mirror of
https://github.com/yt-dlp/yt-dlp
synced 2024-12-26 21:59:08 +01:00
mold mp4_parser into mp4direct
This commit is contained in:
Lesmiscore
parent
2ed0b5568e
commit
302b23a9a3
2 changed files with 155 additions and 166 deletions
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@ -1,157 +0,0 @@
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import struct
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from typing import Tuple
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from io import BytesIO, RawIOBase
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class LengthLimiter(RawIOBase):
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"""
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A bytes IO to limit length to be read.
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"""
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def __init__(self, r: RawIOBase, size: int):
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self.r = r
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self.remaining = size
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def read(self, sz: int = None) -> bytes:
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if self.remaining == 0:
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return b''
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if sz in (-1, None):
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sz = self.remaining
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sz = min(sz, self.remaining)
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ret = self.r.read(sz)
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if ret:
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self.remaining -= len(ret)
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return ret
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def readall(self) -> bytes:
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if self.remaining == 0:
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return b''
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ret = self.read(self.remaining)
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if ret:
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self.remaining -= len(ret)
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return ret
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def readable(self) -> bool:
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return bool(self.remaining)
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def read_harder(r, size):
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"""
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Try to read from the stream.
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@params r byte stream to read
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@params size Number of bytes to read in total
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"""
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retry = 0
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buf = b''
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while len(buf) < size and retry < 3:
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ret = r.read(size - len(buf))
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if not ret:
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retry += 1
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continue
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retry = 0
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buf += ret
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return buf
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def pack_be32(value: int) -> bytes:
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""" Pack value to 4-byte-long bytes in the big-endian byte order """
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return struct.pack('>I', value)
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def pack_be64(value: int) -> bytes:
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""" Pack value to 8-byte-long bytes in the big-endian byte order """
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return struct.pack('>L', value)
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def unpack_be32(value: bytes) -> int:
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""" Convert 4-byte-long bytes in the big-endian byte order, to an integer value """
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return struct.unpack('>I', value)[0]
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def unpack_be64(value: bytes) -> int:
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""" Convert 8-byte-long bytes in the big-endian byte order, to an integer value """
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return struct.unpack('>L', value)[0]
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def unpack_ver_flags(value: bytes) -> Tuple[int, int]:
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"""
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Unpack 4-byte-long value into version and flags.
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@returns (version, flags)
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"""
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ver, up_flag, down_flag = struct.unpack('>BBH', value)
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return ver, (up_flag << 16 | down_flag)
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# https://github.com/gpac/mp4box.js/blob/4e1bc23724d2603754971abc00c2bd5aede7be60/src/box.js#L13-L40
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MP4_CONTAINER_BOXES = ('moov', 'trak', 'edts', 'mdia', 'minf', 'dinf', 'stbl', 'mvex', 'moof', 'traf', 'vttc', 'tref', 'iref', 'mfra', 'meco', 'hnti', 'hinf', 'strk', 'strd', 'sinf', 'rinf', 'schi', 'trgr', 'udta', 'iprp', 'ipco')
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""" List of boxes that nests the other boxes """
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def parse_mp4_boxes(r: RawIOBase):
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"""
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Parses an ISO BMFF (which MP4 follows) and yields its boxes as a sequence.
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This does not interpret content of these boxes.
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Sequence details:
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('atom', b'blablabla'): A box, with content (not container boxes)
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('atom', b''): Possibly container box (must check MP4_CONTAINER_BOXES) or really an empty box
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(None, 'atom'): End of a container box
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Example: Path:
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('test', b'123456') /test
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('moov', b'') /moov (start of container box)
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('helo', b'abcdef') /moov/helo
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('1984', b'1q84') /moov/1984
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('trak', b'') /moov/trak (start of container box)
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('keys', b'2022') /moov/trak/keys
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(None , 'trak') /moov/trak (end of container box)
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('topp', b'1991') /moov/topp
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(None , 'moov') /moov (end of container box)
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"""
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while True:
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size_b = read_harder(r, 4)
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if not size_b:
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break
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type_b = r.read(4)
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# 00 00 00 20 is big-endian
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box_size = unpack_be32(size_b)
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type_s = type_b.decode()
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if type_s in MP4_CONTAINER_BOXES:
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yield (type_s, b'')
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yield from parse_mp4_boxes(LengthLimiter(r, box_size - 8))
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yield (None, type_s)
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continue
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# subtract by 8
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full_body = read_harder(r, box_size - 8)
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yield (type_s, full_body)
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def write_mp4_boxes(w: RawIOBase, box_iter):
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"""
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Writes an ISO BMFF file from a given sequence to a given writer.
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The iterator to be passed must follow parse_mp4_boxes's protocol.
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"""
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stack = [
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(None, w), # parent box, IO
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]
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for btype, content in box_iter:
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if btype in MP4_CONTAINER_BOXES:
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bio = BytesIO()
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stack.append((btype, bio))
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continue
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elif btype is None:
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assert stack[-1][0] == content
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btype, bio = stack.pop()
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content = bio.getvalue()
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wt = stack[-1][1]
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wt.write(pack_be32(len(content) + 8))
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wt.write(btype.encode()[:4])
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wt.write(content)
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@ -1,19 +1,165 @@
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import os
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import struct
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from io import BytesIO, RawIOBase
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from math import inf
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from typing import Tuple
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from .common import PostProcessor
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from ..utils import prepend_extension
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from ..mp4_parser import (
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write_mp4_boxes,
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parse_mp4_boxes,
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pack_be32,
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pack_be64,
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unpack_ver_flags,
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unpack_be32,
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unpack_be64,
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)
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class LengthLimiter(RawIOBase):
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"""
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A bytes IO to limit length to be read.
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"""
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def __init__(self, r: RawIOBase, size: int):
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self.r = r
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self.remaining = size
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def read(self, sz: int = None) -> bytes:
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if self.remaining == 0:
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return b''
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if sz in (-1, None):
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sz = self.remaining
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sz = min(sz, self.remaining)
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ret = self.r.read(sz)
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if ret:
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self.remaining -= len(ret)
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return ret
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def readall(self) -> bytes:
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if self.remaining == 0:
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return b''
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ret = self.read(self.remaining)
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if ret:
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self.remaining -= len(ret)
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return ret
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def readable(self) -> bool:
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return bool(self.remaining)
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def read_harder(r, size):
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"""
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Try to read from the stream.
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@params r byte stream to read
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@params size Number of bytes to read in total
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"""
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retry = 0
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buf = b''
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while len(buf) < size and retry < 3:
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ret = r.read(size - len(buf))
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if not ret:
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retry += 1
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continue
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retry = 0
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buf += ret
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return buf
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def pack_be32(value: int) -> bytes:
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""" Pack value to 4-byte-long bytes in the big-endian byte order """
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return struct.pack('>I', value)
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def pack_be64(value: int) -> bytes:
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""" Pack value to 8-byte-long bytes in the big-endian byte order """
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return struct.pack('>L', value)
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def unpack_be32(value: bytes) -> int:
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""" Convert 4-byte-long bytes in the big-endian byte order, to an integer value """
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return struct.unpack('>I', value)[0]
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def unpack_be64(value: bytes) -> int:
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""" Convert 8-byte-long bytes in the big-endian byte order, to an integer value """
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return struct.unpack('>L', value)[0]
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def unpack_ver_flags(value: bytes) -> Tuple[int, int]:
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"""
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Unpack 4-byte-long value into version and flags.
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@returns (version, flags)
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"""
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ver, up_flag, down_flag = struct.unpack('>BBH', value)
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return ver, (up_flag << 16 | down_flag)
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# https://github.com/gpac/mp4box.js/blob/4e1bc23724d2603754971abc00c2bd5aede7be60/src/box.js#L13-L40
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MP4_CONTAINER_BOXES = ('moov', 'trak', 'edts', 'mdia', 'minf', 'dinf', 'stbl', 'mvex', 'moof', 'traf', 'vttc', 'tref', 'iref', 'mfra', 'meco', 'hnti', 'hinf', 'strk', 'strd', 'sinf', 'rinf', 'schi', 'trgr', 'udta', 'iprp', 'ipco')
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""" List of boxes that nests the other boxes """
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def parse_mp4_boxes(r: RawIOBase):
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"""
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Parses an ISO BMFF (which MP4 follows) and yields its boxes as a sequence.
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This does not interpret content of these boxes.
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Sequence details:
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('atom', b'blablabla'): A box, with content (not container boxes)
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('atom', b''): Possibly container box (must check MP4_CONTAINER_BOXES) or really an empty box
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(None, 'atom'): End of a container box
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Example: Path:
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('test', b'123456') /test
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('moov', b'') /moov (start of container box)
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('helo', b'abcdef') /moov/helo
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('1984', b'1q84') /moov/1984
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('trak', b'') /moov/trak (start of container box)
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('keys', b'2022') /moov/trak/keys
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(None , 'trak') /moov/trak (end of container box)
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('topp', b'1991') /moov/topp
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(None , 'moov') /moov (end of container box)
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"""
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while True:
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size_b = read_harder(r, 4)
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if not size_b:
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break
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type_b = r.read(4)
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# 00 00 00 20 is big-endian
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box_size = unpack_be32(size_b)
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type_s = type_b.decode()
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if type_s in MP4_CONTAINER_BOXES:
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yield (type_s, b'')
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yield from parse_mp4_boxes(LengthLimiter(r, box_size - 8))
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yield (None, type_s)
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continue
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# subtract by 8
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full_body = read_harder(r, box_size - 8)
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yield (type_s, full_body)
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def write_mp4_boxes(w: RawIOBase, box_iter):
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"""
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Writes an ISO BMFF file from a given sequence to a given writer.
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The iterator to be passed must follow parse_mp4_boxes's protocol.
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"""
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stack = [
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(None, w), # parent box, IO
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]
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for btype, content in box_iter:
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if btype in MP4_CONTAINER_BOXES:
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bio = BytesIO()
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stack.append((btype, bio))
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continue
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elif btype is None:
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assert stack[-1][0] == content
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btype, bio = stack.pop()
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content = bio.getvalue()
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wt = stack[-1][1]
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wt.write(pack_be32(len(content) + 8))
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wt.write(btype.encode()[:4])
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wt.write(content)
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class MP4FixupTimestampPP(PostProcessor):
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