/* Copyright (c) 2005, The Musepack Development Team All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the The Musepack Development Team nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /// \file mpc_decoder.c /// Core decoding routines and logic. #include #include "musepack.h" #include "internal.h" #include "requant.h" #include "huffman.h" //------------------------------------------------------------------------------ // types //------------------------------------------------------------------------------ enum { EQ_TAP = 13, // length of FIR filter for EQ DELAY = ((EQ_TAP + 1) / 2), // delay of FIR FIR_BANDS = 4, // number of subbands to be FIR filtered MEMSIZE = MPC_DECODER_MEMSIZE, // overall buffer size MEMSIZE2 = (MEMSIZE/2), // size of one buffer MEMMASK = (MEMSIZE-1) }; //------------------------------------------------------------------------------ // forward declarations //------------------------------------------------------------------------------ void mpc_decoder_init_huffman_sv6(mpc_decoder *d); void mpc_decoder_init_huffman_sv7(mpc_decoder *d); void mpc_decoder_read_bitstream_sv6(mpc_decoder *d); void mpc_decoder_read_bitstream_sv7(mpc_decoder *d); void mpc_decoder_update_buffer(mpc_decoder *d, mpc_uint32_t RING); bool mpc_decoder_seek_sample(mpc_decoder *d, mpc_int64_t destsample); void mpc_decoder_requantisierung(mpc_decoder *d, const mpc_int32_t Last_Band); //------------------------------------------------------------------------------ // utility functions //------------------------------------------------------------------------------ static mpc_int32_t f_read(mpc_decoder *d, void *ptr, size_t size) { return d->r->read(d->r->data, ptr, size); }; static bool f_seek(mpc_decoder *d, mpc_int32_t offset) { return d->r->seek(d->r->data, offset); }; static mpc_int32_t f_read_dword(mpc_decoder *d, mpc_uint32_t * ptr, mpc_uint32_t count) { count = f_read(d, ptr, count << 2) >> 2; #ifndef MPC_LITTLE_ENDIAN mpc_uint32_t n; for(n = 0; n< count; n++) { ptr[n] = swap32(ptr[n]); } #endif return count; } //------------------------------------------------------------------------------ // huffman & bitstream functions //------------------------------------------------------------------------------ static const mpc_uint32_t mask [33] = { 0x00000000, 0x00000001, 0x00000003, 0x00000007, 0x0000000F, 0x0000001F, 0x0000003F, 0x0000007F, 0x000000FF, 0x000001FF, 0x000003FF, 0x000007FF, 0x00000FFF, 0x00001FFF, 0x00003FFF, 0x00007FFF, 0x0000FFFF, 0x0001FFFF, 0x0003FFFF, 0x0007FFFF, 0x000FFFFF, 0x001FFFFF, 0x003FFFFF, 0x007FFFFF, 0x00FFFFFF, 0x01FFFFFF, 0x03FFFFFF, 0x07FFFFFF, 0x0FFFFFFF, 0x1FFFFFFF, 0x3FFFFFFF, 0x7FFFFFFF, 0xFFFFFFFF }; /* F U N C T I O N S */ // resets bitstream decoding static void mpc_decoder_reset_bitstream_decode(mpc_decoder *d) { d->dword = 0; d->pos = 0; d->Zaehler = 0; d->WordsRead = 0; } // reports the number of read bits static mpc_uint32_t mpc_decoder_bits_read(mpc_decoder *d) { return 32 * d->WordsRead + d->pos; } // read desired number of bits out of the bitstream static mpc_uint32_t mpc_decoder_bitstream_read(mpc_decoder *d, const mpc_uint32_t bits) { mpc_uint32_t out = d->dword; d->pos += bits; if (d->pos < 32) { out >>= (32 - d->pos); } else { d->dword = d->Speicher[d->Zaehler = (d->Zaehler + 1) & MEMMASK]; d->pos -= 32; if (d->pos) { out <<= d->pos; out |= d->dword >> (32 - d->pos); } ++(d->WordsRead); } return out & mask[bits]; } // decode SCFI-bundle (sv4,5,6) static void mpc_decoder_scfi_bundle_read( mpc_decoder *d, HuffmanTyp* Table, mpc_int32_t* SCFI, mpc_int32_t* DSCF) { // load preview and decode mpc_uint32_t code = d->dword << d->pos; if (d->pos > 26) { code |= d->Speicher[(d->Zaehler + 1) & MEMMASK] >> (32 - d->pos); } while (code < Table->Code) { Table++; } // set the new position within bitstream without performing a dummy-read if ((d->pos += Table->Length) >= 32) { d->pos -= 32; d->dword = d->Speicher[d->Zaehler = (d->Zaehler+1) & MEMMASK]; ++(d->WordsRead); } *SCFI = Table->Value >> 1; *DSCF = Table->Value & 1; } static int mpc_decoder_huffman_typ_cmpfn(const void* p1, const void* p2) { if (((HuffmanTyp*) p1)->Code < ((HuffmanTyp*) p2)->Code ) return +1; if (((HuffmanTyp*) p1)->Code > ((HuffmanTyp*) p2)->Code ) return -1; return 0; } // sort huffman-tables by codeword // offset resulting value void mpc_decoder_resort_huff_tables( const mpc_uint32_t elements, HuffmanTyp* Table, const mpc_int32_t offset ) { mpc_uint32_t i; for ( i = 0; i < elements; i++ ) { Table[i].Code <<= 32 - Table[i].Length; Table[i].Value = i - offset; } qsort(Table, elements, sizeof(*Table), mpc_decoder_huffman_typ_cmpfn); } // basic huffman decoding routine // works with maximum lengths up to 14 static mpc_int32_t mpc_decoder_huffman_decode(mpc_decoder *d, const HuffmanTyp *Table) { // load preview and decode mpc_uint32_t code = d->dword << d->pos; if (d->pos > 18) { code |= d->Speicher[(d->Zaehler + 1) & MEMMASK] >> (32 - d->pos); } while (code < Table->Code) { Table++; } // set the new position within bitstream without performing a dummy-read if ((d->pos += Table->Length) >= 32) { d->pos -= 32; d->dword = d->Speicher[d->Zaehler = (d->Zaehler + 1) & MEMMASK]; ++(d->WordsRead); } return Table->Value; } // faster huffman through previewing less bits // works with maximum lengths up to 10 static mpc_int32_t mpc_decoder_huffman_decode_fast(mpc_decoder *d, const HuffmanTyp* Table) { // load preview and decode mpc_uint32_t code = d->dword << d->pos; if (d->pos > 22) { code |= d->Speicher[(d->Zaehler + 1) & MEMMASK] >> (32 - d->pos); } while (code < Table->Code) { Table++; } // set the new position within bitstream without performing a dummy-read if ((d->pos += Table->Length) >= 32) { d->pos -= 32; d->dword = d->Speicher[d->Zaehler = (d->Zaehler + 1) & MEMMASK]; ++(d->WordsRead); } return Table->Value; } // even faster huffman through previewing even less bits // works with maximum lengths up to 5 static mpc_int32_t mpc_decoder_huffman_decode_faster(mpc_decoder *d, const HuffmanTyp* Table) { // load preview and decode mpc_uint32_t code = d->dword << d->pos; if (d->pos > 27) { code |= d->Speicher[(d->Zaehler + 1) & MEMMASK] >> (32 - d->pos); } while (code < Table->Code) { Table++; } // set the new position within bitstream without performing a dummy-read if ((d->pos += Table->Length) >= 32) { d->pos -= 32; d->dword = d->Speicher[d->Zaehler = (d->Zaehler + 1) & MEMMASK]; ++(d->WordsRead); } return Table->Value; } static void mpc_decoder_reset_v(mpc_decoder *d) { memset(d->V_L, 0, sizeof d->V_L); memset(d->V_R, 0, sizeof d->V_R); } static void mpc_decoder_reset_synthesis(mpc_decoder *d) { mpc_decoder_reset_v(d); } static void mpc_decoder_reset_y(mpc_decoder *d) { memset(d->Y_L, 0, sizeof d->Y_L); memset(d->Y_R, 0, sizeof d->Y_R); } static void mpc_decoder_reset_globals(mpc_decoder *d) { mpc_decoder_reset_bitstream_decode(d); d->DecodedFrames = 0; d->StreamVersion = 0; d->MS_used = 0; memset(d->Y_L , 0, sizeof d->Y_L ); memset(d->Y_R , 0, sizeof d->Y_R ); memset(d->SCF_Index_L , 0, sizeof d->SCF_Index_L ); memset(d->SCF_Index_R , 0, sizeof d->SCF_Index_R ); memset(d->Res_L , 0, sizeof d->Res_L ); memset(d->Res_R , 0, sizeof d->Res_R ); memset(d->SCFI_L , 0, sizeof d->SCFI_L ); memset(d->SCFI_R , 0, sizeof d->SCFI_R ); memset(d->DSCF_Flag_L , 0, sizeof d->DSCF_Flag_L ); memset(d->DSCF_Flag_R , 0, sizeof d->DSCF_Flag_R ); memset(d->DSCF_Reference_L, 0, sizeof d->DSCF_Reference_L ); memset(d->DSCF_Reference_R, 0, sizeof d->DSCF_Reference_R ); memset(d->Q , 0, sizeof d->Q ); memset(d->MS_Flag , 0, sizeof d->MS_Flag ); } static mpc_uint32_t mpc_decoder_decode_internal(mpc_decoder *d, MPC_SAMPLE_FORMAT *buffer) { mpc_uint32_t output_frame_length = MPC_FRAME_LENGTH; mpc_uint32_t FrameBitCnt = 0; if (d->DecodedFrames >= d->OverallFrames) { return (mpc_uint32_t)(-1); // end of file -> abort decoding } // read jump-info for validity check of frame d->FwdJumpInfo = mpc_decoder_bitstream_read(d, 20); d->ActDecodePos = (d->Zaehler << 5) + d->pos; // decode data and check for validity of frame FrameBitCnt = mpc_decoder_bits_read(d); switch (d->StreamVersion) { case 0x04: case 0x05: case 0x06: mpc_decoder_read_bitstream_sv6(d); break; case 0x07: case 0x17: mpc_decoder_read_bitstream_sv7(d); break; default: return (mpc_uint32_t)(-1); } d->FrameWasValid = mpc_decoder_bits_read(d) - FrameBitCnt == d->FwdJumpInfo; // synthesize signal mpc_decoder_requantisierung(d, d->Max_Band); //if ( d->EQ_activated && PluginSettings.EQbyMPC ) // perform_EQ (); mpc_decoder_synthese_filter_float(d, buffer); d->DecodedFrames++; // cut off first MPC_DECODER_SYNTH_DELAY zero-samples if (d->DecodedFrames == d->OverallFrames && d->StreamVersion >= 6) { // reconstruct exact filelength mpc_int32_t mod_block = mpc_decoder_bitstream_read(d, 11); mpc_int32_t FilterDecay; if (mod_block == 0) { // Encoder bugfix mod_block = 1152; } FilterDecay = (mod_block + MPC_DECODER_SYNTH_DELAY) % MPC_FRAME_LENGTH; // additional FilterDecay samples are needed for decay of synthesis filter if (MPC_DECODER_SYNTH_DELAY + mod_block >= MPC_FRAME_LENGTH) { // ********************************************************************** // Rhoades 4/16/2002 // Commented out are blocks of code which cause gapless playback to fail. // Temporary fix... // ********************************************************************** if (!d->TrueGaplessPresent) { mpc_decoder_reset_y(d); } else { //if ( MPC_FRAME_LENGTH != d->LastValidSamples ) { mpc_decoder_bitstream_read(d, 20); mpc_decoder_read_bitstream_sv7(d); mpc_decoder_requantisierung(d, d->Max_Band); //FilterDecay = d->LastValidSamples; //} //else { //FilterDecay = 0; //} } mpc_decoder_synthese_filter_float(d, buffer + 2304); output_frame_length = MPC_FRAME_LENGTH + FilterDecay; } else { // there are only FilterDecay samples needed for this frame output_frame_length = FilterDecay; } } if (d->samples_to_skip) { if (output_frame_length < d->samples_to_skip) { d->samples_to_skip -= output_frame_length; output_frame_length = 0; } else { output_frame_length -= d->samples_to_skip; memmove( buffer, buffer + d->samples_to_skip * 2, output_frame_length * 2 * sizeof (MPC_SAMPLE_FORMAT)); d->samples_to_skip = 0; } } return output_frame_length; } mpc_uint32_t mpc_decoder_decode( mpc_decoder *d, MPC_SAMPLE_FORMAT *buffer, mpc_uint32_t *vbr_update_acc, mpc_uint32_t *vbr_update_bits) { for(;;) { //const mpc_int32_t MaxBrokenFrames = 0; // PluginSettings.MaxBrokenFrames mpc_uint32_t RING = d->Zaehler; mpc_int32_t vbr_ring = (RING << 5) + d->pos; mpc_uint32_t valid_samples = mpc_decoder_decode_internal(d, buffer); if (valid_samples == (mpc_uint32_t)(-1) ) { return 0; } /**************** ERROR CONCEALMENT *****************/ if (d->FrameWasValid == 0 ) { // error occurred in bitstream return (mpc_uint32_t)(-1); } else { if (vbr_update_acc && vbr_update_bits) { (*vbr_update_acc) ++; vbr_ring = (d->Zaehler << 5) + d->pos - vbr_ring; if (vbr_ring < 0) { vbr_ring += 524288; } (*vbr_update_bits) += vbr_ring; } } mpc_decoder_update_buffer(d, RING); if (valid_samples > 0) { return valid_samples; } } } void mpc_decoder_requantisierung(mpc_decoder *d, const mpc_int32_t Last_Band) { mpc_int32_t Band; mpc_int32_t n; MPC_SAMPLE_FORMAT facL; MPC_SAMPLE_FORMAT facR; MPC_SAMPLE_FORMAT templ; MPC_SAMPLE_FORMAT tempr; MPC_SAMPLE_FORMAT* YL; MPC_SAMPLE_FORMAT* YR; mpc_int32_t* L; mpc_int32_t* R; #ifdef MPC_FIXED_POINT #if MPC_FIXED_POINT_FRACTPART == 14 #define MPC_MULTIPLY_SCF(CcVal, SCF_idx) \ MPC_MULTIPLY_EX(CcVal, d->SCF[SCF_idx], d->SCF_shift[SCF_idx]) #else #error FIXME, Cc table is in 18.14 format #endif #else #define MPC_MULTIPLY_SCF(CcVal, SCF_idx) \ MPC_MULTIPLY(CcVal, d->SCF[SCF_idx]) #endif // requantization and scaling of subband-samples for ( Band = 0; Band <= Last_Band; Band++ ) { // setting pointers YL = d->Y_L[0] + Band; YR = d->Y_R[0] + Band; L = d->Q[Band].L; R = d->Q[Band].R; /************************** MS-coded **************************/ if ( d->MS_Flag [Band] ) { if ( d->Res_L [Band] ) { if ( d->Res_R [Band] ) { // M!=0, S!=0 facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][0]); facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][0]); for ( n = 0; n < 12; n++, YL += 32, YR += 32 ) { *YL = (templ = MPC_MULTIPLY_FLOAT_INT(facL,*L++))+(tempr = MPC_MULTIPLY_FLOAT_INT(facR,*R++)); *YR = templ - tempr; } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][1]); facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][1]); for ( ; n < 24; n++, YL += 32, YR += 32 ) { *YL = (templ = MPC_MULTIPLY_FLOAT_INT(facL,*L++))+(tempr = MPC_MULTIPLY_FLOAT_INT(facR,*R++)); *YR = templ - tempr; } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][2]); facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][2]); for ( ; n < 36; n++, YL += 32, YR += 32 ) { *YL = (templ = MPC_MULTIPLY_FLOAT_INT(facL,*L++))+(tempr = MPC_MULTIPLY_FLOAT_INT(facR,*R++)); *YR = templ - tempr; } } else { // M!=0, S==0 facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][0]); for ( n = 0; n < 12; n++, YL += 32, YR += 32 ) { *YR = *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][1]); for ( ; n < 24; n++, YL += 32, YR += 32 ) { *YR = *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][2]); for ( ; n < 36; n++, YL += 32, YR += 32 ) { *YR = *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); } } } else { if (d->Res_R[Band]) // M==0, S!=0 { facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][0]); for ( n = 0; n < 12; n++, YL += 32, YR += 32 ) { *YR = - (*YL = MPC_MULTIPLY_FLOAT_INT(facR,*(R++))); } facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][1]); for ( ; n < 24; n++, YL += 32, YR += 32 ) { *YR = - (*YL = MPC_MULTIPLY_FLOAT_INT(facR,*(R++))); } facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][2]); for ( ; n < 36; n++, YL += 32, YR += 32 ) { *YR = - (*YL = MPC_MULTIPLY_FLOAT_INT(facR,*(R++))); } } else { // M==0, S==0 for ( n = 0; n < 36; n++, YL += 32, YR += 32 ) { *YR = *YL = 0; } } } } /************************** LR-coded **************************/ else { if ( d->Res_L [Band] ) { if ( d->Res_R [Band] ) { // L!=0, R!=0 facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][0]); facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][0]); for (n = 0; n < 12; n++, YL += 32, YR += 32 ) { *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); *YR = MPC_MULTIPLY_FLOAT_INT(facR,*R++); } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][1]); facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][1]); for (; n < 24; n++, YL += 32, YR += 32 ) { *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); *YR = MPC_MULTIPLY_FLOAT_INT(facR,*R++); } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][2]); facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][2]); for (; n < 36; n++, YL += 32, YR += 32 ) { *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); *YR = MPC_MULTIPLY_FLOAT_INT(facR,*R++); } } else { // L!=0, R==0 facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][0]); for ( n = 0; n < 12; n++, YL += 32, YR += 32 ) { *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); *YR = 0; } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][1]); for ( ; n < 24; n++, YL += 32, YR += 32 ) { *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); *YR = 0; } facL = MPC_MULTIPLY_SCF( Cc[d->Res_L[Band]] , (unsigned char)d->SCF_Index_L[Band][2]); for ( ; n < 36; n++, YL += 32, YR += 32 ) { *YL = MPC_MULTIPLY_FLOAT_INT(facL,*L++); *YR = 0; } } } else { if ( d->Res_R [Band] ) { // L==0, R!=0 facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][0]); for ( n = 0; n < 12; n++, YL += 32, YR += 32 ) { *YL = 0; *YR = MPC_MULTIPLY_FLOAT_INT(facR,*R++); } facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][1]); for ( ; n < 24; n++, YL += 32, YR += 32 ) { *YL = 0; *YR = MPC_MULTIPLY_FLOAT_INT(facR,*R++); } facR = MPC_MULTIPLY_SCF( Cc[d->Res_R[Band]] , (unsigned char)d->SCF_Index_R[Band][2]); for ( ; n < 36; n++, YL += 32, YR += 32 ) { *YL = 0; *YR = MPC_MULTIPLY_FLOAT_INT(facR,*R++); } } else { // L==0, R==0 for ( n = 0; n < 36; n++, YL += 32, YR += 32 ) { *YR = *YL = 0; } } } } } } /****************************************** SV 6 ******************************************/ void mpc_decoder_read_bitstream_sv6(mpc_decoder *d) { mpc_int32_t n,k; mpc_int32_t Max_used_Band=0; HuffmanTyp *Table; const HuffmanTyp *x1; const HuffmanTyp *x2; mpc_int32_t *L; mpc_int32_t *R; mpc_int32_t *ResL = d->Res_L; mpc_int32_t *ResR = d->Res_R; /************************ HEADER **************************/ ResL = d->Res_L; ResR = d->Res_R; for (n=0; n <= d->Max_Band; ++n, ++ResL, ++ResR) { if (n<11) Table = d->Region_A; else if (n>=11 && n<=22) Table = d->Region_B; else /*if (n>=23)*/ Table = d->Region_C; *ResL = d->Q_res[n][mpc_decoder_huffman_decode(d, Table)]; if (d->MS_used) { d->MS_Flag[n] = mpc_decoder_bitstream_read(d, 1); } *ResR = d->Q_res[n][mpc_decoder_huffman_decode(d, Table)]; // only perform the following procedure up to the maximum non-zero subband if (*ResL || *ResR) Max_used_Band = n; } /************************* SCFI-Bundle *****************************/ ResL = d->Res_L; ResR = d->Res_R; for (n=0; n<=Max_used_Band; ++n, ++ResL, ++ResR) { if (*ResL) mpc_decoder_scfi_bundle_read(d, d->SCFI_Bundle, &(d->SCFI_L[n]), &(d->DSCF_Flag_L[n])); if (*ResR) mpc_decoder_scfi_bundle_read(d, d->SCFI_Bundle, &(d->SCFI_R[n]), &(d->DSCF_Flag_R[n])); } /***************************** SCFI ********************************/ ResL = d->Res_L; ResR = d->Res_R; L = d->SCF_Index_L[0]; R = d->SCF_Index_R[0]; for (n=0; n <= Max_used_Band; ++n, ++ResL, ++ResR, L+=3, R+=3) { if (*ResL) { /*********** DSCF ************/ if (d->DSCF_Flag_L[n]==1) { L[2] = d->DSCF_Reference_L[n]; switch (d->SCFI_L[n]) { case 3: L[0] = L[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); L[1] = L[0]; L[2] = L[1]; break; case 1: L[0] = L[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); L[1] = L[0] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); L[2] = L[1]; break; case 2: L[0] = L[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); L[1] = L[0]; L[2] = L[1] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); break; case 0: L[0] = L[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); L[1] = L[0] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); L[2] = L[1] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); break; default: return; break; } } /************ SCF ************/ else { switch (d->SCFI_L[n]) { case 3: L[0] = mpc_decoder_bitstream_read(d, 6); L[1] = L[0]; L[2] = L[1]; break; case 1: L[0] = mpc_decoder_bitstream_read(d, 6); L[1] = mpc_decoder_bitstream_read(d, 6); L[2] = L[1]; break; case 2: L[0] = mpc_decoder_bitstream_read(d, 6); L[1] = L[0]; L[2] = mpc_decoder_bitstream_read(d, 6); break; case 0: L[0] = mpc_decoder_bitstream_read(d, 6); L[1] = mpc_decoder_bitstream_read(d, 6); L[2] = mpc_decoder_bitstream_read(d, 6); break; default: return; break; } } // update Reference for DSCF d->DSCF_Reference_L[n] = L[2]; } if (*ResR) { R[2] = d->DSCF_Reference_R[n]; /*********** DSCF ************/ if (d->DSCF_Flag_R[n]==1) { switch (d->SCFI_R[n]) { case 3: R[0] = R[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); R[1] = R[0]; R[2] = R[1]; break; case 1: R[0] = R[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); R[1] = R[0] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); R[2] = R[1]; break; case 2: R[0] = R[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); R[1] = R[0]; R[2] = R[1] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); break; case 0: R[0] = R[2] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); R[1] = R[0] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); R[2] = R[1] + mpc_decoder_huffman_decode_fast(d, d->DSCF_Entropie); break; default: return; break; } } /************ SCF ************/ else { switch (d->SCFI_R[n]) { case 3: R[0] = mpc_decoder_bitstream_read(d, 6); R[1] = R[0]; R[2] = R[1]; break; case 1: R[0] = mpc_decoder_bitstream_read(d, 6); R[1] = mpc_decoder_bitstream_read(d, 6); R[2] = R[1]; break; case 2: R[0] = mpc_decoder_bitstream_read(d, 6); R[1] = R[0]; R[2] = mpc_decoder_bitstream_read(d, 6); break; case 0: R[0] = mpc_decoder_bitstream_read(d, 6); R[1] = mpc_decoder_bitstream_read(d, 6); R[2] = mpc_decoder_bitstream_read(d, 6); break; default: return; break; } } // update Reference for DSCF d->DSCF_Reference_R[n] = R[2]; } } /**************************** Samples ****************************/ ResL = d->Res_L; ResR = d->Res_R; for (n=0; n <= Max_used_Band; ++n, ++ResL, ++ResR) { // setting pointers x1 = d->SampleHuff[*ResL]; x2 = d->SampleHuff[*ResR]; L = d->Q[n].L; R = d->Q[n].R; if (x1!=NULL || x2!=NULL) for (k=0; k<36; ++k) { if (x1 != NULL) *L++ = mpc_decoder_huffman_decode_fast(d, x1); if (x2 != NULL) *R++ = mpc_decoder_huffman_decode_fast(d, x2); } if (*ResL>7 || *ResR>7) for (k=0; k<36; ++k) { if (*ResL>7) *L++ = (mpc_int32_t)mpc_decoder_bitstream_read(d, Res_bit[*ResL]) - Dc[*ResL]; if (*ResR>7) *R++ = (mpc_int32_t)mpc_decoder_bitstream_read(d, Res_bit[*ResR]) - Dc[*ResR]; } } } /****************************************** SV 7 ******************************************/ void mpc_decoder_read_bitstream_sv7(mpc_decoder *d) { // these arrays hold decoding results for bundled quantizers (3- and 5-step) /*static*/ mpc_int32_t idx30[] = { -1, 0, 1,-1, 0, 1,-1, 0, 1,-1, 0, 1,-1, 0, 1,-1, 0, 1,-1, 0, 1,-1, 0, 1,-1, 0, 1}; /*static*/ mpc_int32_t idx31[] = { -1,-1,-1, 0, 0, 0, 1, 1, 1,-1,-1,-1, 0, 0, 0, 1, 1, 1,-1,-1,-1, 0, 0, 0, 1, 1, 1}; /*static*/ mpc_int32_t idx32[] = { -1,-1,-1,-1,-1,-1,-1,-1,-1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1}; /*static*/ mpc_int32_t idx50[] = { -2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2,-2,-1, 0, 1, 2}; /*static*/ mpc_int32_t idx51[] = { -2,-2,-2,-2,-2,-1,-1,-1,-1,-1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2}; mpc_int32_t n,k; mpc_int32_t Max_used_Band=0; const HuffmanTyp *Table; mpc_int32_t idx; mpc_int32_t *L ,*R; mpc_int32_t *ResL,*ResR; mpc_uint32_t tmp; /***************************** Header *****************************/ ResL = d->Res_L; ResR = d->Res_R; // first subband *ResL = mpc_decoder_bitstream_read(d, 4); *ResR = mpc_decoder_bitstream_read(d, 4); if (d->MS_used && !(*ResL==0 && *ResR==0)) { d->MS_Flag[0] = mpc_decoder_bitstream_read(d, 1); } // consecutive subbands ++ResL; ++ResR; // increase pointers for (n=1; n <= d->Max_Band; ++n, ++ResL, ++ResR) { idx = mpc_decoder_huffman_decode_fast(d, d->HuffHdr); *ResL = (idx!=4) ? *(ResL-1) + idx : (int)mpc_decoder_bitstream_read(d, 4); idx = mpc_decoder_huffman_decode_fast(d, d->HuffHdr); *ResR = (idx!=4) ? *(ResR-1) + idx : (int)mpc_decoder_bitstream_read(d, 4); if (d->MS_used && !(*ResL==0 && *ResR==0)) { d->MS_Flag[n] = mpc_decoder_bitstream_read(d, 1); } // only perform following procedures up to the maximum non-zero subband if (*ResL!=0 || *ResR!=0) { Max_used_Band = n; } } /****************************** SCFI ******************************/ L = d->SCFI_L; R = d->SCFI_R; ResL = d->Res_L; ResR = d->Res_R; for (n=0; n <= Max_used_Band; ++n, ++L, ++R, ++ResL, ++ResR) { if (*ResL) *L = mpc_decoder_huffman_decode_faster(d, d->HuffSCFI); if (*ResR) *R = mpc_decoder_huffman_decode_faster(d, d->HuffSCFI); } /**************************** SCF/DSCF ****************************/ ResL = d->Res_L; ResR = d->Res_R; L = d->SCF_Index_L[0]; R = d->SCF_Index_R[0]; for (n=0; n<=Max_used_Band; ++n, ++ResL, ++ResR, L+=3, R+=3) { if (*ResL) { L[2] = d->DSCF_Reference_L[n]; switch (d->SCFI_L[n]) { case 1: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[0] = (idx!=8) ? L[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[1] = (idx!=8) ? L[0] + idx : (int)mpc_decoder_bitstream_read(d, 6); L[2] = L[1]; break; case 3: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[0] = (idx!=8) ? L[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); L[1] = L[0]; L[2] = L[1]; break; case 2: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[0] = (idx!=8) ? L[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); L[1] = L[0]; idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[2] = (idx!=8) ? L[1] + idx : (int)mpc_decoder_bitstream_read(d, 6); break; case 0: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[0] = (idx!=8) ? L[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[1] = (idx!=8) ? L[0] + idx : (int)mpc_decoder_bitstream_read(d, 6); idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); L[2] = (idx!=8) ? L[1] + idx : (int)mpc_decoder_bitstream_read(d, 6); break; default: return; break; } // update Reference for DSCF d->DSCF_Reference_L[n] = L[2]; } if (*ResR) { R[2] = d->DSCF_Reference_R[n]; switch (d->SCFI_R[n]) { case 1: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[0] = (idx!=8) ? R[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[1] = (idx!=8) ? R[0] + idx : (int)mpc_decoder_bitstream_read(d, 6); R[2] = R[1]; break; case 3: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[0] = (idx!=8) ? R[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); R[1] = R[0]; R[2] = R[1]; break; case 2: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[0] = (idx!=8) ? R[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); R[1] = R[0]; idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[2] = (idx!=8) ? R[1] + idx : (int)mpc_decoder_bitstream_read(d, 6); break; case 0: idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[0] = (idx!=8) ? R[2] + idx : (int)mpc_decoder_bitstream_read(d, 6); idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[1] = (idx!=8) ? R[0] + idx : (int)mpc_decoder_bitstream_read(d, 6); idx = mpc_decoder_huffman_decode_fast(d, d->HuffDSCF); R[2] = (idx!=8) ? R[1] + idx : (int)mpc_decoder_bitstream_read(d, 6); break; default: return; break; } // update Reference for DSCF d->DSCF_Reference_R[n] = R[2]; } } /***************************** Samples ****************************/ ResL = d->Res_L; ResR = d->Res_R; L = d->Q[0].L; R = d->Q[0].R; for (n=0; n <= Max_used_Band; ++n, ++ResL, ++ResR, L+=36, R+=36) { /************** links **************/ switch (*ResL) { case -2: case -3: case -4: case -5: case -6: case -7: case -8: case -9: case -10: case -11: case -12: case -13: case -14: case -15: case -16: case -17: L += 36; break; case -1: for (k=0; k<36; k++ ) { tmp = random_int(d); *L++ = ((tmp >> 24) & 0xFF) + ((tmp >> 16) & 0xFF) + ((tmp >> 8) & 0xFF) + ((tmp >> 0) & 0xFF) - 510; } break; case 0: L += 36;// increase pointer break; case 1: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][1]; for (k=0; k<12; ++k) { idx = mpc_decoder_huffman_decode_fast(d, Table); *L++ = idx30[idx]; *L++ = idx31[idx]; *L++ = idx32[idx]; } break; case 2: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][2]; for (k=0; k<18; ++k) { idx = mpc_decoder_huffman_decode_fast(d, Table); *L++ = idx50[idx]; *L++ = idx51[idx]; } break; case 3: case 4: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][*ResL]; for (k=0; k<36; ++k) *L++ = mpc_decoder_huffman_decode_faster(d, Table); break; case 5: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][*ResL]; for (k=0; k<36; ++k) *L++ = mpc_decoder_huffman_decode_fast(d, Table); break; case 6: case 7: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][*ResL]; for (k=0; k<36; ++k) *L++ = mpc_decoder_huffman_decode(d, Table); break; case 8: case 9: case 10: case 11: case 12: case 13: case 14: case 15: case 16: case 17: tmp = Dc[*ResL]; for (k=0; k<36; ++k) *L++ = (mpc_int32_t)mpc_decoder_bitstream_read(d, Res_bit[*ResL]) - tmp; break; default: return; } /************** rechts **************/ switch (*ResR) { case -2: case -3: case -4: case -5: case -6: case -7: case -8: case -9: case -10: case -11: case -12: case -13: case -14: case -15: case -16: case -17: R += 36; break; case -1: for (k=0; k<36; k++ ) { tmp = random_int(d); *R++ = ((tmp >> 24) & 0xFF) + ((tmp >> 16) & 0xFF) + ((tmp >> 8) & 0xFF) + ((tmp >> 0) & 0xFF) - 510; } break; case 0: R += 36;// increase pointer break; case 1: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][1]; for (k=0; k<12; ++k) { idx = mpc_decoder_huffman_decode_fast(d, Table); *R++ = idx30[idx]; *R++ = idx31[idx]; *R++ = idx32[idx]; } break; case 2: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][2]; for (k=0; k<18; ++k) { idx = mpc_decoder_huffman_decode_fast(d, Table); *R++ = idx50[idx]; *R++ = idx51[idx]; } break; case 3: case 4: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][*ResR]; for (k=0; k<36; ++k) *R++ = mpc_decoder_huffman_decode_faster(d, Table); break; case 5: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][*ResR]; for (k=0; k<36; ++k) *R++ = mpc_decoder_huffman_decode_fast(d, Table); break; case 6: case 7: Table = d->HuffQ[mpc_decoder_bitstream_read(d, 1)][*ResR]; for (k=0; k<36; ++k) *R++ = mpc_decoder_huffman_decode(d, Table); break; case 8: case 9: case 10: case 11: case 12: case 13: case 14: case 15: case 16: case 17: tmp = Dc[*ResR]; for (k=0; k<36; ++k) *R++ = (mpc_int32_t)mpc_decoder_bitstream_read(d, Res_bit[*ResR]) - tmp; break; default: return; } } } void mpc_decoder_setup(mpc_decoder *d, mpc_reader *r) { d->r = r; d->HuffQ[0][0] = 0; d->HuffQ[1][0] = 0; d->HuffQ[0][1] = d->HuffQ1[0]; d->HuffQ[1][1] = d->HuffQ1[1]; d->HuffQ[0][2] = d->HuffQ2[0]; d->HuffQ[1][2] = d->HuffQ2[1]; d->HuffQ[0][3] = d->HuffQ3[0]; d->HuffQ[1][3] = d->HuffQ3[1]; d->HuffQ[0][4] = d->HuffQ4[0]; d->HuffQ[1][4] = d->HuffQ4[1]; d->HuffQ[0][5] = d->HuffQ5[0]; d->HuffQ[1][5] = d->HuffQ5[1]; d->HuffQ[0][6] = d->HuffQ6[0]; d->HuffQ[1][6] = d->HuffQ6[1]; d->HuffQ[0][7] = d->HuffQ7[0]; d->HuffQ[1][7] = d->HuffQ7[1]; d->SampleHuff[0] = NULL; d->SampleHuff[1] = d->Entropie_1; d->SampleHuff[2] = d->Entropie_2; d->SampleHuff[3] = d->Entropie_3; d->SampleHuff[4] = d->Entropie_4; d->SampleHuff[5] = d->Entropie_5; d->SampleHuff[6] = d->Entropie_6; d->SampleHuff[7] = d->Entropie_7; d->SampleHuff[8] = NULL; d->SampleHuff[9] = NULL; d->SampleHuff[10] = NULL; d->SampleHuff[11] = NULL; d->SampleHuff[12] = NULL; d->SampleHuff[13] = NULL; d->SampleHuff[14] = NULL; d->SampleHuff[15] = NULL; d->SampleHuff[16] = NULL; d->SampleHuff[17] = NULL; d->EQ_activated = 0; d->MPCHeaderPos = 0; d->StreamVersion = 0; d->MS_used = 0; d->FwdJumpInfo = 0; d->ActDecodePos = 0; d->FrameWasValid = 0; d->OverallFrames = 0; d->DecodedFrames = 0; d->LastValidSamples = 0; d->TrueGaplessPresent = 0; d->WordsRead = 0; d->Max_Band = 0; d->SampleRate = 0; // clips = 0; d->__r1 = 1; d->__r2 = 1; d->dword = 0; d->pos = 0; d->Zaehler = 0; d->WordsRead = 0; d->Max_Band = 0; mpc_decoder_initialisiere_quantisierungstabellen(d, 1.0f); mpc_decoder_init_huffman_sv6(d); mpc_decoder_init_huffman_sv7(d); } static void mpc_decoder_set_streaminfo(mpc_decoder *d, mpc_streaminfo *si) { mpc_decoder_reset_synthesis(d); mpc_decoder_reset_globals(d); d->StreamVersion = si->stream_version; d->MS_used = si->ms; d->Max_Band = si->max_band; d->OverallFrames = si->frames; d->MPCHeaderPos = si->header_position; d->LastValidSamples = si->last_frame_samples; d->TrueGaplessPresent = si->is_true_gapless; d->SampleRate = (mpc_int32_t)si->sample_freq; d->samples_to_skip = MPC_DECODER_SYNTH_DELAY; } bool mpc_decoder_initialize(mpc_decoder *d, mpc_streaminfo *si) { mpc_decoder_set_streaminfo(d, si); // AB: setting position to the beginning of the data-bitstream switch (d->StreamVersion) { case 0x04: f_seek(d, 4 + d->MPCHeaderPos); d->pos = 16; break; // Geht auch über eine der Helperfunktionen case 0x05: case 0x06: f_seek(d, 8 + d->MPCHeaderPos); d->pos = 0; break; case 0x07: case 0x17: /*f_seek ( 24 + d->MPCHeaderPos );*/ d->pos = 8; break; default: return false; } // AB: fill buffer and initialize decoder f_read_dword(d, d->Speicher, MEMSIZE ); d->dword = d->Speicher[d->Zaehler = 0]; return true; } //--------------------------------------------------------------- // will seek from the beginning of the file to the desired // position in ms (given by seek_needed) //--------------------------------------------------------------- #if 0 static void helper1(mpc_decoder *d, mpc_uint32_t bitpos) { f_seek(d, (bitpos >> 5) * 4 + d->MPCHeaderPos); f_read_dword(d, d->Speicher, 2); d->dword = d->Speicher[d->Zaehler = 0]; d->pos = bitpos & 31; } #endif static void helper2(mpc_decoder *d, mpc_uint32_t bitpos) { f_seek(d, (bitpos>>5) * 4 + d->MPCHeaderPos); f_read_dword(d, d->Speicher, MEMSIZE); d->dword = d->Speicher[d->Zaehler = 0]; d->pos = bitpos & 31; } #if 0 static void helper3(mpc_decoder *d, mpc_uint32_t bitpos, mpc_uint32_t* buffoffs) { d->pos = bitpos & 31; bitpos >>= 5; if ((mpc_uint32_t)(bitpos - *buffoffs) >= MEMSIZE - 2) { *buffoffs = bitpos; f_seek(d, bitpos * 4L + d->MPCHeaderPos); f_read_dword(d, d->Speicher, MEMSIZE ); } d->dword = d->Speicher[d->Zaehler = bitpos - *buffoffs ]; } #endif static mpc_uint32_t get_initial_fpos(mpc_decoder *d, mpc_uint32_t StreamVersion) { mpc_uint32_t fpos = 0; (void)StreamVersion; switch ( d->StreamVersion ) { // setting position to the beginning of the data-bitstream case 0x04: fpos = 48; break; case 0x05: case 0x06: fpos = 64; break; case 0x07: case 0x17: fpos = 200; break; } return fpos; } bool mpc_decoder_seek_seconds(mpc_decoder *d, double seconds) { return mpc_decoder_seek_sample(d, (mpc_int64_t)(seconds * (double)d->SampleRate + 0.5)); } bool mpc_decoder_seek_sample(mpc_decoder *d, mpc_int64_t destsample) { mpc_uint32_t fpos; mpc_uint32_t fwd; fwd = (mpc_uint32_t) (destsample / MPC_FRAME_LENGTH); d->samples_to_skip = MPC_DECODER_SYNTH_DELAY + (mpc_uint32_t)(destsample % MPC_FRAME_LENGTH); memset(d->Y_L , 0, sizeof d->Y_L ); memset(d->Y_R , 0, sizeof d->Y_R ); memset(d->SCF_Index_L , 0, sizeof d->SCF_Index_L ); memset(d->SCF_Index_R , 0, sizeof d->SCF_Index_R ); memset(d->Res_L , 0, sizeof d->Res_L ); memset(d->Res_R , 0, sizeof d->Res_R ); memset(d->SCFI_L , 0, sizeof d->SCFI_L ); memset(d->SCFI_R , 0, sizeof d->SCFI_R ); memset(d->DSCF_Flag_L , 0, sizeof d->DSCF_Flag_L ); memset(d->DSCF_Flag_R , 0, sizeof d->DSCF_Flag_R ); memset(d->DSCF_Reference_L, 0, sizeof d->DSCF_Reference_L ); memset(d->DSCF_Reference_R, 0, sizeof d->DSCF_Reference_R ); memset(d->Q , 0, sizeof d->Q ); memset(d->MS_Flag , 0, sizeof d->MS_Flag ); // resetting synthesis filter to avoid "clicks" mpc_decoder_reset_synthesis(d); // prevent from desired position out of allowed range fwd = fwd < d->OverallFrames ? fwd : d->OverallFrames; // reset number of decoded frames d->DecodedFrames = 0; fpos = get_initial_fpos(d, d->StreamVersion); if (fpos == 0) { return false; } helper2(d, fpos); // read the last 32 frames before the desired position to scan the scalefactors (artifactless jumping) for ( ; d->DecodedFrames < fwd; d->DecodedFrames++ ) { mpc_uint32_t FrameBitCnt; mpc_uint32_t RING; RING = d->Zaehler; d->FwdJumpInfo = mpc_decoder_bitstream_read(d, 20); // read jump-info d->ActDecodePos = (d->Zaehler << 5) + d->pos; FrameBitCnt = mpc_decoder_bits_read(d); // scanning the scalefactors and check for validity of frame if (d->StreamVersion >= 7) { mpc_decoder_read_bitstream_sv7(d); } else { mpc_decoder_read_bitstream_sv6(d); } if (mpc_decoder_bits_read(d) - FrameBitCnt != d->FwdJumpInfo ) { // Box ("Bug in perform_jump"); return false; } // update buffer if ((RING ^ d->Zaehler) & MEMSIZE2) { f_read_dword(d, d->Speicher + (RING & MEMSIZE2), MEMSIZE2); } } // LastBitsRead = BitsRead (); // LastFrame = d->DecodedFrames; return true; } void mpc_decoder_update_buffer(mpc_decoder *d, mpc_uint32_t RING) { if ((RING ^ d->Zaehler) & MEMSIZE2 ) { // update buffer f_read_dword(d, d->Speicher + (RING & MEMSIZE2), MEMSIZE2); } }