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  • Paul Wilkins's avatar
    Minor rate control refactoring and experiments. · 97da8b8c
    Paul Wilkins authored 
    Some minor refactoring code relating to estimates of
bits per MB at a given Q and estimating the allowed Q range.

Most of the changes here were included in a previous commit.
This commit seeks to separate out the refactoring from more
the material changes.

Two #define control flags have been added for experimentation.

ONE_SHOT_Q_ESTIMATE force the two pass encoder to
use its initial Q range estimate for the whole clip even if this results
in a miss on the target data rate. In effect this tightens the Q range
seen at the expense of rate control accuracy.

DISABLE_RC_LONG_TERM_MEM is a related flag that disables the
long term memory in the rate control. Local adjustments are still
made to try and better hit the rate target on a per frame basis but
the impact of rate control misses is not propagated to the remainder
of the clip. This means that for example an overshoot early on will not
cause frames later in the clip to be starved of bits. Again the result
of this relaxation amy be less rate control accuracy especially on short
clips.

The flags are disabled by default for now.

Change-Id: I7482f980146d8ea033b5d50cc689f772e4bd119e
    97da8b8c
vp9_ratectrl.h 1.38 KiB
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/*
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 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
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 *
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 *  Use of this source code is governed by a BSD-style license
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 *  that can be found in the LICENSE file in the root of the source
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 *  tree. An additional intellectual property rights grant can be found
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 *  in the file PATENTS.  All contributing project authors may
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 *  be found in the AUTHORS file in the root of the source tree.
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 */
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#ifndef VP9_ENCODER_VP9_RATECTRL_H_
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#define VP9_ENCODER_VP9_RATECTRL_H_
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#include "vp9/encoder/vp9_onyx_int.h"
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#define FRAME_OVERHEAD_BITS 200
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void vp9_save_coding_context(VP9_COMP *cpi);
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void vp9_restore_coding_context(VP9_COMP *cpi);
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void vp9_setup_key_frame(VP9_COMP *cpi);
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void vp9_update_rate_correction_factors(VP9_COMP *cpi, int damp_var);
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int vp9_regulate_q(VP9_COMP *cpi, int target_bits_per_frame);
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void vp9_adjust_key_frame_context(VP9_COMP *cpi);
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void vp9_compute_frame_size_bounds(VP9_COMP *cpi,
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                                   int *frame_under_shoot_limit,
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                                   int *frame_over_shoot_limit);
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// return of 0 means drop frame
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int vp9_pick_frame_size(VP9_COMP *cpi);
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double vp9_convert_qindex_to_q(int qindex);
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int vp9_gfboost_qadjust(int qindex);
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extern int vp9_bits_per_mb(FRAME_TYPE frame_type, int qindex,
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                           double correction_factor);
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void vp9_setup_inter_frame(VP9_COMP *cpi);
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#endif  // VP9_ENCODER_VP9_RATECTRL_H_
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