ffmpeg | branch: release/4.1 | Andreas Rheinhardt <andreas.rheinha...@gmail.com> | Mon Jan 20 20:20:42 2020 +0100| [68e67bb187657173354c233edd4db5f81ffdbf80] | committer: Andreas Rheinhardt
avcodec/adxenc: Avoid undefined left shift of negative numbers Replace "((a << shift) + b) >> shift" by "a + (b >> shift)". This avoids a left shift which also happens to trigger undefined behaviour in case "a" is negative. This affected the FATE-tests acodec-adpcm-adx and acodec-adpcm-adx-trellis; it also fixes ticket #8008. Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> (cherry picked from commit 59a9d65e0d790821f88527a82569f56eb2f8a9be) Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=68e67bb187657173354c233edd4db5f81ffdbf80 --- libavcodec/adxenc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/libavcodec/adxenc.c b/libavcodec/adxenc.c index f1ba5911b3..77f6bf0487 100644 --- a/libavcodec/adxenc.c +++ b/libavcodec/adxenc.c @@ -48,7 +48,7 @@ static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, s2 = prev->s2; for (i = 0, j = 0; j < 32; i += channels, j++) { s0 = wav[i]; - d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; + d = s0 + ((-c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS); if (max < d) max = d; if (min > d) @@ -79,13 +79,13 @@ static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, s1 = prev->s1; s2 = prev->s2; for (i = 0, j = 0; j < 32; i += channels, j++) { - d = ((wav[i] << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; + d = wav[i] + ((-c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS); d = av_clip_intp2(ROUNDED_DIV(d, scale), 3); put_sbits(&pb, 4, d); - s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS; + s0 = d * scale + ((c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS); s2 = s1; s1 = s0; } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
