Commit 976f7f42 authored by Marco's avatar Marco

VP8: For high overshoot, force drop frame and max-out QP.

This allows rate control to react to content of current frame being encoded.
Enabling this feature via the setting: screen_content_mode = 2.

Change-Id: Ib2c6670551d96f4907495d5b7b76bb8c49e673db
parent 37d03809
......@@ -587,7 +587,8 @@ static void cyclic_background_refresh(VP8_COMP *cpi, int Q, int lf_adjustment)
// Turn-off under certain conditions (i.e., away from key frame, and if
// we are at good quality (low Q) and most of the blocks were skipped-encoded
// in previous frame.
if (Q >= 100) {
int qp_thresh = (cpi->oxcf.screen_content_mode == 2) ? 80 : 100;
if (Q >= qp_thresh) {
cpi->cyclic_refresh_mode_max_mbs_perframe =
(cpi->common.mb_rows * cpi->common.mb_cols) / 10;
} else if (cpi->frames_since_key > 250 &&
......@@ -2011,6 +2012,8 @@ struct VP8_COMP* vp8_create_compressor(VP8_CONFIG *oxcf)
cpi->source_alt_ref_active = 0;
cpi->common.refresh_alt_ref_frame = 0;
cpi->force_maxqp = 0;
cpi->b_calculate_psnr = CONFIG_INTERNAL_STATS;
#if CONFIG_INTERNAL_STATS
cpi->b_calculate_ssimg = 0;
......@@ -4184,7 +4187,10 @@ static void encode_frame_to_data_rate
*/
if (cpi->cyclic_refresh_mode_enabled)
{
if (cpi->current_layer==0)
// Special case for screen_content_mode with golden frame updates.
int disable_cr_gf = (cpi->oxcf.screen_content_mode == 2 &&
cm->refresh_golden_frame);
if (cpi->current_layer == 0 && cpi->force_maxqp == 0 && !disable_cr_gf)
cyclic_background_refresh(cpi, Q, 0);
else
disable_segmentation(cpi);
......@@ -4406,6 +4412,11 @@ static void encode_frame_to_data_rate
/* transform / motion compensation build reconstruction frame */
vp8_encode_frame(cpi);
if (cpi->oxcf.screen_content_mode == 2) {
if (vp8_drop_encodedframe_overshoot(cpi, Q))
return;
}
cpi->projected_frame_size -= vp8_estimate_entropy_savings(cpi);
cpi->projected_frame_size = (cpi->projected_frame_size > 0) ? cpi->projected_frame_size : 0;
#endif
......
......@@ -526,6 +526,8 @@ typedef struct VP8_COMP
// Measure of average squared difference between source and denoised signal.
int mse_source_denoised;
int force_maxqp;
#if CONFIG_MULTITHREAD
/* multithread data */
int * mt_current_mb_col;
......
......@@ -1215,6 +1215,11 @@ int vp8_regulate_q(VP8_COMP *cpi, int target_bits_per_frame)
{
int Q = cpi->active_worst_quality;
if (cpi->force_maxqp == 1) {
cpi->active_worst_quality = cpi->worst_quality;
return cpi->worst_quality;
}
/* Reset Zbin OQ value */
cpi->mb.zbin_over_quant = 0;
......@@ -1559,3 +1564,44 @@ int vp8_pick_frame_size(VP8_COMP *cpi)
}
return 1;
}
// If this just encoded frame (mcomp/transform/quant, but before loopfilter and
// pack_bitstream) has large overshoot, and was not being encoded close to the
// max QP, then drop this frame and force next frame to be encoded at max QP.
// Condition this on 1 pass CBR with screen content mode and frame dropper off.
// TODO(marpan): Should do this exit condition during the encode_frame
// (i.e., halfway during the encoding of the frame) to save cycles.
int vp8_drop_encodedframe_overshoot(VP8_COMP *cpi, int Q) {
if (cpi->pass == 0 &&
cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER &&
cpi->drop_frames_allowed == 0 &&
cpi->common.frame_type != KEY_FRAME) {
// 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
// that projected_frame_size is somewhat greater than per-frame-bandwidth,
// but add additional condition with high threshold on prediction residual.
// QP threshold: only allow dropping if we are not close to qp_max.
int thresh_qp = 3 * cpi->worst_quality >> 2;
// Rate threshold, in bytes.
int thresh_rate = 2 * (cpi->av_per_frame_bandwidth >> 3);
// Threshold for the average (over all macroblocks) of the pixel-sum
// residual error over 16x16 block. Should add QP dependence on threshold?
int thresh_pred_err_mb = (256 << 4);
int pred_err_mb = cpi->mb.prediction_error / cpi->common.MBs;
if (Q < thresh_qp &&
cpi->projected_frame_size > thresh_rate &&
pred_err_mb > thresh_pred_err_mb) {
// Drop this frame: advance frame counters, and set force_maxqp flag.
cpi->common.current_video_frame++;
cpi->frames_since_key++;
// Flag to indicate we will force next frame to be encoded at max QP.
cpi->force_maxqp = 1;
return 1;
} else {
cpi->force_maxqp = 0;
return 0;
}
return 0;
}
return 0;
}
......@@ -30,6 +30,8 @@ extern void vp8_compute_frame_size_bounds(VP8_COMP *cpi, int *frame_under_shoot_
/* return of 0 means drop frame */
extern int vp8_pick_frame_size(VP8_COMP *cpi);
extern int vp8_drop_encodedframe_overshoot(VP8_COMP *cpi, int Q);
#ifdef __cplusplus
} // extern "C"
#endif
......
......@@ -199,7 +199,7 @@ static vpx_codec_err_t validate_config(vpx_codec_alg_priv_t *ctx,
RANGE_CHECK_HI(vp8_cfg, arnr_strength, 6);
RANGE_CHECK(vp8_cfg, arnr_type, 1, 3);
RANGE_CHECK(vp8_cfg, cq_level, 0, 63);
RANGE_CHECK_BOOL(vp8_cfg, screen_content_mode);
RANGE_CHECK_HI(vp8_cfg, screen_content_mode, 2);
if (finalize && (cfg->rc_end_usage == VPX_CQ || cfg->rc_end_usage == VPX_Q))
RANGE_CHECK(vp8_cfg, cq_level,
cfg->rc_min_quantizer, cfg->rc_max_quantizer);
......
......@@ -326,6 +326,8 @@ enum vp8e_enc_control_id {
VP8E_SET_TEMPORAL_LAYER_ID,
/*!\brief Codec control function to set encoder screen content mode.
*
* 0: off, 1: On, 2: On with more aggressive rate control.
*
* Supported in codecs: VP8
*/
......
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