diff options
| -rw-r--r-- | src/frontend/Util_Audio.cpp | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/src/frontend/Util_Audio.cpp b/src/frontend/Util_Audio.cpp index 02b3026..25e04db 100644 --- a/src/frontend/Util_Audio.cpp +++ b/src/frontend/Util_Audio.cpp @@ -63,21 +63,28 @@ int AudioOut_GetNumSamples(int outlen) void AudioOut_Resample(s16* inbuf, int inlen, s16* outbuf, int outlen, int volume) { - float res_incr = inlen / (float)outlen; - float res_timer = 0; - int res_pos = 0; + double factor = (double) inlen / (double) outlen; + double inpos = -(factor / 2); + double vol = (double) volume / 256.f; - for (int i = 0; i < outlen; i++) + for (int i = 0; i < outlen * 2; i += 2) { - outbuf[i*2 ] = (inbuf[res_pos*2 ] * volume) >> 8; - outbuf[i*2+1] = (inbuf[res_pos*2+1] * volume) >> 8; - - res_timer += res_incr; - while (res_timer >= 1.0) - { - res_timer -= 1.0; - res_pos++; - } + double intpart_d; + double frac = modf(inpos, &intpart_d); + int intpart = (int) intpart_d; + + double l1 = inbuf[ intpart * 2]; + double l2 = inbuf[(intpart * 2) + 2]; + double r1 = inbuf[(intpart * 2) + 1]; + double r2 = inbuf[(intpart * 2) + 3]; + + double ldiff = l2 - l1; + double rdiff = r2 - r1; + + outbuf[i] = (s16) round((l1 + ldiff * frac) * vol); + outbuf[i+1] = (s16) round((r1 + rdiff * frac) * vol); + + inpos += factor; } } |