Files
meshcore-sar_android/lib/utils/voice_message_parser.dart
2026-03-01 11:00:30 +01:00

368 lines
11 KiB
Dart

import 'dart:convert';
import 'dart:typed_data';
/// Identifies which Codec2 mode was used for a voice packet.
/// Matches the modeId byte in the text/binary packet header.
enum VoicePacketMode {
mode700c(0, '700C'),
mode1200(1, '1200'),
mode2400(2, '2400'),
mode1300(3, '1300'),
mode1400(4, '1400'),
mode1600(5, '1600'),
mode3200(6, '3200');
const VoicePacketMode(this.id, this.label);
final int id;
final String label;
static VoicePacketMode fromId(int id) => VoicePacketMode.values.firstWhere(
(m) => m.id == id,
orElse: () => VoicePacketMode.mode1300,
);
}
/// A single Codec2-encoded chunk belonging to a multi-packet voice session.
///
/// Text format (channels):
/// V:{sessionId8hex}:{modeId}:{index}/{total}:{base64Codec2}
///
/// Binary format (direct contacts, received via pushRawData):
/// [0x56 'V'][sessionId:4B][modeId:1B][index:1B][total:1B][codec2Data...]
class VoicePacket {
final String sessionId; // 8 hex chars (4 bytes)
final VoicePacketMode mode;
final int index; // 0-based
final int total; // total packet count
final Uint8List codec2Data;
const VoicePacket({
required this.sessionId,
required this.mode,
required this.index,
required this.total,
required this.codec2Data,
});
// ── Text (channel) format ────────────────────────────────────────────────
static const String _textPrefix = 'V:';
static bool isVoiceText(String text) => text.startsWith(_textPrefix);
/// Parse a text-format voice packet. Returns null on failure.
static VoicePacket? tryParseText(String text) {
if (!text.startsWith(_textPrefix)) return null;
try {
final body = text.substring(_textPrefix.length);
final parts = body.split(':');
// parts: [sessionId, modeId, 'idx/total', base64data]
if (parts.length != 4) return null;
final sessionId = parts[0];
if (sessionId.length != 8) return null;
final modeId = int.tryParse(parts[1]);
if (modeId == null) return null;
final indexTotal = parts[2].split('/');
if (indexTotal.length != 2) return null;
final index = int.tryParse(indexTotal[0]);
final total = int.tryParse(indexTotal[1]);
if (index == null || total == null || total < 1) return null;
final codec2Data = base64.decode(parts[3]);
return VoicePacket(
sessionId: sessionId,
mode: VoicePacketMode.fromId(modeId),
index: index,
total: total,
codec2Data: codec2Data,
);
} catch (_) {
return null;
}
}
/// Encode as text (channel format). Max ~198 chars for 700C/1200/2400.
String encodeText() {
final b64 = base64.encode(codec2Data);
return 'V:$sessionId:${mode.id}:$index/$total:$b64';
}
// ── Binary format ────────────────────────────────────────────────────────
static const int _binaryMagic = 0x56; // 'V'
static const int _binaryHeaderLen =
8; // magic(1)+session(4)+mode(1)+idx(1)+total(1)
static bool isVoiceBinary(Uint8List payload) =>
payload.isNotEmpty && payload[0] == _binaryMagic;
/// Parse binary-format voice packet (from pushRawData payload).
static VoicePacket? tryParseBinary(Uint8List payload) {
if (payload.length < _binaryHeaderLen) return null;
if (payload[0] != _binaryMagic) return null;
try {
final sessionBytes = payload.sublist(1, 5);
final sessionId = sessionBytes
.map((b) => b.toRadixString(16).padLeft(2, '0'))
.join();
final modeId = payload[5];
final index = payload[6];
final total = payload[7];
if (total < 1) return null;
final codec2Data = payload.sublist(_binaryHeaderLen);
return VoicePacket(
sessionId: sessionId,
mode: VoicePacketMode.fromId(modeId),
index: index,
total: total,
codec2Data: codec2Data,
);
} catch (_) {
return null;
}
}
/// Encode as binary payload (for cmdSendRawData).
Uint8List encodeBinary() {
final sessionBytes = Uint8List(4);
for (var i = 0; i < 4; i++) {
sessionBytes[i] = int.parse(
sessionId.substring(i * 2, i * 2 + 2),
radix: 16,
);
}
final out = Uint8List(_binaryHeaderLen + codec2Data.length);
out[0] = _binaryMagic;
out.setRange(1, 5, sessionBytes);
out[5] = mode.id;
out[6] = index;
out[7] = total;
out.setRange(_binaryHeaderLen, out.length, codec2Data);
return out;
}
// ── Duration helpers ─────────────────────────────────────────────────────
/// Estimated audio duration of this packet in milliseconds.
int get durationMs {
// bytesPerSecond for each mode
final bps = switch (mode) {
VoicePacketMode.mode700c => 100,
VoicePacketMode.mode1200 => 150,
VoicePacketMode.mode1300 => 175,
VoicePacketMode.mode1400 => 175,
VoicePacketMode.mode1600 => 200,
VoicePacketMode.mode2400 => 300,
VoicePacketMode.mode3200 => 400,
};
if (bps == 0) return 0;
return (codec2Data.length * 1000 ~/ bps).clamp(0, 1500);
}
@override
String toString() =>
'VoicePacket($sessionId ${mode.label} [$index/${total - 1}] ${codec2Data.length}B)';
}
/// Lightweight public/direct message envelope advertising voice availability.
///
/// Text format:
/// VE1:{sid}:{mode}:{total}:{durMs}:{senderKey6}:{ts}:{ver}
/// Example:
/// VE1:00112233:1:4:3200:aabbccddeeff:1234567890:1
class VoiceEnvelope {
static const String _prefix = 'VE1:';
final String sessionId;
final VoicePacketMode mode;
final int total;
final int durationMs;
final String senderKey6;
final int timestampSec;
final int version;
const VoiceEnvelope({
required this.sessionId,
required this.mode,
required this.total,
required this.durationMs,
required this.senderKey6,
required this.timestampSec,
this.version = 1,
});
static bool isVoiceEnvelopeText(String text) => text.startsWith(_prefix);
static VoiceEnvelope? tryParseText(String text) {
if (!isVoiceEnvelopeText(text)) return null;
final body = text.substring(_prefix.length);
return _tryParseCompact(body);
}
static VoiceEnvelope? _tryParseCompact(String body) {
final parts = body.split(':');
if (parts.length != 7) return null;
try {
final sid = parts[0];
final mode = int.tryParse(parts[1]);
final total = int.tryParse(parts[2]);
final durMs = int.tryParse(parts[3]);
final senderKey6 = parts[4];
final ts = int.tryParse(parts[5]);
final ver = int.tryParse(parts[6]);
if (!RegExp(r'^[0-9a-fA-F]{8}$').hasMatch(sid)) {
return null;
}
if (mode == null || mode < 0 || mode >= VoicePacketMode.values.length) {
return null;
}
if (total == null || total < 1 || total > 255) return null;
if (durMs == null || durMs < 0 || durMs > 10 * 60 * 1000) return null;
if (!RegExp(r'^[0-9a-fA-F]{12}$').hasMatch(senderKey6)) {
return null;
}
if (ts == null || ts <= 0) return null;
if (ver == null || ver != 1) return null;
return VoiceEnvelope(
sessionId: sid.toLowerCase(),
mode: VoicePacketMode.fromId(mode),
total: total,
durationMs: durMs,
senderKey6: senderKey6.toLowerCase(),
timestampSec: ts,
version: ver,
);
} catch (_) {
return null;
}
}
String encodeText() {
return '$_prefix${sessionId.toLowerCase()}:${mode.id}:$total:$durationMs:${senderKey6.toLowerCase()}:$timestampSec:$version';
}
}
/// Direct control-plane request to fetch voice packets for a session.
///
/// Text format:
/// VR1:{sid}:{want}:{requesterKey6}:{ts}:{ver}
/// Example:
/// VR1:00112233:a:aabbccddeeff:1234567890:1
class VoiceFetchRequest {
static const String _prefix = 'VR1:';
final String sessionId;
final String want;
final String requesterKey6;
final int timestampSec;
final int version;
const VoiceFetchRequest({
required this.sessionId,
this.want = 'all',
required this.requesterKey6,
required this.timestampSec,
this.version = 1,
});
static bool isVoiceFetchRequestText(String text) => text.startsWith(_prefix);
static VoiceFetchRequest? tryParseText(String text) {
if (!isVoiceFetchRequestText(text)) return null;
final body = text.substring(_prefix.length);
return _tryParseCompact(body);
}
static VoiceFetchRequest? _tryParseCompact(String body) {
final parts = body.split(':');
if (parts.length != 5) return null;
try {
final sid = parts[0];
final wantToken = parts[1];
final requesterKey6 = parts[2];
final ts = int.tryParse(parts[3]);
final ver = int.tryParse(parts[4]);
final normalizedWant = wantToken == 'a' ? 'all' : wantToken;
if (!RegExp(r'^[0-9a-fA-F]{8}$').hasMatch(sid)) {
return null;
}
if (normalizedWant != 'all') return null;
if (!RegExp(r'^[0-9a-fA-F]{12}$').hasMatch(requesterKey6)) {
return null;
}
if (ts == null || ts <= 0) return null;
if (ver == null || ver != 1) return null;
return VoiceFetchRequest(
sessionId: sid.toLowerCase(),
want: normalizedWant,
requesterKey6: requesterKey6.toLowerCase(),
timestampSec: ts,
version: ver,
);
} catch (_) {
return null;
}
}
String encodeText() {
final wantToken = want == 'all' ? 'a' : want;
return '$_prefix${sessionId.toLowerCase()}:$wantToken:${requesterKey6.toLowerCase()}:$timestampSec:$version';
}
}
/// Builds a compact visual waveform from real voice packet bytes.
///
/// Note: This uses the encoded Codec2 packet bytes as the source so it works
/// even before full PCM decode/playback is available.
class VoiceWaveform {
static List<double> buildBarsFromPackets(
Iterable<VoicePacket?> packets, {
int bars = 24,
}) {
if (bars <= 0) return const [];
final merged = <int>[];
for (final pkt in packets) {
if (pkt == null || pkt.codec2Data.isEmpty) continue;
merged.addAll(pkt.codec2Data);
}
if (merged.isEmpty) return List<double>.filled(bars, 0.0);
final out = List<double>.filled(bars, 0.0);
for (var i = 0; i < bars; i++) {
final start = (i * merged.length) ~/ bars;
var end = ((i + 1) * merged.length) ~/ bars;
if (end <= start) end = start + 1;
if (end > merged.length) end = merged.length;
var sum = 0.0;
for (var j = start; j < end; j++) {
final centered = (merged[j] - 128).abs();
sum += centered / 127.0;
}
out[i] = (sum / (end - start)).clamp(0.0, 1.0);
}
// Light smoothing to avoid jittery adjacent bars.
if (bars > 2) {
final smoothed = List<double>.from(out);
for (var i = 1; i < bars - 1; i++) {
smoothed[i] = ((out[i - 1] + out[i] + out[i + 1]) / 3.0).clamp(
0.0,
1.0,
);
}
return smoothed;
}
return out;
}
}