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dts: use a single core sample-rate table

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Matthew Jackson
2026-09-29 19:10:26 -07:00
parent eb185797ca
commit c981655851
1 changed files with 6 additions and 15 deletions
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src/mux/codec/dts.rs
+6 -15
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@@ -638,18 +638,6 @@ fn dts_core_frame_size(data: &[u8]) -> usize {
fsize + 1
}
/// DTS core `SFREQ` → sample rate (Hz). 4-bit index; reserved/invalid entries
/// fall back to 48 kHz (the DVD/UHD norm) so a bogus value never yields a zero
/// rate (division) or a wildly wrong frame duration.
const DTS_CORE_SAMPLE_RATES: [u32; 16] = [
48_000, // 0: invalid → fallback
8_000, 16_000, 32_000, 48_000, // 4: invalid → fallback
48_000, // 5: invalid → fallback
11_025, 22_050, 44_100, 48_000, // 9: invalid → fallback
48_000, // 10: invalid → fallback
12_000, 24_000, 48_000, 96_000, 192_000,
];
// Samples per DTS core frame: `(NBLKS + 1) * 32`. NBLKS (7 bits, ETSI TS 102 114) = byte4 bit0
// + byte5 bits7-2, after FTYPE/SHORT/CPF.
fn dts_core_samples(data: &[u8]) -> u32 {
@@ -660,14 +648,17 @@ fn dts_core_samples(data: &[u8]) -> u32 {
(nblks + 1) * 32
}
/// DTS core sample rate (Hz) from `SFREQ` (4 bits: byte8 bits5-2), with a 48 kHz
/// fallback for reserved indices.
/// DTS core sample rate (Hz) from `SFREQ` (4 bits: byte8 bits5-2); reserved
/// indices fall back to 48 kHz so the rate is never zero.
fn dts_core_sample_rate(data: &[u8]) -> u32 {
if data.len() < CORE_HEADER_MIN_BYTES {
return 48_000;
}
let sfreq = (data[8] as usize >> 2) & 0x0F;
DTS_CORE_SAMPLE_RATES[sfreq]
match DTS_CORE_SR_VALID[sfreq] {
0 => 48_000,
r => r,
}
}
/// Duration of one DTS core access unit in nanoseconds: `samples / rate`,