Files
2026-01-09 10:28:44 +11:00

233 lines
6.4 KiB
Python

import cython
from cython.cimports.cpython import PyBuffer_FillInfo, PyBytes_FromString
from cython.cimports.libc.stdint import uint64_t
@cython.cclass
class SubtitleProxy:
def __dealloc__(self):
lib.avsubtitle_free(cython.address(self.struct))
@cython.cclass
class SubtitleSet:
"""
A :class:`SubtitleSet` can contain many :class:`Subtitle` objects.
Wraps :ffmpeg:`AVSubtitle`.
"""
def __cinit__(self, proxy: SubtitleProxy):
self.proxy = proxy
self.rects = tuple(
build_subtitle(self, i) for i in range(self.proxy.struct.num_rects)
)
def __repr__(self):
return (
f"<{self.__class__.__module__}.{self.__class__.__name__} at 0x{id(self):x}>"
)
@property
def format(self):
return self.proxy.struct.format
@property
def start_display_time(self):
return self.proxy.struct.start_display_time
@property
def end_display_time(self):
return self.proxy.struct.end_display_time
@property
def pts(self):
"""Same as packet pts, in av.time_base."""
return self.proxy.struct.pts
def __len__(self):
return len(self.rects)
def __iter__(self):
return iter(self.rects)
def __getitem__(self, i):
return self.rects[i]
@cython.cfunc
def build_subtitle(subtitle: SubtitleSet, index: cython.int) -> Subtitle:
"""Build an av.Stream for an existing AVStream.
The AVStream MUST be fully constructed and ready for use before this is called.
"""
if index < 0 or cython.cast(cython.uint, index) >= subtitle.proxy.struct.num_rects:
raise ValueError("subtitle rect index out of range")
ptr: cython.pointer[lib.AVSubtitleRect] = subtitle.proxy.struct.rects[index]
if ptr.type == lib.SUBTITLE_BITMAP:
return BitmapSubtitle(subtitle, index)
if ptr.type == lib.SUBTITLE_ASS or ptr.type == lib.SUBTITLE_TEXT:
return AssSubtitle(subtitle, index)
raise ValueError("unknown subtitle type %r" % ptr.type)
@cython.cclass
class Subtitle:
"""
An abstract base class for each concrete type of subtitle.
Wraps :ffmpeg:`AVSubtitleRect`
"""
def __cinit__(self, subtitle: SubtitleSet, index: cython.int):
if (
index < 0
or cython.cast(cython.uint, index) >= subtitle.proxy.struct.num_rects
):
raise ValueError("subtitle rect index out of range")
self.proxy = subtitle.proxy
self.ptr = self.proxy.struct.rects[index]
if self.ptr.type == lib.SUBTITLE_NONE:
self.type = b"none"
elif self.ptr.type == lib.SUBTITLE_BITMAP:
self.type = b"bitmap"
elif self.ptr.type == lib.SUBTITLE_TEXT:
self.type = b"text"
elif self.ptr.type == lib.SUBTITLE_ASS:
self.type = b"ass"
else:
raise ValueError(f"unknown subtitle type {self.ptr.type!r}")
def __repr__(self):
return f"<av.{self.__class__.__name__} at 0x{id(self):x}>"
@cython.cclass
class BitmapSubtitle(Subtitle):
def __cinit__(self, subtitle: SubtitleSet, index: cython.int):
self.planes = tuple(
BitmapSubtitlePlane(self, i) for i in range(4) if self.ptr.linesize[i]
)
def __repr__(self):
return (
f"<{self.__class__.__module__}.{self.__class__.__name__} "
f"{self.width}x{self.height} at {self.x},{self.y}; at 0x{id(self):x}>"
)
@property
def x(self):
return self.ptr.x
@property
def y(self):
return self.ptr.y
@property
def width(self):
return self.ptr.w
@property
def height(self):
return self.ptr.h
@property
def nb_colors(self):
return self.ptr.nb_colors
def __len__(self):
return len(self.planes)
def __iter__(self):
return iter(self.planes)
def __getitem__(self, i):
return self.planes[i]
@cython.cclass
class BitmapSubtitlePlane:
def __cinit__(self, subtitle: BitmapSubtitle, index: cython.int):
if index >= 4:
raise ValueError("BitmapSubtitles have only 4 planes")
if not subtitle.ptr.linesize[index]:
raise ValueError("plane does not exist")
self.subtitle = subtitle
self.index = index
self.buffer_size = subtitle.ptr.w * subtitle.ptr.h
self._buffer = cython.cast(cython.p_void, subtitle.ptr.data[index])
# New-style buffer support.
def __getbuffer__(self, view: cython.pointer[Py_buffer], flags: cython.int):
PyBuffer_FillInfo(view, self, self._buffer, self.buffer_size, 0, flags)
@cython.cclass
class AssSubtitle(Subtitle):
"""
Represents an ASS/Text subtitle format, as opposed to a bitmap Subtitle format.
"""
def __repr__(self):
return f"<av.AssSubtitle {self.dialogue!r} at 0x{id(self):x}>"
@property
def ass(self):
"""
Returns the subtitle in the ASS/SSA format. Used by the vast majority of subtitle formats.
"""
if self.ptr.ass is not cython.NULL:
return PyBytes_FromString(self.ptr.ass)
return b""
@property
def dialogue(self):
"""
Extract the dialogue from the ass format. Strip comments.
"""
comma_count: cython.short = 0
i: uint64_t = 0
state: cython.bint = False
ass_text: bytes = self.ass
char, next_char = cython.declare(cython.char)
result: bytearray = bytearray()
text_len: cython.Py_ssize_t = len(ass_text)
while comma_count < 8 and i < text_len:
if ass_text[i] == b","[0]:
comma_count += 1
i += 1
while i < text_len:
char = ass_text[i]
next_char = 0 if i + 1 >= text_len else ass_text[i + 1]
if char == b"\\"[0] and next_char == b"N"[0]:
result.append(b"\n"[0])
i += 2
continue
if not state:
if char == b"{"[0] and next_char != b"\\"[0]:
state = True
else:
result.append(char)
elif char == b"}"[0]:
state = False
i += 1
return bytes(result)
@property
def text(self):
"""
Rarely used attribute. You're probably looking for dialogue.
"""
if self.ptr.text is not cython.NULL:
return PyBytes_FromString(self.ptr.text)
return b""