize, usize), (usize, &[u8])> = HashMap::new(); | ||
| let mut cur_track = 0; | ||
| let mut cur_side = 0; | ||
| let mut cur_len = 0; | ||
| let mut saw_header = false; | ||
|
|
||
| // Parse chunks from file | ||
| while let Ok(chunk) = ChunkHeader::read(&mut cursor) { | ||
| let startpos = cursor.position(); | ||
|
|
||
| // Check CRC of the entire chunk | ||
| let checksum = crc::Crc::<u32>::new(&CRC_PRI).checksum( | ||
| &data[(startpos as usize - 8)..(startpos as usize + chunk.size as usize)], | ||
| ); | ||
| let chunk_checksum = u32::from_be_bytes( | ||
| data[(startpos as usize + chunk.size as usize) | ||
| ..(startpos as usize + chunk.size as usize + 4)] | ||
| .try_into()?, | ||
| ); | ||
| if checksum != chunk_checksum { | ||
| bail!( | ||
| "Checksum for chunk '{}' incorrect, saw {:08X}, expected {:08X}", | ||
| String::from_utf8_lossy(&chunk.id), | ||
| chunk_checksum, | ||
| checksum | ||
| ); | ||
| } | ||
|
|
||
| if &chunk.id != b"PRI " && !saw_header { | ||
| bail!("File header not found"); | ||
| } | ||
|
|
||
| match &chunk.id { | ||
| b"PRI " => { | ||
| saw_header = true; | ||
| } | ||
| b"TRAK" => { | ||
| let payload = PayloadTrack::read(&mut cursor)?; | ||
|
|
||
| if payload.clock != 500_000 { | ||
| bail!( | ||
| "Unsupported clock rate {} on side {} track {}", | ||
| payload.clock, | ||
| cur_side, | ||
| cur_track | ||
| ); | ||
| } | ||
| cur_track = payload.track as usize; | ||
| cur_side = payload.head as usize; | ||
| cur_len = payload.length as usize; | ||
| } | ||
| b"TEXT" => (), | ||
| b"DATA" => { | ||
| tracks.insert( | ||
| (cur_side, cur_track), | ||
| ( | ||
| cur_len, | ||
| &data[(startpos as usize + 8) | ||
| ..(startpos as usize + chunk.size as usize)], | ||
| ), | ||
| ); | ||
| } | ||
| b"BCLK" => { | ||
| bail!( | ||
| "BCLK encountered on side {}, track {}. Currently unsupported", | ||
| cur_side, | ||
| cur_track | ||
| ); | ||
| } | ||
| b"END " => break, | ||
| _ => { | ||
| warn!( | ||
| "Found unsupported chunk '{}', skipping", | ||
| String::from_utf8_lossy(&chunk.id) | ||
| ); | ||
| } | ||
| } | ||
|
|
||
| // Always consume the amount of bytes the chunk header reports | ||
| cursor.seek(SeekFrom::Start(startpos + u64::from(chunk.size) + 4))?; | ||
| } | ||
|
|
||
| let mut img = FloppyImage::new_empty( | ||
| if tracks.keys().any(|&(s, _t)| s > 0) { | ||
| FloppyType::Mac800K | ||
| } else { | ||
| FloppyType::Mac400K | ||
| }, | ||
| filename.unwrap_or_default(), | ||
| ); | ||
|
|
||
| // Fill tracks | ||
| for ((side, track), (bitlen, data)) in tracks { | ||
| if let TrackLength::Bits(t) = img.get_track_length(side, track) { | ||
| if t > 0 { | ||
| // Multiple captures encountered, we just use the first and hope it's good. | ||
| continue; | ||
| } | ||
| } | ||
| img.origtracktype[side][track] = OriginalTrackType::Bitstream; | ||
| img.set_actual_track_length(side, track, bitlen); | ||
|
|
||
| // The DATA chunk may be shorter than the track length in the | ||
| // preceding TRAK chunk suggests. In that case the remainder of | ||
| // the track data should be set to 0. | ||
| img.trackdata[side][track][0..data.len()].copy_from_slice(data); | ||
| } | ||
|
|
||
| Ok(img) | ||
| } | ||
| } |