Library¶

JLIP-specific functionality.

class vcrtool.jlip.BandInfo(*values)¶

Band information codes.

BROADCAST_SATELLITE = 64¶: Broadcast satellite.

TERRESTRIAL_BROADCAST = 48¶: Terrestrial broadcast.

class vcrtool.jlip.CommandResponse(checksum: int, raw: bytes, return_data: bytes, status: CommandStatus, tuple: CommandResponseTuple)¶

Command response information.

checksum : int¶: Checksum.

static from_bytes(resp: bytes) → CommandResponse¶

Initialise from bytes.

Parameters:¶

resp : bytes¶: Raw response bytes.

Returns:¶

Parsed command response.

Return type:¶

CommandResponse

raw : bytes¶: Raw response.

return_data : bytes¶: Return data.

status : CommandStatus¶: Command status.

tuple : CommandResponseTuple¶: Lower-level command response information.

class vcrtool.jlip.CommandResponseTuple(jlip_id: int, command_status: CommandStatus, return_data: bytes)¶

Lower-level command response information.

command_status : CommandStatus¶: Command status.

jlip_id : int¶: JLIP ID.

return_data : bytes¶: Return data.

class vcrtool.jlip.CommandStatus(*values)¶

JLIP command status codes.

COMMAND_ACCEPTED = 3¶: Command accepted.

COMMAND_ACCEPTED_NOT_COMPLETE = 4¶: Command accepted but not complete.

COMMAND_NOT_IMPLEMENTED = 1¶: Command not implemented.

COMMAND_NOT_POSSIBLE = 5¶: Command not possible.

class vcrtool.jlip.DeviceNameResponse(checksum: int, raw: bytes, return_data: bytes, status: CommandStatus, tuple: CommandResponseTuple, name: str)¶

Device name response.

static from_bytes(resp: bytes) → DeviceNameResponse¶

Initialise from bytes.

Parameters:¶

resp : bytes¶: Raw response bytes.

Returns:¶

Parsed device name response.

Return type:¶

DeviceNameResponse

name : str¶: Device name.

class vcrtool.jlip.JLIPTransport(serial_path: str, *, jlip_id: int = 1, raise_on_error_response: bool = True)¶

Send commands to HR-S9600U VCRs and similar devices over JLIP.

The serial port is the only I/O this class performs; the request framing and response validation live in JLIPCodec.

References

codec¶: The sans-I/O codec used to build and validate frames.

comm¶: Serial port object.

eject() → CommandResponse¶

Eject the tape.

Returns:¶: Command response.
Return type:¶: CommandResponse

eject_wait() → CommandResponse¶

Eject the tape and wait until it is done.

Returns:¶: Command response.
Return type:¶: CommandResponse

fast_forward() → CommandResponse¶

Fast forward the tape.

Returns:¶: Command response.
Return type:¶: CommandResponse

fast_play_backward() → CommandResponse¶

Fast play backward.

Returns:¶: Command response.
Return type:¶: CommandResponse

fast_play_forward() → CommandResponse¶

Fast play forward.

Returns:¶: Command response.
Return type:¶: CommandResponse

frame_step() → CommandResponse¶

Move forward one frame.

Returns:¶: Command response.
Return type:¶: CommandResponse

frame_step_back() → CommandResponse¶

Move back one frame.

Returns:¶: Command response.
Return type:¶: CommandResponse

get_baud_rate_supported() → CommandResponse¶

Get the baud rate supported by the device.

0x21 is returned, meaning 19200 baud, but this cannot be trusted.

Returns:¶: Command response.
Return type:¶: CommandResponse

get_device_code() → CommandResponse¶

Get the device code.

Returns:¶: Command response.
Return type:¶: CommandResponse

get_device_name() → CommandResponse¶

Get the device name.

Returns:¶: Command response.
Return type:¶: CommandResponse

get_input() → CommandResponse¶

Get the input of the device.

Returns:¶: Command response.
Return type:¶: CommandResponse

get_machine_code() → CommandResponse¶

Get the machine code.

Returns:¶: Command response.
Return type:¶: CommandResponse

get_play_speed() → CommandResponse¶

Get playback speed.

Known responses in the first data field:

0x67 means playing backward quickly.
0x6D means paused or frame advancing.
0x75 means normal.
0x77 means playing forward quickly.
0x7F is returned when inapplicable.

Returns:¶: Command response.
Return type:¶: CommandResponse

get_power_state() → PowerStateResponse¶

Get the power state of the device.

Returns:¶: Power state response.
Return type:¶: PowerStateResponse

get_tuner_mode() → VTUModeResponse¶

Get the tuner mode.

Returns:¶: Tuner mode response.
Return type:¶: VTUModeResponse

get_vtr_mode(*, fast: bool = False) → VTRModeResponse¶

Get the VTR mode.

Parameters:¶

fast : bool¶: Use faster rate limit.

Returns:¶

VTR mode response.

Return type:¶

VTRModeResponse

jlip_id¶: JLIP ID.

nop() → CommandResponse¶

No operation command.

Returns:¶: Command response.
Return type:¶: CommandResponse

pause() → CommandResponse¶

Pause playback.

Returns:¶: Command response.
Return type:¶: CommandResponse

pause_recording() → CommandResponse¶

Pause recording.

Returns:¶: Command response.
Return type:¶: CommandResponse

play() → CommandResponse¶

Start playback.

Returns:¶: Command response.
Return type:¶: CommandResponse

presence_check() → CommandResponse¶

Check if the device is present and responding.

Returns:¶: Command response.
Return type:¶: CommandResponse

preset_channel_down() → CommandResponse¶

Change to the previous preset channel.

Returns:¶: Command response.
Return type:¶: CommandResponse

preset_channel_up() → CommandResponse¶

Change to the next preset channel.

Returns:¶: Command response.
Return type:¶: CommandResponse

raise_on_error_response¶: Raise on error response.

real_channel_down() → CommandResponse¶

Change to the previous channel.

Returns:¶: Command response.
Return type:¶: CommandResponse

real_channel_up() → CommandResponse¶

Change to the next channel.

Returns:¶: Command response.
Return type:¶: CommandResponse

record() → CommandResponse¶

Start recording.

Returns:¶: Command response.
Return type:¶: CommandResponse

reset_counter() → CommandResponse¶

Reset the timecode counter.

Returns:¶: Command response.
Return type:¶: CommandResponse

rewind() → CommandResponse¶

Rewind the tape.

Returns:¶: Command response.
Return type:¶: CommandResponse

rewind_wait() → CommandResponse¶

Rewind the tape and wait until it is done.

Returns:¶: Command response.
Return type:¶: CommandResponse

select_band(n: int) → CommandResponse¶

Select a band.

Parameters:¶

n : int¶: Band value.

Returns:¶

Command response.

Return type:¶

CommandResponse

select_preset_channel(n: int, nn: int, nnn: int) → CommandResponse¶

Select a preset channel.

Parameters:¶

n : int¶: First channel parameter.
nn : int¶: Second channel parameter.
nnn : int¶: Third channel parameter.

Returns:¶

Command response.

Return type:¶

CommandResponse

select_real_channel(n: int, nn: int, nnn: int) → CommandResponse¶

Select a channel.

Parameters:¶

n : int¶: First channel parameter.
nn : int¶: Second channel parameter.
nnn : int¶: Third channel parameter.

Returns:¶

Command response.

Return type:¶

CommandResponse

send_command(*args: int) → bytes¶

Send a command at a slower rate limit.

This will raise pyrate_limiter’s pyrate_limiter.BucketFullException if the rate limit is exceeded.

Parameters:¶

*args : int¶: Command bytes to send.

Returns:¶

Raw response bytes.

Return type:¶

bytes

send_command_base(*args: int) → bytes¶

Send a command (base method).

Parameters:¶

*args : int¶: Command bytes to send.

Returns:¶

Raw response bytes.

Return type:¶

bytes

send_command_fast(*args: int) → bytes¶

Send a command with a faster rate limit.

This will raise pyrate_limiter’s pyrate_limiter.BucketFullException if the rate limit is exceeded.

Parameters:¶

*args : int¶: Command bytes to send.

Returns:¶

Raw response bytes.

Return type:¶

bytes

set_channel(channel: int) → CommandResponse¶

Set the channel to a specific value.

Parameters:¶

channel : int¶: Channel number.

Returns:¶

Command response.

Return type:¶

CommandResponse

set_input(n: int, nn: int) → CommandResponse¶

Set the input to a specific value.

Parameters:¶

n : int¶: Input number.
nn : int¶: Input sub-number.

Returns:¶

Command response.

Return type:¶

CommandResponse

set_jlip_id(n: int) → CommandResponse¶

Set the JLIP ID of the device.

Parameters:¶

n : int¶: JLIP ID to set (1-99).

Returns:¶

Command response.

Return type:¶

CommandResponse

Raises:¶

ValueError – If the ID is not between 1 and 99.

set_record_mode(n: int) → CommandResponse¶

Set the recording mode.

Parameters:¶

n : int¶: Record mode value.

Returns:¶

Command response.

Return type:¶

CommandResponse

set_record_speed(n: int) → CommandResponse¶

Set the recording speed.

Parameters:¶

n : int¶: Record speed value.

Returns:¶

Command response.

Return type:¶

CommandResponse

slow_play_backward() → CommandResponse¶

Slow play backward.

Returns:¶: Command response.
Return type:¶: CommandResponse

slow_play_forward() → CommandResponse¶

Slow play forward.

Returns:¶: Command response.
Return type:¶: CommandResponse

stop() → CommandResponse¶

Stop playback or recording.

Returns:¶: Command response.
Return type:¶: CommandResponse

turn_off() → CommandResponse¶

Turn the device off.

Returns:¶: Command response.
Return type:¶: CommandResponse

turn_on() → CommandResponse¶

Turn the device on.

Returns:¶: Command response.
Return type:¶: CommandResponse

class vcrtool.jlip.PowerStateResponse(checksum: int, raw: bytes, return_data: bytes, status: CommandStatus, tuple: CommandResponseTuple, is_on: bool)¶

Power state response.

static from_bytes(resp: bytes) → PowerStateResponse¶

Initialise from bytes.

Parameters:¶

resp : bytes¶: Raw response bytes.

Returns:¶

Parsed power state response.

Return type:¶

PowerStateResponse

is_on : bool¶: If device is on.

class vcrtool.jlip.VTRMode(*values)¶

VTR mode codes.

EJECT = 0¶: Eject.

FF = 2¶: Fast forward.

NO_MODE = 15¶: No mode.

PAUSE = 7¶: Pause.

PLAY_BWD = 5¶: Play backward.

PLAY_FWD = 6¶: Play forward.

REC = 14¶: Record.

REC_PAUSE = 13¶: Record pause.

REW = 3¶: Rewind.

STOP = 1¶: Stop.

class vcrtool.jlip.VTRModeResponse(checksum: int, raw: bytes, return_data: bytes, status: CommandStatus, tuple: CommandResponseTuple, drop_frame_mode_enabled: bool, framerate: int, hour: int, minute: int, second: int, frame: int, is_ntsc: bool, is_pal: bool, recordable: bool, tape_inserted: bool, vtr_mode: VTRMode)¶

VTR mode response information.

drop_frame_mode_enabled : bool¶: Drop frame mode enabled.

frame : int¶: Frame number.

framerate : int¶: Framerate.

static from_bytes(resp: bytes) → VTRModeResponse¶

Initialise from bytes.

Parameters:¶

resp : bytes¶: Raw response bytes.

Returns:¶

Parsed VTR mode response.

Return type:¶

VTRModeResponse

hour : int¶: Hour.

is_ntsc : bool¶: Is NTSC.

is_pal : bool¶: Is PAL.

minute : int¶: Minute.

recordable : bool¶: Recordable.

second : int¶: Second.

tape_inserted : bool¶: Tape inserted.

vtr_mode : VTRMode¶: VTR mode.

Sans-I/O protocol layer for the devices this package controls.

The classes here contain pure framing logic and perform no input or output. SIRCSCodec turns a SIRCSCommand into a tuple of Pulse intervals (the modulated carrier “marks” and silent “spaces” of an infrared frame) and reverses the process, while JLIPCodec builds JLIP request frames and validates response frames. The transport classes in vcrtool.sircs and vcrtool.jlip drive the actual hardware using the bytes and pulses produced here, which keeps the protocol logic trivially testable without devices or real-time sleeping.

The SIRCS timing values follow the canonical Sony specification where every interval is a multiple of a single unit T of 600 microseconds, and each frame is padded to a fixed 45 millisecond period.

vcrtool.sansio.CARRIER_FREQUENCY_HZ¶

Nominal infrared carrier frequency in hertz.

class vcrtool.sansio.CommandStatus(*values)¶

JLIP command status codes.

COMMAND_ACCEPTED = 3¶: Command accepted.

COMMAND_ACCEPTED_NOT_COMPLETE = 4¶: Command accepted but not complete.

COMMAND_NOT_IMPLEMENTED = 1¶: Command not implemented.

COMMAND_NOT_POSSIBLE = 5¶: Command not possible.

vcrtool.sansio.FRAME_DURATION_US¶

Total period of a single SIRCS frame in microseconds. The trailing space is stretched to it.

class vcrtool.sansio.JLIPCodec¶

Sans-I/O builder and validator for JLIP command frames.

static build_command(jlip_id: int, *args: int) → bytes¶

Build the bytes of a JLIP request frame.

Parameters:¶

jlip_id : int¶: The JLIP ID of the target device.
*args : int¶: The command bytes, right-padded with zeros to fill the frame.

Returns:¶

The eleven-byte frame, including its trailing checksum.

Return type:¶

bytes

static validate_response(data: bytes, *, raise_on_error: bool = True) → bytes¶

Validate a JLIP response frame.

Parameters:¶

data : bytes¶: The eleven-byte response frame.
raise_on_error : bool¶: If True, raise when the device reports an unaccepted status.

Returns:¶

The response frame unchanged.

Return type:¶

bytes

Raises:¶

ValueError – If the checksum does not match or, when raise_on_error is True, the command status is not accepted.

vcrtool.sansio.ONE_MARK_US¶

Duration of the mark that encodes a logical one, in microseconds.

class vcrtool.sansio.Pulse(carrier_on: bool, duration_us: int)¶

A single carrier interval that makes up part of a SIRCS frame.

carrier_on : bool¶: Whether the carrier is modulated (a mark) or silent (a space).

duration_us : int¶: Duration of the interval in microseconds.

class vcrtool.sansio.SIRCSCodec¶

Sans-I/O encoder and decoder for SIRCS infrared frames.

static decode(pulses: Iterable[Pulse]) → SIRCSCommand¶

Decode the first frame of a pulse train back into a command.

Only the marks are inspected; spaces are ignored because their durations carry no information beyond separating marks. The variant is inferred from the number of data bits found. Trailing pulses beyond the first complete frame are ignored, which lets a captured repeated signal be decoded directly.

Parameters:¶

pulses : Iterable[Pulse]¶: The marks and spaces to decode.

Returns:¶

The recovered payload.

Return type:¶

SIRCSCommand

Raises:¶

ValueError – If no start mark is present, a mark does not match a known duration, or the number of data bits does not correspond to a known variant.

static encode(command: SIRCSCommand, *, repeat: int = 1) → tuple[Pulse, ...]¶

Encode a command into the pulse train of one or more frames.

Bits are transmitted least-significant first, ordered command, then address, then extended field. Every frame begins with a start mark and is padded with a final space so that its total duration equals FRAME_DURATION_US.

Parameters:¶

command : SIRCSCommand¶: The payload to encode.
repeat : int¶: Number of identical frames to emit back to back. Real receivers expect at least three.

Returns:¶

The marks and spaces for repeat consecutive frames.

Return type:¶

tuple[Pulse, …]

Raises:¶

ValueError – If repeat is less than one or any field does not fit in its variant’s bit width.

class vcrtool.sansio.SIRCSCommand(command: int, address: int, extended: int = 0, variant: SIRCSVariant = SIRCSVariant.TWELVE_BIT)¶

A SIRCS payload independent of its wire representation.

address : int¶: The device address.

command : int¶: The 7-bit command (button) code.

extended : int¶: The extended field. Only meaningful for SIRCSVariant.TWENTY_BIT.

variant : SIRCSVariant¶: The frame width that determines how the fields are packed.

class vcrtool.sansio.SIRCSVariant(*values)¶

A SIRCS frame width.

Each member’s value is a (command_bits, address_bits, extended_bits) tuple describing how the payload is partitioned.

FIFTEEN_BIT = (7, 8, 0)¶

a 7-bit command and an 8-bit address.

Type:¶: Fifteen-bit frame

TWELVE_BIT = (7, 5, 0)¶

a 7-bit command and a 5-bit address.

Type:¶: Twelve-bit frame

TWENTY_BIT = (7, 5, 8)¶

a 7-bit command, a 5-bit address, and an 8-bit extended field.

Type:¶: Twenty-bit frame

property address_bits : int¶

Number of address bits in this variant.

Return type:¶: int

property command_bits : int¶

Number of command bits in this variant.

Return type:¶: int

property extended_bits : int¶

Number of extended bits in this variant.

Return type:¶: int

property total_bits : int¶

Total number of payload bits in this variant.

Return type:¶: int

vcrtool.sansio.SPACE_US¶

Duration of the silent space that separates every mark, in microseconds.

vcrtool.sansio.START_MARK_US¶

Duration of the leading start (header) mark in microseconds.

vcrtool.sansio.UNIT_US¶

Base SIRCS timing unit T in microseconds. Every other interval is a multiple of this value.

vcrtool.sansio.ZERO_MARK_US¶

Duration of the mark that encodes a logical zero, in microseconds.

vcrtool.sansio.checksum(vals: collections.abc.Sequence[int]) → int¶

Compute the checksum for a JLIP frame.

Parameters:¶

vals : Sequence[int]¶: The first ten bytes of the frame to checksum.

Returns:¶

The computed checksum.

Return type:¶

int

SIRCS (Sony Infrared Remote Control System) transport over a Raspberry Pi Pico.

class vcrtool.sircs.PicoSIRCSTransport(serial_path: str, *, baud_rate: int = 115200, invert: bool = False)¶

Transport that delegates SIRCS timing to a Raspberry Pi Pico over USB serial.

The protocol framing lives in SIRCSCodec. This class serialises the pulse train it produces into a compact message and writes it to the Pico, whose firmware clocks the pin edges out with a PIO state machine for jitter-free timing. The PC therefore keeps all protocol knowledge and the Pico stays a dumb, precisely-timed output peripheral.

The message is a sync byte, a 16-bit big-endian pulse count, and then one three-byte record per pulse: a level byte followed by a 16-bit big-endian duration in microseconds. The level is the final pin state, so invert (used for an active-low CONTROL S jack) is resolved here and the firmware simply holds the pin at the given level.

codec¶: The sans-I/O codec used to build pulse trains.

comm¶: Serial connection to the Pico.

send_command(command: SIRCSCommand, *, repeat: int = 3) → None¶

Encode a command and send it to the Pico.

Parameters:¶

command : SIRCSCommand¶: The payload to send.
repeat : int¶: Number of identical frames to play. Sony receivers expect at least three.

static serialize(pulses: Iterable[Pulse], *, invert: bool = False) → bytes¶

Serialise a pulse train into the Pico wire message.

Parameters:¶

pulses : Iterable[Pulse]¶: The marks and spaces to serialise.
invert : bool¶: If True, mark and space levels are swapped.

Returns:¶

The complete message, ready to write to the Pico.

Return type:¶

bytes

Raises:¶

ValueError – If any pulse duration or the pulse count does not fit in 16 bits.

transmit(pulses: Iterable[Pulse]) → None¶

Serialise a pulse train and write it to the Pico.

Parameters:¶

pulses : Iterable[Pulse]¶: The marks and spaces to transmit.

Utilities.

async vcrtool.utils.adebug_create_subprocess_exec(*args: Any, **kwargs: Any) → Process¶

Run a subprocess and log the command at the logging.DEBUG level.

Return type:¶: asp.CompletedProcess[Any]

async vcrtool.utils.adebug_sleep(interval: float) → None¶: Sleep for a given interval and log the sleep time at the logging.DEBUG level.

vcrtool.utils.audio_device_is_available(audio_device: str) → bool¶

Check if an ALSA device can be used by attempting to open it with ffmpeg.

Return type:¶: bool

vcrtool.utils.debug_sleep(interval: float) → None¶: Sleep for a given interval and log the sleep time at the logging.DEBUG level.

vcrtool.utils.debug_sp_run(*args: Any, **kwargs: Any) → CompletedProcess[Any]¶

Run a subprocess and log the command at the logging.DEBUG level.

Return type:¶: sp.CompletedProcess[Any]

vcrtool.utils.get_pipewire_audio_device_node_id(name: str) → tuple[str, str] | tuple[None, None]¶

Get the Pipewire node ID of an ALSA device.

Parameters:¶

name : str¶: The name of the audio device.

Returns:¶

The name and node ID of the audio device, or (None, None) if not found.

Return type:¶

tuple[str, str] | tuple[None, None]

Raises:¶

ValueError – If the ALSA device string is invalid.

vcrtool.utils.pad_right(value: T, list_: collections.abc.Sequence[T], max_length: int) → list[T]¶

Pad a sequence to the right with a value.

Return type:¶: list[T]
Raises:¶: ValueError –