1c21a9c2fSMilanka Ringwald#!/usr/bin/env python 2c21a9c2fSMilanka Ringwaldimport numpy as np 3c21a9c2fSMilanka Ringwaldimport wave 4c21a9c2fSMilanka Ringwaldimport struct 5c21a9c2fSMilanka Ringwaldimport sys 6c21a9c2fSMilanka Ringwaldfrom sbc import * 7c21a9c2fSMilanka Ringwald 85c9bef5bSMilanka RingwaldX = np.zeros(shape=(2,80), dtype = np.int16) 9c21a9c2fSMilanka Ringwald 10ad470863SMilanka Ringwald 11ad470863SMilanka Ringwalddef fetch_samples_for_next_sbc_frame(fin, frame): 125c9bef5bSMilanka Ringwald nr_samples = frame.nr_blocks * frame.nr_subbands 131522543dSMilanka Ringwald raw_data = fin.readframes(nr_samples) # Returns byte data 145c9bef5bSMilanka Ringwald fmt = "%ih" % (len(raw_data) / 2) 151522543dSMilanka Ringwald data = struct.unpack(fmt, raw_data) 161522543dSMilanka Ringwald 175c9bef5bSMilanka Ringwald if frame.nr_channels == 2: 189462b3daSMilanka Ringwald for i in range(len(data)/2): 195c9bef5bSMilanka Ringwald frame.pcm[0][i] = data[2*i] 205c9bef5bSMilanka Ringwald frame.pcm[1][i] = data[2*i+1] 211522543dSMilanka Ringwald else: 225c9bef5bSMilanka Ringwald for i in range(len(data)): 235c9bef5bSMilanka Ringwald frame.pcm[0][i] = data[i] 24c21a9c2fSMilanka Ringwald 25c21a9c2fSMilanka Ringwald 26ad470863SMilanka Ringwalddef sbc_frame_analysis(frame, ch, blk, C): 27c21a9c2fSMilanka Ringwald global X 28ad470863SMilanka Ringwald 29c21a9c2fSMilanka Ringwald M = frame.nr_subbands 30c21a9c2fSMilanka Ringwald L = 10 * M 31c21a9c2fSMilanka Ringwald M2 = 2*M 32c21a9c2fSMilanka Ringwald L2 = 2*L 33c21a9c2fSMilanka Ringwald 34c21a9c2fSMilanka Ringwald Z = np.zeros(L) 35c21a9c2fSMilanka Ringwald Y = np.zeros(M2) 36c21a9c2fSMilanka Ringwald W = np.zeros(shape=(M, M2)) 37c21a9c2fSMilanka Ringwald S = np.zeros(M) 38c21a9c2fSMilanka Ringwald 39c21a9c2fSMilanka Ringwald for i in range(L-1, M-1, -1): 405c9bef5bSMilanka Ringwald X[ch][i] = X[ch][i-M] 41c21a9c2fSMilanka Ringwald for i in range(M-1, -1, -1): 425c9bef5bSMilanka Ringwald X[ch][i] = frame.EX[M-1-i] 43c21a9c2fSMilanka Ringwald for i in range(L): 445c9bef5bSMilanka Ringwald Z[i] = X[ch][i] * C[i] 45c21a9c2fSMilanka Ringwald 46c21a9c2fSMilanka Ringwald for i in range(M2): 47c21a9c2fSMilanka Ringwald for k in range(5): 48af086c98SMilanka Ringwald Y[i] += Z[i+k*M2] 49c21a9c2fSMilanka Ringwald 50c21a9c2fSMilanka Ringwald for i in range(M): 51c21a9c2fSMilanka Ringwald for k in range(M2): 52af086c98SMilanka Ringwald W[i][k] = np.cos((i+0.5)*(k-M/2)*np.pi/M) 53c21a9c2fSMilanka Ringwald S[i] += W[i][k] * Y[k] 54c21a9c2fSMilanka Ringwald 55c21a9c2fSMilanka Ringwald for sb in range(M): 56c21a9c2fSMilanka Ringwald frame.sb_sample[blk][ch][sb] = S[sb] 57c21a9c2fSMilanka Ringwald 58ad470863SMilanka Ringwalddef sbc_analysis(frame): 59c21a9c2fSMilanka Ringwald if frame.nr_subbands == 4: 60ad470863SMilanka Ringwald C = Proto_4_40 61c21a9c2fSMilanka Ringwald elif frame.nr_subbands == 8: 62ad470863SMilanka Ringwald C = Proto_8_80 63c21a9c2fSMilanka Ringwald else: 64c21a9c2fSMilanka Ringwald return -1 65c21a9c2fSMilanka Ringwald 66c21a9c2fSMilanka Ringwald frame.sb_sample = np.ndarray(shape=(frame.nr_blocks, frame.nr_channels, frame.nr_subbands)) 67c21a9c2fSMilanka Ringwald for ch in range(frame.nr_channels): 685c9bef5bSMilanka Ringwald index = 0 69c21a9c2fSMilanka Ringwald for blk in range(frame.nr_blocks): 70c21a9c2fSMilanka Ringwald for sb in range(frame.nr_subbands): 71c9498b12SMilanka Ringwald frame.EX[sb] = frame.pcm[ch][index] 72c21a9c2fSMilanka Ringwald index+=1 73ad470863SMilanka Ringwald sbc_frame_analysis(frame, ch, blk, C) 74ad470863SMilanka Ringwald return 0 75c21a9c2fSMilanka Ringwald 76ad470863SMilanka Ringwalddef sbc_encode(frame): 77ad470863SMilanka Ringwald err = sbc_analysis(frame) 78ad470863SMilanka Ringwald if err >= 0: 79ad470863SMilanka Ringwald err = sbc_quantization(frame) 80ad470863SMilanka Ringwald return err 81c21a9c2fSMilanka Ringwald 82c21a9c2fSMilanka Ringwalddef sbc_quantization(frame): 83c9498b12SMilanka Ringwald calculate_channel_mode_and_scale_factors(frame) 84c21a9c2fSMilanka Ringwald frame.bits = sbc_bit_allocation(frame) 85c21a9c2fSMilanka Ringwald 86c21a9c2fSMilanka Ringwald # Reconstruct the Audio Samples 87c21a9c2fSMilanka Ringwald frame.levels = np.zeros(shape=(frame.nr_channels, frame.nr_subbands), dtype = np.int32) 88c21a9c2fSMilanka Ringwald for ch in range(frame.nr_channels): 89c21a9c2fSMilanka Ringwald for sb in range(frame.nr_subbands): 90ad470863SMilanka Ringwald frame.levels[ch][sb] = (1 << frame.bits[ch][sb]) - 1 #pow(2.0, frame.bits[ch][sb]) - 1 91c21a9c2fSMilanka Ringwald 92*57f2bc22SMilanka Ringwald frame.syncword = 0x9c 93c21a9c2fSMilanka Ringwald frame.crc_check = calculate_crc(frame) 94c21a9c2fSMilanka Ringwald 95*57f2bc22SMilanka Ringwald 96c21a9c2fSMilanka Ringwald for blk in range(frame.nr_blocks): 97c21a9c2fSMilanka Ringwald for ch in range(frame.nr_channels): 98c21a9c2fSMilanka Ringwald for sb in range(frame.nr_subbands): 99c21a9c2fSMilanka Ringwald if frame.levels[ch][sb] > 0: 100c21a9c2fSMilanka Ringwald SB = frame.sb_sample[blk][ch][sb] 101c21a9c2fSMilanka Ringwald L = frame.levels[ch][sb] 102ad470863SMilanka Ringwald SF = frame.scalefactor[ch][sb] 103*57f2bc22SMilanka Ringwald 104*57f2bc22SMilanka Ringwald # if frame.channel_mode == JOINT_STEREO and frame.join[sb]: 105*57f2bc22SMilanka Ringwald # SB = SB * 2 106*57f2bc22SMilanka Ringwald 10741a4a18dSMilanka Ringwald frame.audio_sample[blk][ch][sb] = np.uint16(((SB * L / SF + L) - 1.0)/2.0) 108c21a9c2fSMilanka Ringwald else: 109c21a9c2fSMilanka Ringwald frame.audio_sample[blk][ch][sb] = 0 110c21a9c2fSMilanka Ringwald 111c21a9c2fSMilanka Ringwald return 0 112c21a9c2fSMilanka Ringwald 113ad470863SMilanka Ringwalddef sbc_write_frame(fout, sbc_encoder_frame): 114ad470863SMilanka Ringwald stream = frame_to_bitstream(sbc_encoder_frame) 115ad470863SMilanka Ringwald barray = bytearray(stream) 116ad470863SMilanka Ringwald fout.write(barray) 117ad470863SMilanka Ringwald 118ba114a98SMatthias Ringwaldif __name__ == "__main__": 119ba114a98SMatthias Ringwald usage = ''' 1205665ea35SMilanka Ringwald Usage: ./sbc_encoder.py input.wav blocks subbands bitpool allocation_method[0-LOUDNESS,1-SNR] 1215665ea35SMilanka Ringwald Example: ./sbc_encoder.py fanfare.wav 16 4 31 0 122ba114a98SMatthias Ringwald ''' 123ba114a98SMatthias Ringwald nr_blocks = 0 124ba114a98SMatthias Ringwald nr_subbands = 0 125c21a9c2fSMilanka Ringwald 126ad470863SMilanka Ringwald 1275665ea35SMilanka Ringwald if (len(sys.argv) < 6): 128ba114a98SMatthias Ringwald print(usage) 129ba114a98SMatthias Ringwald sys.exit(1) 130ba114a98SMatthias Ringwald try: 131ba114a98SMatthias Ringwald infile = sys.argv[1] 132ba114a98SMatthias Ringwald if not infile.endswith('.wav'): 133ba114a98SMatthias Ringwald print(usage) 134ba114a98SMatthias Ringwald sys.exit(1) 135ad470863SMilanka Ringwald sbcfile = infile.replace('.wav', '-encoded.sbc') 136ad470863SMilanka Ringwald 137ba114a98SMatthias Ringwald nr_blocks = int(sys.argv[2]) 138ba114a98SMatthias Ringwald nr_subbands = int(sys.argv[3]) 139ba114a98SMatthias Ringwald bitpool = int(sys.argv[4]) 1405665ea35SMilanka Ringwald allocation_method = int(sys.argv[5]) 141c21a9c2fSMilanka Ringwald 142ba114a98SMatthias Ringwald fin = wave.open(infile, 'rb') 143ad470863SMilanka Ringwald nr_channels = fin.getnchannels() 144ad470863SMilanka Ringwald sampling_frequency = fin.getframerate() 145ad470863SMilanka Ringwald nr_audio_frames = fin.getnframes() 146c21a9c2fSMilanka Ringwald 147ad470863SMilanka Ringwald subband_frame_count = 0 148ba114a98SMatthias Ringwald audio_frame_count = 0 149ad470863SMilanka Ringwald nr_samples = nr_blocks * nr_subbands 150ad470863SMilanka Ringwald fout = open(sbcfile, 'wb') 151ad470863SMilanka Ringwald while audio_frame_count < nr_audio_frames: 152ad470863SMilanka Ringwald if subband_frame_count % 200 == 0: 153ad470863SMilanka Ringwald print("== Frame %d ==" % (subband_frame_count)) 154c21a9c2fSMilanka Ringwald 1555665ea35SMilanka Ringwald sbc_encoder_frame = SBCFrame(nr_blocks, nr_subbands, nr_channels, bitpool, sampling_frequency, allocation_method) 156ad470863SMilanka Ringwald fetch_samples_for_next_sbc_frame(fin, sbc_encoder_frame) 157c21a9c2fSMilanka Ringwald 158ad470863SMilanka Ringwald sbc_encode(sbc_encoder_frame) 159ad470863SMilanka Ringwald sbc_write_frame(fout, sbc_encoder_frame) 160c21a9c2fSMilanka Ringwald 161*57f2bc22SMilanka Ringwald # if subband_frame_count == 1: 162*57f2bc22SMilanka Ringwald # exit(0) 163ad470863SMilanka Ringwald audio_frame_count += nr_samples 164ad470863SMilanka Ringwald subband_frame_count += 1 165c21a9c2fSMilanka Ringwald 1665c9bef5bSMilanka Ringwald 167ad470863SMilanka Ringwald fin.close() 168ad470863SMilanka Ringwald fout.close() 169ad470863SMilanka Ringwald print("DONE, WAV file %s encoded into SBC file %s " % (infile, sbcfile)) 170c21a9c2fSMilanka Ringwald 171c21a9c2fSMilanka Ringwald 172ba114a98SMatthias Ringwald except IOError as e: 173ba114a98SMatthias Ringwald print(usage) 174ba114a98SMatthias Ringwald sys.exit(1) 175c21a9c2fSMilanka Ringwald 176c21a9c2fSMilanka Ringwald 177c21a9c2fSMilanka Ringwald 178c21a9c2fSMilanka Ringwald 179c21a9c2fSMilanka Ringwald 180