From 2799c29792ebaa7c01e22457013000fecb18169e Mon Sep 17 00:00:00 2001 From: "Timothy B. Terriberry" Date: Tue, 1 Feb 2011 12:53:05 -0800 Subject: [PATCH] Add assertions for band size restrictions. The way folding is implemented requires two restrictions: 1. The last band must be the largest (so we can use its size to allocate a temporary buffer to handle interleaving/TF changes). 2. No band can be larger than twice the size of the previous band (so that once we have enough data to start folding, we will always have enough data to fold). Mode creation makes a heuristic attempt to satisfy these conditions, but nothing actually guarantees it. This adds some asserts to check them during mode creation. They current pass for all supported custom modes. --- libcelt/modes.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/libcelt/modes.c b/libcelt/modes.c index c5302b7a..ddb50714 100644 --- a/libcelt/modes.c +++ b/libcelt/modes.c @@ -196,6 +196,14 @@ static celt_int16 *compute_ebands(celt_int32 Fs, int frame_size, int res, int *n eBands[++j]=eBands[i+1]; *nbEBands=j; + for (i=1;i<*nbEBands;i++) + { + /* Every band must be smaller than the last band. */ + celt_assert(eBands[i]-eBands[i-1]<=eBands[*nbEBands]-eBands[*nbEBands-1]); + /* Each band must be no larger than twice the size of the previous one. */ + celt_assert(eBands[i+1]-eBands[i]<=2*(eBands[i]-eBands[i-1])); + } + /*for (i=0;i<=*nbEBands+1;i++) printf ("%d ", eBands[i]); printf ("\n");