235 lines
7.1 KiB
C++
235 lines
7.1 KiB
C++
/*
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* Siren Encoder/Decoder library
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*
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* @author: Youness Alaoui <kakaroto@kakaroto.homelinux.net>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#include "siren7.h"
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SirenDecoder Siren7_NewDecoder(int sample_rate) {
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SirenDecoder decoder = (SirenDecoder) malloc(sizeof(struct stSirenDecoder));
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decoder->sample_rate = sample_rate;
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decoder->WavHeader.riff.RiffId = ME_TO_LE32(RIFF_ID);
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decoder->WavHeader.riff.RiffSize = sizeof(PCMWavHeader) - 2*sizeof(int);
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decoder->WavHeader.riff.RiffSize = ME_TO_LE32(decoder->WavHeader.riff.RiffSize);
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decoder->WavHeader.WaveId = ME_TO_LE32(WAVE_ID);
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decoder->WavHeader.FmtId = ME_TO_LE32(FMT__ID);
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decoder->WavHeader.FmtSize = ME_TO_LE32(sizeof(FmtChunk));
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decoder->WavHeader.fmt.Format = ME_TO_LE16(0x01);
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decoder->WavHeader.fmt.Channels = ME_TO_LE16(1);
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decoder->WavHeader.fmt.SampleRate = ME_TO_LE32(16000);
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decoder->WavHeader.fmt.ByteRate = ME_TO_LE32(32000);
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decoder->WavHeader.fmt.BlockAlign = ME_TO_LE16(2);
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decoder->WavHeader.fmt.BitsPerSample = ME_TO_LE16(16);
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decoder->WavHeader.FactId = ME_TO_LE32(FACT_ID);
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decoder->WavHeader.FactSize = ME_TO_LE32(sizeof(int));
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decoder->WavHeader.Samples = ME_TO_LE32(0);
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decoder->WavHeader.DataId = ME_TO_LE32(DATA_ID);
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decoder->WavHeader.DataSize = ME_TO_LE32(0);
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memset(decoder->context, 0, sizeof(decoder->context));
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memset(decoder->backup_frame, 0, sizeof(decoder->backup_frame));
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decoder->dw1 = 1;
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decoder->dw2 = 1;
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decoder->dw3 = 1;
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decoder->dw4 = 1;
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siren_init();
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return decoder;
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}
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void Siren7_CloseDecoder(SirenDecoder decoder) {
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free(decoder);
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}
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int Siren7_DecodeFrame(SirenDecoder decoder, unsigned char *DataIn, unsigned char *DataOut) {
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int number_of_coefs,
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sample_rate_bits,
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rate_control_bits,
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rate_control_possibilities,
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checksum_bits,
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esf_adjustment,
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scale_factor,
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number_of_regions,
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sample_rate_code,
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bits_per_frame;
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int decoded_sample_rate_code;
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static int absolute_region_power_index[28] = {0};
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static float decoder_standard_deviation[28] = {0};
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static int power_categories[28] = {0};
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static int category_balance[28] = {0};
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int ChecksumTable[4] = {0x7F80, 0x7878, 0x6666, 0x5555};
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int i, j;
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int dwRes = 0;
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int envelope_bits = 0;
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int rate_control = 0;
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int number_of_available_bits;
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int number_of_valid_coefs;
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int frame_error = 0;
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int In[20];
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float coefs[320];
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float BufferOut[320];
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int sum;
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int checksum;
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int calculated_checksum;
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int idx;
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int temp1;
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int temp2;
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for (i = 0; i < 20; i++)
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#ifdef __BIG_ENDIAN__
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In[i] = ((short *) DataIn)[i];
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#else
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In[i] = ((((short *) DataIn)[i] << 8) & 0xFF00) | ((((short *) DataIn)[i] >> 8) & 0x00FF);
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#endif
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dwRes = GetSirenCodecInfo(1, decoder->sample_rate, &number_of_coefs, &sample_rate_bits, &rate_control_bits, &rate_control_possibilities, &checksum_bits, &esf_adjustment, &scale_factor, &number_of_regions, &sample_rate_code, &bits_per_frame );
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if (dwRes != 0)
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return dwRes;
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set_bitstream(In);
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decoded_sample_rate_code = 0;
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for (i = 0; i < sample_rate_bits; i++) {
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decoded_sample_rate_code <<= 1;
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decoded_sample_rate_code |= next_bit();
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}
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if (decoded_sample_rate_code != sample_rate_code)
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return 7;
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number_of_valid_coefs = region_size * number_of_regions;
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number_of_available_bits = bits_per_frame - sample_rate_bits - checksum_bits ;
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envelope_bits = decode_envelope(number_of_regions, decoder_standard_deviation, absolute_region_power_index, esf_adjustment);
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number_of_available_bits -= envelope_bits;
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for (i = 0; i < rate_control_bits; i++) {
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rate_control <<= 1;
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rate_control |= next_bit();
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}
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number_of_available_bits -= rate_control_bits;
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categorize_regions(number_of_regions, number_of_available_bits, absolute_region_power_index, power_categories, category_balance);
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for (i = 0; i < rate_control; i++) {
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power_categories[category_balance[i]]++;
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}
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number_of_available_bits = decode_vector(decoder, number_of_regions, number_of_available_bits, decoder_standard_deviation, power_categories, coefs, scale_factor);
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frame_error = 0;
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if (number_of_available_bits > 0) {
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for (i = 0; i < number_of_available_bits; i++) {
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if (next_bit() == 0)
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frame_error = 1;
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}
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} else if (number_of_available_bits < 0 && rate_control + 1 < rate_control_possibilities) {
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frame_error |= 2;
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}
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for (i = 0; i < number_of_regions; i++) {
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if (absolute_region_power_index[i] > 33 || absolute_region_power_index[i] < -31)
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frame_error |= 4;
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}
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if (checksum_bits > 0) {
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bits_per_frame >>= 4;
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checksum = In[bits_per_frame - 1] & ((1 << checksum_bits) - 1);
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In[bits_per_frame - 1] &= ~checksum;
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sum = 0;
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idx = 0;
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do {
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sum ^= (In[idx] & 0xFFFF) << (idx % 15);
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} while (++idx < bits_per_frame);
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sum = (sum >> 15) ^ (sum & 0x7FFF);
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calculated_checksum = 0;
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for (i = 0; i < 4; i++) {
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temp1 = ChecksumTable[i] & sum;
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for (j = 8; j > 0; j >>= 1) {
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temp2 = temp1 >> j;
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temp1 ^= temp2;
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}
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calculated_checksum <<= 1;
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calculated_checksum |= temp1 & 1;
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}
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if (checksum != calculated_checksum)
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frame_error |= 8;
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}
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if (frame_error != 0) {
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for (i = 0; i < number_of_valid_coefs; i++) {
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coefs[i] = decoder->backup_frame[i];
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decoder->backup_frame[i] = 0;
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}
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} else {
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for (i = 0; i < number_of_valid_coefs; i++)
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decoder->backup_frame[i] = coefs[i];
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}
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for (i = number_of_valid_coefs; i < number_of_coefs; i++)
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coefs[i] = 0;
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dwRes = siren_rmlt_decode_samples(coefs, decoder->context, 320, BufferOut);
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for (i = 0; i < 320; i++) {
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if (BufferOut[i] > 32767.0)
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((short *)DataOut)[i] = (short) ME_TO_LE16((short) 32767);
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else if (BufferOut[i] <= -32768.0)
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((short *)DataOut)[i] = (short) ME_TO_LE16((short) 32768);
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else
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((short *)DataOut)[i] = (short) ME_TO_LE16((short) BufferOut[i]);
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}
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decoder->WavHeader.Samples = ME_FROM_LE32(decoder->WavHeader.Samples);
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decoder->WavHeader.Samples += 320;
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decoder->WavHeader.Samples = ME_TO_LE32(decoder->WavHeader.Samples);
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decoder->WavHeader.DataSize = ME_FROM_LE32(decoder->WavHeader.DataSize);
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decoder->WavHeader.DataSize += 640;
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decoder->WavHeader.DataSize = ME_TO_LE32(decoder->WavHeader.DataSize);
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decoder->WavHeader.riff.RiffSize = ME_FROM_LE32(decoder->WavHeader.riff.RiffSize);
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decoder->WavHeader.riff.RiffSize += 640;
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decoder->WavHeader.riff.RiffSize = ME_TO_LE32(decoder->WavHeader.riff.RiffSize);
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return 0;
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}
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