392 lines
13 KiB
C
392 lines
13 KiB
C
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/* ***** BEGIN LICENSE BLOCK *****
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* Version: RCSL 1.0/RPSL 1.0
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*
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* Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
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*
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* The contents of this file, and the files included with this file, are
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* subject to the current version of the RealNetworks Public Source License
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* Version 1.0 (the "RPSL") available at
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* http://www.helixcommunity.org/content/rpsl unless you have licensed
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* the file under the RealNetworks Community Source License Version 1.0
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* (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
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* in which case the RCSL will apply. You may also obtain the license terms
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* directly from RealNetworks. You may not use this file except in
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* compliance with the RPSL or, if you have a valid RCSL with RealNetworks
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* applicable to this file, the RCSL. Please see the applicable RPSL or
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* RCSL for the rights, obligations and limitations governing use of the
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* contents of the file.
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*
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* This file is part of the Helix DNA Technology. RealNetworks is the
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* developer of the Original Code and owns the copyrights in the portions
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* it created.
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*
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* This file, and the files included with this file, is distributed and made
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* available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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* EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
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*
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* Technology Compatibility Kit Test Suite(s) Location:
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* http://www.helixcommunity.org/content/tck
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*
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* Contributor(s):
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*
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* ***** END LICENSE BLOCK ***** */
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/**************************************************************************************
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* Fixed-point MP3 decoder
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* Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com)
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* June 2003
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*
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* scalfact.c - scalefactor unpacking functions
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**************************************************************************************/
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#include "coder.h"
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/* scale factor lengths (num bits) */
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static const char SFLenTab[16][2] = {
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{0, 0}, {0, 1},
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{0, 2}, {0, 3},
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{3, 0}, {1, 1},
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{1, 2}, {1, 3},
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{2, 1}, {2, 2},
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{2, 3}, {3, 1},
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{3, 2}, {3, 3},
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{4, 2}, {4, 3},
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};
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/**************************************************************************************
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* Function: UnpackSFMPEG1
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*
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* Description: unpack MPEG 1 scalefactors from bitstream
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*
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* Inputs: BitStreamInfo, SideInfoSub, ScaleFactorInfoSub structs for this
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* granule/channel
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* vector of scfsi flags from side info, length = 4 (MAX_SCFBD)
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* index of current granule
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* ScaleFactorInfoSub from granule 0 (for granule 1, if scfsi[i] is set,
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* then we just replicate the scale factors from granule 0 in the
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* i'th set of scalefactor bands)
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*
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* Outputs: updated BitStreamInfo struct
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* scalefactors in sfis (short and/or long arrays, as appropriate)
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*
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* Return: none
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*
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* Notes: set order of short blocks to s[band][window] instead of s[window][band]
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* so that we index through consectutive memory locations when unpacking
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* (make sure dequantizer follows same convention)
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* Illegal Intensity Position = 7 (always) for MPEG1 scale factors
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**************************************************************************************/
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static void UnpackSFMPEG1(BitStreamInfo *bsi, SideInfoSub *sis, ScaleFactorInfoSub *sfis, int *scfsi, int gr, ScaleFactorInfoSub *sfisGr0)
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{
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int sfb;
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int slen0, slen1;
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/* these can be 0, so make sure GetBits(bsi, 0) returns 0 (no >> 32 or anything) */
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slen0 = (int)SFLenTab[sis->sfCompress][0];
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slen1 = (int)SFLenTab[sis->sfCompress][1];
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if (sis->blockType == 2) {
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/* short block, type 2 (implies winSwitchFlag == 1) */
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if (sis->mixedBlock) {
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/* do long block portion */
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for (sfb = 0; sfb < 8; sfb++)
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sfis->l[sfb] = (char)GetBits(bsi, slen0);
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sfb = 3;
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} else {
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/* all short blocks */
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sfb = 0;
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}
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for ( ; sfb < 6; sfb++) {
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sfis->s[sfb][0] = (char)GetBits(bsi, slen0);
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sfis->s[sfb][1] = (char)GetBits(bsi, slen0);
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sfis->s[sfb][2] = (char)GetBits(bsi, slen0);
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}
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for ( ; sfb < 12; sfb++) {
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sfis->s[sfb][0] = (char)GetBits(bsi, slen1);
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sfis->s[sfb][1] = (char)GetBits(bsi, slen1);
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sfis->s[sfb][2] = (char)GetBits(bsi, slen1);
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}
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/* last sf band not transmitted */
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sfis->s[12][0] = sfis->s[12][1] = sfis->s[12][2] = 0;
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} else {
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/* long blocks, type 0, 1, or 3 */
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if(gr == 0) {
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/* first granule */
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for (sfb = 0; sfb < 11; sfb++)
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sfis->l[sfb] = (char)GetBits(bsi, slen0);
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for (sfb = 11; sfb < 21; sfb++)
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sfis->l[sfb] = (char)GetBits(bsi, slen1);
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return;
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} else {
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/* second granule
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* scfsi: 0 = different scalefactors for each granule, 1 = copy sf's from granule 0 into granule 1
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* for block type == 2, scfsi is always 0
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*/
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sfb = 0;
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if(scfsi[0]) for( ; sfb < 6 ; sfb++) sfis->l[sfb] = sfisGr0->l[sfb];
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else for( ; sfb < 6 ; sfb++) sfis->l[sfb] = (char)GetBits(bsi, slen0);
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if(scfsi[1]) for( ; sfb <11 ; sfb++) sfis->l[sfb] = sfisGr0->l[sfb];
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else for( ; sfb <11 ; sfb++) sfis->l[sfb] = (char)GetBits(bsi, slen0);
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if(scfsi[2]) for( ; sfb <16 ; sfb++) sfis->l[sfb] = sfisGr0->l[sfb];
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else for( ; sfb <16 ; sfb++) sfis->l[sfb] = (char)GetBits(bsi, slen1);
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if(scfsi[3]) for( ; sfb <21 ; sfb++) sfis->l[sfb] = sfisGr0->l[sfb];
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else for( ; sfb <21 ; sfb++) sfis->l[sfb] = (char)GetBits(bsi, slen1);
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}
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/* last sf band not transmitted */
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sfis->l[21] = 0;
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sfis->l[22] = 0;
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}
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}
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/* NRTab[size + 3*is_right][block type][partition]
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* block type index: 0 = (bt0,bt1,bt3), 1 = bt2 non-mixed, 2 = bt2 mixed
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* partition: scale factor groups (sfb1 through sfb4)
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* for block type = 2 (mixed or non-mixed) / by 3 is rolled into this table
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* (for 3 short blocks per long block)
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* see 2.4.3.2 in MPEG 2 (low sample rate) spec
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* stuff rolled into this table:
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* NRTab[x][1][y] --> (NRTab[x][1][y]) / 3
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* NRTab[x][2][>=1] --> (NRTab[x][2][>=1]) / 3 (first partition is long block)
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*/
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static const char NRTab[6][3][4] = {
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/* non-intensity stereo */
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{ {6, 5, 5, 5},
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{3, 3, 3, 3}, /* includes / 3 */
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{6, 3, 3, 3}, /* includes / 3 except for first entry */
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},
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{ {6, 5, 7, 3},
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{3, 3, 4, 2},
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{6, 3, 4, 2},
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},
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{ {11, 10, 0, 0},
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{6, 6, 0, 0},
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{6, 3, 6, 0}, /* spec = [15,18,0,0], but 15 = 6L + 9S, so move 9/3=3 into col 1, 18/3=6 into col 2 and adj. slen[1,2] below */
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},
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/* intensity stereo, right chan */
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{ {7, 7, 7, 0},
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{4, 4, 4, 0},
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{6, 5, 4, 0},
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},
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{ {6, 6, 6, 3},
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{4, 3, 3, 2},
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{6, 4, 3, 2},
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},
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{ {8, 8, 5, 0},
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{5, 4, 3, 0},
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{6, 6, 3, 0},
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}
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};
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/**************************************************************************************
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* Function: UnpackSFMPEG2
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*
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* Description: unpack MPEG 2 scalefactors from bitstream
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*
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* Inputs: BitStreamInfo, SideInfoSub, ScaleFactorInfoSub structs for this
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* granule/channel
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* index of current granule and channel
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* ScaleFactorInfoSub from this granule
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* modeExt field from frame header, to tell whether intensity stereo is on
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* ScaleFactorJS struct for storing IIP info used in Dequant()
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*
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* Outputs: updated BitStreamInfo struct
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* scalefactors in sfis (short and/or long arrays, as appropriate)
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* updated intensityScale and preFlag flags
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*
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* Return: none
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*
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* Notes: Illegal Intensity Position = (2^slen) - 1 for MPEG2 scale factors
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*
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* TODO: optimize the / and % stuff (only do one divide, get modulo x
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* with (x / m) * m, etc.)
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**************************************************************************************/
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static void UnpackSFMPEG2(BitStreamInfo *bsi, SideInfoSub *sis, ScaleFactorInfoSub *sfis, int gr, int ch, int modeExt, ScaleFactorJS *sfjs)
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{
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int i, sfb, sfcIdx, btIdx, nrIdx, iipTest;
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int slen[4], nr[4];
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int sfCompress, preFlag, intensityScale;
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sfCompress = sis->sfCompress;
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preFlag = 0;
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intensityScale = 0;
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/* stereo mode bits (1 = on): bit 1 = mid-side on/off, bit 0 = intensity on/off */
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if (! ((modeExt & 0x01) && (ch == 1)) ) {
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/* in other words: if ((modeExt & 0x01) == 0 || ch == 0) */
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if (sfCompress < 400) {
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/* max slen = floor[(399/16) / 5] = 4 */
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slen[0] = (sfCompress >> 4) / 5;
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slen[1]= (sfCompress >> 4) % 5;
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slen[2]= (sfCompress & 0x0f) >> 2;
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slen[3]= (sfCompress & 0x03);
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sfcIdx = 0;
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} else if (sfCompress < 500) {
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/* max slen = floor[(99/4) / 5] = 4 */
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sfCompress -= 400;
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slen[0] = (sfCompress >> 2) / 5;
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slen[1]= (sfCompress >> 2) % 5;
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slen[2]= (sfCompress & 0x03);
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slen[3]= 0;
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sfcIdx = 1;
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} else {
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/* max slen = floor[11/3] = 3 (sfCompress = 9 bits in MPEG2) */
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sfCompress -= 500;
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slen[0] = sfCompress / 3;
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slen[1] = sfCompress % 3;
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slen[2] = slen[3] = 0;
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if (sis->mixedBlock) {
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/* adjust for long/short mix logic (see comment above in NRTab[] definition) */
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slen[2] = slen[1];
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slen[1] = slen[0];
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}
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preFlag = 1;
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sfcIdx = 2;
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}
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} else {
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/* intensity stereo ch = 1 (right) */
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intensityScale = sfCompress & 0x01;
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sfCompress >>= 1;
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if (sfCompress < 180) {
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/* max slen = floor[35/6] = 5 (from mod 36) */
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slen[0] = (sfCompress / 36);
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slen[1] = (sfCompress % 36) / 6;
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slen[2] = (sfCompress % 36) % 6;
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slen[3] = 0;
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sfcIdx = 3;
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} else if (sfCompress < 244) {
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/* max slen = floor[63/16] = 3 */
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sfCompress -= 180;
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slen[0] = (sfCompress & 0x3f) >> 4;
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slen[1] = (sfCompress & 0x0f) >> 2;
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slen[2] = (sfCompress & 0x03);
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slen[3] = 0;
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sfcIdx = 4;
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} else {
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/* max slen = floor[11/3] = 3 (max sfCompress >> 1 = 511/2 = 255) */
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sfCompress -= 244;
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slen[0] = (sfCompress / 3);
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slen[1] = (sfCompress % 3);
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slen[2] = slen[3] = 0;
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sfcIdx = 5;
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}
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}
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/* set index based on block type: (0,1,3) --> 0, (2 non-mixed) --> 1, (2 mixed) ---> 2 */
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btIdx = 0;
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if (sis->blockType == 2)
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btIdx = (sis->mixedBlock ? 2 : 1);
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for (i = 0; i < 4; i++)
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nr[i] = (int)NRTab[sfcIdx][btIdx][i];
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/* save intensity stereo scale factor info */
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if( (modeExt & 0x01) && (ch == 1) ) {
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for (i = 0; i < 4; i++) {
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sfjs->slen[i] = slen[i];
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sfjs->nr[i] = nr[i];
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}
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sfjs->intensityScale = intensityScale;
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}
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sis->preFlag = preFlag;
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/* short blocks */
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if(sis->blockType == 2) {
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if(sis->mixedBlock) {
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/* do long block portion */
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iipTest = (1 << slen[0]) - 1;
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for (sfb=0; sfb < 6; sfb++) {
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sfis->l[sfb] = (char)GetBits(bsi, slen[0]);
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}
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sfb = 3; /* start sfb for short */
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nrIdx = 1;
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} else {
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/* all short blocks, so start nr, sfb at 0 */
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sfb = 0;
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nrIdx = 0;
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}
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/* remaining short blocks, sfb just keeps incrementing */
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for ( ; nrIdx <= 3; nrIdx++) {
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iipTest = (1 << slen[nrIdx]) - 1;
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for (i=0; i < nr[nrIdx]; i++, sfb++) {
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sfis->s[sfb][0] = (char)GetBits(bsi, slen[nrIdx]);
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sfis->s[sfb][1] = (char)GetBits(bsi, slen[nrIdx]);
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sfis->s[sfb][2] = (char)GetBits(bsi, slen[nrIdx]);
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}
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}
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/* last sf band not transmitted */
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sfis->s[12][0] = sfis->s[12][1] = sfis->s[12][2] = 0;
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} else {
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/* long blocks */
|
||
|
|
sfb = 0;
|
||
|
|
for (nrIdx = 0; nrIdx <= 3; nrIdx++) {
|
||
|
|
iipTest = (1 << slen[nrIdx]) - 1;
|
||
|
|
for(i=0; i < nr[nrIdx]; i++, sfb++) {
|
||
|
|
sfis->l[sfb] = (char)GetBits(bsi, slen[nrIdx]);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/* last sf band not transmitted */
|
||
|
|
sfis->l[21] = sfis->l[22] = 0;
|
||
|
|
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**************************************************************************************
|
||
|
|
* Function: UnpackScaleFactors
|
||
|
|
*
|
||
|
|
* Description: parse the fields of the MP3 scale factor data section
|
||
|
|
*
|
||
|
|
* Inputs: MP3DecInfo structure filled by UnpackFrameHeader() and UnpackSideInfo()
|
||
|
|
* buffer pointing to the MP3 scale factor data
|
||
|
|
* pointer to bit offset (0-7) indicating starting bit in buf[0]
|
||
|
|
* number of bits available in data buffer
|
||
|
|
* index of current granule and channel
|
||
|
|
*
|
||
|
|
* Outputs: updated platform-specific ScaleFactorInfo struct
|
||
|
|
* updated bitOffset
|
||
|
|
*
|
||
|
|
* Return: length (in bytes) of scale factor data, -1 if null input pointers
|
||
|
|
**************************************************************************************/
|
||
|
|
int UnpackScaleFactors(MP3DecInfo *mp3DecInfo, unsigned char *buf, int *bitOffset, int bitsAvail, int gr, int ch)
|
||
|
|
{
|
||
|
|
int bitsUsed;
|
||
|
|
unsigned char *startBuf;
|
||
|
|
BitStreamInfo bitStreamInfo, *bsi;
|
||
|
|
FrameHeader *fh;
|
||
|
|
SideInfo *si;
|
||
|
|
ScaleFactorInfo *sfi;
|
||
|
|
|
||
|
|
/* validate pointers */
|
||
|
|
if (!mp3DecInfo || !mp3DecInfo->FrameHeaderPS || !mp3DecInfo->SideInfoPS || !mp3DecInfo->ScaleFactorInfoPS)
|
||
|
|
return -1;
|
||
|
|
fh = ((FrameHeader *)(mp3DecInfo->FrameHeaderPS));
|
||
|
|
si = ((SideInfo *)(mp3DecInfo->SideInfoPS));
|
||
|
|
sfi = ((ScaleFactorInfo *)(mp3DecInfo->ScaleFactorInfoPS));
|
||
|
|
|
||
|
|
/* init GetBits reader */
|
||
|
|
startBuf = buf;
|
||
|
|
bsi = &bitStreamInfo;
|
||
|
|
SetBitstreamPointer(bsi, (bitsAvail + *bitOffset + 7) / 8, buf);
|
||
|
|
if (*bitOffset)
|
||
|
|
GetBits(bsi, *bitOffset);
|
||
|
|
|
||
|
|
if (fh->ver == MPEG1)
|
||
|
|
UnpackSFMPEG1(bsi, &si->sis[gr][ch], &sfi->sfis[gr][ch], si->scfsi[ch], gr, &sfi->sfis[0][ch]);
|
||
|
|
else
|
||
|
|
UnpackSFMPEG2(bsi, &si->sis[gr][ch], &sfi->sfis[gr][ch], gr, ch, fh->modeExt, &sfi->sfjs);
|
||
|
|
|
||
|
|
mp3DecInfo->part23Length[gr][ch] = si->sis[gr][ch].part23Length;
|
||
|
|
|
||
|
|
bitsUsed = CalcBitsUsed(bsi, buf, *bitOffset);
|
||
|
|
buf += (bitsUsed + *bitOffset) >> 3;
|
||
|
|
*bitOffset = (bitsUsed + *bitOffset) & 0x07;
|
||
|
|
|
||
|
|
return (buf - startBuf);
|
||
|
|
}
|
||
|
|
|