from enum import Flag, IntEnum import cython from cython.cimports import libav as lib from cython.cimports.av.buffer import ByteSource, bytesource from cython.cimports.av.codec.codec import Codec, wrap_codec from cython.cimports.av.dictionary import Dictionary from cython.cimports.av.error import err_check from cython.cimports.av.packet import Packet from cython.cimports.av.utils import avrational_to_fraction, to_avrational from cython.cimports.libc.errno import EAGAIN from cython.cimports.libc.stdint import uint8_t from cython.cimports.libc.string import memcpy _cinit_sentinel = cython.declare(object, object()) @cython.cfunc def wrap_codec_context( c_ctx: cython.pointer[lib.AVCodecContext], c_codec: cython.pointer[cython.const[lib.AVCodec]], hwaccel: HWAccel, ) -> CodecContext: """Build an bv.CodecContext for an existing AVCodecContext.""" py_ctx: CodecContext if c_ctx.codec_type == lib.AVMEDIA_TYPE_VIDEO: from av.video.codeccontext import VideoCodecContext py_ctx = VideoCodecContext(_cinit_sentinel) elif c_ctx.codec_type == lib.AVMEDIA_TYPE_AUDIO: from av.audio.codeccontext import AudioCodecContext py_ctx = AudioCodecContext(_cinit_sentinel) elif c_ctx.codec_type == lib.AVMEDIA_TYPE_SUBTITLE: from av.subtitles.codeccontext import SubtitleCodecContext py_ctx = SubtitleCodecContext(_cinit_sentinel) else: py_ctx = CodecContext(_cinit_sentinel) py_ctx._init(c_ctx, c_codec, hwaccel) return py_ctx class ThreadType(Flag): NONE = 0 FRAME: "Decode more than one frame at once" = lib.FF_THREAD_FRAME SLICE: "Decode more than one part of a single frame at once" = lib.FF_THREAD_SLICE AUTO: "Decode using both FRAME and SLICE methods." = ( lib.FF_THREAD_SLICE | lib.FF_THREAD_FRAME ) class Flags(IntEnum): unaligned = lib.AV_CODEC_FLAG_UNALIGNED qscale = lib.AV_CODEC_FLAG_QSCALE four_mv = lib.AV_CODEC_FLAG_4MV output_corrupt = lib.AV_CODEC_FLAG_OUTPUT_CORRUPT qpel = lib.AV_CODEC_FLAG_QPEL recon_frame = lib.AV_CODEC_FLAG_RECON_FRAME copy_opaque = lib.AV_CODEC_FLAG_COPY_OPAQUE frame_duration = lib.AV_CODEC_FLAG_FRAME_DURATION pass1 = lib.AV_CODEC_FLAG_PASS1 pass2 = lib.AV_CODEC_FLAG_PASS2 loop_filter = lib.AV_CODEC_FLAG_LOOP_FILTER gray = lib.AV_CODEC_FLAG_GRAY psnr = lib.AV_CODEC_FLAG_PSNR interlaced_dct = lib.AV_CODEC_FLAG_INTERLACED_DCT low_delay = lib.AV_CODEC_FLAG_LOW_DELAY global_header = lib.AV_CODEC_FLAG_GLOBAL_HEADER bitexact = lib.AV_CODEC_FLAG_BITEXACT ac_pred = lib.AV_CODEC_FLAG_AC_PRED interlaced_me = lib.AV_CODEC_FLAG_INTERLACED_ME closed_gop = lib.AV_CODEC_FLAG_CLOSED_GOP class Flags2(IntEnum): fast = lib.AV_CODEC_FLAG2_FAST no_output = lib.AV_CODEC_FLAG2_NO_OUTPUT local_header = lib.AV_CODEC_FLAG2_LOCAL_HEADER chunks = lib.AV_CODEC_FLAG2_CHUNKS ignore_crop = lib.AV_CODEC_FLAG2_IGNORE_CROP show_all = lib.AV_CODEC_FLAG2_SHOW_ALL export_mvs = lib.AV_CODEC_FLAG2_EXPORT_MVS skip_manual = lib.AV_CODEC_FLAG2_SKIP_MANUAL ro_flush_noop = lib.AV_CODEC_FLAG2_RO_FLUSH_NOOP @cython.cclass class CodecContext: @staticmethod def create(codec, mode=None, hwaccel=None): cy_codec: Codec = codec if isinstance(codec, Codec) else Codec(codec, mode) c_ctx: cython.pointer[lib.AVCodecContext] = lib.avcodec_alloc_context3( cy_codec.ptr ) return wrap_codec_context(c_ctx, cy_codec.ptr, hwaccel) def __cinit__(self, sentinel=None, *args, **kwargs): if sentinel is not _cinit_sentinel: raise RuntimeError("Cannot instantiate CodecContext") self.options = {} self.stream_index = -1 # This is set by the container immediately. self.is_open = False @cython.cfunc def _init( self, ptr: cython.pointer[lib.AVCodecContext], codec: cython.pointer[cython.const[lib.AVCodec]], hwaccel: HWAccel, ): self.ptr = ptr if self.ptr.codec and codec and self.ptr.codec != codec: raise RuntimeError("Wrapping CodecContext with mismatched codec.") self.codec = wrap_codec(codec if codec != cython.NULL else self.ptr.codec) self.hwaccel = hwaccel # Set reasonable threading defaults. self.ptr.thread_count = 0 # use as many threads as there are CPUs. self.ptr.thread_type = 0x02 # thread within a frame. Does not change the API. @property def flags(self): """ Get and set the flags bitmask of CodecContext. :rtype: int """ return self.ptr.flags @flags.setter def flags(self, value: cython.int): self.ptr.flags = value @property def qscale(self): """ Use fixed qscale. :rtype: bool """ return bool(self.ptr.flags & lib.AV_CODEC_FLAG_QSCALE) @qscale.setter def qscale(self, value): if value: self.ptr.flags |= lib.AV_CODEC_FLAG_QSCALE else: self.ptr.flags &= ~lib.AV_CODEC_FLAG_QSCALE @property def copy_opaque(self): return bool(self.ptr.flags & lib.AV_CODEC_FLAG_COPY_OPAQUE) @copy_opaque.setter def copy_opaque(self, value): if value: self.ptr.flags |= lib.AV_CODEC_FLAG_COPY_OPAQUE else: self.ptr.flags &= ~lib.AV_CODEC_FLAG_COPY_OPAQUE @property def flags2(self): """ Get and set the flags2 bitmask of CodecContext. :rtype: int """ return self.ptr.flags2 @flags2.setter def flags2(self, value: cython.int): self.ptr.flags2 = value @property def extradata(self): if self.ptr is cython.NULL: return None if self.ptr.extradata_size > 0: return cython.cast( bytes, cython.cast(cython.pointer[uint8_t], self.ptr.extradata)[ : self.ptr.extradata_size ], ) return None @extradata.setter def extradata(self, data): if data is None: lib.av_freep(cython.address(self.ptr.extradata)) self.ptr.extradata_size = 0 else: source = bytesource(data) self.ptr.extradata = cython.cast( cython.pointer[uint8_t], lib.av_realloc( self.ptr.extradata, source.length + lib.AV_INPUT_BUFFER_PADDING_SIZE ), ) if not self.ptr.extradata: raise MemoryError("Cannot allocate extradata") memcpy(self.ptr.extradata, source.ptr, source.length) self.ptr.extradata_size = source.length @property def extradata_size(self): return self.ptr.extradata_size @property def is_encoder(self): if self.ptr is cython.NULL: return False return lib.av_codec_is_encoder(self.ptr.codec) @property def is_decoder(self): if self.ptr is cython.NULL: return False return lib.av_codec_is_decoder(self.ptr.codec) @cython.ccall def open(self, strict: cython.bint = True): if self.is_open: if strict: raise ValueError("CodecContext is already open.") return options: Dictionary = Dictionary() options.update(self.options or {}) if not self.ptr.time_base.num and self.is_encoder: if self.type == "video": self.ptr.time_base.num = self.ptr.framerate.den or 1 self.ptr.time_base.den = self.ptr.framerate.num or lib.AV_TIME_BASE elif self.type == "audio": self.ptr.time_base.num = 1 self.ptr.time_base.den = self.ptr.sample_rate else: self.ptr.time_base.num = 1 self.ptr.time_base.den = lib.AV_TIME_BASE err_check( lib.avcodec_open2(self.ptr, self.codec.ptr, cython.address(options.ptr)), f'avcodec_open2("{self.codec.name}", {self.options})', ) self.is_open = True self.options = dict(options) def __dealloc__(self): if self.ptr: lib.av_freep(cython.address(self.ptr.extradata)) lib.avcodec_free_context(cython.address(self.ptr)) if self.parser: lib.av_parser_close(self.parser) def __repr__(self): _type = self.type or "" name = self.name or "" return f"" def parse(self, raw_input=None): """Split up a byte stream into list of :class:`.Packet`. This is only effectively splitting up a byte stream, and does no actual interpretation of the data. It will return all packets that are fully contained within the given input, and will buffer partial packets until they are complete. Any timing information the parser is able to infer (``pts``, ``dts``, ``duration``, ``pos`` and the keyframe flag) is assigned onto the returned packets. Fields the parser cannot determine are left unset. :param ByteSource raw_input: A chunk of a byte-stream to process. Anything that can be turned into a :class:`.ByteSource` is fine. ``None`` or empty inputs will flush the parser's buffers. :return: ``list`` of :class:`.Packet` newly available. """ if not self.parser: self.parser = lib.av_parser_init(self.codec.ptr.id) if not self.parser: raise ValueError(f"No parser for {self.codec.name}") source: ByteSource = bytesource(raw_input, allow_none=True) in_data: cython.p_uchar = source.ptr if source is not None else cython.NULL in_size: cython.int = source.length if source is not None else 0 out_data: cython.p_uchar out_size: cython.int consumed: cython.int packet: Packet = None packets: list = [] while True: with cython.nogil: consumed = lib.av_parser_parse2( self.parser, self.ptr, cython.address(out_data), cython.address(out_size), in_data, in_size, lib.AV_NOPTS_VALUE, lib.AV_NOPTS_VALUE, 0, ) err_check(consumed) if out_size: # We copy the data immediately, as we have yet to figure out # the expected lifetime of the buffer we get back. All of the # examples decode it immediately. # # We've also tried: # packet = Packet() # packet.data = out_data # packet.size = out_size # packet.source = source # # ... but this results in corruption. packet = Packet(out_size) memcpy(packet.ptr.data, out_data, out_size) # Propagate the timing information the parser inferred for # this frame onto the packet (mirrors FFmpeg's parse_packet). packet.ptr.pts = self.parser.pts packet.ptr.dts = self.parser.dts packet.ptr.pos = self.parser.pos if self.parser.duration: packet.ptr.duration = self.parser.duration if self.parser.key_frame == 1: packet.ptr.flags |= lib.AV_PKT_FLAG_KEY packets.append(packet) if not in_size: # This was a flush. Only one packet should ever be returned. break in_data += consumed in_size -= consumed if not in_size: break return packets @property def is_hwaccel(self): """ Returns ``True`` if this codec context is hardware accelerated, ``False`` otherwise. """ return self.hwaccel_ctx is not None def _send_frame_and_recv(self, frame: Frame | None): packet: Packet res: cython.int with cython.nogil: res = lib.avcodec_send_frame( self.ptr, frame.ptr if frame is not None else cython.NULL ) err_check(res, "avcodec_send_frame()") packet = self._recv_packet() while packet: yield packet packet = self._recv_packet() @cython.cfunc def _prepare_frames_for_encode(self, frame: Frame | None) -> list: return [frame] @cython.cfunc def _alloc_next_frame(self) -> Frame: raise NotImplementedError("Base CodecContext cannot decode.") @cython.cfunc def _recv_frame(self): if not self._next_frame: self._next_frame = self._alloc_next_frame() frame: Frame = self._next_frame res: cython.int with cython.nogil: res = lib.avcodec_receive_frame(self.ptr, frame.ptr) if res == -EAGAIN or res == lib.AVERROR_EOF: return err_check(res, "avcodec_receive_frame()") frame = self._transfer_hwframe(frame) if not res: self._next_frame = None return frame @cython.cfunc def _transfer_hwframe(self, frame: Frame): return frame @cython.cfunc def _recv_packet(self): packet: Packet = Packet() res: cython.int with cython.nogil: res = lib.avcodec_receive_packet(self.ptr, packet.ptr) if res == -EAGAIN or res == lib.AVERROR_EOF: return err_check(res, "avcodec_receive_packet()") if not res: return packet @cython.cfunc def _prepare_and_time_rebase_frames_for_encode(self, frame: Frame): if self.ptr.codec_type not in [lib.AVMEDIA_TYPE_VIDEO, lib.AVMEDIA_TYPE_AUDIO]: raise NotImplementedError("Encoding is only supported for audio and video.") self.open(strict=False) frames = self._prepare_frames_for_encode(frame) # Assert the frames are in our time base. # TODO: Don't mutate time. for frame in frames: if frame is not None: frame._rebase_time(self.ptr.time_base) return frames @cython.ccall def encode(self, frame: Frame | None = None): """Encode a list of :class:`.Packet` from the given :class:`.Frame`.""" res = [] for frame in self._prepare_and_time_rebase_frames_for_encode(frame): for packet in self._send_frame_and_recv(frame): self._setup_encoded_packet(packet) res.append(packet) return res def encode_lazy(self, frame: Frame | None = None): for frame in self._prepare_and_time_rebase_frames_for_encode(frame): for packet in self._send_frame_and_recv(frame): self._setup_encoded_packet(packet) yield packet @cython.cfunc def _setup_encoded_packet(self, packet: Packet): # We coerced the frame's time_base into the CodecContext's during encoding, # and FFmpeg copied the frame's pts/dts to the packet, so keep track of # this time_base in case the frame needs to be muxed to a container with # a different time_base. # # NOTE: if the CodecContext's time_base is altered during encoding, all bets # are off! packet.ptr.time_base = self.ptr.time_base @cython.ccall def decode(self, packet: Packet | None = None): """Decode a list of :class:`.Frame` from the given :class:`.Packet`. If the packet is None, the buffers will be flushed. This is useful if you do not want the library to automatically re-order frames for you (if they are encoded with a codec that has B-frames). .. warning:: This method is **not thread-safe**. Calling :meth:`decode` concurrently from multiple threads on the same :class:`CodecContext` will corrupt internal FFmpeg state and likely cause a crash (segfault). FFmpeg 8.1 enforces this more strictly than earlier releases. If you need to decode from multiple threads, give each thread its own :class:`CodecContext`. """ if not self.codec.ptr: raise ValueError("cannot decode unknown codec") self.open(strict=False) res: cython.int with cython.nogil: res = lib.avcodec_send_packet( self.ptr, packet.ptr if packet is not None else cython.NULL ) err_check(res, "avcodec_send_packet()") out: list = [] frame = self._recv_frame() while frame: self._setup_decoded_frame(frame, packet) out.append(frame) frame = self._recv_frame() return out @cython.ccall def flush_buffers(self): """Reset the internal codec state and discard all internal buffers. Should be called before you start decoding from a new position e.g. when seeking or when switching to a different stream. """ if self.is_open: with cython.nogil: lib.avcodec_flush_buffers(self.ptr) @cython.cfunc def _setup_decoded_frame(self, frame: Frame, packet: Packet | None): # Propagate our manual times. # While decoding, frame times are in stream time_base, which PyAV # is carrying around. # TODO: Somehow get this from the stream so we can not pass the # packet here (because flushing packets are bogus). if packet is not None: frame._time_base = packet.ptr.time_base @property def name(self): return self.codec.name @property def type(self): return self.codec.type @property def profiles(self): """ List the available profiles for this stream. :type: list[str] """ ret: list = [] if not self.ptr.codec or not self.codec.desc or not self.codec.desc.profiles: return ret # Profiles are always listed in the codec descriptor, but not necessarily in # the codec itself. So use the descriptor here. desc = self.codec.desc i: cython.int = 0 while desc.profiles[i].profile != lib.AV_PROFILE_UNKNOWN: ret.append(desc.profiles[i].name) i += 1 return ret @property def profile(self): if not self.ptr.codec or not self.codec.desc or not self.codec.desc.profiles: return # Profiles are always listed in the codec descriptor, but not necessarily in # the codec itself. So use the descriptor here. desc = self.codec.desc i: cython.int = 0 while desc.profiles[i].profile != lib.AV_PROFILE_UNKNOWN: if desc.profiles[i].profile == self.ptr.profile: return desc.profiles[i].name i += 1 @profile.setter def profile(self, value): if not self.codec or not self.codec.desc or not self.codec.desc.profiles: return # Profiles are always listed in the codec descriptor, but not necessarily in # the codec itself. So use the descriptor here. desc = self.codec.desc i: cython.int = 0 while desc.profiles[i].profile != lib.AV_PROFILE_UNKNOWN: if desc.profiles[i].name == value: self.ptr.profile = desc.profiles[i].profile return i += 1 @property def time_base(self): if self.is_decoder: raise RuntimeError("Cannot access 'time_base' as a decoder") return avrational_to_fraction(cython.address(self.ptr.time_base)) @time_base.setter def time_base(self, value): if self.is_decoder: raise RuntimeError("Cannot access 'time_base' as a decoder") to_avrational(value, cython.address(self.ptr.time_base)) @property def codec_tag(self): return self.ptr.codec_tag.to_bytes(4, byteorder="little", signed=False).decode( encoding="ascii" ) @codec_tag.setter def codec_tag(self, value): if isinstance(value, str) and len(value) == 4: self.ptr.codec_tag = int.from_bytes( value.encode(encoding="ascii"), byteorder="little", signed=False ) else: raise ValueError("Codec tag should be a 4 character string.") @property @cython.cdivision(True) def global_quality(self): """Global quality for codecs which cannot change it per frame. Stored internally in lambda units; this property converts to/from QP units using ``FF_QP2LAMBDA``. Wraps :ffmpeg:`AVCodecContext.global_quality`. """ return self.ptr.global_quality // lib.FF_QP2LAMBDA @global_quality.setter def global_quality(self, value: cython.int): self.ptr.global_quality = value * lib.FF_QP2LAMBDA @property def bit_rate(self): return self.ptr.bit_rate if self.ptr.bit_rate > 0 else None @bit_rate.setter def bit_rate(self, value: cython.int): self.ptr.bit_rate = value @property def max_bit_rate(self): if self.ptr.rc_max_rate > 0: return self.ptr.rc_max_rate else: return None @property def bit_rate_tolerance(self): self.ptr.bit_rate_tolerance @bit_rate_tolerance.setter def bit_rate_tolerance(self, value: cython.int): self.ptr.bit_rate_tolerance = value @property def thread_count(self): """How many threads to use; 0 means auto. Wraps :ffmpeg:`AVCodecContext.thread_count`. """ return self.ptr.thread_count @thread_count.setter def thread_count(self, value: cython.int): if self.is_open: raise RuntimeError("Cannot change thread_count after codec is open.") self.ptr.thread_count = value @property def thread_type(self): """One of :class:`.ThreadType`. Wraps :ffmpeg:`AVCodecContext.thread_type`. """ return ThreadType(self.ptr.thread_type) @thread_type.setter def thread_type(self, value): if self.is_open: raise RuntimeError("Cannot change thread_type after codec is open.") if type(value) is int: self.ptr.thread_type = value elif type(value) is str: self.ptr.thread_type = ThreadType[value].value else: self.ptr.thread_type = value.value @property def skip_frame(self): """Returns one of the following str literals: "NONE" Discard nothing "DEFAULT" Discard useless packets like 0 size packets in AVI "NONREF" Discard all non reference "BIDIR" Discard all bidirectional frames "NONINTRA" Discard all non intra frames "NONKEY Discard all frames except keyframes "ALL" Discard all Wraps :ffmpeg:`AVCodecContext.skip_frame`. """ value = self.ptr.skip_frame if value == lib.AVDISCARD_NONE: return "NONE" if value == lib.AVDISCARD_DEFAULT: return "DEFAULT" if value == lib.AVDISCARD_NONREF: return "NONREF" if value == lib.AVDISCARD_BIDIR: return "BIDIR" if value == lib.AVDISCARD_NONINTRA: return "NONINTRA" if value == lib.AVDISCARD_NONKEY: return "NONKEY" if value == lib.AVDISCARD_ALL: return "ALL" return f"{value}" @skip_frame.setter def skip_frame(self, value): if value == "NONE": self.ptr.skip_frame = lib.AVDISCARD_NONE elif value == "DEFAULT": self.ptr.skip_frame = lib.AVDISCARD_DEFAULT elif value == "NONREF": self.ptr.skip_frame = lib.AVDISCARD_NONREF elif value == "BIDIR": self.ptr.skip_frame = lib.AVDISCARD_BIDIR elif value == "NONINTRA": self.ptr.skip_frame = lib.AVDISCARD_NONINTRA elif value == "NONKEY": self.ptr.skip_frame = lib.AVDISCARD_NONKEY elif value == "ALL": self.ptr.skip_frame = lib.AVDISCARD_ALL else: raise ValueError("Invalid skip_frame type") @property def delay(self): """Codec delay. Wraps :ffmpeg:`AVCodecContext.delay`. """ return self.ptr.delay