/****************************************************************************** * * Copyright (C) 2015 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 */ #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) ****************************************************************************************/ typedef struct vbr_storage_vbv_t* vbr_storage_vbv_handle; WORD32 irc_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 irc_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 irc_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 irc_get_max_target_bits(vbr_storage_vbv_handle ps_vbr_storage_vbv); WORD32 irc_get_max_bits_inflow_per_frm_periode(vbr_storage_vbv_handle ps_vbr_storage_vbv); WORD32 irc_get_max_bits_per_tgt_frm(vbr_storage_vbv_handle ps_vbr_storage_vbv); WORD32 irc_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 irc_get_vbv_buffer_status(vbr_storage_vbv_handle ps_vbr_storage_vbv, WORD32 i4_total_frame_bits, WORD32 *pi4_num_bits_to_prevent_vbv_underflow); UWORD8 irc_restrict_swing_dvd_comp(vbr_storage_vbv_handle ps_vbr_storage_vbv); WORD32 irc_get_max_vbv_buf_size(vbr_storage_vbv_handle ps_vbr_storage_vbv); WORD32 irc_vbv_get_vbv_buf_fullness(vbr_storage_vbv_handle ps_vbr_storage_vbv, UWORD32 u4_bits); WORD32 irc_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 irc_change_vbr_vbv_bit_rate(vbr_storage_vbv_handle ps_vbr_storage_vbv, WORD32 i4_max_bit_rate); void irc_change_vbr_vbv_frame_rate(vbr_storage_vbv_handle ps_vbr_storage_vbv, WORD32 i4_frm_rate); void irc_change_vbr_max_bits_per_tgt_frm(vbr_storage_vbv_handle ps_vbr_storage_vbv, WORD32 i4_tgt_frm_rate); #endif