On Sat, 27 Oct 2012, Mans Rullgard wrote:
Subtracting a (positive) value from the address of an array violates C99 section 6.5.6:If both the pointer operand and the result point to elements of the same array object, or one past the last element of the array object, the evaluation shall not produce an overflow; otherwise, the behavior is undefined. Signed-off-by: Mans Rullgard <m...@mansr.com> --- libavcodec/amrwbdec.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/libavcodec/amrwbdec.c b/libavcodec/amrwbdec.c index 5cc96ab..c9c793f 100644 --- a/libavcodec/amrwbdec.c +++ b/libavcodec/amrwbdec.c @@ -902,10 +902,9 @@ static float auto_correlation(float *diff_isf, float mean, int lag) static void extrapolate_isf(float isf[LP_ORDER_16k]) { float diff_isf[LP_ORDER - 2], diff_mean; - float *diff_hi = diff_isf - LP_ORDER + 1; // diff array for extrapolated indexes float corr_lag[3]; float est, scale; - int i, i_max_corr; + int i, j, i_max_corr; isf[LP_ORDER_16k - 1] = isf[LP_ORDER - 1]; @@ -936,20 +935,20 @@ static void extrapolate_isf(float isf[LP_ORDER_16k]) scale = 0.5 * (FFMIN(est, 7600) - isf[LP_ORDER - 2]) / (isf[LP_ORDER_16k - 2] - isf[LP_ORDER - 2]); - for (i = LP_ORDER - 1; i < LP_ORDER_16k - 1; i++) - diff_hi[i] = scale * (isf[i] - isf[i - 1]); + for (i = LP_ORDER - 1, j = 0; i < LP_ORDER_16k - 1; i++, j++) + diff_isf[j] = scale * (isf[i] - isf[i - 1]); /* Stability insurance */ - for (i = LP_ORDER; i < LP_ORDER_16k - 1; i++) - if (diff_hi[i] + diff_hi[i - 1] < 5.0) { - if (diff_hi[i] > diff_hi[i - 1]) { - diff_hi[i - 1] = 5.0 - diff_hi[i]; + for (i = 1; i < LP_ORDER_16k - LP_ORDER; i++) + if (diff_isf[i] + diff_isf[i - 1] < 5.0) { + if (diff_isf[i] > diff_isf[i - 1]) { + diff_isf[i - 1] = 5.0 - diff_isf[i]; } else - diff_hi[i] = 5.0 - diff_hi[i - 1]; + diff_isf[i] = 5.0 - diff_isf[i - 1]; } - for (i = LP_ORDER - 1; i < LP_ORDER_16k - 1; i++) - isf[i] = isf[i - 1] + diff_hi[i] * (1.0f / (1 << 15)); + for (i = LP_ORDER - 1, j = 0; i < LP_ORDER_16k - 1; i++, j++) + isf[i] = isf[i - 1] + diff_isf[j] * (1.0f / (1 << 15)); /* Scale the ISF vector for 16000 Hz */ for (i = 0; i < LP_ORDER_16k - 1; i++) -- 1.7.12.4
Ok // Martin _______________________________________________ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
