125 lines
4.8 KiB
C
125 lines
4.8 KiB
C
/******************************************************************************
|
|
*
|
|
* 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 vbr_storage_vbv.h
|
|
*
|
|
* \brief
|
|
* This file contains all the necessary declarations for
|
|
* vbr buffer control functions
|
|
*
|
|
* \date
|
|
*
|
|
* \author
|
|
* ittiam
|
|
*
|
|
******************************************************************************
|
|
*/
|
|
#ifndef _VBR_STORAGE_VBV_H_
|
|
#define _VBR_STORAGE_VBV_H_
|
|
/******************************************************************************
|
|
VBR STORAGE (VBV):
|
|
Max. buffer filling rate: Rmax
|
|
Max. buffer size: Bmax (as specified by level and profile)
|
|
Current Buffer Level: Bcur
|
|
Frame Rate: F
|
|
|
|
For a storage scenario, the initial buffer size is assumed to be max. For every
|
|
frame the Maximum bits filled in to the buffer is given by Rmaxfrm = Rmax/F. If
|
|
the buffer overflows then the buffer is thresholded to the max buffer size.
|
|
|
|
(overflow)
|
|
B(0) /|
|
|
---|--------------/-|------------------------------ Bmax
|
|
| / |
|
|
| /|/ |
|
|
| /| / |
|
|
| / | /|/ |
|
|
|/ | / | /|
|
|
|/ |/ |
|
|
|
|
|
|
|
|
-----------------------|---------------------------
|
|
|<->| |
|
|
(1/F)=>1/frame_rate (underflow)
|
|
|
|
|
|
B"(i) - Bits in buffer just before decoding a frame.
|
|
B'(i) - Bits in buffer just after decoding a frame.
|
|
|
|
|
|
B(0) (initBuffer size) = Bmax.
|
|
B'(i) = B"(i) - bits_decoded
|
|
B"(i) = Min( Bmax, B'(i-1) + Rmaxfrm)
|
|
|
|
Overflow Scenario: In VBR case, since we have only a max filling rate (or input bit rate)
|
|
buffer overflow is not a issue (since the buffer filling rate can be reduced to any value
|
|
below this rate)
|
|
|
|
Underflow Scenario: B'(i) should always be > 0. If not then, the buffer underflows. To
|
|
prevent this condition the number bits that needs to be decoded must be equal to B"(i)
|
|
which is equal to Min( Bmax, B'(i-1) + Rmaxfrm)
|
|
****************************************************************************************/
|
|
|
|
/*****************************************************************************/
|
|
/* Function Declarations */
|
|
/*****************************************************************************/
|
|
|
|
typedef struct vbr_storage_vbv_t *vbr_storage_vbv_handle;
|
|
|
|
WORD32 vbr_vbv_num_fill_use_free_memtab(
|
|
vbr_storage_vbv_handle *pps_vbr_storage_vbv,
|
|
itt_memtab_t *ps_memtab,
|
|
ITT_FUNC_TYPE_E e_func_type);
|
|
|
|
/* Initalises the vbv buffer status */
|
|
void init_vbr_vbv(
|
|
vbr_storage_vbv_handle ps_vbr_storage_vbv,
|
|
WORD32 max_bit_rate, /* In bits/sec*/
|
|
WORD32 max_frm_rate, /* In frames/1000 sec*/
|
|
WORD32 i4_max_vbv_buff_size); /* in bits*/
|
|
|
|
/* Updates the buffer after decoding a frame */
|
|
void update_vbr_vbv(vbr_storage_vbv_handle ps_vbr_storage_vbv, WORD32 i4_total_bits_decoded);
|
|
|
|
/* gets the max_number of bits that can be decoded out of the VBV without underflow */
|
|
WORD32 get_max_target_bits(vbr_storage_vbv_handle ps_vbr_storage_vbv);
|
|
WORD32 get_max_bits_inflow_per_frm_periode(vbr_storage_vbv_handle ps_vbr_storage_vbv);
|
|
WORD32 get_cur_vbv_buf_size(vbr_storage_vbv_handle ps_vbr_storage_vbv);
|
|
|
|
/* Queries the VBV buffer for the buffer status */
|
|
vbv_buf_status_e get_vbv_buffer_status(
|
|
vbr_storage_vbv_handle ps_vbr_storage_vbv,
|
|
WORD32 i4_total_frame_bits, /* Total frame bits consumed */
|
|
WORD32 *
|
|
pi4_num_bits_to_prevent_vbv_underflow); /* num bits to prevent from underflow after update */
|
|
|
|
WORD32 get_max_vbv_buf_size(vbr_storage_vbv_handle ps_vbr_storage_vbv);
|
|
WORD32 get_vbv_buf_fullness(vbr_storage_vbv_handle ps_vbr_storage_vbv, UWORD32 u4_bits);
|
|
WORD32 get_max_tgt_bits_dvd_comp(
|
|
vbr_storage_vbv_handle ps_vbr_storage_vbv,
|
|
WORD32 i4_rem_bits_in_gop,
|
|
WORD32 i4_rem_frms_in_gop,
|
|
picture_type_e e_pic_type);
|
|
/* Changing input values at run time */
|
|
void change_vbr_vbv_bit_rate(vbr_storage_vbv_handle ps_vbr_storage_vbv, WORD32 i4_max_bit_rate);
|
|
void change_vbr_vbv_frame_rate(vbr_storage_vbv_handle ps_vbr_storage_vbv, WORD32 i4_frm_rate);
|
|
#endif
|