/****************************************************************************** * * Copyright (C) 2018 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * ***************************************************************************** * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore */ /*! ****************************************************************************** * \file cbr_buffer_control.c * * \brief * This file contains all functions needed for cbr buffer control * \date * 06/05/2008 * * \author * ittiam * * \List of Functions * init_cbr_buffer * cbr_buffer_constraint_check * get_cbr_buffer_status * update_cbr_buffer * ****************************************************************************** */ /*****************************************************************************/ /* File Includes */ /*****************************************************************************/ /* System include files */ #include /* User include files */ #include "assert.h" #include "ittiam_datatypes.h" #include "rc_cntrl_param.h" #include "rc_common.h" #include "mem_req_and_acq.h" #include "fixed_point_error_bits.h" #include "cbr_buffer_control.h" #include "trace_support.h" #include "var_q_operator.h" #define MIN(x, y) ((x) < (y)) ? (x) : (y) /*allow a maximum of 20 percent deviation when input is very large*/ #define VBR_MAX_BIT_DEV_SEC 50LL typedef struct cbr_buffer_t { WORD32 i4_buffer_size; /* Buffer size = Delay * Bitrate*/ WORD32 i4_drain_bits_per_frame[MAX_NUM_DRAIN_RATES]; /* Constant drain rate */ WORD32 i4_ebf; /* Encoder Buffer Fullness */ LWORD64 i8_ebf_bit_alloc; /* current encoder buffer fulness that accounts precise bit consumption (not truncated to max buffer size at skip)*/ LWORD64 i8_credit_level; WORD32 i4_upr_thr[MAX_PIC_TYPE]; /* Upper threshold of the Buffer */ WORD32 i4_low_thr[MAX_PIC_TYPE]; /* Lower threshold of the Buffer */ error_bits_handle aps_bpf_error_bits[MAX_NUM_DRAIN_RATES]; /* For error due to bits per frame calculation */ WORD32 i4_is_cbr_mode; /* Whether the buffer model is used for CBR or VBR streaming */ /* Input parameters stored for initialisation */ WORD32 ai4_bit_rate[MAX_NUM_DRAIN_RATES]; WORD32 i4_max_delay; WORD32 ai4_num_pics_in_delay_period[MAX_PIC_TYPE]; WORD32 i4_tgt_frm_rate; UWORD32 u4_max_vbv_buf_size; WORD32 i4_peak_drain_rate_frame; WORD32 u4_num_frms_in_delay; UWORD32 u4_vbr_max_bit_deviation; rc_type_e e_rc_type; WORD32 i4_vbr_no_peak_rate_duration_limit; LWORD64 i8_tot_frm_to_be_encoded; LWORD64 i8_num_frames_encoded; /*need to track the number of frames encoded to calculate possible deviaiton allowed*/ WORD32 i4_cbr_rc_pass; WORD32 i4_inter_frame_int; WORD32 i4_intra_frame_int; WORD32 i4_capped_vbr_on; float f_max_dur_peak_rate; LWORD64 i4_ebf_estimate; } cbr_buffer_t; #if NON_STEADSTATE_CODE WORD32 cbr_buffer_num_fill_use_free_memtab( cbr_buffer_t **pps_cbr_buffer, itt_memtab_t *ps_memtab, ITT_FUNC_TYPE_E e_func_type) { WORD32 i4_mem_tab_idx = 0, i; static cbr_buffer_t s_cbr_buffer_temp; /* Hack for al alloc, during which we dont have any state memory. Dereferencing can cause issues */ if(e_func_type == GET_NUM_MEMTAB || e_func_type == FILL_MEMTAB) (*pps_cbr_buffer) = &s_cbr_buffer_temp; if(e_func_type != GET_NUM_MEMTAB) { fill_memtab( &ps_memtab[i4_mem_tab_idx], sizeof(cbr_buffer_t), MEM_TAB_ALIGNMENT, PERSISTENT, DDR); use_or_fill_base(&ps_memtab[0], (void **)pps_cbr_buffer, e_func_type); } i4_mem_tab_idx++; for(i = 0; i < MAX_NUM_DRAIN_RATES; i++) { i4_mem_tab_idx += error_bits_num_fill_use_free_memtab( &pps_cbr_buffer[0]->aps_bpf_error_bits[i], &ps_memtab[i4_mem_tab_idx], e_func_type); } return (i4_mem_tab_idx); } static void set_upper_lower_vbv_threshold(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_bits_per_frm) { WORD32 i; for(i = 0; i < MAX_PIC_TYPE; i++) { ps_cbr_buffer->i4_upr_thr[i] = (WORD32)(((LWORD64)ps_cbr_buffer->i4_buffer_size >> 4) * UPPER_THRESHOLD_EBF_Q4); if(ps_cbr_buffer->e_rc_type == VBR_STREAMING) { /*lower threshold can be zero as there is no problem of studffing in this mode (VBR STORAGE)*/ if(ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit) ps_cbr_buffer->i4_low_thr[i] = 0; else ps_cbr_buffer->i4_low_thr[i] = ps_cbr_buffer->i4_inter_frame_int * i4_bits_per_frm; } else { if(ps_cbr_buffer->i4_inter_frame_int == 1) ps_cbr_buffer->i4_low_thr[i] = 0; else { ps_cbr_buffer->i4_low_thr[i] = ps_cbr_buffer->i4_inter_frame_int * i4_bits_per_frm; } } /*For huge buffer low limit can be higher*/ if(ps_cbr_buffer->i4_low_thr[i] < (ps_cbr_buffer->i4_buffer_size >> 6)) ps_cbr_buffer->i4_low_thr[i] = (ps_cbr_buffer->i4_buffer_size >> 6); if(ps_cbr_buffer->i4_low_thr[i] > (ps_cbr_buffer->i4_buffer_size >> 3)) //KISH_DEBUG ps_cbr_buffer->i4_low_thr[i] = (ps_cbr_buffer->i4_buffer_size >> 3); ASSERT(ps_cbr_buffer->i4_upr_thr[i] > ps_cbr_buffer->i4_low_thr[i]); } } /* ******************************************************************************/ /** * @brief Initialise the CBR VBV buffer state. * This could however be used for VBR streaming VBV also * * @param ps_cbr_buffer * @param i4_buffer_delay * @param i4_tgt_frm_rate * @param i4_bit_rate * @param u4_num_pics_in_delay_prd * @param u4_vbv_buf_size */ /* ******************************************************************************/ void init_cbr_buffer( cbr_buffer_t *ps_cbr_buffer, WORD32 i4_buffer_delay, WORD32 i4_tgt_frm_rate, UWORD32 u4_bit_rate, UWORD32 *u4_num_pics_in_delay_prd, UWORD32 u4_vbv_buf_size, UWORD32 u4_intra_frm_int, rc_type_e e_rc_type, UWORD32 u4_peak_bit_rate, UWORD32 u4_num_frames_in_delay, float f_max_dur_peak_rate, LWORD64 i8_num_frames_to_encode, WORD32 i4_inter_frm_int, WORD32 i4_cbr_rc_pass, WORD32 i4_capped_vbr_flag) { WORD32 i4_bits_per_frm[MAX_NUM_DRAIN_RATES]; int i; /* Initially Encoder buffer fullness is zero */ ps_cbr_buffer->i4_ebf = 0; ps_cbr_buffer->i4_ebf_estimate = 0; ps_cbr_buffer->i8_ebf_bit_alloc = 0; ps_cbr_buffer->i8_credit_level = 0; ps_cbr_buffer->e_rc_type = e_rc_type; ps_cbr_buffer->i4_capped_vbr_on = i4_capped_vbr_flag; /*If this is set to 1, it acts similar to storage VBR which allows peak rate to be sustained for infinite duration*/ ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit = 0; ps_cbr_buffer->i8_num_frames_encoded = 0; ps_cbr_buffer->i8_tot_frm_to_be_encoded = i8_num_frames_to_encode; ps_cbr_buffer->i4_cbr_rc_pass = i4_cbr_rc_pass; ps_cbr_buffer->i4_inter_frame_int = i4_inter_frm_int; ps_cbr_buffer->i4_intra_frame_int = u4_intra_frm_int; ps_cbr_buffer->f_max_dur_peak_rate = f_max_dur_peak_rate; for(i = 0; i < MAX_NUM_DRAIN_RATES; i++) { X_PROD_Y_DIV_Z(u4_bit_rate, 1000, i4_tgt_frm_rate, i4_bits_per_frm[i]); /* Drain rate = bitrate/(framerate/1000) */ ps_cbr_buffer->i4_drain_bits_per_frame[i] = i4_bits_per_frm[i]; /* initialise the bits per frame error bits calculation */ init_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i], i4_tgt_frm_rate, u4_bit_rate); } /* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/ if(e_rc_type == CBR_NLDRC) /* This would mean CBR mode */ { //buffer size should be independent of initial delay //X_PROD_Y_DIV_Z(u4_bit_rate,i4_buffer_delay,1000,ps_cbr_buffer->i4_buffer_size); ps_cbr_buffer->i4_buffer_size = (WORD32)u4_vbv_buf_size; ps_cbr_buffer->i4_is_cbr_mode = 1; ps_cbr_buffer->i4_peak_drain_rate_frame = i4_bits_per_frm[0]; /*In CBR the max file size deviaiton allowed is specified by buffer size*/ ps_cbr_buffer->u4_vbr_max_bit_deviation = ps_cbr_buffer->i4_buffer_size; } else if(e_rc_type == VBR_STREAMING) { /*this is raw vbv buffer size, also initilize the buffer window to bit alloc (credit limit)*/ ps_cbr_buffer->i4_buffer_size = (WORD32)u4_vbv_buf_size; /*if there is no limit on duration for which peak bitrate can be sustained, bits can be moved from any region to other region giving better quality*/ if(f_max_dur_peak_rate < 0) ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit = 1; /*To avoid file size deviation in case of VBR mode of rate control, clip the max deviaiton allowed based on number of frames to enode*/ { ULWORD64 u8_vbr_max_bit_deviation; ULWORD64 file_size = (ULWORD64)( (((LWORD64)u4_bit_rate * 1000) / i4_tgt_frm_rate) * i8_num_frames_to_encode); /*When f_max_dur_peak_rate is -ve, it implies user is not worried about duration for which peak is sustained, hence go with max possible value*/ if(f_max_dur_peak_rate > 0) u8_vbr_max_bit_deviation = (ULWORD64)(f_max_dur_peak_rate * u4_bit_rate); else u8_vbr_max_bit_deviation = (ULWORD64)(VBR_MAX_BIT_DEV_SEC * u4_bit_rate); /*when num frames to encode is negative is -ve it implies total frames data is not available (as in case of live encoding)*/ if(i8_num_frames_to_encode > 0) { /*allow atleast one second deviation or 12% of total file size whichever is higher*/ if(u8_vbr_max_bit_deviation > (file_size >> 3)) u8_vbr_max_bit_deviation = (UWORD32)(file_size >> 3); /*allow atleast one second for shorter sequence*/ if(u8_vbr_max_bit_deviation < u4_bit_rate) u8_vbr_max_bit_deviation = u4_bit_rate; } else { /*the data of number of frames to be encoded is not available*/ /*start off with one second delay, this will be later adjusted once large number of frames are encoded*/ u8_vbr_max_bit_deviation = u4_bit_rate; } ps_cbr_buffer->u4_vbr_max_bit_deviation = u8_vbr_max_bit_deviation; } ps_cbr_buffer->i4_is_cbr_mode = 0; X_PROD_Y_DIV_Z( u4_peak_bit_rate, 1000, i4_tgt_frm_rate, ps_cbr_buffer->i4_peak_drain_rate_frame); } else { /*currently only two modes are supported*/ ASSERT(e_rc_type == CONST_QP); } if(ps_cbr_buffer->i4_buffer_size > (WORD32)u4_vbv_buf_size) { ps_cbr_buffer->i4_buffer_size = u4_vbv_buf_size; } /* Uppr threshold for I frame = 1 * bits per frame P Frame = 4 * bits per frame. The threshold for I frame is only 1 * bits per frame as the threshold should only account for error in estimated bits. In P frame it should account for difference bets bits consumed by I(Scene change) and P frame I to P complexity is assumed to be 5. */ /*HEVC_hierarchy*/ if(e_rc_type != CONST_QP) set_upper_lower_vbv_threshold(ps_cbr_buffer, i4_bits_per_frm[0]); /* Storing the input parameters for using it for change functions */ for(i = 0; i < MAX_NUM_DRAIN_RATES; i++) ps_cbr_buffer->ai4_bit_rate[i] = u4_bit_rate; for(i = 0; i < MAX_PIC_TYPE; i++) { ps_cbr_buffer->ai4_num_pics_in_delay_period[i] = u4_num_pics_in_delay_prd[i]; } ps_cbr_buffer->i4_tgt_frm_rate = i4_tgt_frm_rate; ps_cbr_buffer->i4_max_delay = i4_buffer_delay; ps_cbr_buffer->u4_max_vbv_buf_size = u4_vbv_buf_size; ps_cbr_buffer->u4_num_frms_in_delay = u4_num_frames_in_delay; } #endif /* #if NON_STEADSTATE_CODE */ /* ******************************************************************************/ /** * @brief Condition check for constrining the number of bits allocated based on bufer size * * @param ps_cbr_buffer * @param i4_tgt_bits * @param e_pic_type * * @return */ /* ******************************************************************************/ WORD32 cbr_buffer_constraint_check( cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tgt_bits, picture_type_e e_pic_type, WORD32 *pi4_max_tgt_bits, WORD32 *pi4_min_tgt_bits) { WORD32 i4_max_tgt_bits, i4_min_tgt_bits; WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC) ? ps_cbr_buffer->i4_drain_bits_per_frame[0] : ps_cbr_buffer->i4_drain_bits_per_frame[1]; WORD32 i4_error_bits = (e_pic_type == I_PIC) ? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0]) : get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]); /*trace_printf(" ebf = %d bebf = %d ",ps_cbr_buffer->i4_ebf,ps_cbr_buffer->i8_ebf_bit_alloc);*/ /* Max tgt bits = Upper threshold - current encoder buffer fullness */ i4_max_tgt_bits = (WORD32)(ps_cbr_buffer->i4_upr_thr[e_pic_type] - ps_cbr_buffer->i4_ebf_estimate); /* Max tgt bits cannot be negative */ if(i4_max_tgt_bits < 0) i4_max_tgt_bits = 0; /* Min tgt bits , least number of bits in the Encoder after draining such that it is greater than lower threshold */ i4_min_tgt_bits = (WORD32)( ps_cbr_buffer->i4_low_thr[e_pic_type] - (ps_cbr_buffer->i4_ebf_estimate - i4_drain_bits_per_frame - i4_error_bits)); /*Min tgt bits cannot be negative*/ if(i4_min_tgt_bits < 0) i4_min_tgt_bits = 0; /* current tgt bits should be between max and min tgt bits*/ CLIP(i4_tgt_bits, i4_max_tgt_bits, i4_min_tgt_bits); pi4_min_tgt_bits[0] = i4_min_tgt_bits; pi4_max_tgt_bits[0] = i4_max_tgt_bits; return i4_tgt_bits; } /* ******************************************************************************/ /** * @brief constaints the bit allocation based on buffer size * * @param ps_cbr_buffer * @param i4_tgt_bits * @param e_pic_type * * @return */ /* ******************************************************************************/ WORD32 vbr_stream_buffer_constraint_check( cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tgt_bits, picture_type_e e_pic_type, WORD32 *pi4_max_bits, WORD32 *pi4_min_bits) { WORD32 i4_max_tgt_bits, i4_min_tgt_bits = 0; /* Max tgt bits = Upper threshold - current encoder buffer fullness */ /*maximum target for a pic is amount of bits that can be transmitted to decoder buffer in delay assuming max drain rate This above limit has to be constrained wrt a single frame being accomodated in the buffer*/ i4_max_tgt_bits = (WORD32)( (ps_cbr_buffer->u4_num_frms_in_delay * ps_cbr_buffer->i4_peak_drain_rate_frame) - ps_cbr_buffer->i4_ebf_estimate); /*the below check is necessary to make sure that a single frame to be accomodated in encoder buffer*/ if(i4_max_tgt_bits > ps_cbr_buffer->i4_upr_thr[e_pic_type] - ps_cbr_buffer->i4_ebf_estimate) { i4_max_tgt_bits = (WORD32)(ps_cbr_buffer->i4_upr_thr[e_pic_type] - ps_cbr_buffer->i4_ebf_estimate); } /*In VBR streaming though encoder buffer underflow is not a problem, at any point of time the bitrate underconsumption cannot go below specified limit. Hence it is limited based on possible bitrate deviation allowed*/ /*Enabling movement of stuffing bits always*/ if(ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit) { /*If the content has underconsumed force it to consume atleast per frame bits so that end of encoding there wont be too much undersonsumption*/ if(ps_cbr_buffer->i8_ebf_bit_alloc < 0 && ps_cbr_buffer->i4_cbr_rc_pass != 2) i4_min_tgt_bits = (ps_cbr_buffer->i4_drain_bits_per_frame[0] >> 1); } else { /*In this case buffer is always guranteed to be positive, to avoid stuffing give decent amount of min bits*/ i4_min_tgt_bits = (WORD32)(ps_cbr_buffer->i4_low_thr[0] - ps_cbr_buffer->i8_ebf_bit_alloc); } /*Clip min target bit*/ if(i4_min_tgt_bits < 0) i4_min_tgt_bits = 0; if(i4_tgt_bits < i4_min_tgt_bits) i4_tgt_bits = i4_min_tgt_bits; pi4_min_bits[0] = i4_min_tgt_bits; /* Max tgt bits cannot be negative */ if(i4_max_tgt_bits < 0) i4_max_tgt_bits = 0; if(i4_tgt_bits > i4_max_tgt_bits) i4_tgt_bits = i4_max_tgt_bits; pi4_max_bits[0] = i4_max_tgt_bits; return i4_tgt_bits; } /* ******************************************************************************/ /** * @brief Verifies the buffer state and returns whether it is overflowing, underflowing or normal * * @param ps_cbr_buffer * @param i4_tot_consumed_bits * @param pi4_num_bits_to_prevent_overflow * @param e_pic_type * * @return */ /* ******************************************************************************/ vbv_buf_status_e get_cbr_buffer_status( cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tot_consumed_bits, WORD32 *pi4_num_bits_to_prevent_overflow, picture_type_e e_pic_type, rc_type_e e_rc_type) { vbv_buf_status_e e_buf_status; WORD32 i4_cur_enc_buf; WORD32 i4_error_bits = (e_pic_type == I_PIC) ? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0]) : get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]); WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC) ? ps_cbr_buffer->i4_drain_bits_per_frame[0] : ps_cbr_buffer->i4_drain_bits_per_frame[1]; /* Add the tot consumed bits to the Encoder Buffer*/ i4_cur_enc_buf = ps_cbr_buffer->i4_ebf + i4_tot_consumed_bits; /* If the Encoder exceeds the Buffer Size signal an Overflow*/ if(i4_cur_enc_buf > ps_cbr_buffer->i4_buffer_size) { e_buf_status = VBV_OVERFLOW; i4_cur_enc_buf = ps_cbr_buffer->i4_buffer_size; } else { /* Subtract the constant drain bits and error bits due to fixed point implementation*/ i4_cur_enc_buf -= (i4_drain_bits_per_frame + i4_error_bits); if(e_rc_type == VBR_STREAMING) { /*In VBR suffing scenerio will not occur*/ if(i4_cur_enc_buf < 0) i4_cur_enc_buf = 0; } /* If the buffer is less than stuffing threshold an Underflow is signaled else its NORMAL*/ if(i4_cur_enc_buf < 0) { e_buf_status = VBV_UNDERFLOW; } else { e_buf_status = VBV_NORMAL; } if(i4_cur_enc_buf < 0) i4_cur_enc_buf = 0; } /* The RC lib models the encoder buffer, but the VBV buffer characterises the decoder buffer */ if(e_buf_status == VBV_OVERFLOW) { e_buf_status = VBV_UNDERFLOW; } else if(e_buf_status == VBV_UNDERFLOW) { e_buf_status = VBV_OVERFLOW; } pi4_num_bits_to_prevent_overflow[0] = (ps_cbr_buffer->i4_buffer_size - i4_cur_enc_buf); return e_buf_status; } /* ******************************************************************************/ /** * @brief Based on the bits consumed the buffer model is updated * * @param ps_cbr_buffer * @param i4_tot_consumed_bits * @param e_pic_type */ /* ******************************************************************************/ void update_cbr_buffer( cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tot_consumed_bits, picture_type_e e_pic_type) { WORD32 i; WORD32 i4_error_bits = (e_pic_type == I_PIC) ? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0]) : get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]); WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC) ? ps_cbr_buffer->i4_drain_bits_per_frame[0] : ps_cbr_buffer->i4_drain_bits_per_frame[1]; ps_cbr_buffer->i8_num_frames_encoded++; if(ps_cbr_buffer->e_rc_type == VBR_STREAMING && ps_cbr_buffer->i8_tot_frm_to_be_encoded < 0) { LWORD64 i8_max_bit_dev_allowed = ps_cbr_buffer->ai4_bit_rate[0]; LWORD64 approx_file_size = ps_cbr_buffer->i8_num_frames_encoded * ps_cbr_buffer->ai4_bit_rate[0] * 1000 / ps_cbr_buffer->i4_tgt_frm_rate; if(i8_max_bit_dev_allowed < (approx_file_size >> 4)) i8_max_bit_dev_allowed = (approx_file_size >> 4); /*have a max limit so that bit dev does not grow for very long sequence like 24 hours of encoding (max can be 20 second)*/ if(i8_max_bit_dev_allowed > (VBR_MAX_BIT_DEV_SEC * ps_cbr_buffer->ai4_bit_rate[0])) i8_max_bit_dev_allowed = (VBR_MAX_BIT_DEV_SEC * ps_cbr_buffer->ai4_bit_rate[0]); ps_cbr_buffer->u4_max_vbv_buf_size = (UWORD32)i8_max_bit_dev_allowed; } /* Update the Encoder buffer with the total consumed bits*/ if(ps_cbr_buffer->i4_is_cbr_mode != 0) { ps_cbr_buffer->i4_ebf += i4_tot_consumed_bits; ps_cbr_buffer->i8_ebf_bit_alloc += i4_tot_consumed_bits; /* Subtract the drain bits and error bits due to fixed point implementation*/ ps_cbr_buffer->i4_ebf -= (i4_drain_bits_per_frame + i4_error_bits); ps_cbr_buffer->i8_ebf_bit_alloc -= (i4_drain_bits_per_frame + i4_error_bits); } else { ps_cbr_buffer->i4_ebf += i4_tot_consumed_bits; ps_cbr_buffer->i4_ebf -= ((MIN(ps_cbr_buffer->i4_peak_drain_rate_frame, ps_cbr_buffer->i4_ebf)) + i4_error_bits); ps_cbr_buffer->i8_ebf_bit_alloc += i4_tot_consumed_bits; ps_cbr_buffer->i8_ebf_bit_alloc -= (ps_cbr_buffer->i4_drain_bits_per_frame[0] + i4_error_bits); ps_cbr_buffer->i8_credit_level += i4_tot_consumed_bits; ps_cbr_buffer->i8_credit_level -= (ps_cbr_buffer->i4_drain_bits_per_frame[0] + i4_error_bits); /*To keep limit on duration for which peak rate can be sustained limit the accumulation of bits from simpler regions*/ if(!ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit) { if(ps_cbr_buffer->i8_ebf_bit_alloc < 0) ps_cbr_buffer->i8_ebf_bit_alloc = 0; /*This will make VBR buffer believe that the bits are lost*/ } } /*SS - Fix for lack of stuffing*/ if(ps_cbr_buffer->i4_ebf < 0) { //trace_printf("Error: Should not be coming here with bit stuffing \n"); ps_cbr_buffer->i4_ebf = 0; } if(ps_cbr_buffer->i4_ebf > ps_cbr_buffer->i4_buffer_size) { //trace_printf("Error: Frame should be skipped\n"); ps_cbr_buffer->i4_ebf = ps_cbr_buffer->i4_buffer_size; } ps_cbr_buffer->i4_ebf_estimate = ps_cbr_buffer->i4_ebf; trace_printf( "VBR ebf = %d bebf = %d ", ps_cbr_buffer->i4_ebf, ps_cbr_buffer->i8_ebf_bit_alloc); /* Update the error bits */ for(i = 0; i < MAX_NUM_DRAIN_RATES; i++) update_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i]); } /* ******************************************************************************/ /** * @brief If the buffer underflows then return the number of bits to prevent underflow * * @param ps_cbr_buffer * @param i4_tot_consumed_bits * @param e_pic_type * * @return */ /* ******************************************************************************/ WORD32 get_cbr_bits_to_stuff( cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tot_consumed_bits, picture_type_e e_pic_type) { WORD32 i4_bits_to_stuff; WORD32 i4_error_bits = (e_pic_type == I_PIC) ? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0]) : get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]); WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC) ? ps_cbr_buffer->i4_drain_bits_per_frame[0] : ps_cbr_buffer->i4_drain_bits_per_frame[1]; /* Stuffing bits got from the following equation Stuffing_threshold = ebf + tcb - drain bits - error bits + stuff_bits*/ i4_bits_to_stuff = i4_drain_bits_per_frame + i4_error_bits - (ps_cbr_buffer->i4_ebf + i4_tot_consumed_bits); return i4_bits_to_stuff; } /* ******************************************************************************/ /** * @brief Change the state for change in bit rate * * @param ps_cbr_buffer * @param i4_bit_rate */ /* ******************************************************************************/ void change_cbr_vbv_bit_rate( cbr_buffer_t *ps_cbr_buffer, WORD32 *i4_bit_rate, WORD32 i4_peak_bitrate) { WORD32 i4_bits_per_frm[MAX_NUM_DRAIN_RATES]; int i; for(i = 0; i < MAX_NUM_DRAIN_RATES; i++) { X_PROD_Y_DIV_Z(i4_bit_rate[i], 1000, ps_cbr_buffer->i4_tgt_frm_rate, i4_bits_per_frm[i]); /* Drain rate = bitrate/(framerate/1000) */ ps_cbr_buffer->i4_drain_bits_per_frame[i] = i4_bits_per_frm[i]; /* initialise the bits per frame error bits calculation */ change_bitrate_in_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i], i4_bit_rate[i]); } X_PROD_Y_DIV_Z( i4_peak_bitrate, 1000, ps_cbr_buffer->i4_tgt_frm_rate, ps_cbr_buffer->i4_peak_drain_rate_frame); /* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/ //if(i4_bit_rate[0] == i4_bit_rate[1]) /* This would mean CBR mode */ { X_PROD_Y_DIV_Z( i4_bit_rate[0], ps_cbr_buffer->i4_max_delay, 1000, ps_cbr_buffer->i4_buffer_size); //the delay term is supposed to remain constant //ps_cbr_buffer->i4_is_cbr_mode = 1; ps_cbr_buffer->u4_max_vbv_buf_size = ps_cbr_buffer->i4_buffer_size; } if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size) { ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size; } set_upper_lower_vbv_threshold(ps_cbr_buffer, i4_bits_per_frm[0]); if(ps_cbr_buffer->e_rc_type == CBR_NLDRC) { ps_cbr_buffer->u4_vbr_max_bit_deviation = ps_cbr_buffer->i4_buffer_size; } else { /*DCB: the deviaiton must be altered for VBR case, when bitrate is lowered quality might be bad because of this*/ { ULWORD64 u8_vbr_max_bit_deviation = (ULWORD64)(ps_cbr_buffer->f_max_dur_peak_rate * i4_bit_rate[0]); ULWORD64 file_size = (ULWORD64)( (((LWORD64)i4_bit_rate[0] * 1000) / ps_cbr_buffer->i4_tgt_frm_rate) * (ps_cbr_buffer->i8_tot_frm_to_be_encoded - ps_cbr_buffer->i8_num_frames_encoded)); /*When f_max_dur_peak_rate is -ve, it implies user is not worried about duration for which peak is sustained, hence go with max possible value*/ if(ps_cbr_buffer->f_max_dur_peak_rate > 0) u8_vbr_max_bit_deviation = (ULWORD64)(ps_cbr_buffer->f_max_dur_peak_rate * i4_bit_rate[0]); else u8_vbr_max_bit_deviation = VBR_MAX_BIT_DEV_SEC * i4_bit_rate[0]; /*when num frames to encode is negative is -ve it implies total frames data is not available (as in case of live encoding)*/ if(ps_cbr_buffer->i8_tot_frm_to_be_encoded > 0) { /*allow atleast one second deviation or 12% of total file size whichever is higher*/ if(u8_vbr_max_bit_deviation > (file_size >> 3)) u8_vbr_max_bit_deviation = (UWORD32)(file_size >> 3); } else { u8_vbr_max_bit_deviation = (UWORD32)(file_size >> 3); } /*allow atleast one second for shorter sequence*/ if(u8_vbr_max_bit_deviation < (ULWORD64)i4_bit_rate[0]) u8_vbr_max_bit_deviation = (ULWORD64)i4_bit_rate[0]; ps_cbr_buffer->u4_vbr_max_bit_deviation = u8_vbr_max_bit_deviation; } } /* Storing the input parameters for using it for change functions */ for(i = 0; i < MAX_NUM_DRAIN_RATES; i++) ps_cbr_buffer->ai4_bit_rate[i] = i4_bit_rate[i]; } /* ******************************************************************************/ /** * @brief Update the state for change in number of pics in the delay period * * @param ps_cbr_buffer * @param u4_num_pics_in_delay_prd */ /* ******************************************************************************/ void change_cbr_vbv_num_pics_in_delay_period( cbr_buffer_t *ps_cbr_buffer, UWORD32 *u4_num_pics_in_delay_prd) { WORD32 i; if(!ps_cbr_buffer->i4_is_cbr_mode) { ps_cbr_buffer->i4_buffer_size = u4_num_pics_in_delay_prd[0] * ps_cbr_buffer->i4_drain_bits_per_frame[0] + u4_num_pics_in_delay_prd[1] * ps_cbr_buffer->i4_drain_bits_per_frame[1]; if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size) { ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size; } for(i = 0; i < MAX_PIC_TYPE; i++) { ps_cbr_buffer->i4_upr_thr[i] = ps_cbr_buffer->i4_buffer_size - (ps_cbr_buffer->i4_buffer_size >> 3); } /* Re-initilise the number of pics in delay period */ for(i = 0; i < MAX_PIC_TYPE; i++) { ps_cbr_buffer->ai4_num_pics_in_delay_period[i] = u4_num_pics_in_delay_prd[i]; } } } /* ******************************************************************************/ /** * @ modifies the ebf estimated parameter based on error * * @param ps_cbr_buffer * @param i4_bit_error */ /* ******************************************************************************/ void cbr_modify_ebf_estimate(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_bit_error) { ps_cbr_buffer->i4_ebf_estimate = ps_cbr_buffer->i4_ebf + i4_bit_error; if(ps_cbr_buffer->i4_ebf_estimate < 0) { ps_cbr_buffer->i4_ebf_estimate = 0; } else if(ps_cbr_buffer->i4_ebf_estimate > ps_cbr_buffer->i4_buffer_size) { ps_cbr_buffer->i4_ebf_estimate = ps_cbr_buffer->i4_buffer_size; } } /* ******************************************************************************/ /** * @ get the buffer size * * @param ps_cbr_buffer */ /* ******************************************************************************/ WORD32 get_cbr_buffer_size(cbr_buffer_t *ps_cbr_buffer) { return (ps_cbr_buffer->i4_buffer_size); } #if NON_STEADSTATE_CODE /* ******************************************************************************/ /** * @brief update the state for change in target frame rate * * @param ps_cbr_buffer * @param i4_tgt_frm_rate */ /* ******************************************************************************/ void change_cbr_vbv_tgt_frame_rate(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tgt_frm_rate) { WORD32 i4_i, i4_bits_per_frm[MAX_NUM_DRAIN_RATES]; int i; for(i = 0; i < MAX_NUM_DRAIN_RATES; i++) { X_PROD_Y_DIV_Z(ps_cbr_buffer->ai4_bit_rate[i], 1000, i4_tgt_frm_rate, i4_bits_per_frm[i]); /* Drain rate = bitrate/(framerate/1000) */ ps_cbr_buffer->i4_drain_bits_per_frame[i] = i4_bits_per_frm[i]; /* initialise the bits per frame error bits calculation */ change_frm_rate_in_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i], i4_tgt_frm_rate); } /* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/ if(!ps_cbr_buffer->i4_is_cbr_mode) { /* VBR streaming case which has different drain rates for I and P */ ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->ai4_num_pics_in_delay_period[0] * ps_cbr_buffer->i4_drain_bits_per_frame[0] + ps_cbr_buffer->ai4_num_pics_in_delay_period[1] * ps_cbr_buffer->i4_drain_bits_per_frame[1]; } if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size) { ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size; } for(i4_i = 0; i4_i < MAX_PIC_TYPE; i4_i++) { /* Uppr threshold for I frame = 1 * bits per frame P Frame = 4 * bits per frame. The threshold for I frame is only 1 * bits per frame as the threshold should only account for error in estimated bits. In P frame it should account for difference bets bits consumed by I(Scene change) and P frame I to P complexity is assumed to be 5. */ WORD32 i4_index; i4_index = i4_i > 0 ? 1 : 0; ps_cbr_buffer->i4_upr_thr[i4_i] = ps_cbr_buffer->i4_buffer_size - (ps_cbr_buffer->i4_buffer_size >> 3); /* For both I and P frame Lower threshold is equal to drain rate. Even if the encoder consumes zero bits it should have enough bits to drain*/ ps_cbr_buffer->i4_low_thr[i4_i] = i4_bits_per_frm[i4_index]; } /* Storing the input parameters for using it for change functions */ ps_cbr_buffer->i4_tgt_frm_rate = i4_tgt_frm_rate; } /* ******************************************************************************/ /** * @brief update the state for change in buffer delay * * @param ps_cbr_buffer * @param i4_buffer_delay */ /* ******************************************************************************/ void change_cbr_buffer_delay(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_buffer_delay) { WORD32 i4_i; /* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/ if(ps_cbr_buffer->i4_is_cbr_mode) { X_PROD_Y_DIV_Z( ps_cbr_buffer->ai4_bit_rate[0], i4_buffer_delay, 1000, ps_cbr_buffer->i4_buffer_size); } if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size) { ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size; } for(i4_i = 0; i4_i < MAX_PIC_TYPE; i4_i++) { /* Uppr threshold for I frame = 1 * bits per frame P Frame = 4 * bits per frame. The threshold for I frame is only 1 * bits per frame as the threshold should only account for error in estimated bits. In P frame it should account for difference bets bits consumed by I(Scene change) and P frame I to P complexity is assumed to be 5. */ ps_cbr_buffer->i4_upr_thr[i4_i] = ps_cbr_buffer->i4_buffer_size - (ps_cbr_buffer->i4_buffer_size >> 3); } /* Storing the input parameters for using it for change functions */ ps_cbr_buffer->i4_max_delay = i4_buffer_delay; } /* ******************************************************************************/ /** * @brief update the state for change in buffer delay * * @param ps_cbr_buffer * @param i4_buffer_delay */ /* ******************************************************************************/ WORD32 get_cbr_buffer_delay(cbr_buffer_t *ps_cbr_buffer) { return (ps_cbr_buffer->i4_max_delay); } /* ******************************************************************************/ /** * @brief get_cbr_ebf * * @param ps_cbr_buffer */ /* ******************************************************************************/ WORD32 get_cbr_ebf(cbr_buffer_t *ps_cbr_buffer) { return (ps_cbr_buffer->i4_ebf); } /* ******************************************************************************/ /** * @brief get_cbr_max_ebf * * @param ps_cbr_buffer */ /* ******************************************************************************/ WORD32 get_cbr_max_ebf(cbr_buffer_t *ps_cbr_buffer) { return (ps_cbr_buffer->i4_upr_thr[0]); } /* ******************************************************************************/ /** * @brief set_cbr_ebf * * @param ps_cbr_buffer * @param i32_init_ebf */ /* ******************************************************************************/ void set_cbr_ebf(cbr_buffer_t *ps_cbr_buffer, WORD32 i32_init_ebf) { ps_cbr_buffer->i4_ebf = i32_init_ebf; } /* ******************************************************************************/ /** * @brief update_cbr_buf_mismatch_bit * * @param ps_cbr_buffer * @param i4_error_bits */ /* ******************************************************************************/ void update_cbr_buf_mismatch_bit(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_error_bits) { ps_cbr_buffer->i4_ebf -= i4_error_bits; ps_cbr_buffer->i8_ebf_bit_alloc -= i4_error_bits; ps_cbr_buffer->i8_credit_level -= i4_error_bits; } /* ******************************************************************************/ /** * @brief get encoded number of frames * * @param ps_cbr_buffer */ /* ******************************************************************************/ LWORD64 get_num_frms_encoded(cbr_buffer_t *ps_cbr_buffer) { return ps_cbr_buffer->i8_num_frames_encoded; } /* ******************************************************************************/ /** * @brief get num frames to encode * * @param ps_cbr_buffer */ /* ******************************************************************************/ LWORD64 get_num_frms_to_encode(cbr_buffer_t *ps_cbr_buffer) { return ps_cbr_buffer->i8_tot_frm_to_be_encoded; } /* ******************************************************************************/ /** * @brief get peak drain rate * * @param ps_cbr_buffer */ /* ******************************************************************************/ /* The buffer limit in bit allocation should be according to peak bitrate */ WORD32 get_buf_max_drain_rate(cbr_buffer_t *ps_cbr_buffer) { if(ps_cbr_buffer->e_rc_type == VBR_STREAMING) return ps_cbr_buffer->i4_peak_drain_rate_frame; else if(ps_cbr_buffer->e_rc_type != CONST_QP) { ASSERT( ps_cbr_buffer->i4_peak_drain_rate_frame == ps_cbr_buffer->i4_drain_bits_per_frame[0]); return ps_cbr_buffer->i4_drain_bits_per_frame[0]; } return ps_cbr_buffer->i4_drain_bits_per_frame[0]; } /* ******************************************************************************/ /** * @brief get excess bits by moving in VBV buffer to enable bitrate greater than peak rate for shorter duration in very * complex contents * * @param ps_cbr_buffer * @param i4_tgt_frm_rate */ /* ******************************************************************************/ WORD32 get_vbv_buffer_based_excess( cbr_buffer_t *ps_cbr_buffer, float f_complexity_peak_rate, float f_cur_bits_complexity, WORD32 bit_alloc_period, WORD32 i4_num_gops_for_excess) { LWORD64 max_buffer_level = (LWORD64)((float)ps_cbr_buffer->i4_buffer_size * 0.8f); LWORD64 i8_excess_bits; /*LWORD64target_buf_level;*/ WORD32 num_frm_to_be_distributed; //Number of frames for which excess bits should be distributed, using number of frames corresponding to buffer size for now if(ps_cbr_buffer->i4_upr_thr[0] < max_buffer_level) /*choose max allowed level to min(upper_threshold,80% of buffer*/ max_buffer_level = ps_cbr_buffer->i4_upr_thr[0]; if(ps_cbr_buffer->e_rc_type == VBR_STREAMING) max_buffer_level = (LWORD64)( ps_cbr_buffer->i4_peak_drain_rate_frame * ps_cbr_buffer->u4_num_frms_in_delay * 0.8f); if(f_cur_bits_complexity > 0.9f) /*clip current to max of 80% of buffer size to avoid dangerous buffer level by end of GOP*/ f_cur_bits_complexity = 0.9f; if(f_cur_bits_complexity < f_complexity_peak_rate || f_cur_bits_complexity < 0.1f || ps_cbr_buffer->i4_buffer_size < ps_cbr_buffer->ai4_bit_rate [0]) //For buffer size less than 1 sec disable any contribution from buffer based for extra complex contents { /*For very low compleity content or Cavg do not allow buffer movement*/ return 0; } i8_excess_bits = (LWORD64)( ((f_cur_bits_complexity - f_complexity_peak_rate) / (0.9f - f_complexity_peak_rate)) * (max_buffer_level - ps_cbr_buffer->i4_ebf)); if(i8_excess_bits < 0) i8_excess_bits = 0; num_frm_to_be_distributed = (WORD32)( ((float)ps_cbr_buffer->i4_buffer_size / ps_cbr_buffer->ai4_bit_rate[0] * ps_cbr_buffer->i4_tgt_frm_rate / 1000) + 0.5); /*Excess bits should be proportional to bit alloc period, shorter intra period should get in small incentives*/ if(bit_alloc_period < num_frm_to_be_distributed) i8_excess_bits = (LWORD64)((float)i8_excess_bits * bit_alloc_period / num_frm_to_be_distributed); if(ps_cbr_buffer->e_rc_type == VBR_STREAMING) { if(i4_num_gops_for_excess > 1) i8_excess_bits = i8_excess_bits * i4_num_gops_for_excess; if(i8_excess_bits > (LWORD64)( (float)ps_cbr_buffer->i4_peak_drain_rate_frame * ps_cbr_buffer->u4_num_frms_in_delay * 0.8f)) i8_excess_bits = (LWORD64)( (float)ps_cbr_buffer->i4_peak_drain_rate_frame * ps_cbr_buffer->u4_num_frms_in_delay * 0.8f); } trace_printf( "Excess bits %d %f %f num gops %d", i8_excess_bits, f_cur_bits_complexity, f_complexity_peak_rate, i4_num_gops_for_excess); return ((WORD32)i8_excess_bits); } /* ******************************************************************************/ /** * @brief get gop correction error bits for the current gop. This will be added to rbip. * * @param ps_cbr_buffer * @param i4_lap_complexity_q7 * @param i4_bit_alloc_period */ /* ******************************************************************************/ WORD32 get_error_bits_for_desired_buf( cbr_buffer_t *ps_cbr_buffer, WORD32 i4_lap_complexity_q7, WORD32 i4_bit_alloc_period) { if(ps_cbr_buffer->e_rc_type == CBR_NLDRC) { LWORD64 error_bits = 0, complexity_mov_buf_size = 0; LWORD64 i8_default_bits_in_period, i8_max_additional_bits_in_period; LWORD64 i8_buf_based_limit_red, i8_buf_based_limit_inc, i8_buf_diff_bits; float buf_diff, abs_lap_complexity; /*calculate default allocation*/ i8_default_bits_in_period = (LWORD64)ps_cbr_buffer->ai4_bit_rate[0] * 1000 * i4_bit_alloc_period / ps_cbr_buffer->i4_tgt_frm_rate; /*In case of VBR give additional bits according to peak bitrate*/ if(ps_cbr_buffer->e_rc_type == VBR_STREAMING) { i8_max_additional_bits_in_period = ((LWORD64)ps_cbr_buffer->i4_peak_drain_rate_frame * i4_bit_alloc_period) - i8_default_bits_in_period; ASSERT(i8_max_additional_bits_in_period >= 0); if(i8_max_additional_bits_in_period > (i8_default_bits_in_period)) { /*clip max bits that can be given to 2x bitrate since its too riskly to give more than that in single pass encoding where long future is not known*/ i8_max_additional_bits_in_period = (i8_default_bits_in_period); } } else { i8_max_additional_bits_in_period = i8_default_bits_in_period; } { float X = ((float)i4_lap_complexity_q7 / 128); float desired_buf_level; /*For CBR VBV buffer size is "complexity_mov_buf_size" and In case of VBR it is determined by bit deviaiton*/ if(ps_cbr_buffer->e_rc_type == CBR_NLDRC) { complexity_mov_buf_size = (LWORD64)ps_cbr_buffer->i4_upr_thr[0]; } else if(ps_cbr_buffer->e_rc_type == VBR_STREAMING) { complexity_mov_buf_size = ps_cbr_buffer->u4_vbr_max_bit_deviation; } abs_lap_complexity = X; if(ps_cbr_buffer->i4_cbr_rc_pass == 2) desired_buf_level = COMP_TO_BITS_MAP_2_PASS(X, complexity_mov_buf_size); else desired_buf_level = COMP_TO_BITS_MAP(X, complexity_mov_buf_size); if(desired_buf_level < 0) desired_buf_level = 0; /*map complexity to buffer level*/ error_bits = (LWORD64)(desired_buf_level - ps_cbr_buffer->i8_ebf_bit_alloc); i8_buf_diff_bits = error_bits; /*For VBR its possible that i8_ebf_bit_alloc can go below 0, that the extent of giving should only be desired - cur( = 0 for cur < 0)*/ buf_diff = (float)error_bits / complexity_mov_buf_size; /*clipping based on buffer size should depend on gop size. Assuming 7% of gop of gop = 32, calculate for other GOP intervals max 7% while giving from buffer and 10% while stealing from buffer(for GOP of 32)*/ /*try to be conservative when giving extra bits to gop and limit while reducing bits to GOP needs to be higher inorder to be buffer compliant if necessary*/ i8_buf_based_limit_red = ((LWORD64)complexity_mov_buf_size * i4_bit_alloc_period * 12) >> 12; i8_buf_based_limit_inc = ((LWORD64)complexity_mov_buf_size * i4_bit_alloc_period * 8) >> 12; /*(shd be 7 even if GOP size goes lesser)*/ if(i8_buf_based_limit_red < (((LWORD64)complexity_mov_buf_size * 10) >> 7)) i8_buf_based_limit_red = (((LWORD64)complexity_mov_buf_size * 10) >> 7); if(i8_buf_based_limit_inc < (((LWORD64)complexity_mov_buf_size * 10) >> 7)) i8_buf_based_limit_inc = (((LWORD64)complexity_mov_buf_size * 10) >> 7); /*if error bits is too high it is given in stages so that buffer is utilized for entire complex content*/ /*error bits should not exceed ten 7% of buffer*/ /*error bits can be max equal to bitrate*/ if(error_bits > 0) { /*if lap compleixty is higher and buffer allows give the bits*/ error_bits = (WORD32)(abs_lap_complexity * i8_max_additional_bits_in_period); /*if lap complexity is too simple do not give additional bits to make sure that simple scenes never get additional bits whatsoever*/ if(abs_lap_complexity < 0.2f && ps_cbr_buffer->i8_ebf_bit_alloc >= 0) { error_bits = 0; } if(error_bits > i8_buf_diff_bits) error_bits = i8_buf_diff_bits; if(error_bits > i8_buf_based_limit_inc) { error_bits = i8_buf_based_limit_inc; } /*If buffer is already half filled be conservative. Allocate 1.5 times bits else allocate twice the bits*/ if(ps_cbr_buffer->i8_ebf_bit_alloc > (LWORD64)(ps_cbr_buffer->i4_buffer_size * 0.75)) { if(error_bits > (i8_max_additional_bits_in_period >> 1)) { error_bits = (i8_max_additional_bits_in_period >> 1); } } else { if(error_bits > i8_max_additional_bits_in_period) { error_bits = i8_max_additional_bits_in_period; } } } else { error_bits = (WORD32)(buf_diff * (i8_default_bits_in_period >> 1)); if(error_bits < -i8_buf_based_limit_red) { error_bits = -i8_buf_based_limit_red; } /*when buffer level needs to reduce bits in period*/ /*If current level is less than half min bits in period = 70% of constant bit in period else 50%*/ if(ps_cbr_buffer->i8_ebf_bit_alloc > (ps_cbr_buffer->i4_buffer_size >> 1)) { if(error_bits < -(i8_default_bits_in_period >> 1)) { error_bits = -(i8_default_bits_in_period >> 1); } } else { if(error_bits < -((i8_default_bits_in_period * 5) >> 4)) { error_bits = -((i8_default_bits_in_period * 5) >> 4); } } } } return (WORD32)error_bits; } else { LWORD64 max_excess_bits, default_allocation_for_period, comp_based_excess = 0; LWORD64 i8_excess_bits = 0, bit_dev_so_far, credit_limit_level; LWORD64 Ravg_dur, num_intra_period_in_Ravg_dur, num_intra_in_clip; //duration for which Ravg has to be met, for shorter slips this can be equal to clip duration LWORD64 i8_buf_based_limit_red, i8_buf_based_limit_inc; float comp_to_bit_mapped, X; /*default allocation for period in absence of complexity based bit allocation*/ default_allocation_for_period = ps_cbr_buffer->i4_drain_bits_per_frame[0] * i4_bit_alloc_period; bit_dev_so_far = ps_cbr_buffer->i8_ebf_bit_alloc; credit_limit_level = ps_cbr_buffer->i8_credit_level; Ravg_dur = ps_cbr_buffer->u4_vbr_max_bit_deviation * 5 / ps_cbr_buffer->i4_drain_bits_per_frame[0]; if(Ravg_dur > 20 * ps_cbr_buffer->i8_tot_frm_to_be_encoded / 100) Ravg_dur = 20 * ps_cbr_buffer->i8_tot_frm_to_be_encoded / 100; if(Ravg_dur <= 0) Ravg_dur = 1; /*map the complexity to bits ratio*/ X = (float)i4_lap_complexity_q7 / 128; if(ps_cbr_buffer->i4_cbr_rc_pass == 2) comp_to_bit_mapped = COMP_TO_BITS_MAP_2_PASS(X, 1.0f); else comp_to_bit_mapped = COMP_TO_BITS_MAP(X, 1.0f); comp_to_bit_mapped *= 10; //mapping it to absolute peak bitrate /*calculate the number of bit alloc periods over which the credit limit needs to build up*/ num_intra_in_clip = ps_cbr_buffer->i8_tot_frm_to_be_encoded / i4_bit_alloc_period; num_intra_period_in_Ravg_dur = Ravg_dur / i4_bit_alloc_period; //ASSERT(ps_cbr_buffer->i8_tot_frm_to_be_encoded > i4_bit_alloc_period); if(ps_cbr_buffer->i8_tot_frm_to_be_encoded < i4_bit_alloc_period) { num_intra_period_in_Ravg_dur = 1; num_intra_in_clip = 1; } if(num_intra_period_in_Ravg_dur <= 0) { num_intra_period_in_Ravg_dur = 1; } /*max excess bits possible according to given peak bitrate*/ { max_excess_bits = (ps_cbr_buffer->i4_peak_drain_rate_frame - ps_cbr_buffer->i4_drain_bits_per_frame[0]) * i4_bit_alloc_period; /*constrain max excess bits allocated to a region if buffer is already at critical level*/ /*assume room for 20% over-consumption due to mismatch between allocation and consumption*/ if(ps_cbr_buffer->i4_ebf > (ps_cbr_buffer->i4_upr_thr[0] - (WORD32)(max_excess_bits * 0.2))) { max_excess_bits = (LWORD64)(max_excess_bits * 0.8); } } /*clipping based on buffer size should depend on gop size. Assuming 7% of gop of gop = 32, calculate for other GOP intervals max 7% while giving from buffer and 10% while stealing from buffer(for GOP of 32)*/ /*try to be conservative when giving extra bits to gop and limit while reducing bits to GOP needs to be higher inorder to be buffer compliant if necessary*/ i8_buf_based_limit_red = ((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * i4_bit_alloc_period * 12) >> 12; i8_buf_based_limit_inc = ((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * i4_bit_alloc_period * 8) >> 12; /*(shd be 7 even if GOP size goes lesser)*/ if(i8_buf_based_limit_red < (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7)) i8_buf_based_limit_red = (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7); if(i8_buf_based_limit_inc < (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7)) i8_buf_based_limit_inc = (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7); /*The credit limit is not completly built, hence the average operating bitrate will be lesser than average*/ //if(ps_cbr_buffer->i8_ebf_bit_alloc >= 0) //Disabling this to avoid under-consumption of bits since mostly contents will end with simpler sequence if(1 != ps_cbr_buffer->i4_capped_vbr_on) { /*adjust the excess bits to account for deviation in bitrate If bit deviation is positive then overconsumption, hence resuce the default bit allocation*/ /* In capped vbr mode this is not calculated as there is no constraint to meet the configured bitrate */ i8_excess_bits -= (bit_dev_so_far / num_intra_period_in_Ravg_dur); } /*allocate bits based on complexity*/ /*comp_to_bit_mapped less than 1 implies a content that requires less than average bitrate, hence due to sign reversal we tend to steal bits*/ comp_based_excess = (LWORD64)((comp_to_bit_mapped - 1) * default_allocation_for_period); if(1 != ps_cbr_buffer->i4_capped_vbr_on) { /*clip the complexity based on intra period and credit limit buffer size so that when credit limit is lower not everything is used for first GOP*/ if(comp_based_excess > i8_buf_based_limit_inc) { comp_based_excess = i8_buf_based_limit_inc; } else if(comp_based_excess < -i8_buf_based_limit_red) { comp_based_excess = -i8_buf_based_limit_red; } /*when the credit limit is fully used, stop giving extra*/ if(credit_limit_level > ps_cbr_buffer->u4_vbr_max_bit_deviation) { if(comp_based_excess < 0) i8_excess_bits += comp_based_excess; } /*when credit limit is almost full (80 percent full)*/ else if(credit_limit_level > (LWORD64)(ps_cbr_buffer->u4_vbr_max_bit_deviation * 0.8f)) { /*follow smooth transition, at 80% utilized the excess should be 100 percent, it should move to zero percent as it approaches 100% utlization*/ if(comp_based_excess > 0) i8_excess_bits += (LWORD64)( ((ps_cbr_buffer->u4_vbr_max_bit_deviation - credit_limit_level) / (0.2f * ps_cbr_buffer->u4_vbr_max_bit_deviation)) * comp_based_excess); else i8_excess_bits += comp_based_excess; } else if(credit_limit_level > (LWORD64)(ps_cbr_buffer->u4_vbr_max_bit_deviation * 0.2f)) { i8_excess_bits += comp_based_excess; } /*When credit limit is almost unutilized*/ else if( credit_limit_level < (WORD32)(ps_cbr_buffer->u4_vbr_max_bit_deviation * 0.2f) && credit_limit_level > 0) { if(comp_based_excess < 0) i8_excess_bits += (LWORD64)( (credit_limit_level / (0.2f * ps_cbr_buffer->u4_vbr_max_bit_deviation)) * comp_based_excess); else i8_excess_bits += comp_based_excess; } /*If the credit limit still uutilized stop drawing bits from simpler content*/ else if(credit_limit_level <= 0) { if(comp_based_excess > 0) i8_excess_bits += comp_based_excess; } else ASSERT(0); } else { /* In capped vbr mode excess bits will be based on complexity of content alone*/ i8_excess_bits = comp_based_excess; } /*Clip the excess bits such that it will never violate peak bitrate and also Rmin*/ if(i8_excess_bits > max_excess_bits) i8_excess_bits = max_excess_bits; /*assuming atleast 0.4 times average bitrate even for the simplest content*/ if(i8_excess_bits < -(default_allocation_for_period * 0.6f)) i8_excess_bits = (LWORD64)(-(default_allocation_for_period * 0.6f)); ASSERT(i8_excess_bits <= 0x7FFFFFFF); return (WORD32)i8_excess_bits; } } /* ******************************************************************************/ /** * @brief get_rc_type. * * @param ps_cbr_buffer */ /* ******************************************************************************/ rc_type_e get_rc_type(cbr_buffer_t *ps_cbr_buffer) { return (ps_cbr_buffer->e_rc_type); } /* ******************************************************************************/ /** * @brief cbr_get_delay_frames * * @param ps_cbr_buffer */ /* ******************************************************************************/ UWORD32 cbr_get_delay_frames(cbr_buffer_t *ps_cbr_buffer) { return (ps_cbr_buffer->u4_num_frms_in_delay); } #endif /* #if NON_STEADSTATE_CODE */