.vscode/tasks.json

@@ -3,10 +3,15 @@
     // for the documentation about the tasks.json format
     "version": "2.0.0",
     "tasks": [
+        {
+            "label": "Setup project for development",
+            "type": "shell",
+            "command": "./venv/bin/python -m pip install -e ."
+        },
         {
             "label": "pip install -e bumble",
             "type": "shell",
             "command": "./venv/bin/python -m pip install -e ../bumble --config-settings editable_mode=compat"
-        }
+        },
     ]
 }

auracast/auracast_config.py

@@ -54,7 +54,7 @@ class AuracastBigConfig:
     program_info: str = 'Some Announcements'
     audio_source: str = 'file:./auracast/announcement_48_10_96000_en.wav'
     input_format: str = 'auto'
-    loop_wav: bool = True
+    loop: bool = True
     precode_wav: bool = False
     iso_que_len: int = 64
 
@@ -66,7 +66,7 @@ broadcast_de = AuracastBigConfig(
     name = 'Broadcast0',
     language='deu',
     program_info = 'Announcements German',
-    audio_source = 'file:./auracast/announcement_48_10_96000_de.wav',
+    audio_source = 'file:./auracast/testdata/announcement_de.wav',
 )
 
 broadcast_en = AuracastBigConfig(
@@ -75,7 +75,7 @@ broadcast_en = AuracastBigConfig(
     name = 'Broadcast1',
     language='eng',
     program_info = 'Announcements English',
-    audio_source = 'file:./auracast/announcement_48_10_96000_en.wav',
+    audio_source = 'file:./auracast/testdata/announcement_en.wav',
 )
 
 broadcast_fr = AuracastBigConfig(
@@ -84,7 +84,7 @@ broadcast_fr = AuracastBigConfig(
     name = 'Broadcast2',
     language='fra',
     program_info = 'Announcements French',
-    audio_source = 'file:./auracast/announcement_48_10_96000_fr.wav',
+    audio_source = 'file:./auracast/testdata/announcement_fr.wav',
 )
 
 broadcast_es = AuracastBigConfig(
@@ -93,7 +93,7 @@ broadcast_es = AuracastBigConfig(
     name = 'Broadcast3',
     language='spa',
     program_info = 'Announcements Spanish',
-    audio_source = 'file:./auracast/announcement_48_10_96_es.wav',
+    audio_source = 'file:./auracast/testdata/announcement_es.wav',
 )
 
 broadcast_it = AuracastBigConfig(
@@ -102,5 +102,5 @@ broadcast_it = AuracastBigConfig(
     name = 'Broadcast4',
     language='ita',
     program_info = 'Announcements Italian',
-    audio_source = 'file:./auracast/announcement_48_10_96_it.wav',
+    audio_source = 'file:./auracast/testdata/announcement_it.wav',
 )

auracast/multicast.py

@@ -94,6 +94,36 @@ class ModWaveAudioInput(audio_io.ThreadedAudioInput):
 
 audio_io.WaveAudioInput = ModWaveAudioInput
 
+
+def read_lc3_file(filepath):
+    filepath = filepath.replace('file:', '')
+    with open(filepath, 'rb') as f_lc3:
+        header = struct.unpack('=HHHHHHHI', f_lc3.read(18))
+        if header[0] != 0xcc1c:
+            raise ValueError('Invalid bitstream file')
+
+        # found in liblc3 - decoder.py
+        samplerate = header[2] * 100
+        nchannels = header[4]
+        frame_duration = header[5] * 10
+        stream_length = header[7]
+        #lc3_frame_size = struct.unpack('=H', f_lc3.read(2))[0]
+        logging.info('Loaded lc3 file: %s', filepath)
+        logging.info('samplerate: %s', samplerate)
+        logging.info('nchannels %s', nchannels)
+        logging.info('frame_duration %s', frame_duration)
+        logging.info('stream_length %s', stream_length)
+
+        lc3_bytes= b''
+        while True:
+            b = f_lc3.read(2)
+            if b == b'':
+                break
+            lc3_frame_size = struct.unpack('=H', b)[0]
+            lc3_bytes += f_lc3.read(lc3_frame_size)
+
+        return lc3_bytes
+
 # -----------------------------------------------------------------------------
 # Logging
 # -----------------------------------------------------------------------------
@@ -303,8 +333,8 @@ async def init_audio(
             pass
         else:
             audio_input = await audio_io.create_audio_input(audio_source, input_format)
-        
-        audio_input.rewind = big_config[i].loop_wav
+
+        audio_input.rewind = big_config[i].loop
         pcm_format = await audio_input.open()
 
         #try:
@@ -335,8 +365,18 @@ async def init_audio(
         big['encoder'] = encoder
 
 class Streamer():
+    """
+    Streamer class that supports multiple input formats. See bumble for streaming from wav or device
+    Added functionallity on top of bumble:
+        - precode wav files, 
+        - lc3 coded files
+            - just use a .lc3 file as audio_source
+        - lc3 coded from ram
+            - use a bytestring b'' as audio_source
+    """
+
     def __init__(
-            self, 
+            self,
             bigs,
             global_config : auracast_config.AuracastGlobalConfig,
             big_config: List[auracast_config.AuracastBigConfig]
@@ -362,7 +402,6 @@ class Streamer():
                 self.task = None
 
     async def stream(self):
-
         bigs = self.bigs
         big_config = self.big_config
         global_config = self.global_config
@@ -374,26 +413,28 @@ class Streamer():
             # precoded lc3 from ram
             if isinstance(big_config[i].audio_source, bytes):
                 big['precoded'] = True
-                lc3_frames = big_config[i].audio_source,
 
-                if big_config[i].loop_wav:
+                lc3_frames = iter(big_config[i].audio_source)
+
+                if big_config[i].loop:
                     lc3_frames = itertools.cycle(lc3_frames)
                 big['lc3_frames'] = lc3_frames
 
             # precoded lc3 file
             elif big_config[i].audio_source.endswith('.lc3'):
                 big['precoded'] = True
+                filename = big_config[i].audio_source.replace('file:', '')
 
-                with open (big_config[i].audio_source, 'r') as f:
-                    lc3_frames = f.read()
+                lc3_bytes = read_lc3_file(filename)
+                lc3_frames = iter(lc3_bytes)
 
-                if big_config[i].loop_wav:
+                if big_config[i].loop:
                     lc3_frames = itertools.cycle(lc3_frames)
                 big['lc3_frames'] = lc3_frames
 
             # use wav files and code them entirely before streaming
             elif big_config[i].precode_wav and big_config[i].audio_source.endswith('.wav'):
-                big['precoded'] = True 
+                big['precoded'] = True
 
                 audio_input = await audio_io.create_audio_input(audio_source, input_format)
                 audio_input.rewind = False
@@ -416,22 +457,23 @@ class Streamer():
                     input_sample_rate_hz=pcm_format.sample_rate,
                 )
                 lc3_frame_samples = encoder.get_frame_samples() # number of the pcm samples per lc3 frame
-                
-                lc3_frames = b''
+
+                lc3_bytes = b''
                 async for pcm_frame in audio_input.frames(lc3_frame_samples):
-                    lc3_frames += encoder.encode(
+                    lc3_bytes += encoder.encode(
                             pcm_frame, num_bytes=global_config.octets_per_frame, bit_depth=pcm_bit_depth
                         )
+                lc3_frames = iter(lc3_bytes)
 
                 # have a look at itertools.islice
-                if big_config[i].loop_wav: 
+                if big_config[i].loop:
                     lc3_frames = itertools.cycle(lc3_frames)
-                big['lc3_frames'] = lc3_frames 
+                big['lc3_frames'] = lc3_frames
 
-            # anything else, e.g. realtime stream from device
-            else: 
+            # anything else, e.g. realtime stream from device (bumble)
+            else:
                 audio_input = await audio_io.create_audio_input(audio_source, input_format)
-                audio_input.rewind = big_config[i].loop_wav
+                audio_input.rewind = big_config[i].loop
                 pcm_format = await audio_input.open()
 
                 #try:
@@ -457,8 +499,8 @@ class Streamer():
                 big['lc3_frame_samples'] = lc3_frame_samples
                 big['audio_input'] = audio_input
                 big['encoder'] = encoder
-                big['precoded'] = False 
-            
+                big['precoded'] = False
+
             # Need for coded an uncoded audio
             lc3_frame_size = global_config.octets_per_frame #encoder.get_frame_bytes(bitrate)
             lc3_bytes_per_frame = lc3_frame_size #* 2 #multiplied by number of channels
@@ -475,6 +517,7 @@ class Streamer():
 
                 if big['precoded']:# everything was already lc3 coded beforehand
                     lc3_frame = b""
+                    # list(itertools.islice(iterator, 3))
                     for _ in range(big['lc3_bytes_per_frame']): # have a look at itertools.islice
                         lc3_frame += next(big['lc3_frames']).to_bytes() # TODO: use async ?
                 else:
@@ -548,11 +591,13 @@ if __name__ == "__main__":
         #auracast_config.broadcast_es,
         #auracast_config.broadcast_it,
         ]
-    for big in bigs: # TODO. investigate this further
+    for big in bigs: # TODO: encrypted streams are not working
         #big.code = 'ff'*16 # returns hci/HCI_ENCRYPTION_MODE_NOT_ACCEPTABLE_ERROR
         #big.code = '78 e5 dc f1 34 ab 42 bf c1 92 ef dd 3a fd 67 ae'
         big.precode_wav = True
-
+        big.audio_source = big.audio_source.replace('.wav', '_10_16_32.lc3') #lc3 precoded files
+        big.audio_source = read_lc3_file(big.audio_source)  # load files in advance
+    
     # 16kHz works reliably with 3 streams
     # 24kHz is only working with 2 streams - probably airtime constraint
     # TODO: with more than three broadcasters (16kHz) no advertising (no primary channels is present anymore)

auracast/multicast_control.py

@@ -131,7 +131,7 @@ async def main():
         #auracast_config.broadcast_it,
         ]
     for conf in big_conf:
-        conf.loop_wav = False
+        conf.loop = False
 
     # look into:
     #async with MyAPI() as api:

auracast/testdata/encode_lc3.py

@@ -0,0 +1,25 @@
+# use liblc3
+import os
+import subprocess
+
+frame_dur_ms=10
+srate=16000
+bps=32000
+
+if __name__ == '__main__':
+    workdir = os.path.dirname(__file__)
+    os.chdir(workdir)
+    files = os.listdir(workdir)
+    filtered = [file for file in files if file.endswith('.wav')]
+
+    for file in filtered:
+        cmd = [
+            'elc3', 
+            '-b', f'{bps}',
+            '-m', f'{frame_dur_ms}' , 
+            '-r', f'{srate}',
+            f'{file}', f'{file.replace('.wav', '')}_{frame_dur_ms}_{srate//1000}_{bps//1000}.lc3'
+            ]
+        print("Executing: ", " ".join(cmd))
+        ret = subprocess.run(cmd, check=True)
+        print(ret.returncode, ret.stdout, ret.stderr)