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sbc: forced stereo, a glich in encoded data is still present

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This commit is contained in:
Milanka Ringwald 2016-05-18 15:56:38 +02:00
parent 5c9bef5ba2
commit c9498b1266
3 changed files with 35 additions and 41 deletions
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64
test/sbc/sbc.py
View File

@ -155,41 +155,41 @@ def calculate_scalefactors(nr_blocks, nr_channels, nr_subbands, sb_sample):
(scale_factor[ch][sb], scalefactor[ch][sb]) = calculate_scalefactor(max_subbandsample[ch][sb])
return scale_factor, scalefactor
def calculate_channel_mode(frame):
def calculate_channel_mode_and_scale_factors(frame):
frame.scale_factor, frame.scalefactor = calculate_scalefactors(frame.nr_blocks, frame.nr_channels, frame.nr_subbands, frame.sb_sample)
if frame.nr_channels == 1:
frame.channel_mode = MONO
else:
frame.channel_mode = STEREO
frame.join = np.zeros(frame.nr_subbands, dtype = np.uint8)
return
sb_sample1 = np.zeros(shape = (frame.nr_blocks,2,frame.nr_subbands), dtype = np.uint16)
for blk in range(frame.nr_blocks):
for sb in range(frame.nr_subbands):
sb_sample1[blk][0][sb] = (frame.sb_sample[blk][0][sb] + frame.sb_sample[blk][1][sb])/2
sb_sample1[blk][1][sb] = (frame.sb_sample[blk][0][sb] - frame.sb_sample[blk][1][sb])/2
scale_factor, scalefactor = calculate_scalefactors(frame.nr_blocks, frame.nr_channels, frame.nr_subbands, sb_sample1)
frame.channel_mode = STEREO
frame.join = np.zeros(frame.nr_subbands, dtype = np.uint8)
return
sb_sample = np.zeros(shape = (frame.nr_blocks,2,frame.nr_subbands), dtype = np.uint16)
for blk in range(frame.nr_blocks):
for sb in range(frame.nr_subbands):
suma = frame.scale_factor[0][sb] + frame.scale_factor[1][sb]
sumb = scale_factor[0][sb] + scale_factor[1][sb]
if suma > sumb:
frame.channel_mode = JOINT_STEREO
frame.join[sb] = 1
sb_sample[blk][0][sb] = np.uint16(frame.sb_sample[blk][0][sb] + frame.sb_sample[blk][1][sb])/2
sb_sample[blk][1][sb] = np.uint16(frame.sb_sample[blk][0][sb] - frame.sb_sample[blk][1][sb])/2
frame.scale_factor[0][sb] = scale_factor[0][sb]
frame.scale_factor[1][sb] = scale_factor[1][sb]
frame.scalefactor[0][sb] = scalefactor[0][sb]
frame.scalefactor[1][sb] = scalefactor[1][sb]
scale_factor, scalefactor = calculate_scalefactors(frame.nr_blocks, frame.nr_channels, frame.nr_subbands, sb_sample)
for blk in range(frame.nr_blocks):
frame.sb_sample[blk][0][sb] = sb_sample1[blk][0][sb]
frame.sb_sample[blk][1][sb] = sb_sample1[blk][1][sb]
for sb in range(frame.nr_subbands):
suma = frame.scale_factor[0][sb] + frame.scale_factor[1][sb]
sumb = scale_factor[0][sb] + scale_factor[1][sb]
if suma > sumb:
frame.channel_mode = JOINT_STEREO
frame.join[sb] = 1
print " channel_mode = JOINT_STEREO"
frame.scale_factor[0][sb] = scale_factor[0][sb]
frame.scale_factor[1][sb] = scale_factor[1][sb]
frame.scalefactor[0][sb] = scalefactor[0][sb]
frame.scalefactor[1][sb] = scalefactor[1][sb]
for blk in range(frame.nr_blocks):
frame.sb_sample[blk][0][sb] = sb_sample[blk][0][sb]
frame.sb_sample[blk][1][sb] = sb_sample[blk][1][sb]
class SBCFrame:
@ -287,7 +287,7 @@ def sbc_bit_allocation_stereo_joint(frame):
bitneed[ch][sb] = -5
else:
if frame.nr_subbands == 4:
loudness = scale_factor[ch][sb] - offset4[frame.sampling_frequency][sb]
loudness = frame.scale_factor[ch][sb] - offset4[frame.sampling_frequency][sb]
else:
loudness = frame.scale_factor[ch][sb] - offset8[frame.sampling_frequency][sb]
@ -328,8 +328,8 @@ def sbc_bit_allocation_stereo_joint(frame):
# bits are distributed until the last bitslice is reached
for ch in range(frame.nr_channels):
for sb in range(frame.nr_subbands):
if bitneed[ch][sb] < bitslice+2 :
bits[ch][sb]=0;
if bitneed[ch][sb] < bitslice+2:
bits[ch][sb]=0
else:
bits[ch][sb] = min(bitneed[ch][sb]-bitslice,16)
@ -547,9 +547,7 @@ def calculate_crc(frame):
add_bits(frame.allocation_method, 1)
add_bits(frame.nr_subbands/4-1, 1)
add_bits(frame.bitpool, 8)
if frame.channel_mode == JOINT_STEREO:
#print ("Joint Stereo!")
for sb in range(frame.nr_subbands):
add_bits(frame.join[sb],1)
@ -560,7 +558,7 @@ def calculate_crc(frame):
bitstream_len = (bitstream_index + 1) * 8
if bitstream_bits_available:
bitstream_len -= bitstream_bits_available
return sbc_crc8(bitstream, bitstream_len)

7
test/sbc/sbc_decoder.py
View File

@ -32,19 +32,16 @@ def sbc_unpack_frame(fin, available_bytes, frame):
frame.bitpool = get_bits(fin,8)
frame.crc_check = get_bits(fin,8)
# frame.join = np.zeros(frame.nr_subbands, dtype = np.uint8)
if frame.channel_mode == JOINT_STEREO:
frame.join = np.zeros(frame.nr_subbands-1)
for sb in range(frame.nr_subbands-1):
frame.join[sb] = get_bits(fin,1)
get_bits(fin,1) # RFA
frame.scale_factor = np.zeros(shape=(frame.nr_channels, frame.nr_subbands), dtype = np.int32)
# print frame.audio_sample
for ch in range(frame.nr_channels):
for sb in range(frame.nr_subbands):
frame.scale_factor[ch][sb] = get_bits(fin, 4)
@ -91,7 +88,7 @@ def sbc_reconstruct_subband_samples(frame):
frame.sb_sample[blk][ch][sb] = SF * ((AS*2.0+1.0) / L -1.0 )
else:
frame.sb_sample[blk][ch][sb] = 0
frame.sb_sample[blk][ch][sb] = 0
# sythesis filter
if frame.channel_mode == JOINT_STEREO:

5
test/sbc/sbc_encoder.py
View File

@ -69,7 +69,7 @@ def sbc_analysis(frame):
index = 0
for blk in range(frame.nr_blocks):
for sb in range(frame.nr_subbands):
frame.EX[sb] = np.int16(frame.pcm[ch][index])
frame.EX[sb] = frame.pcm[ch][index]
index+=1
sbc_frame_analysis(frame, ch, blk, C)
return 0
@ -81,8 +81,7 @@ def sbc_encode(frame):
return err
def sbc_quantization(frame):
frame.scale_factor, frame.scalefactor = calculate_scalefactors(frame.nr_blocks, frame.nr_channels, frame.nr_subbands, frame.sb_sample)
calculate_channel_mode(frame)
calculate_channel_mode_and_scale_factors(frame)
frame.bits = sbc_bit_allocation(frame)
# Reconstruct the Audio Samples