/***************************************************************************** * * XviD VBR Library * - CBR/ABR bitrate controller implementation - * * Copyright (C) 2002 Edouard Gomez * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * $Id: plugin_cbr.c,v 1.1.2.2 2003-03-23 09:39:29 suxen_drol Exp $ * ****************************************************************************/ #include "../xvid.h" #include "../image/image.h" #define INITIAL_QUANT 5 typedef struct { int max_quantizer; int min_quantizer; int reaction_delay_factor; int averaging_period; int buffer; int bytes_per_sec; double target_framesize; double time; int64_t total_size; int rtn_quant; double sequence_quality; double avg_framesize; double quant_error[31]; } rc_cbr_t; static int rc_cbr_create(xvid_plg_create_t * create, rc_cbr_t ** handle) { xvid_plugin_cbr_t * param = (xvid_plugin_cbr_t *)create->param; rc_cbr_t * rc; int i; /* cbr need to caclulate the average frame size. in order to do that, we need some fps */ if (create->fincr == 0) { return XVID_ERR_FAIL; } /* allocate context struct */ if((rc = malloc(sizeof(rc_cbr_t))) == NULL) return(XVID_ERR_MEMORY); /* constants */ rc->bytes_per_sec = param->bitrate / 8; rc->target_framesize = (double)rc->bytes_per_sec / ((double)create->fbase / create->fincr); rc->max_quantizer = param->max_quantizer>0 ? param->max_quantizer : 12; rc->min_quantizer = param->min_quantizer>0 ? param->min_quantizer : 2; rc->reaction_delay_factor = param->reaction_delay_factor>0 ? param->reaction_delay_factor : 16; rc->averaging_period = param->averaging_period>0 ? param->averaging_period : 100; rc->buffer = param->buffer>0 ? param->buffer : 100; rc->time = 0; rc->total_size = 0; rc->rtn_quant = INITIAL_QUANT; /* Reset quant error accumulators */ for (i = 0; i < 31; i++) rc->quant_error[i] = 0.0; /* Last bunch of variables */ DPRINTF(DPRINTF_RC, "bytes_per_sec: %i\n", rc->bytes_per_sec); DPRINTF(DPRINTF_RC, "frame rate : %f\n", (double)create->fbase / create->fincr); DPRINTF(DPRINTF_RC, "target_framesize: %f\n",rc->target_framesize); rc->sequence_quality = 2.0 / (double) rc->rtn_quant; rc->avg_framesize = rc->target_framesize; *handle = rc; return(0); } static int rc_cbr_destroy(rc_cbr_t * rc, xvid_plg_destroy_t * destroy) { free(rc); return(0); } static int rc_cbr_before(rc_cbr_t * rc, xvid_plg_data_t * data) { data->quant = rc->rtn_quant; data->type = XVID_TYPE_AUTO; return 0; } static int rc_cbr_after(rc_cbr_t * rc, xvid_plg_data_t * data) { int64_t deviation; int rtn_quant; double overflow; double averaging_period; double reaction_delay_factor; double quality_scale; double base_quality; double target_quality; /* Update internal values */ rc->time += (double)data->fincr / data->fbase; rc->total_size += data->length; /* Compute the deviation from expected total size */ deviation = (int64_t) ((double)rc->total_size - (double)rc->bytes_per_sec*rc->time); if(rc->rtn_quant >= 2) { averaging_period = (double) rc->averaging_period; rc->sequence_quality -= rc->sequence_quality / averaging_period; rc->sequence_quality += 2.0 / (double) rc->rtn_quant / averaging_period; if (rc->sequence_quality < 0.1) rc->sequence_quality = 0.1; if (data->type != XVID_TYPE_IVOP) { reaction_delay_factor = (double) rc->reaction_delay_factor; rc->avg_framesize -= rc->avg_framesize / reaction_delay_factor; rc->avg_framesize += data->length / reaction_delay_factor; } } quality_scale = rc->target_framesize / rc->avg_framesize * rc->target_framesize / rc->avg_framesize; base_quality = rc->sequence_quality; if (quality_scale >= 1.0) { base_quality = 1.0 - (1.0 - base_quality) / quality_scale; } else { base_quality = 0.06452 + (base_quality - 0.06452) * quality_scale; } overflow = -((double) deviation / (double) rc->buffer); target_quality = base_quality + (base_quality - 0.06452) * overflow / rc->target_framesize; if (target_quality > 2.0) target_quality = 2.0; else if (target_quality < 0.06452) target_quality = 0.06452; rtn_quant = (int) (2.0 / target_quality); if (rtn_quant < 31) { rc->quant_error[rtn_quant-1] += 2.0 / target_quality - rtn_quant; if (rc->quant_error[rtn_quant-1] >= 1.0) { rc->quant_error[rtn_quant-1] -= 1.0; rtn_quant++; } } if (rtn_quant > rc->rtn_quant + 1) rtn_quant = rc->rtn_quant + 1; else if (rtn_quant < rc->rtn_quant - 1) rtn_quant = rc->rtn_quant - 1; if (rtn_quant > rc->max_quantizer) rtn_quant = rc->max_quantizer; else if (rtn_quant < rc->min_quantizer) rtn_quant = rc->min_quantizer; rc->rtn_quant = rtn_quant; return(0); } int xvid_plugin_cbr(void * handle, int opt, void * param1, void * param2) { switch(opt) { case XVID_PLG_INFO : return 0; case XVID_PLG_CREATE : return rc_cbr_create((xvid_plg_create_t*)param1, param2); case XVID_PLG_DESTROY : return rc_cbr_destroy((rc_cbr_t*)handle, (xvid_plg_destroy_t*)param1); case XVID_PLG_BEFORE : return rc_cbr_before((rc_cbr_t*)handle, (xvid_plg_data_t*)param1); case XVID_PLG_AFTER : return rc_cbr_after((rc_cbr_t*)handle, (xvid_plg_data_t*)param1); } return XVID_ERR_FAIL; }