vp8: Increase rate correction threshold for drop-overshoot

For 1 pass cbr encoding mode, with frame-dropping on:
increase the rate correction threshold for drop-overshoot detection,
to better capture cases of large overshoot.

Change-Id: I1153b1b71cf106749dd985074d6bc8f37d163c7e

diff --git a/vp8/encoder/ratectrl.c b/vp8/encoder/ratectrl.c
index fc833bccc9445ef08eb12caeb7f6fc8669e0860a..ce07a6f197f3b2261e5f894b22282f6ae94caf56 100644 (file)
--- a/vp8/encoder/ratectrl.c
+++ b/vp8/encoder/ratectrl.c
@@ -1464,7 +1464,7 @@ int vp8_drop_encodedframe_overshoot(VP8_COMP *cpi, int Q) {
       (cpi->oxcf.screen_content_mode == 2 ||
        (cpi->drop_frames_allowed &&
         (force_drop_overshoot ||
-         (cpi->rate_correction_factor < (4.0f * MIN_BPB_FACTOR) &&
+         (cpi->rate_correction_factor < (8.0f * MIN_BPB_FACTOR) &&
           cpi->frames_since_last_drop_overshoot > (int)cpi->framerate))))) {
     // Note: the "projected_frame_size" from encode_frame() only gives estimate
     // of mode/motion vector rate (in non-rd mode): so below we only require