mirror of
https://github.com/KrisKennaway/ii-vision.git
synced 2024-08-31 14:29:14 +00:00
For some reason playback speed is only about 1.6x (probably due to slowing down accesses to the I/O page to 1MHz, so as not to mess up hardware timings), but happily this comes within 3% of being 44100/2.
141 lines
4.6 KiB
Python
141 lines
4.6 KiB
Python
"""Multiplexes video and audio inputs to encoded byte stream."""
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from typing import Iterable, Iterator
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import audio
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import frame_grabber
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import machine
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import opcodes
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import video
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from palette import Palette
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from video_mode import VideoMode
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class Movie:
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def __init__(
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self, filename: str,
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every_n_video_frames: int = 1,
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audio_bitrate: int = 14700,
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audio_normalization: float = None,
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max_bytes_out: int = None,
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video_mode: VideoMode = VideoMode.HGR,
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palette: Palette = Palette.NTSC,
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):
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self.filename = filename # type: str
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self.every_n_video_frames = every_n_video_frames # type: int
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self.max_bytes_out = max_bytes_out # type: int
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self.video_mode = video_mode # type: VideoMode
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self.palette = palette # type: Palette
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self.audio = audio.Audio(
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filename, bitrate=audio_bitrate,
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normalization=audio_normalization) # type: audio.Audio
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self.frame_grabber = frame_grabber.FileFrameGrabber(
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filename, mode=video_mode, palette=self.palette)
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self.video = video.Video(
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self.frame_grabber,
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ticks_per_second=self.audio.sample_rate,
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mode=video_mode,
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palette=self.palette
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) # type: video.Video
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# Byte offset within TCP stream
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self.stream_pos = 0 # type: int
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# Current audio tick opcode count within movie stream.
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self.ticks = 0 # type: int
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# Tracks internal state of player virtual machine
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self.state = machine.Machine()
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# Currently operating on AUX memory bank?
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self.aux_memory_bank = False
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def encode(self) -> Iterator[opcodes.Opcode]:
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"""
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:return:
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"""
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video_frames = self.frame_grabber.frames()
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main_seq = None
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aux_seq = None
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yield opcodes.Header(mode=self.video_mode)
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for au in self.audio.audio_stream():
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self.ticks += 1
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if self.video.tick(self.ticks):
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try:
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main, aux = next(video_frames)
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except StopIteration:
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break
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if ((self.video.frame_number - 1) % self.every_n_video_frames
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== 0):
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print("Starting frame %d" % self.video.frame_number)
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main_seq = self.video.encode_frame(main, is_aux=False)
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if aux:
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aux_seq = self.video.encode_frame(aux, is_aux=True)
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# au has range -15 .. 16 (step=1)
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# Tick cycles are units of 2
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tick = au * 2 # -30 .. 32 (step=2)
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tick += 34 # 4 .. 66 (step=2)
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(page, content, offsets) = next(
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aux_seq if self.aux_memory_bank else main_seq)
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yield opcodes.TICK_OPCODES[(tick, page)](content, offsets)
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def _emit_bytes(self, _op: opcodes.Opcode) -> Iterable[int]:
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"""Emit compiled bytes corresponding to a player opcode.
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Also tracks byte stream position.
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"""
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for b in self.state.emit(_op):
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yield b
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self.stream_pos += 1
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def emit_stream(self, ops: Iterable[opcodes.Opcode]) -> Iterator[int]:
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"""Emit compiled byte stream corresponding to opcode stream.
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Inserts padding opcodes at 2KB stream boundaries, to instruct player
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to manage the TCP socket buffer.
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:param ops:
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:return:
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"""
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for op in ops:
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if self.max_bytes_out and self.stream_pos >= self.max_bytes_out:
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yield from self.done()
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return
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yield from self._emit_bytes(op)
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# Keep track of where we are in TCP client socket buffer
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socket_pos = self.stream_pos % 2048
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if socket_pos >= 2044:
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# 2 op_ack address bytes + 2 payload bytes from ACK must
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# terminate 2K stream frame
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if self.video_mode == VideoMode.DHGR:
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# Flip-flop between MAIN and AUX banks
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self.aux_memory_bank = not self.aux_memory_bank
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yield from self._emit_bytes(opcodes.Ack(self.aux_memory_bank))
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assert self.stream_pos % 2048 == 0, self.stream_pos % 2048
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yield from self.done()
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def done(self) -> Iterator[int]:
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"""Terminate byte stream by emitting terminal opcode and padding to 2KB.
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:return:
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"""
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yield from self._emit_bytes(opcodes.Terminate())
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# Player expects to fill 2K TCP buffer so pad it out
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for _ in range(2048 - (self.stream_pos % 2048)):
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yield 0x00
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