zqz/platform-external-webrtc
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix for integer overflow in NetEq.

Browse Source 
BUG=chromium:668736

Review-Url: https://codereview.webrtc.org/2571483002
Cr-Commit-Position: refs/heads/master@{#15654}
This commit is contained in:
ivoc
2016-12-16 05:51:49 -08:00
committed by Commit bot
parent 70f39a30e9
commit ffecbbf5d0
3 changed files with 38 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
webrtc/modules/audio_coding/neteq/expand.cc
View File

@ -675,12 +675,20 @@ void Expand::AnalyzeSignal(int16_t* random_vector) {
parameters.ar_filter,
kUnvoicedLpcOrder + 1,
128);
int16_t unvoiced_prescale;
if (WebRtcSpl_MaxAbsValueW16(unvoiced_vector, 128) > 4000) {
unvoiced_prescale = 4;
} else {
unvoiced_prescale = 0;
}
const int unvoiced_max_abs = [&] {
const int16_t max_abs = WebRtcSpl_MaxAbsValueW16(unvoiced_vector, 128);
// Since WebRtcSpl_MaxAbsValueW16 returns 2^15 - 1 when the input contains
// -2^15, we have to conservatively bump the return value by 1
// if it is 2^15 - 1.
return max_abs == WEBRTC_SPL_WORD16_MAX ? max_abs + 1 : max_abs;
}();
// Pick the smallest n such that 2^n > unvoiced_max_abs; then the maximum
// value of the dot product is less than 2^7 * 2^(2*n) = 2^(2*n + 7), so to
// prevent overflows we want 2n + 7 <= 31, which means we should shift by
// 2n + 7 - 31 bits, if this value is greater than zero.
int unvoiced_prescale =
std::max(0, 2 * WebRtcSpl_GetSizeInBits(unvoiced_max_abs) - 24);
int32_t unvoiced_energy = WebRtcSpl_DotProductWithScale(unvoiced_vector,
unvoiced_vector,
128,