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+/* ------------------------------------------------------------------
+ * Copyright (C) 1998-2009 PacketVideo
+ *
+ * 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.
+ * -------------------------------------------------------------------
+ */
+/*
+
+ Pathname: apply_tns.c
+
+------------------------------------------------------------------------------
+ INPUT AND OUTPUT DEFINITIONS
+
+ Inputs:
+ coef = Array of input coefficients.
+ [Int32 *, length 1024]
+
+ q_format = Array of q-formats, one per scalefactor band, for the
+ entire frame. In the case of tns_inv_filter, only the
+ first element is used, since the input to tns_inv_filter
+ is all of the same q-format.
+ [Int * const, length MAX_SFB]
+
+ pFrameInfo = Pointer to structure that holds information about each group.
+ (long block flag, number of windows, scalefactor bands
+ per group, etc.)
+ [const FrameInfo * const]
+
+ pTNS_frame_info = pointer to structure containing the details on each
+ TNS filter (order, filter coefficients,
+ coefficient res., etc.)
+ [TNS_frame_info * const]
+
+ inverse_flag = TRUE if inverse filter is to be applied.
+ FALSE if forward filter is to be applied.
+ [Bool]
+
+ scratch_Int_buffer = Pointer to scratch memory to store the
+ filter's state memory. Used by both
+ tns_inv_filter.
+ [Int *, length TNS_MAX_ORDER]
+
+ Local Stores/Buffers/Pointers Needed:
+ None
+
+ Global Stores/Buffers/Pointers Needed:
+ None
+
+ Outputs:
+ None
+
+ Pointers and Buffers Modified:
+ coef[] = TNS altered data.
+ q_format = q-formats in TNS scalefactor bands may be modified.
+
+ Local Stores Modified:
+ None
+
+ Global Stores Modified:
+ None
+
+------------------------------------------------------------------------------
+ FUNCTION DESCRIPTION
+
+ This function applies either the TNS forward or TNS inverse filter, based
+ on inverse_flag being FALSE or TRUE, respectively.
+
+ For the TNS forward filter, the data fed into tns_ar_filter is normalized
+ all to the same q-format.
+
+------------------------------------------------------------------------------
+ REQUIREMENTS
+
+ The input, coef, should use all 32-bits, else the scaling by tns_ar_filter
+ may eliminate the data.
+
+------------------------------------------------------------------------------
+ REFERENCES
+
+ (1) ISO/IEC 14496-3:1999(E)
+ Part 3
+ Subpart 4.6.8 (Temporal Noise Shaping)
+
+------------------------------------------------------------------------------
+ PSEUDO-CODE
+
+ NO PSEUDO-CODE
+
+------------------------------------------------------------------------------
+ RESOURCES USED
+ When the code is written for a specific target processor
+ the resources used should be documented below.
+
+ STACK USAGE: [stack count for this module] + [variable to represent
+ stack usage for each subroutine called]
+
+ where: [stack usage variable] = stack usage for [subroutine
+ name] (see [filename].ext)
+
+ DATA MEMORY USED: x words
+
+ PROGRAM MEMORY USED: x words
+
+ CLOCK CYCLES: [cycle count equation for this module] + [variable
+ used to represent cycle count for each subroutine
+ called]
+
+ where: [cycle count variable] = cycle count for [subroutine
+ name] (see [filename].ext)
+
+------------------------------------------------------------------------------
+*/
+
+/*----------------------------------------------------------------------------
+; INCLUDES
+----------------------------------------------------------------------------*/
+#include "pv_audio_type_defs.h"
+#include "s_tns_frame_info.h"
+#include "s_tnsfilt.h"
+#include "s_frameinfo.h"
+#include "tns_inv_filter.h"
+#include "tns_ar_filter.h"
+#include "apply_tns.h"
+
+/*----------------------------------------------------------------------------
+; MACROS
+; Define module specific macros here
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; DEFINES
+; Include all pre-processor statements here. Include conditional
+; compile variables also.
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL FUNCTION DEFINITIONS
+; Function Prototype declaration
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL STORE/BUFFER/POINTER DEFINITIONS
+; Variable declaration - defined here and used outside this module
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; EXTERNAL FUNCTION REFERENCES
+; Declare functions defined elsewhere and referenced in this module
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
+; Declare variables used in this module but defined elsewhere
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; FUNCTION CODE
+----------------------------------------------------------------------------*/
+
+void apply_tns(
+ Int32 coef[],
+ Int q_format[],
+ const FrameInfo * const pFrameInfo,
+ TNS_frame_info * const pTNS_frame_info,
+ const Bool inverse_flag,
+ Int32 scratch_Int_buffer[])
+{
+ Int num_tns_bands;
+ Int num_TNS_coef;
+
+ Int f;
+
+ Int tempInt;
+ Int tempInt2;
+
+ Int sfb_per_win;
+ Int sfbWidth;
+
+ Int coef_per_win;
+ Int min_q;
+ Int win;
+
+ Int32 *pCoef = coef;
+ Int32 *pTempCoef;
+
+ Int *pStartQformat = q_format;
+
+ Int *pQformat;
+ Int32 *pLpcCoef;
+
+ Int sfb_offset;
+
+ const Int16 *pWinSfbTop;
+
+ TNSfilt *pFilt;
+
+ coef_per_win = pFrameInfo->coef_per_win[0];
+ sfb_per_win = pFrameInfo->sfb_per_win[0];
+
+ win = 0;
+
+ pLpcCoef = pTNS_frame_info->lpc_coef;
+
+ pFilt = pTNS_frame_info->filt;
+
+ do
+ {
+ for (f = pTNS_frame_info->n_filt[win]; f > 0; f--)
+ {
+ /* Skip to the next filter if the order is 0 */
+ tempInt = pFilt->order;
+
+ if (tempInt > 0)
+ {
+ /*
+ * Do not call tns_ar_filter or tns_inv_filter
+ * if the difference
+ * between start_coef and stop_stop is <= 0.
+ *
+ */
+ num_TNS_coef = (pFilt->stop_coef - pFilt->start_coef);
+
+ if (num_TNS_coef > 0)
+ {
+ if (inverse_flag != FALSE)
+ {
+ tns_inv_filter(
+ &(pCoef[pFilt->start_coef]),
+ num_TNS_coef,
+ pFilt->direction,
+ pLpcCoef,
+ pFilt->q_lpc,
+ pFilt->order,
+ scratch_Int_buffer);
+ }
+ else
+ {
+ num_tns_bands = (pFilt->stop_band - pFilt->start_band);
+
+ /*
+ * pQformat is initialized only once.
+ *
+ * Here is how TNS is applied on scalefactor bands
+ *
+ * [0][1][2][3][4][5][6][7][8]
+ * | \
+ * start_band stop_band
+ *
+ * In this example, TNS would be applied to 8
+ * scalefactor bands, 0-7.
+ *
+ * pQformat is initially set to &(pStartQformat[8])
+ *
+ * 1st LOOP
+ * Entry: pQformat = &(pStartQformat[8])
+ *
+ * pQformat is pre-decremented 8 times in the
+ * search for min_q
+ *
+ * Exit: pQformat = &(pStartQformat[0])
+ *
+ * 2nd LOOP
+ * Entry: pQformat = &(pStartQformat[0])
+ *
+ * pQformat is post-incremented 8 times in the
+ * normalization of the data loop.
+ *
+ * Exit: pQformat = &(pStartQformat[8]
+ *
+ *
+ * shift_amt = tns_ar_filter(...)
+ *
+ * 3rd LOOP
+ * Entry: pQformat = &(pStartQformat[8])
+ *
+ * pQformat is pre-decremented 8 times in the
+ * adjustment of the q-format to min_q - shift_amt
+ *
+ * Exit: pQformat = &(pStartQformat[0])
+ *
+ */
+
+ pQformat =
+ &(pStartQformat[pFilt->stop_band]);
+
+ /*
+ * Scan the array of q-formats and find the minimum over
+ * the range where the filter is to be applied.
+ *
+ * At the end of this scan,
+ * pQformat = &(q-format[pFilt->start_band]);
+ *
+ */
+
+ min_q = INT16_MAX;
+
+ for (tempInt = num_tns_bands; tempInt > 0; tempInt--)
+ {
+ tempInt2 = *(--pQformat);
+
+ if (tempInt2 < min_q)
+ {
+ min_q = tempInt2;
+ }
+ } /* for(tempInt = num_bands; tempInt > 0; tempInt--)*/
+
+ /*
+ * Set up the pointers so we can index into coef[]
+ * on a scalefactor band basis.
+ */
+ tempInt = pFilt->start_band;
+
+ tempInt--;
+
+ /* Initialize sfb_offset and pWinSfbTop */
+ if (tempInt >= 0)
+ {
+ pWinSfbTop =
+ &(pFrameInfo->win_sfb_top[win][tempInt]);
+
+ sfb_offset = *(pWinSfbTop++);
+ }
+ else
+ {
+ pWinSfbTop = pFrameInfo->win_sfb_top[win];
+ sfb_offset = 0;
+ }
+
+ pTempCoef = pCoef + pFilt->start_coef;
+
+ /* Scale the data in the TNS bands to min_q q-format */
+ for (tempInt = num_tns_bands; tempInt > 0; tempInt--)
+ {
+ sfbWidth = *(pWinSfbTop++) - sfb_offset;
+
+ sfb_offset += sfbWidth;
+
+ tempInt2 = *(pQformat++) - min_q;
+
+ /*
+ * This should zero out the data in one scalefactor
+ * band if it is so much less than the neighboring
+ * scalefactor bands.
+ *
+ * The only way this "should" happen is if one
+ * scalefactor band contains zero data.
+ *
+ * Zero data can be of any q-format, but we always
+ * set it very high to avoid the zero-data band being
+ * picked as the one to normalize to in the scan for
+ * min_q.
+ *
+ */
+ if (tempInt2 > 31)
+ {
+ tempInt2 = 31;
+ }
+
+ for (sfbWidth >>= 2; sfbWidth > 0; sfbWidth--)
+ {
+ *(pTempCoef++) >>= tempInt2;
+ *(pTempCoef++) >>= tempInt2;
+ *(pTempCoef++) >>= tempInt2;
+ *(pTempCoef++) >>= tempInt2;
+ }
+
+ } /* for(tempInt = num_bands; tempInt > 0; tempInt--)*/
+
+ tempInt2 =
+ tns_ar_filter(
+ &(pCoef[pFilt->start_coef]),
+ num_TNS_coef,
+ pFilt->direction,
+ pLpcCoef,
+ pFilt->q_lpc,
+ pFilt->order);
+
+ /*
+ * Update the q-format for all the scalefactor bands
+ * taking into account the adjustment caused by
+ * tns_ar_filter
+ */
+
+ min_q -= tempInt2;
+
+ for (tempInt = num_tns_bands; tempInt > 0; tempInt--)
+ {
+ *(--pQformat) = min_q;
+ }
+
+ } /* if (inverse_flag != FALSE) */
+
+ } /* if (num_TNS_coef > 0) */
+
+ pLpcCoef += pFilt->order;
+
+ } /* if (tempInt > 0) */
+
+ pFilt++;
+
+ } /* for (f = pTNSinfo->n_filt; f > 0; f--) */
+
+ pCoef += coef_per_win;
+ pStartQformat += sfb_per_win;
+
+ win++;
+
+ }
+ while (win < pFrameInfo->num_win);
+
+ return;
+
+} /* apply_tns() */
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