From 989193c797722dd2a37d481ab7cbd01a5d37270f Mon Sep 17 00:00:00 2001 From: Alex Converse Date: Thu, 8 Oct 2015 16:01:42 -0700 Subject: Make the zero handling in extend_to_full_distribution more explicit. The old workaround "p = 0 ? 0 : p -1" is misleading. ?: happens before = assigning back to p truncates to one byte. Therefore it is equivalent to (p - 1) & 0xFF, but the check just exists to work around a first pass bug, so let's make the work around more clear. https://bugs.chromium.org/p/webm/issues/detail?id=1089 Change-Id: I587c44dd61c1f3767543c0126376f881889935af --- vp10/common/entropy.c | 5 +++-- vp10/common/entropy.h | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) (limited to 'vp10') diff --git a/vp10/common/entropy.c b/vp10/common/entropy.c index 56dd73a4a..3da08a61b 100644 --- a/vp10/common/entropy.c +++ b/vp10/common/entropy.c @@ -403,7 +403,6 @@ const vpx_prob vp10_pareto8_full[COEFF_PROB_MODELS][MODEL_NODES] = { {255, 241, 243, 255, 236, 255, 252, 254}, {255, 243, 245, 255, 237, 255, 252, 254}, {255, 246, 247, 255, 239, 255, 253, 255}, - {255, 246, 247, 255, 239, 255, 253, 255}, }; static const vp10_coeff_probs_model default_coef_probs_4x4[PLANE_TYPES] = { @@ -743,7 +742,9 @@ static const vp10_coeff_probs_model default_coef_probs_32x32[PLANE_TYPES] = { }; static void extend_to_full_distribution(vpx_prob *probs, vpx_prob p) { - memcpy(probs, vp10_pareto8_full[p = 0 ? 0 : p - 1], + // TODO(aconverse): model[PIVOT_NODE] should never be zero. + // https://code.google.com/p/webm/issues/detail?id=1089 + memcpy(probs, vp10_pareto8_full[p == 0 ? 254 : p - 1], MODEL_NODES * sizeof(vpx_prob)); } diff --git a/vp10/common/entropy.h b/vp10/common/entropy.h index fba7020a5..2f93cb31c 100644 --- a/vp10/common/entropy.h +++ b/vp10/common/entropy.h @@ -153,7 +153,7 @@ static INLINE const uint8_t *get_band_translate(TX_SIZE tx_size) { // 1, 3, 5, 7, ..., 253, 255 // In between probabilities are interpolated linearly -#define COEFF_PROB_MODELS 256 +#define COEFF_PROB_MODELS 255 #define UNCONSTRAINED_NODES 3 -- cgit v1.2.3