From f79769c541eb7235b09625cb084dfdfe6069cb96 Mon Sep 17 00:00:00 2001 From: Andree Buschmann Date: Sun, 8 May 2011 19:36:08 +0000 Subject: Minor loop optimization in libfaad's is/ms decoding. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29837 a1c6a512-1295-4272-9138-f99709370657 --- apps/codecs/libfaad/ms.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'apps/codecs/libfaad/ms.c') diff --git a/apps/codecs/libfaad/ms.c b/apps/codecs/libfaad/ms.c index f01e5caa07..b42e95a408 100644 --- a/apps/codecs/libfaad/ms.c +++ b/apps/codecs/libfaad/ms.c @@ -41,7 +41,6 @@ void ms_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec, uint16_t nshort = frame_len/8; uint16_t i, k; - real_t tmp; if (ics->ms_mask_present >= 1) { @@ -58,12 +57,12 @@ void ms_decode(ic_stream *ics, ic_stream *icsr, real_t *l_spec, real_t *r_spec, if ((ics->ms_used[g][sfb] || ics->ms_mask_present == 2) && !is_intensity(icsr, g, sfb) && !is_noise(ics, g, sfb)) { - for (i = ics->swb_offset[sfb]; i < ics->swb_offset[sfb+1]; i++) + k = (group*nshort) + ics->swb_offset[sfb]; + for (i = ics->swb_offset[sfb]; i < ics->swb_offset[sfb+1]; i++, k++) { - k = (group*nshort) + i; - tmp = l_spec[k] - r_spec[k]; + /* L' = L+R, R' = L-R */ l_spec[k] = l_spec[k] + r_spec[k]; - r_spec[k] = tmp; + r_spec[k] = l_spec[k] - (r_spec[k]<<1); } } } -- cgit v1.2.3