Mirror/squeezelite-esp32
1
0
Fork 0
mirror of https://github.com/sle118/squeezelite-esp32.git synced 2025-12-08 04:27:12 +03:00
Code Issues Packages Projects Releases Wiki Activity

Tweak 32 bits mode (enable 20 bits spdif)

Browse Source
This commit is contained in:
Philippe G
2021-03-05 22:13:20 -08:00
parent b3ff717d32
commit 6d45f6d1b6
3 changed files with 21 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
components/squeezelite/output_i2s.c
View File

@@ -541,7 +541,7 @@ static void *output_thread_i2s(void *arg) {
if (spdif) {
spdif_convert((ISAMPLE_T*) obuf, oframes, (u32_t*) sbuf, &count);
i2s_write(CONFIG_I2S_NUM, sbuf, oframes * 16, &bytes, portMAX_DELAY);
bytes /= 4;
bytes /= 16 / BYTES_PER_FRAME;
#if BYTES_PER_FRAME == 4
} else if (i2s_config.bits_per_sample == 32) {
i2s_write_expand(CONFIG_I2S_NUM, obuf, oframes * BYTES_PER_FRAME, 16, 32, &bytes, portMAX_DELAY);
@@ -621,8 +621,9 @@ extern const u16_t spdif_bmclookup[256];
*/
void spdif_convert(ISAMPLE_T *src, size_t frames, u32_t *dst, size_t *count) {
u16_t hi, lo, aux;
register size_t cnt = *count;
// frames are 2 channels of 16 bits
// frames are 2 channels of 16/32 bits
frames *= 2;
while (frames--) {
@@ -631,28 +632,38 @@ void spdif_convert(ISAMPLE_T *src, size_t frames, u32_t *dst, size_t *count) {
lo = spdif_bmclookup[(u8_t) *src];
#else
hi = spdif_bmclookup[(u8_t)(*src >> 24)];
lo = spdif_bmclookup[(u8_t) *src >> 16];
lo = spdif_bmclookup[(u8_t)(*src >> 16)];
#endif
// invert if last preceeding bit is 1
lo ^= ~((s16_t)hi) >> 16;
// 16 bits sample:
// first 16 bits
*(dst+0) = ((u32_t)lo << 16) | hi;
// 4 bits auxillary-audio-databits, the first used as parity
#if BYTES_PER_FRAME == 4
aux = 0xb333 ^ (((u32_t)((s16_t)lo)) >> 17);
#else
// we use 20 bits samples as we need to force parity
aux = spdif_bmclookup[(u8_t)(*src >> 12)];
aux = (u8_t) (aux ^ (~((s16_t)lo) >> 16));
aux |= (0xb3 ^ (((u16_t)((s8_t)aux)) >> 9)) << 8;
#endif
// VUCP-Bits: Valid, Subcode, Channelstatus, Parity = 0
// As parity is always 0, we can use fixed preambles
if (++(*count) > 383) {
if (++cnt > 383) {
*(dst+1) = VUCP | (PREAMBLE_B << 16 ) | aux; //special preamble for one of 192 frames
*count = 0;
cnt = 0;
} else {
*(dst+1) = VUCP | ((((*count) & 0x01) ? PREAMBLE_W : PREAMBLE_M) << 16) | aux;
*(dst+1) = VUCP | (((cnt & 0x01) ? PREAMBLE_W : PREAMBLE_M) << 16) | aux;
}
src++;
dst += 2;
}
*count = cnt;
}
const u16_t spdif_bmclookup[256] = { //biphase mark encoded values (least significant bit first)