ref: 89fd5d9b410e93a72767913b8cce285b44e24036
parent: 7e899b5d0cce717b5aa17bd671efc331ee61c0a1
author: menno <menno>
date: Thu Aug 10 16:04:57 EDT 2000
removed IS
--- a/is.c
+++ /dev/null
@@ -1,202 +1,0 @@
-/************************* MPEG-2 NBC Audio Decoder **************************
- * *
-"This software module was originally developed in the course of
-development of the MPEG-2 NBC/MPEG-4 Audio standard ISO/IEC 13818-7,
-14496-1,2 and 3. This software module is an implementation of a part of one or more
-MPEG-2 NBC/MPEG-4 Audio tools as specified by the MPEG-2 NBC/MPEG-4
-Audio standard. ISO/IEC gives users of the MPEG-2 NBC/MPEG-4 Audio
-standards free license to this software module or modifications thereof for use in
-hardware or software products claiming conformance to the MPEG-2 NBC/MPEG-4
-Audio standards. Those intending to use this software module in hardware or
-software products are advised that this use may infringe existing patents.
-The original developer of this software module and his/her company, the subsequent
-editors and their companies, and ISO/IEC have no liability for use of this software
-module or modifications thereof in an implementation. Copyright is not released for
-non MPEG-2 NBC/MPEG-4 Audio conforming products.The original developer
-retains full right to use the code for his/her own purpose, assign or donate the
-code to a third party and to inhibit third party from using the code for non
-MPEG-2 NBC/MPEG-4 Audio conforming products. This copyright notice must
-be included in all copies or derivative works."
-Copyright(c)1996.
- * *
- ****************************************************************************/
-
-/*******************************************************************************************
- *
- * IS stereo coding module
- *
- * Authors:
- * CL Chuck Lueck, TI <lueck@ti.com>
- *
- * Changes:
- * 22-jan-98 CL Initial revision. Simple IS stereo support.
- ***************************************************************************************/
-
-
-#include "is.h"
-
-/* Perform IS encoding. Spectrum is non-interleaved. */
-/* This would be a lot simpler on interleaved spectral data */
-void ISEncode(double *spectrum[MAX_TIME_CHANNELS], /* array of pointers to spectral data */
- Ch_Info *channelInfo, /* Pointer to Ch_Info */
- int sfb_offset_table[][MAX_SCFAC_BANDS+1],
- enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */
- AACQuantInfo* quantInfo,
- int numberOfChannels)
-{- int chanNum;
- int sfbNum;
- int lineNum,line_offset;
- int startWindow,stopWindow,w;
-
- /* Look for channel_pair_elements */
- for (chanNum=0;chanNum<numberOfChannels;chanNum++) {- if (channelInfo[chanNum].present) {- if ((channelInfo[chanNum].cpe)&&(channelInfo[chanNum].ch_is_left)) {- int leftChan=chanNum;
- int rightChan=channelInfo[chanNum].paired_ch;
- channelInfo[leftChan].is_info.is_present=0;
- channelInfo[rightChan].is_info.is_present=0;
-
- /* Perform IS if block_types are the same */
- if (block_type[leftChan]==block_type[rightChan]) {- int numGroups;
- int maxSfb;
- int g,b,minBand;
- IS_Info *isInfo;
-
- channelInfo[leftChan].common_window = 1; /* Use common window */
- channelInfo[rightChan].is_info.is_present=1;
-
- numGroups = quantInfo[leftChan].num_window_groups;
- maxSfb = quantInfo[leftChan].max_sfb;
-
- /* Currently, enable Intensity Stereo above band IS_MIN_BAND */
- isInfo = &(channelInfo[rightChan].is_info);
- minBand = (block_type[rightChan]==ONLY_SHORT_WINDOW) ? IS_MIN_BAND_S : IS_MIN_BAND_L;
- minBand = (minBand>maxSfb) ? maxSfb : minBand;
- startWindow=0;
- for (g=0;g<numGroups;g++) {-
- int numWindows;
-
- /* Disable lower frequency bands */
- for (sfbNum=0;sfbNum<minBand;sfbNum++) {- b = g*maxSfb+sfbNum;
- isInfo->is_used[b] = 0; /* Disable IS */
- }
-
- /* Enable IS bands */
- numWindows = quantInfo[leftChan].window_group_length[g];
- stopWindow = startWindow + numWindows;
- for (sfbNum=minBand;sfbNum<maxSfb;sfbNum++) {- double ratio,log_ratio;
- int is_position;
-
- /* First, compute energies and intensity stereo position */
- double energy_l=0.0; /* Left channel energy */
- double energy_r=0.0; /* Right channel energy */
- double energy_s=0.0; /* Sum channel energy */
- for (w=startWindow;w<stopWindow;w++) {- line_offset = w*BLOCK_LEN_SHORT;
- for (lineNum=sfb_offset_table[rightChan][sfbNum];
- lineNum<sfb_offset_table[rightChan][sfbNum+1];
- lineNum++) {- double l = spectrum[leftChan][line_offset+lineNum];
- double r = spectrum[rightChan][line_offset+lineNum];
- double s = l+r;
- energy_l += l*l;
- energy_r += r*r;
- energy_s += s*s;
- }
- }
- b = g*maxSfb+sfbNum;
- ratio = energy_l/energy_r;
- log_ratio = 2.0 * log(ratio) / log(2.0);
- is_position = (int) floor( log_ratio + 0.5);
- isInfo->fac[b] = is_position;
- quantInfo[rightChan].scale_factor[b] = is_position;
- isInfo->is_used[b] = 1; /* Enable IS */
- isInfo->sign[b] = 0; /* In phase only */
-
- /* Now replace right and left spectral coefficients */
- for (w=startWindow;w<stopWindow;w++) {- line_offset = w*BLOCK_LEN_SHORT;
- for (lineNum=sfb_offset_table[rightChan][sfbNum];
- lineNum<sfb_offset_table[rightChan][sfbNum+1];
- lineNum++) {- double l = spectrum[leftChan][line_offset+lineNum];
- double r = spectrum[rightChan][line_offset+lineNum];
- double new_spec = (l+r) * sqrt(energy_l/(energy_s+1));
- spectrum[leftChan][line_offset+lineNum] = new_spec; /* Replace left */
- spectrum[rightChan][line_offset+lineNum] = 0.0;
- }
- }
- }
- startWindow = stopWindow;
- }
- } /* if (block_type... */
- } /* if ((channelInfo... */
- } /* if (channelInfo... */
- } /* for (chanNum... */
-}
-
-
-void ISReconstruct(double *spectrum[MAX_TIME_CHANNELS], /* array of pointers to spectral data */
- Ch_Info *channelInfo, /* Pointer to Ch_Info */
- int sfb_offset_table[][MAX_SCFAC_BANDS+1],
-// enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */
- AACQuantInfo* quantInfo,
- int numberOfChannels) /* Number of channels */
-{- int chanNum;
- int sfbNum;
- int lineNum,line_offset;
- int startWindow,stopWindow,w;
-
- /* Look for channel_pair_elements */
- for (chanNum=0;chanNum<numberOfChannels;chanNum++) {- if (channelInfo[chanNum].present) {- if ((channelInfo[chanNum].cpe)&&(channelInfo[chanNum].ch_is_left)) {- int leftChan=chanNum;
- int rightChan=channelInfo[chanNum].paired_ch;
-
- /* If intensity stereo is present in right channel, reconstruct spectrum */
- IS_Info *isInfo;
- isInfo = &(channelInfo[rightChan].is_info);
- if (isInfo->is_present) {- int numGroups = quantInfo[rightChan].num_window_groups;
- int maxSfb = quantInfo[rightChan].max_sfb;
- int g,b;
-
- /* Currently, enable Intensity Stereo above band IS_MIN_BAND */
- startWindow=0;
- for (g=0;g<numGroups;g++) {-
- /* Enable IS bands */
- int numWindows = quantInfo[leftChan].window_group_length[g];
- stopWindow = startWindow + numWindows;
- for (sfbNum=0;sfbNum<maxSfb;sfbNum++) {- b = g*maxSfb+sfbNum;
- if (isInfo->is_used[b]) {- double scale = pow( 0.5, 0.25 * ((double)isInfo->fac[b]));
- scale = scale * (-2.0 * isInfo->sign[b] + 1.0);
- for (w=startWindow;w<stopWindow;w++) {- line_offset = w*BLOCK_LEN_SHORT;
- for (lineNum=sfb_offset_table[rightChan][sfbNum];
- lineNum<sfb_offset_table[rightChan][sfbNum+1];
- lineNum++) {- spectrum[rightChan][line_offset+lineNum] =
- spectrum[leftChan][line_offset+lineNum] * scale;
- }
- }
- } /* if (isInfo... */
- } /* for (sfbNum... */
- startWindow = stopWindow;
- }
- } /* if (block_type... */
- } /* if ((channelInfo... */
- } /* if (channelInfo... */
- } /* for (chanNum... */
-}
-
--- a/is.h
+++ /dev/null
@@ -1,40 +1,0 @@
-/*******************************************************************************************
- *
- * IS stereo coding module
- *
- * Authors:
- * CL Chuck Lueck, TI <lueck@ti.com>
- *
- * Changes:
- * 22-jan-98 CL Initial revision. Simple IS stereo support.
- ***************************************************************************************/
-
-#ifndef IS_ENC
-#define IS_ENC
-
-#include "all.h"
-#include "tf_main.h"
-#include "quant.h"
-#include <math.h>
-
-#define IS_MIN_BAND_L 0 //28
-#define IS_MIN_BAND_S 0 //7
-
-void ISEncode(double *spectrum[MAX_TIME_CHANNELS], /* array of pointers to spectral data */
- Ch_Info *channelInfo, /* Pointer to Ch_Info */
- int sfb_offset_table[][MAX_SCFAC_BANDS+1],
- enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */
- AACQuantInfo* quantInfo,
- int numberOfChannels); /* Number of channels */
-
-void ISReconstruct(double *spectrum[MAX_TIME_CHANNELS], /* array of pointers to spectral data */
- Ch_Info *channelInfo, /* Pointer to Ch_Info */
- int sfb_offset_table[][MAX_SCFAC_BANDS+1],
-// enum WINDOW_TYPE block_type[MAX_TIME_CHANNELS], /* Block type */
- AACQuantInfo* quantInfo,
- int numberOfChannels); /* Number of channels */
-
-
-
-#endif
-