Qmode: Change how qp adjusted to delta_q_res
av1_adjust_q_from_delta_q_res adjusts per SB qp depending on the qp
indices of the last SB. For each centroid it could end up being rounded
up or rounded down, which leads to more than 8 qp indices for each
frame.
Instead, just round the centroids closer to frame qp, with the offset to
be multiple of delta_q_res.
Bug: b/256852795
Change-Id: Idfee62d443715bcd388e26bc5ad20c887116d99a
diff --git a/av1/qmode_rc/ratectrl_qmode.cc b/av1/qmode_rc/ratectrl_qmode.cc
index 901a19c..9370774 100644
--- a/av1/qmode_rc/ratectrl_qmode.cc
+++ b/av1/qmode_rc/ratectrl_qmode.cc
@@ -1460,11 +1460,12 @@
std::unordered_map<int, int> qindex_centroids = internal::KMeans(
superblock_q_indices, rc_param_.max_distinct_q_indices_per_frame);
for (size_t i = 0; i < superblock_q_indices.size(); ++i) {
- const int last_sb_qindex =
- i == 0 ? param.q_index : superblock_q_indices[i - 1];
- const int adjusted_qindex = av1_adjust_q_from_delta_q_res(
- 4, last_sb_qindex,
- qindex_centroids.find(superblock_q_indices[i])->second);
+ const int curr_sb_qindex =
+ qindex_centroids.find(superblock_q_indices[i])->second;
+ const int delta_q_res = 4;
+ const int adjusted_qindex =
+ param.q_index +
+ (curr_sb_qindex - param.q_index) / delta_q_res * delta_q_res;
const int rd_mult = GetRDMult(gop_frame, adjusted_qindex);
param.superblock_encode_params.push_back(
{ static_cast<uint8_t>(adjusted_qindex), rd_mult });
