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| author | Fraunhofer IIS FDK <audio-fdk@iis.fraunhofer.de> | 2019-09-20 14:00:27 +0200 |
|---|---|---|
| committer | Jean-Michel Trivi <jmtrivi@google.com> | 2019-10-15 15:48:32 -0700 |
| commit | 1b4a3bedbb9d512c929c2fa191cc44c8dae8bce9 (patch) | |
| tree | 8e9e5760716f808d767220536ac20f33fc5c268a /libAACdec | |
| parent | 40d2a1d8b055ebe17b67195029029ecdc5bc3268 (diff) | |
| download | fdk-aac-1b4a3bedbb9d512c929c2fa191cc44c8dae8bce9.tar.gz fdk-aac-1b4a3bedbb9d512c929c2fa191cc44c8dae8bce9.tar.bz2 fdk-aac-1b4a3bedbb9d512c929c2fa191cc44c8dae8bce9.zip | |
Overcome potential integer overflows in M/S module for complex prediction.
Bug: 131430997
Test: atest DecoderTestXheAac ; atest DecoderTestAacDrc
Change-Id: Ic0648203b6a61ebff8bcc93c4b1099e033bc6860
Diffstat (limited to 'libAACdec')
| -rw-r--r-- | libAACdec/src/stereo.cpp | 40 |
1 files changed, 15 insertions, 25 deletions
diff --git a/libAACdec/src/stereo.cpp b/libAACdec/src/stereo.cpp index a90ae35..47f1a31 100644 --- a/libAACdec/src/stereo.cpp +++ b/libAACdec/src/stereo.cpp @@ -989,7 +989,7 @@ void CJointStereo_ApplyMS( } /* if ( pJointStereoData->complex_coef == 1 ) */ /* 4. upmix process */ - INT pred_dir = cplxPredictionData->pred_dir ? -1 : 1; + LONG pred_dir = cplxPredictionData->pred_dir ? -1 : 1; /* 0.1 in Q-3.34 */ const FIXP_DBL pointOne = 0x66666666; /* 0.8 */ /* Shift value for the downmix */ @@ -1039,34 +1039,24 @@ void CJointStereo_ApplyMS( the downmix. "dmx_re" and "specL" are two different pointers pointing to separate arrays, which may or may not contain the same data (with different scaling). - */ - - /* help1: alpha_re[i] * dmx_re[i] */ - FIXP_DBL help1 = fMultDiv2(alpha_re_tmp, *p2dmxRe++); - - /* tmp: dmx_im[i] */ - FIXP_DBL tmp = (*p2dmxIm++) << shift_dmx; - /* help2: alpha_im[i] * dmx_im[i] */ - FIXP_DBL help2 = fMultDiv2(alpha_im_tmp, tmp); - - /* help3: alpha_re[i] * dmx_re[i] + alpha_im[i] * dmx_im[i] */ - FIXP_DBL help3 = help1 + help2; + specL[i] = + (specL[i] + side); + specR[i] = -/+ (specL[i] - side); + */ + FIXP_DBL side, left, right; - /* side (= help4) = specR[i] - (dmx_re[i] * specL[i] + alpha_im[i] - * * dmx_im[i]) */ - FIXP_DBL help4 = *p2CoeffR - scaleValue(help3, help3_shift); + side = fMultAddDiv2(fMultDiv2(alpha_re_tmp, *p2dmxRe++), + alpha_im_tmp, (*p2dmxIm++) << shift_dmx); + side = ((*p2CoeffR) >> 2) - + (FIXP_DBL)SATURATE_SHIFT(side, -(help3_shift - 2), + DFRACT_BITS - 2); - /* We calculate the left and right output by using the helper - * function */ - /* specR[i] = -/+ (specL[i] - side); */ - *p2CoeffR = - (FIXP_DBL)((LONG)(*p2CoeffL - help4) * (LONG)pred_dir); - p2CoeffR++; + left = ((*p2CoeffL) >> 2) + side; + right = ((*p2CoeffL) >> 2) - side; + right = (FIXP_DBL)((LONG)right * pred_dir); - /* specL[i] = specL[i] + side; */ - *p2CoeffL = *p2CoeffL + help4; - p2CoeffL++; + *p2CoeffL++ = SATURATE_LEFT_SHIFT_ALT(left, 2, DFRACT_BITS); + *p2CoeffR++ = SATURATE_LEFT_SHIFT_ALT(right, 2, DFRACT_BITS); } } |