feature/1khz_testtone (#27)

- 1kHz test tone added
- all audio file converted to lc3 to save space
- streaming loop for lc3 files fixed

@pober

Reviewed-on: #27
Co-authored-by: pstruebi <struebin.patrick@gmail.com>
Co-committed-by: pstruebi <struebin.patrick@gmail.com>

src/auracast/auracast_config.py

@@ -81,7 +81,7 @@ class AuracastBigConfigDeu(AuracastBigConfig):
     name: str = 'Hörsaal A'
     language: str ='deu'
     program_info: str = 'Vorlesung DE'
-    audio_source: str = 'file:./testdata/wave_particle_5min_de.wav'
+    audio_source: str = 'file:./testdata/wave_particle_5min_de.lc3'
 
 class AuracastBigConfigEng(AuracastBigConfig):
     id: int = 123
@@ -89,7 +89,7 @@ class AuracastBigConfigEng(AuracastBigConfig):
     name: str  = 'Lecture Hall A'
     language: str ='eng'
     program_info: str = 'Lecture EN'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_en.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_en.lc3'
 
 class AuracastBigConfigFra(AuracastBigConfig):
     id: int = 1234
@@ -98,7 +98,7 @@ class AuracastBigConfigFra(AuracastBigConfig):
     name: str  = 'Auditoire A'
     language: str ='fra'
     program_info: str = 'Auditoire FR'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_fr.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_fr.lc3'
 
 class AuracastBigConfigSpa(AuracastBigConfig):
     id: int =12345
@@ -106,7 +106,7 @@ class AuracastBigConfigSpa(AuracastBigConfig):
     name: str  = 'Auditorio A'
     language: str ='spa'
     program_info: str = 'Auditorio ES'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_es.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_es.lc3'
 
 class AuracastBigConfigIta(AuracastBigConfig):
     id: int =1234567
@@ -114,7 +114,7 @@ class AuracastBigConfigIta(AuracastBigConfig):
     name: str  = 'Aula A'
     language: str ='ita'
     program_info: str = 'Aula IT'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_it.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_it.lc3'
 
 
 class AuracastBigConfigPol(AuracastBigConfig):
@@ -123,7 +123,7 @@ class AuracastBigConfigPol(AuracastBigConfig):
     name: str  = 'Sala Wykładowa'
     language: str ='pol'
     program_info: str = 'Sala Wykładowa PL'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_pl.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_pl.lc3'
 
 
 class AuracastConfigGroup(AuracastGlobalConfig):

src/auracast/multicast.py

@@ -655,6 +655,29 @@ async def init_broadcast(
     return bigs
 
 
+def _lc3_file_byte_gen(filename: str, loop: bool = False):
+    """Stream LC3 frames from disk as individual bytes, with optional looping.
+
+    Yields one byte (int) at a time so it is compatible with the existing
+    ``bytes(itertools.islice(gen, bytes_per_frame))`` consumer without loading
+    the whole file into memory.
+    """
+    while True:
+        with open(filename, 'rb') as f:
+            f.read(18)  # skip 18-byte LC3 header
+            while True:
+                size_b = f.read(2)
+                if len(size_b) < 2:
+                    break
+                frame_size = struct.unpack('=H', size_b)[0]
+                frame = f.read(frame_size)
+                if len(frame) < frame_size:
+                    break
+                yield from frame
+        if not loop:
+            return
+
+
 class Streamer():
     """
     Streamer class that supports multiple input formats. See bumble for streaming from wav or device
@@ -810,13 +833,7 @@ class Streamer():
                 big['precoded'] = True
                 big['lc3_bytes_per_frame'] = global_config.octets_per_frame
                 filename = big_config[i].audio_source.replace('file:', '')
-
-                lc3_bytes = read_lc3_file(filename)
-                lc3_frames = iter(lc3_bytes)
-
-                if big_config[i].loop:
-                    lc3_frames = itertools.cycle(lc3_frames)
-                big['lc3_frames'] = lc3_frames
+                big['lc3_frames'] = _lc3_file_byte_gen(filename, loop=big_config[i].loop)
 
             # use wav files and code them entirely before streaming
             elif big_config[i].precode_wav and big_config[i].audio_source.endswith('.wav'):
@@ -933,6 +950,9 @@ class Streamer():
                     if lc3_frame == b'':  # Not all streams may stop at the same time
                         stream_finished[i] = True
                         continue
+
+                    for q_idx in range(big.get('num_bis', 1)):
+                        await big['iso_queues'][q_idx].write(lc3_frame)
                 else:  # code lc3 on the fly with perf counters
                     # Ensure frames generator exists (so we can aclose() on stop)
                     frames_gen = big.get('frames_gen')

src/auracast/server/multicast_frontend.py

@@ -381,6 +381,17 @@ if audio_mode == "Demo":
         disabled=is_streaming,
         help="Select the demo stream configuration."
     )
+    demo_content_options = ["Program material", "1 kHz test tone"]
+    saved_demo_content = saved_settings.get('demo_content', 'Program material')
+    if saved_demo_content not in demo_content_options:
+        saved_demo_content = 'Program material'
+    demo_content = st.selectbox(
+        "Demo Content",
+        demo_content_options,
+        index=demo_content_options.index(saved_demo_content),
+        disabled=is_streaming,
+        help="Select whether demo streams use program audio files or a continuous 1 kHz test tone."
+    )
     # Stream password and flags (same as USB/AES67)
     saved_pwd = saved_settings.get('stream_password', '') or ''
     stream_passwort = st.text_input(
@@ -1623,12 +1634,22 @@ if start_stream:
         bigs1 = []
         for i in range(demo_cfg['streams']):
             cfg_cls, lang = lang_cfgs[i % len(lang_cfgs)]
+            if demo_content == "1 kHz test tone":
+                source_file = f'../testdata/test_tone_1k_{int(q["rate"]/1000)}kHz_mono.lc3'
+                big_kwargs = {
+                    'name': 'test tone',
+                    'program_info': '1khz',
+                }
+            else:
+                source_file = f'../testdata/wave_particle_5min_{lang}_{int(q["rate"]/1000)}kHz_mono.lc3'
+                big_kwargs = {}
             bigs1.append(cfg_cls(
                 code=(stream_passwort.strip() or None),
-                audio_source=f'file:../testdata/wave_particle_5min_{lang}_{int(q["rate"]/1000)}kHz_mono.wav',
+                audio_source=f'file:{source_file}',
                 iso_que_len=32,
                 sampling_frequency=q['rate'],
                 octets_per_frame=q['octets'],
+                **big_kwargs,
             ))
 
         max_per_mc = {48000: 1, 24000: 2, 16000: 3}

src/auracast/server/multicast_server.py

@@ -564,6 +564,13 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
         demo_count = sum(1 for big in conf.bigs if isinstance(big.audio_source, str) and big.audio_source.startswith('file:'))
         demo_rate = int(conf.auracast_sampling_rate_hz or 0)
         demo_type = None
+        demo_sources = [
+            str(b.audio_source)
+            for b in conf.bigs
+            if isinstance(b.audio_source, str) and b.audio_source.startswith('file:')
+        ]
+        is_demo_tone = bool(demo_sources) and all('test_tone_1k_' in src for src in demo_sources)
+        demo_content = '1 kHz test tone' if is_demo_tone else 'Program material'
         if demo_count > 0 and demo_rate > 0:
             if demo_rate in (48000, 24000, 16000):
                 demo_type = f"{demo_count} × {demo_rate//1000}kHz"
@@ -591,8 +598,9 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
             'big_random_addresses': [getattr(big, 'random_address', DEFAULT_RANDOM_ADDRESS) for big in conf.bigs],
             'demo_total_streams': demo_count,
             'demo_stream_type': demo_type,
+            'demo_content': demo_content,
             'is_streaming': auto_started,
-            'demo_sources': [str(b.audio_source) for b in conf.bigs if isinstance(b.audio_source, str) and b.audio_source.startswith('file:')],
+            'demo_sources': demo_sources,
         }
         return mc, persisted
     except HTTPException:

src/auracast/utils/read_lc3_file.py

@@ -21,12 +21,12 @@ def read_lc3_file(filepath):
         logging.info('frame_duration %s', frame_duration)
         logging.info('stream_length %s', stream_length)
 
-        lc3_bytes= b''
+        chunks = []
         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)
+            chunks.append(f_lc3.read(lc3_frame_size))
 
-        return lc3_bytes
+        return b''.join(chunks)