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Support building USM with different HCA audio sample rates #16

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Support building USM with different HCA audio sample rates #16

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61 changes: 21 additions & 40 deletions PyCriCodecs/usm.py
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
import os
import itertools
from typing import BinaryIO
from io import FileIO, BytesIO
from .chunk import *
Expand Down Expand Up @@ -676,7 +677,7 @@ def get_data(self) -> bytes:
)
SFA_chunk += stream.get_header().ljust(stream.hca["HeaderSize"]+ padding, b"\x00")
SFA_chunks[self.streams.index(stream)].append(SFA_chunk)
for i in stream.get_frames():
for i, frame in enumerate(stream.get_frames(), start=1):
padding = (0x20 - (stream.hca["FrameSize"] % 0x20) if stream.hca["FrameSize"] % 0x20 != 0 else 0)
SFA_chunk = USMChunkHeader.pack(
USMChunckHeaderType.SFA.value,
Expand All @@ -693,8 +694,8 @@ def get_data(self) -> bytes:
0,
0
)
SFA_chunk += i[1].ljust(stream.hca["FrameSize"] + padding , b"\x00")
current_interval += self.base_interval_per_SFA_chunk[self.streams.index(stream)]
SFA_chunk += frame[1].ljust(stream.hca["FrameSize"] + padding , b"\x00")
current_interval = round(i * self.base_interval_per_SFA_chunk[self.streams.index(stream)])
SFA_chunks[self.streams.index(stream)].append(SFA_chunk)
else:
SFA_chunk = USMChunkHeader.pack(
Expand Down Expand Up @@ -727,43 +728,15 @@ def get_data(self) -> bytes:
# TODO Add support for Subtitle information.
def build_usm(self, SFV_list: list, SFA_chunks: list = False, SBT_chunks = None):
header = self.build_header(SFV_list, SFA_chunks, SBT_chunks)
len_sfv = len(SFV_list)
if self.audio:
len_sfa = [len(x) for x in SFA_chunks]
else:
len_sfa = [0]
max_len = max(len_sfv, max(len_sfa))

# SFV gets the order priority if the interval is matching that of SFA
# furthermore, SFA chunks keep going until the next SFV interval is reached.
#
current_interval = 0
target_interval = 0
sfa_count = 0
for i in range(max_len):
if i < len_sfv:
header += SFV_list[i]
target_interval += self.SFV_interval_for_VP9
if not self.audio:
chunks = SFV_list
else:
chunks = list(itertools.chain(SFV_list, *SFA_chunks))
chunks.sort(key=chunk_key_sort)
for chunk in chunks:
header += chunk

if self.audio:
while current_interval < target_interval:
idx = 0
for stream in SFA_chunks:
if current_interval > target_interval:
# This would not just break the loop, this would break everything.
# Will not happen in typical cases. But if a video had a really weird framerate, this might skew it.
current_interval += self.base_interval_per_SFA_chunk[0] # Not safe. FIXME
break
if sfa_count == 0:
header += stream[sfa_count]
if sfa_count < len_sfa[idx]-1:
header += stream[sfa_count+1]
idx += 1
else:
current_interval += self.base_interval_per_SFA_chunk[0]
# This is wrong actually, I made the base interval a list in case the intervals are different
# But it seems they are the same no matter what, however I will leave it as this just in case.
sfa_count += 1
self.usm = header

def build_header(self, SFV_list: list, SFA_chunks: list = False, SBT_chunks = None) -> bytes:
Expand Down Expand Up @@ -1174,7 +1147,8 @@ def prepare_SFA(self):
hca.Pyparse_header()
framesize = hca.hca["FrameSize"]
self.SFA_chunk_size.append(framesize)
self.base_interval_per_SFA_chunk.append(64) # I am not sure about this.
# e.g. 64 for 48KHz and ~139 for 22.05KHz
self.base_interval_per_SFA_chunk.append((1024 * 3) / (hca.hca["SampleRate"] / 1000)) # I am not sure about this.

def init_key(self, key: str):
# Copied from USM class, it's hard to combine them at this point with how the USM class is created for extraction.
Expand Down Expand Up @@ -1299,4 +1273,11 @@ def AudioMask(self, memObj: bytes) -> bytes:
return bytes(head + memObj)

def get_usm(self) -> bytes:
return self.usm
return self.usm


def chunk_key_sort(chunk):
header, chuncksize, unk08, offset, padding, chno, unk0D, unk0E, type, frametime, framerate, unk18, unk1C = USMChunkHeader.unpack(chunk[:USMChunkHeader.size])
prio = 0 if header.decode() == "@SFV" else 1
# all stream chunks before section_end chunks, then sort by frametime, with SFV chunks before SFA chunks
return (type, frametime, prio)