rtc: Condition QP adjustment on rc->q_1/2_frame > 0
This fix only affects the initial QPs after very first
frame for TL enhancement frames in CBR mode.
Move the check that rc->q_1/2_frame is set to the top
of the adjustment logic, otherwise if there are dropped
frames after the very first frame, the QP can end up
with oscillation on temporal enhancement frames.
Because of some further logic/adjustments this
behavior would likely only happen when the TL enhancement
frame_bandwidth is not smaller then TL0 frame_bandwidth.
Bug: b/343429192
Change-Id: I121934c2c7e7522e4e40762191ed3005437841c2
diff --git a/av1/encoder/ratectrl.c b/av1/encoder/ratectrl.c
index af707be..86dbdca 100644
--- a/av1/encoder/ratectrl.c
+++ b/av1/encoder/ratectrl.c
@@ -588,18 +588,19 @@
// Apply some control/clamp to QP under certain conditions.
// Delay the use of the clamping for svc until after num_temporal_layers,
// to make they have been set for each temporal layer.
+ // Check for rc->q_1/2_frame > 0 in case they have not been set due to
+ // dropped frames.
if (!frame_is_intra_only(cm) && rc->frames_since_key > 1 &&
+ rc->q_1_frame > 0 && rc->q_2_frame > 0 &&
(!cpi->ppi->use_svc ||
svc->current_superframe > (unsigned int)svc->number_temporal_layers) &&
!change_target_bits_mb && !cpi->rc.rtc_external_ratectrl &&
(!cpi->oxcf.rc_cfg.gf_cbr_boost_pct ||
!(refresh_frame->alt_ref_frame || refresh_frame->golden_frame))) {
// If in the previous two frames we have seen both overshoot and undershoot
- // clamp Q between the two. Check for rc->q_1/2_frame > 0 in case they have
- // not been set due to dropped frames.
+ // clamp Q between the two.
if (rc->rc_1_frame * rc->rc_2_frame == -1 &&
- rc->q_1_frame != rc->q_2_frame && rc->q_1_frame > 0 &&
- rc->q_2_frame > 0 && !overshoot_buffer_low) {
+ rc->q_1_frame != rc->q_2_frame && !overshoot_buffer_low) {
int qclamp = clamp(q, AOMMIN(rc->q_1_frame, rc->q_2_frame),
AOMMAX(rc->q_1_frame, rc->q_2_frame));
// If the previous frame had overshoot and the current q needs to
