fast demod bin

[m17rt] / m17core / src / decode.rs

diff --git a/m17core/src/decode.rs b/m17core/src/decode.rs
old mode 100755 (executable)
new mode 100644 (file)
index 7ec2224..3195ed5
--- a/m17core/src/decode.rs
+++ b/m17core/src/decode.rs
@@ -3,8 +3,8 @@ use crate::{
     fec::{self, p_1, p_2, p_3},
     interleave::interleave,
     protocol::{
-        LsfFrame, PacketFrame, PacketFrameCounter, StreamFrame, BERT_SYNC, LSF_SYNC, PACKET_SYNC,
-        STREAM_SYNC,
+        BERT_SYNC, END_OF_TRANSMISSION, LSF_SYNC, LsfFrame, PACKET_SYNC, PREAMBLE, PacketFrame,
+        PacketFrameCounter, STREAM_SYNC, StreamFrame,
     },
     random::random_xor,
 };
@@ -33,6 +33,8 @@ pub(crate) enum SyncBurst {
     Bert,
     Stream,
     Packet,
+    Preamble,
+    EndOfTransmission,
 }
 
 impl SyncBurst {
@@ -42,6 +44,8 @@ impl SyncBurst {
             Self::Bert => BERT_SYNC,
             Self::Stream => STREAM_SYNC,
             Self::Packet => PACKET_SYNC,
+            Self::Preamble => PREAMBLE,
+            Self::EndOfTransmission => END_OF_TRANSMISSION,
         }
     }
 }
@@ -54,17 +58,18 @@ pub(crate) fn sync_burst_correlation(target: [i8; 8], samples: &[f32]) -> (f32,
     let mut pos_max: f32 = f32::MIN;
     let mut neg_max: f32 = f32::MAX;
     for i in 0..8 {
-        pos_max = pos_max.max(samples[i * 10]);
-        neg_max = neg_max.min(samples[i * 10]);
+        pos_max = pos_max.max(samples[i]);
+        neg_max = neg_max.min(samples[i]);
     }
     let gain = (pos_max - neg_max) / 2.0;
     let shift = pos_max + neg_max;
     if gain < SYNC_MIN_GAIN {
         return (f32::MAX, gain, shift);
     }
+
     let mut diff = 0.0;
     for i in 0..8 {
-        let sym_diff = (((samples[i * 10] - shift) / gain) - target[i] as f32).abs();
+        let sym_diff = (((samples[i] - shift) / gain) - target[i] as f32).abs();
         if sym_diff > SYNC_BIT_THRESHOLD {
             return (f32::MAX, gain, shift);
         }
@@ -86,15 +91,15 @@ pub(crate) fn frame_initial_decode(frame: &[f32] /* length 192 */) -> [u8; 46] {
     interleave(&decoded[2..])
 }
 
-pub(crate) fn parse_lsf(frame: &[f32] /* length 192 */) -> Option<LsfFrame> {
+pub(crate) fn parse_lsf(frame: &[f32] /* length 192 */) -> Option<(LsfFrame, u8)> {
     let deinterleaved = frame_initial_decode(frame);
     debug!("deinterleaved: {:?}", deinterleaved);
-    let lsf = match fec::decode(&deinterleaved, 240, p_1) {
-        Some(lsf) => LsfFrame(lsf),
+    let (lsf, errors) = match fec::decode(&deinterleaved, 240, p_1) {
+        Some((lsf, errors)) => (LsfFrame(lsf), errors),
         None => return None,
     };
     debug!("full lsf: {:?}", lsf.0);
-    let crc = lsf.crc();
+    let crc = lsf.check_crc();
     debug!("recv crc: {:04X}", crc);
     debug!("destination: {:?}", lsf.destination());
     debug!("source: {:?}", lsf.source());
@@ -103,16 +108,13 @@ pub(crate) fn parse_lsf(frame: &[f32] /* length 192 */) -> Option<LsfFrame> {
     debug!("encryption type: {:?}", lsf.encryption_type());
     debug!("can: {}", lsf.channel_access_number());
     debug!("meta: {:?}", lsf.meta());
-    Some(lsf)
+    Some((lsf, errors))
 }
 
-pub(crate) fn parse_stream(frame: &[f32] /* length 192 */) -> Option<StreamFrame> {
+pub(crate) fn parse_stream(frame: &[f32] /* length 192 */) -> Option<(StreamFrame, u8)> {
     let deinterleaved = frame_initial_decode(frame);
     let stream_part = &deinterleaved[12..];
-    let stream = match fec::decode(stream_part, 144, p_2) {
-        Some(stream) => stream,
-        None => return None,
-    };
+    let (stream, errors) = fec::decode(stream_part, 144, p_2)?;
     let frame_num = u16::from_be_bytes([stream[0], stream[1]]);
     let eos = (frame_num & 0x8000) > 0;
     let frame_num = frame_num & 0x7fff; // higher layer has to handle wraparound
@@ -123,26 +125,26 @@ pub(crate) fn parse_stream(frame: &[f32] /* length 192 */) -> Option<StreamFrame
             "LICH: received part {counter} part {part:?} from raw {:?}",
             &deinterleaved[0..12]
         );
-        Some(StreamFrame {
-            lich_idx: counter,
-            lich_part: part,
-            frame_number: frame_num,
-            end_of_stream: eos,
-            stream_data: stream[2..18].try_into().unwrap(),
-        })
+        Some((
+            StreamFrame {
+                lich_idx: counter,
+                lich_part: part,
+                frame_number: frame_num,
+                end_of_stream: eos,
+                stream_data: stream[2..18].try_into().unwrap(),
+            },
+            errors,
+        ))
     } else {
         None
     }
 }
 
-pub(crate) fn parse_packet(frame: &[f32] /* length 192 */) -> Option<PacketFrame> {
+pub(crate) fn parse_packet(frame: &[f32] /* length 192 */) -> Option<(PacketFrame, u8)> {
     let deinterleaved = frame_initial_decode(frame);
-    let packet = match fec::decode(&deinterleaved, 206, p_3) {
-        Some(packet) => packet,
-        None => return None,
-    };
+    let (packet, errors) = fec::decode(&deinterleaved, 206, p_3)?;
     let final_frame = (packet[25] & 0x80) > 0;
-    let number = (packet[25] >> 2) & 0x01f;
+    let number = (packet[25] >> 2) & 0x1f;
     let counter = if final_frame {
         PacketFrameCounter::FinalFrame {
             payload_len: number as usize,
@@ -152,10 +154,13 @@ pub(crate) fn parse_packet(frame: &[f32] /* length 192 */) -> Option<PacketFrame
             index: number as usize,
         }
     };
-    Some(PacketFrame {
-        payload: packet[0..25].try_into().unwrap(),
-        counter,
-    })
+    Some((
+        PacketFrame {
+            payload: packet[0..25].try_into().unwrap(),
+            counter,
+        },
+        errors,
+    ))
 }
 
 pub(crate) fn decode_lich(type2_bits: &[u8]) -> Option<(u8, [u8; 5])> {