Unbewohnte
/
rip
1
0
Fork 0
Code Issues Pull Requests Projects Releases 1 Wiki Activity
Browse Source

NOT FOR RELEASE; MP3 frame header decoding progress

master
Kasianov Nikolai Alekseevich 2 years ago
parent
e89b266c6e
commit
80388f1b47
2 changed files with 50 additions and 40 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 58
      src/audio/mp3.rs
  2. 32
      src/main.rs

58
src/audio/mp3.rs
Unescape View File

@ -22,12 +22,19 @@ use crate::util::content_type::ContentType;
const ID3V2_IDENTIFIER: [u8; 3] = [0x49, 0x44, 0x33];
const ID3V2_HEADER_LENGTH: usize = 10;
const MP3_HEADER_LENGTH: usize = 4;
const MP3_HEADER_SYNC_WORD_MASK: u32 = 0xFFE00000; // 11111111111000000000000000000000
const MP3_HEADER_VERSION_MASK: u32 = 0x180000; // 00000000000110000000000000000000
const MP3_HEADER_LAYER_MASK: u32 = 0x60000; // 00000000000001100000000000000000
const MP3_HEADER_BITRATE_MASK: u32 = 0xF000; // 00000000000000001111000000000000
const MP3_HEADER_SAMPLING_RATE_MASK: u32 = 0xC00; // 00000000000000000000110000000000
const MP3_HEADER_PADDING_MASK: u32 = 0x200; // 00000000000000000000001000000000
const MP3_HEADER_SYNC_WORD_MASK: u32 = 0xFFE00000; // 11111111111000000000000000000000
const MP3_HEADER_VERSION_MASK: u32 = 0x00180000; // 00000000000110000000000000000000
const MP3_HEADER_LAYER_MASK: u32 = 0x00060000; // 00000000000001100000000000000000
const MP3_HEADER_BITRATE_MASK: u32 = 0x0000F000; // 00000000000000001111000000000000
const MP3_HEADER_SAMPLING_RATE_MASK: u32 = 0x00000C00; // 00000000000000000000110000000000
const MP3_HEADER_PADDING_MASK: u32 = 0x00000200; // 00000000000000000000001000000000
// const MP3_HEADER_SYNC_WORD_MASK: u32 = 0xFFF00000; // 11111111111100000000000000000000
// const MP3_HEADER_VERSION_MASK: u32 = 0xC0000; // 00000000000011000000000000000000
// const MP3_HEADER_LAYER_MASK: u32 = 0x30000; // 00000000000000110000000000000000
// const MP3_HEADER_BITRATE_MASK: u32 = 0x7800; // 00000000000000000111100000000000
// const MP3_HEADER_SAMPLING_RATE_MASK: u32 = 0x600; // 00000000000000000000011000000000
// const MP3_HEADER_PADDING_MASK: u32 = 0x100; // 00000000000000000000000100000000
#[derive(Debug)]
enum AudioVersion {
@ -97,8 +104,8 @@ fn get_bitrate(header: u32, audio_version: &AudioVersion, layer: &LayerIndex) ->
AudioVersion::MpegV2 | AudioVersion::MpegV25 => {
match layer {
LayerIndex::LayerI => return Some(32),
LayerIndex::LayerII | LayerIndex::LayerIII => return Some(16),
LayerIndex::LayerI => return Some(56),
LayerIndex::LayerII | LayerIndex::LayerIII => return Some(24),
}
}
}
@ -441,9 +448,9 @@ pub fn rip_mp3(data: &[u8], start_index: usize) -> Option<Position> {
// get tag length
let mut tag_length_bytes: [u8; 4] = [0; 4];
for j in 0..4 {
tag_length_bytes[j] = data[i+ID3V2_IDENTIFIER.len()+5+j];
tag_length_bytes[j] = data[i+ID3V2_IDENTIFIER.len()+3+j];
}
// convert from syncsafe to a normal integer
// convert syncsafe integer to a normal one
let mut tag_length: u32 = 0;
for j in 0..4 {
tag_length = tag_length << 7;
@ -474,6 +481,7 @@ pub fn rip_mp3(data: &[u8], start_index: usize) -> Option<Position> {
// check for sync word
if !mp3_header & MP3_HEADER_SYNC_WORD_MASK == MP3_HEADER_SYNC_WORD_MASK {
println!("SYNCWORD NO");
break;
}
@ -487,7 +495,7 @@ pub fn rip_mp3(data: &[u8], start_index: usize) -> Option<Position> {
let audio_version: AudioVersion;
match get_audio_version(mp3_header) {
Some(version) => audio_version = version,
None => break,
None => {println!("VERSION NO {:032x}", mp3_header & MP3_HEADER_VERSION_MASK); break},
}
println!("audio version is {:?}", audio_version);
@ -496,7 +504,7 @@ pub fn rip_mp3(data: &[u8], start_index: usize) -> Option<Position> {
let layer: LayerIndex;
match get_layer(mp3_header) {
Some(l) => layer = l,
None => break,
None => {println!("LAYER NO"); break},
}
println!("layer is {:?}", layer);
@ -506,7 +514,7 @@ pub fn rip_mp3(data: &[u8], start_index: usize) -> Option<Position> {
let bitrate: u16;
match get_bitrate(mp3_header, &audio_version, &layer) {
Some(rate) => bitrate = rate,
None => break,
None => {println!("BITRATE NO"); break},
}
println!("bitrate is {}", bitrate);
@ -519,7 +527,7 @@ pub fn rip_mp3(data: &[u8], start_index: usize) -> Option<Position> {
let sampling_rate: u16;
match get_sampling_rate(mp3_header, &audio_version) {
Some(rate) => sampling_rate = rate,
None => break,
None => {println!("SAMPLING RATE NO"); break},
}
println!("sampling rate is {}", sampling_rate);
@ -535,18 +543,22 @@ pub fn rip_mp3(data: &[u8], start_index: usize) -> Option<Position> {
println!("padding is {}", padding);
// finally calculate frame size
let frame_size: u32;
let slot_size: u32;
match layer {
LayerIndex::LayerI => {
frame_size = (12 * bitrate as u32 * 1000 / sampling_rate as u32 + padding as u32) * 4;
}
LayerIndex::LayerI => slot_size = 4,
_ => slot_size = 1,
}
LayerIndex::LayerII | LayerIndex::LayerIII => {
frame_size = 144 * bitrate as u32 * 1000 / (sampling_rate as u32 + padding as u32);
}
let multiplier: u32;
match layer {
LayerIndex::LayerI => multiplier = 12,
_ => multiplier = 144000,
}
let slot_count: u32 = ((multiplier as u32 * (bitrate as u32 * 1000)) / sampling_rate as u32) + padding as u32;
// finally calculate frame size
let frame_size: u32 = slot_count * slot_size;
println!("frame size is {}", frame_size);
// set cursor to the next frame

32
src/main.rs
Unescape View File

@ -141,9 +141,7 @@ fn main() {
}
else if file_paths.len() == 0 && &args[arg_index].to_lowercase() == "audio" {
rip_type = RipType::AUDIO;
println!("[INFO] Not implemented");
return;
// println!("Ripping AUDIO (MP3)");
println!("Ripping AUDIO (MP3)");
}
else {
// that's a path to the file to be examined
@ -249,20 +247,20 @@ fn main() {
RipType::AUDIO => {
// find MP3 positions
// let mut cursor_index = 0;
// while (cursor_index as u64) < file_metadata.len() {
// match rip_mp3(&file_contents, cursor_index) {
// Some(pos) => {
// cursor_index = pos.end;
// println!("b {:?}", pos);
// positions.push(pos);
// }
// None => {
// // no MP3s were found
// break;
// }
// }
// }
let mut cursor_index = 0;
while (cursor_index as u64) < file_metadata.len() {
match rip_mp3(&file_contents, cursor_index) {
Some(pos) => {
cursor_index = pos.end;
println!("b {:?}", pos);
positions.push(pos);
}
None => {
// no MP3s were found
break;
}
}
}
}

Write Preview
Loading…
Cancel
Save