diff options
Diffstat (limited to 'decoders/i2s/pd.py')
| -rw-r--r-- | decoders/i2s/pd.py | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/decoders/i2s/pd.py b/decoders/i2s/pd.py index 9f04e10..c934b5d 100644 --- a/decoders/i2s/pd.py +++ b/decoders/i2s/pd.py @@ -56,6 +56,9 @@ class Decoder(srd.Decoder): ['right', 'Right channel'], ['warnings', 'Warnings'], ] + binary = ( + ('wav', 'WAV file'), + ) def __init__(self, **kwargs): self.samplerate = None @@ -67,9 +70,11 @@ class Decoder(srd.Decoder): self.first_sample = None self.start_sample = None self.wordlength = -1 + self.wrote_wav_header = False def start(self): self.out_proto = self.register(srd.OUTPUT_PYTHON) + self.out_bin = self.register(srd.OUTPUT_BINARY) self.out_ann = self.register(srd.OUTPUT_ANN) def metadata(self, key, value): @@ -79,6 +84,9 @@ class Decoder(srd.Decoder): def putpb(self, data): self.put(self.start_sample, self.samplenum, self.out_proto, data) + def putbin(self, data): + self.put(self.start_sample, self.samplenum, self.out_bin, data) + def putb(self, data): self.put(self.start_sample, self.samplenum, self.out_ann, data) @@ -96,6 +104,33 @@ class Decoder(srd.Decoder): return 'I²S: %d %d-bit samples received at %sHz' % \ (self.samplesreceived, self.wordlength, samplerate) + def wav_header(self): + # Chunk descriptor + h = b'RIFF' + h += b'\x24\x80\x00\x00' # Chunk size (2084) + h += b'WAVE' + # Fmt subchunk + h += b'fmt ' + h += b'\x10\x00\x00\x00' # Subchunk size (16 bytes) + h += b'\x01\x00' # Audio format (0x0001 == PCM) + h += b'\x02\x00' # Number of channels (2) + h += b'\x80\x3e\x00\x00' # Samplerate (16000) + h += b'\x00\x7d\x00\x00' # Byterate (32000) + h += b'\x04\x00' # Blockalign (4) + h += b'\x10\x00' # Bits per sample (16) + # Data subchunk + h += b'data' + h += b'\xff\xff\x00\x00' # Subchunk size (65535 bytes) TODO + return h + + def wav_sample(self, sample): + # TODO: This currently assumes U32 samples, and converts to S16. + s = sample >> 16 + if s >= 0x8000: + s -= 0x10000 + lo, hi = s & 0xff, (s >> 8) & 0xff + return bytes([lo, hi]) + def decode(self, ss, es, data): if self.samplerate is None: raise Exception("Cannot decode without samplerate.") @@ -118,6 +153,11 @@ class Decoder(srd.Decoder): # Only submit the sample, if we received the beginning of it. if self.start_sample != None: + + if not self.wrote_wav_header: + self.put(0, 0, self.out_bin, (0, self.wav_header())) + self.wrote_wav_header = True + self.samplesreceived += 1 idx = 0 if self.oldws else 1 @@ -128,6 +168,7 @@ class Decoder(srd.Decoder): self.putpb(['DATA', [c3, self.data]]) self.putb([idx, ['%s: %s' % (c1, v), '%s: %s' % (c2, v), '%s: %s' % (c3, v), c3]]) + self.putbin((0, self.wav_sample(self.data))) # Check that the data word was the correct length. if self.wordlength != -1 and self.wordlength != self.bitcount: |