Case
sendspin-go -> aiosendspin
Start the server first, then the client. The server loads the PCM audio derived from almost_silent.flac, the client advertises a listener and FLAC as its only supported audio format, the server connects in, uses the SDK to encode the PCM into FLAC, streams it to the client, and the matrix compares the transported FLAC header and chunk bytes as received by the client.
Server
sendspin-go
Client
aiosendspin
Status
Passed
FLAC header and chunk bytes match exactly
Inspection
Summaries, logs, and builds
Matrix result
RAW{
"case_dir": "artifacts/results/data/macos__server-initiated-flac__sendspin-go__to__aiosendspin",
"client_exit_code": 0,
"client_impl": "aiosendspin",
"reason": "FLAC header and chunk bytes match exactly",
"scenario_id": "server-initiated-flac",
"server_exit_code": 0,
"server_impl": "sendspin-go",
"status": "passed"
}Server summary (JSON)
RAW{
"audio": {
"bit_depth": 24,
"channels": 1,
"clip_seconds": 5,
"duration_seconds": 5,
"fixture": "/Users/runner/work/conformance/conformance/repos/sendspin-cli/tests/fixtures/almost_silent.flac",
"frame_count": 40000,
"sample_rate": 8000,
"sent_audio_chunk_count": 1,
"sent_codec_header_sha256": "f7c0c5cea7e7afcc5cad7f40b3c292c811132bd60d65f8a55c383722ce6c1edb",
"sent_encoded_byte_count": 14698,
"sent_encoded_sha256": "7bc1b2ee421ee57d7ea84fee6b2a8301c83c56264081475e2c3f4ca7bd53a070",
"source_flac_sha256": "8fdda8244e318c63cd8b699fe461cd7cdddbb729327a0ba00d1bfdbe2192fe17",
"source_pcm_sha256": "f9ae8fe5e6c34fc6baa67cbb4a97224d777a0bfacf6d996449be1054824f66bf"
},
"client": {
"client_id": "aiosendspin-client-id",
"name": "aiosendspin-client",
"supported_roles": [
"player@v1"
]
},
"discovery_method": "registry_advertised",
"implementation": "sendspin-go",
"initiator_role": "server",
"peer_hello": {
"payload": {
"client_id": "aiosendspin-client-id",
"name": "aiosendspin-client",
"player@v1_support": {
"buffer_capacity": 2000000,
"supported_commands": [
"volume",
"mute"
],
"supported_formats": [
{
"bit_depth": 16,
"channels": 1,
"codec": "flac",
"sample_rate": 8000
},
{
"bit_depth": 16,
"channels": 2,
"codec": "flac",
"sample_rate": 44100
},
{
"bit_depth": 16,
"channels": 2,
"codec": "flac",
"sample_rate": 48000
}
]
},
"supported_roles": [
"player@v1"
],
"version": 1
},
"type": "client/hello"
},
"preferred_codec": "flac",
"role": "server",
"scenario_id": "server-initiated-flac",
"server_id": "sendspin-go-server",
"server_name": "sendspin-go server",
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAMAADIAfQBcAAHkwCKnZ7FLvzY30lWx+3k6wJC",
"sample_rate": 8000
}
}Server log
RAW{
"audio": {
"bit_depth": 24,
"channels": 1,
"clip_seconds": 5,
"duration_seconds": 5,
"fixture": "/Users/runner/work/conformance/conformance/repos/sendspin-cli/tests/fixtures/almost_silent.flac",
"frame_count": 40000,
"sample_rate": 8000,
"sent_audio_chunk_count": 1,
"sent_codec_header_sha256": "f7c0c5cea7e7afcc5cad7f40b3c292c811132bd60d65f8a55c383722ce6c1edb",
"sent_encoded_byte_count": 14698,
"sent_encoded_sha256": "7bc1b2ee421ee57d7ea84fee6b2a8301c83c56264081475e2c3f4ca7bd53a070",
"source_flac_sha256": "8fdda8244e318c63cd8b699fe461cd7cdddbb729327a0ba00d1bfdbe2192fe17",
"source_pcm_sha256": "f9ae8fe5e6c34fc6baa67cbb4a97224d777a0bfacf6d996449be1054824f66bf"
},
"client": {
"client_id": "aiosendspin-client-id",
"name": "aiosendspin-client",
"supported_roles": [
"player@v1"
]
},
"discovery_method": "registry_advertised",
"implementation": "sendspin-go",
"initiator_role": "server",
"peer_hello": {
"payload": {
"client_id": "aiosendspin-client-id",
"name": "aiosendspin-client",
"player@v1_support": {
"buffer_capacity": 2000000,
"supported_commands": [
"volume",
"mute"
],
"supported_formats": [
{
"bit_depth": 16,
"channels": 1,
"codec": "flac",
"sample_rate": 8000
},
{
"bit_depth": 16,
"channels": 2,
"codec": "flac",
"sample_rate": 44100
},
{
"bit_depth": 16,
"channels": 2,
"codec": "flac",
"sample_rate": 48000
}
]
},
"supported_roles": [
"player@v1"
],
"version": 1
},
"type": "client/hello"
},
"preferred_codec": "flac",
"role": "server",
"scenario_id": "server-initiated-flac",
"server_id": "sendspin-go-server",
"server_name": "sendspin-go server",
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAMAADIAfQBcAAHkwCKnZ7FLvzY30lWx+3k6wJC",
"sample_rate": 8000
}
}
Client summary (JSON)
RAW{
"audio": {
"audio_chunk_count": 1,
"received_encoded_sha256": "7bc1b2ee421ee57d7ea84fee6b2a8301c83c56264081475e2c3f4ca7bd53a070",
"received_pcm_sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
"received_sample_count": 0
},
"client_id": "aiosendspin-client-id",
"client_name": "aiosendspin-client",
"implementation": "aiosendspin",
"initiator_role": "server",
"peer_hello": {
"payload": {
"active_roles": [
"player@v1"
],
"connection_reason": "playback",
"name": "sendspin-go server",
"server_id": "sendspin-go-server",
"version": 1
},
"type": "server/hello"
},
"preferred_codec": "flac",
"role": "client",
"scenario_id": "server-initiated-flac",
"server": null,
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAMAADIAfQBcAAHkwCKnZ7FLvzY30lWx+3k6wJC",
"sample_rate": 8000
}
}Client log
RAWINFO:aiosendspin.client.listener:ClientListener started on port 20015, path /sendspin
INFO:aiosendspin.client.client:Connected to server 'sendspin-go server' (sendspin-go-server) version 1
INFO:aiosendspin.client.client:Stream started with codec flac
INFO:aiosendspin.client.client:Handshake with server complete
ERROR:aiosendspin.client.client:Error in audio chunk callback <function _run.<locals>.on_audio_chunk at 0x10b3e5120>
Traceback (most recent call last):
File "/Users/runner/work/conformance/conformance/repos/aiosendspin/aiosendspin/client/client.py", line 997, in _handle_audio_chunk
callback(timestamp_us, payload, self._current_audio_format)
File "/Users/runner/work/conformance/conformance/src/conformance/adapters/aiosendspin_client.py", line 270, in on_audio_chunk
pcm = current_decoder.decode(payload)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/runner/work/conformance/conformance/src/conformance/flac.py", line 96, in decode
return self._frames_to_pcm(frames)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/runner/work/conformance/conformance/src/conformance/flac.py", line 109, in _frames_to_pcm
resampler = av.AudioResampler(
^^^^^^^^^^^^^^^^^^
File "av/audio/resampler.py", line 23, in av.audio.resampler.AudioResampler.__cinit__
format if isinstance(format, AudioFormat) else AudioFormat(format)
^^^^^^^^^^^
File "av/audio/format.py", line 38, in av.audio.format.AudioFormat.__cinit__
raise ValueError(f"Not a sample format: {name!r}")
^^^^^^^^^^^
ValueError: Not a sample format: 's24'
INFO:aiohttp.access:127.0.0.1 [16/May/2026:05:36:31 +0000] "GET /sendspin HTTP/1.1" 101 0 "-" "Go-http-client/1.1"
INFO:aiosendspin.client.listener:ClientListener stopped
{
"audio": {
"audio_chunk_count": 1,
"received_encoded_sha256": "7bc1b2ee421ee57d7ea84fee6b2a8301c83c56264081475e2c3f4ca7bd53a070",
"received_pcm_sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
"received_sample_count": 0
},
"client_id": "aiosendspin-client-id",
"client_name": "aiosendspin-client",
"implementation": "aiosendspin",
"initiator_role": "server",
"peer_hello": {
"payload": {
"active_roles": [
"player@v1"
],
"connection_reason": "playback",
"name": "sendspin-go server",
"server_id": "sendspin-go-server",
"version": 1
},
"type": "server/hello"
},
"preferred_codec": "flac",
"role": "client",
"scenario_id": "server-initiated-flac",
"server": null,
"status": "ok",
"stream": {
"bit_depth": 24,
"channels": 1,
"codec": "flac",
"codec_header": "ZkxhQ4AAACICQAJAAAAMAADIAfQBcAAHkwCKnZ7FLvzY30lWx+3k6wJC",
"sample_rate": 8000
}
}
Server build log · sendspin-go-server · built · 1.01s
RAWNo build detail was recorded.
Client build log · python-adapters · built · 0.07s
RAWListing 'src'... Listing 'src/conformance'... Listing 'src/conformance/adapters'... Compiling 'src/conformance/adapters/__init__.py'... Compiling 'src/conformance/adapters/aiosendspin_client.py'... Compiling 'src/conformance/adapters/aiosendspin_server.py'... Compiling 'src/conformance/adapters/placeholder.py'... Compiling 'src/conformance/adapters/sendspin_jvm_client.py'... Compiling 'src/conformance/cli.py'... Compiling 'src/conformance/merge.py'... Compiling 'src/conformance/registry.py'... Listing 'src/sendspin_conformance.egg-info'... Listing 'scripts'... Compiling 'scripts/detect_regressions.py'... Compiling 'scripts/merge_results.py'... Compiling 'scripts/run_all.py'... Compiling 'scripts/setup_repositories.py'... Compiling 'scripts/setup_workspace.py'...