The relevant sections from the RFC are:
Sec.6. Integer Wrap-Around in Inverse Gain Computation
32-bit integer overflow in Levinson recursion. Affects
silk_is_lpc_stable().
Sec.8. Cap on Band Energy
NaN due to large log-energy value. Affects celt_denormalize().
Signed-off-by: Andrew D'Addesio <modchip...@gmail.com>
---
libavcodec/opus_celt.c | 3 ++-
libavcodec/opus_silk.c | 11 +++++++++--
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/libavcodec/opus_celt.c b/libavcodec/opus_celt.c
index 84d4847..ff56041 100644
--- a/libavcodec/opus_celt.c
+++ b/libavcodec/opus_celt.c
@@ -481,7 +481,8 @@ static void celt_denormalize(CeltFrame *f, CeltBlock
*block, float *data)
for (i = f->start_band; i < f->end_band; i++) {
float *dst = data + (ff_celt_freq_bands[i] << f->size);
- float norm = exp2f(block->energy[i] + ff_celt_mean_energy[i]);
+ float log_norm = block->energy[i] + ff_celt_mean_energy[i];
+ float norm = exp2f(FFMIN(log_norm, 32.0f));
for (j = 0; j < ff_celt_freq_range[i] << f->size; j++)
dst[j] *= norm;
diff --git a/libavcodec/opus_silk.c b/libavcodec/opus_silk.c
index 3c9c849..344333c 100644
--- a/libavcodec/opus_silk.c
+++ b/libavcodec/opus_silk.c
@@ -185,8 +185,15 @@ static inline int silk_is_lpc_stable(const int16_t
lpc[16], int order)
row = lpc32[k & 1];
for (j = 0; j < k; j++) {
- int x = prevrow[j] - ROUND_MULL(prevrow[k - j - 1], rc, 31);
- row[j] = ROUND_MULL(x, gain, fbits);
+ int x = av_sat_sub32(prevrow[j], ROUND_MULL(prevrow[k - j - 1],
rc, 31));
+ int64_t tmp = ROUND_MULL(x, gain, fbits);
+
+ /* per RFC 8251 section 6, if this calculation overflows, the
filter
+ is considered unstable. */
+ if (tmp < INT32_MIN || tmp > INT32_MAX)
+ return 0;
+
+ row[j] = (int32_t)tmp;
}
}
}
--
2.15.1.windows.2
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