/* (c) Copyright 1998-2000 - Tord Jansson ====================================== This file is part of the BladeEnc MP3 Encoder, based on ISO's reference code for MPEG Layer 3 compression, and might contain smaller or larger sections that are directly taken from ISO's reference code. All changes to the ISO reference code herein are either copyrighted by Tord Jansson (tord.jansson@swipnet.se) or sublicensed to Tord Jansson by a third party. BladeEnc is free software; you can redistribute this file and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. 2000-03-09 AndrŽ Piotrowski */ #include #include "common.h" #include "encoder.h" #include "l3psy.h" #include "loop.h" #include "l3bitstream.h" #include "formatbitstream2.h" #include "codec.h" #include "mdct.h" extern int fInit_mdct_sub; extern int fInit_mdct; extern void fixStatic_reservoir(); /************************************************************************/ #define SAMPLES_PER_FRAME 1152 static L3SBS l3_sb_sample; static layer info; static FLOAT buffer[2][2048]; static int buffer_idx; static int stereo, error_protection; static int whole_SpF; static double frac_SpF, slot_lag; static CodecInitOut sOut; static frame_params fr_ps; char *pEncodedOutput; int outputBit; /* Has to be global because of codecFlush() */ volatile double avg_slots_per_frame; static III_side_info_t l3_side; /*____ codecInit() ____________________________________________________________*/ CodecInitOut *codecInit (CodecInitIn *psIn) { int j; /* Read psIn */ switch (psIn->frequency) { case 48000: info.sampling_frequency = 1; break; case 44100: info.sampling_frequency = 0; break; case 32000: info.sampling_frequency = 2; break; default : return FALSE; } switch (psIn->mode) { case 0: info.mode = MPG_MD_STEREO ; info.mode_ext = 0; break; case 2: info.mode = MPG_MD_DUAL_CHANNEL; info.mode_ext = 0; break; case 3: info.mode = MPG_MD_MONO ; info.mode_ext = 0; break; default: return FALSE; } j = 0; while (j < 15 && bitratex[1][j] != psIn->bitrate) j++; info.bitrate_index = j; info.version = 1; /* Default: MPEG-1 */ info.emphasis = psIn->emphasis; info.extension = psIn->fPrivate; info.copyright = psIn->fCopyright; info.original = psIn->fOriginal; info.error_protection = psIn->fCRC; /*_______ Static-fix _______________*/ fInit_mdct_sub = 0; fInit_mdct = 0; fixStatic_reservoir(); /*___________________________________*/ psycho_anal_init (info.sampling_frequency); initWindowFilterSubband (); initFormatBitstream (); /* clear buffers */ memset ((char *) buffer, 0, sizeof(buffer)); buffer_idx = 0; fr_ps.header = &info; fr_ps.tab_num = -1; /* no table loaded */ fr_ps.alloc = NULL; fr_ps.actual_mode = info.mode; fr_ps.stereo = (info.mode == MPG_MD_MONO) ? 1 : 2; fr_ps.sblimit = SBLIMIT; fr_ps.jsbound = SBLIMIT; stereo = fr_ps.stereo; error_protection = info.error_protection; avg_slots_per_frame = ((double)SAMPLES_PER_FRAME / s_freq[1][info.sampling_frequency]) * ((double)bitratex[1][info.bitrate_index] / 8.0); whole_SpF = (int) avg_slots_per_frame; frac_SpF = avg_slots_per_frame - (double)whole_SpF; slot_lag = -frac_SpF; /* if (frac_SpF == 0) info.padding = 0; */ /*________________________*/ if( stereo != 2 ) sOut.nSamples = SAMPLES_PER_FRAME; else sOut.nSamples = SAMPLES_PER_FRAME*2; sOut.bufferSize = 2048; return &sOut; /* How many samples we want in each chunk... */ } /*____ codecEncodeChunk() _____________________________________________________*/ unsigned int codecEncodeChunk( int nSamples, short *pSamples, char *pDest ) { static double xr[2][2][576]; static double pe[2][2]; static int l3_enc[2][2][576]; static III_psy_ratio ratio; static III_scalefac_t scalefac; int gr, ch; int mean_bits, sideinfo_len; int bitsPerFrame; int j; /* rebuffer audio */ rebuffer_audio (pSamples, buffer, &buffer_idx, nSamples, stereo); /* psychoacoustic model */ for (gr=0; gr<2; gr++) for (ch=0; ch (frac_SpF-1.0)) { slot_lag -= frac_SpF; info.padding = 0; } else { info.padding = 1; slot_lag -= (frac_SpF-1.0); } } bitsPerFrame = 8 * whole_SpF + (info.padding * 8); /* determine the mean bitrate for main data */ sideinfo_len = 32; if (stereo == 1) sideinfo_len += 136; else sideinfo_len += 256; if (info.error_protection) sideinfo_len += 16; mean_bits = (bitsPerFrame - sideinfo_len) / 2; /* bit and noise allocation */ iteration_loop (pe, xr, &ratio, &l3_side, l3_enc, mean_bits, stereo, &scalefac, &fr_ps, 0, bitsPerFrame); /* write the frame to the bitstream */ III_format_bitstream (bitsPerFrame, &fr_ps, l3_enc, &l3_side, &scalefac, xr, NULL, 0); return pEncodedOutput - pDest; } /*____ codecExit() ____________________________________________________________*/ unsigned int codecExit (char *pDest) { pEncodedOutput = pDest; *pEncodedOutput = 0; outputBit = 8; exitFormatBitstream(); III_FlushBitstream(); return pEncodedOutput - pDest; } /*____ codecFlush() _________________________________________________________*/ unsigned int codecFlush( char * pDest ) { pEncodedOutput = pDest; outputBit = 8; pEncodedOutput[0] = 0; flushFrame(); whole_SpF = (int) avg_slots_per_frame; frac_SpF = avg_slots_per_frame - (double)whole_SpF; slot_lag = -frac_SpF; l3_side.main_data_begin = 0; fixStatic_reservoir(); return pEncodedOutput - pDest; }