license notice

.gitignore

@@ -173,4 +173,4 @@ cython_debug/
 
 # PyPI configuration file
 .pypirc
-
+/test.mp4

mp4/__init__.py

@@ -0,0 +1,15 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.

mp4/codec.py

@@ -0,0 +1,29 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+class Codec:
+    __slots__ = '_ref'
+
+    def __init__(self, ref):
+        self._ref = ref
+
+    @property
+    def _as_parameter_(self):
+        return self._ref
+
+    @property
+    def name(self):
+        return self._ref.contents.name.decode("utf-8")

mp4/decoder.py

@@ -0,0 +1,61 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+from . import libav
+from .packet import Packet
+from .frame import Frame
+
+class Decoder:
+    __slots__ = '_context'
+
+    def __init__(self, stream):
+        self._context = libav.codec_alloc_context(stream.codec)
+        if not self._context:
+            raise MemoryError
+        errcode = libav.codec_parameters_to_context(self._context, stream.parameters)
+        if errcode < 0:
+            libav.codec_free_context(self._context)
+            raise Exception("Failed to set context parameters")
+        errcode = libav.codec_open(self._context, stream.codec)
+        if errcode < 0:
+            libav.codec_free_context(self._context)
+            raise Exception("Failed to open codec context")
+
+    def __del__(self):
+        if self._context:
+            libav.codec_free_context(self._context)
+
+    def _receive(self):
+        frames = []
+        while True:
+            frame = Frame()
+            errcode = libav.codec_receive_frame(self._context, frame)
+            if errcode in (libav.AVERROR_EOF, libav.AVERROR_EAGAIN):
+                break
+            elif errcode < 0:
+                errstring = libav.strerror(errcode)
+                raise Exception(f"Failed to receive frame: {errstring}")
+            frames.append(frame)
+        return frames
+
+    def decode(self, packet):
+        if not self._context:
+            return None
+        errcode = libav.codec_send_packet(self._context, packet)
+        if errcode < 0:
+            errstring = libav.strerror(errcode)
+            raise Exception(f"Failed to send packet: {errstring}")
+        return self._receive()

mp4/demuxer.py

@@ -0,0 +1,69 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+from . import libav
+from .codec import Codec
+from .stream import Stream
+from .packet import Packet
+
+class Demuxer:
+    __slots__ = '_context', 'video_stream', 'audio_stream'
+
+    def __init__(self, path):
+        self._context = libav.format_alloc_context()
+        if not self._context:
+            raise MemoryError
+        errcode = libav.format_open_input(self._context, "file:" + path)
+        if errcode < 0:
+            raise Exception(f"Failed to open: {path}")
+        errcode = libav.format_find_stream_info(self._context)
+        if errcode < 0:
+            libav.format_close_input(self._context)
+            raise Exception("Failed to find stream info")
+        self.video_stream = self._find_stream(libav.AVMEDIA_TYPE_VIDEO)
+        if self.video_stream is None:
+            libav.format_close_input(self._context)
+            raise Exception("Failed to find a video stream")
+        self.audio_stream = self._find_stream(libav.AVMEDIA_TYPE_AUDIO)
+        if self.audio_stream is None:
+            libav.format_close_input(self._context)
+            raise Exception("Failed to find an audio stream")
+
+    def __del__(self):
+        if self._context:
+            libav.format_close_input(self._context)
+
+    def _find_stream(self, type):
+        index, codec_ref = libav.format_find_best_stream(self._context, type)
+        if index < 0 or not codec_ref:
+            return None
+        parameters = self._context.contents.streams[index].contents.codecpar
+        return Stream(index, Codec(codec_ref), parameters)
+
+    @property
+    def nb_streams(self):
+        if not self._context:
+            return 0
+        return self._context.contents.nb_streams
+
+    def read_packet(self):
+        if not self._context:
+            return None
+        packet = Packet()
+        errcode = libav.read_frame(self._context, packet)
+        if errcode < 0:
+            return None
+        return packet

mp4/frame.py

@@ -0,0 +1,33 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+from . import libav
+
+class Frame:
+    __slots__ = '_ref'
+
+    def __init__(self):
+        self._ref = libav.frame_alloc()
+        if not self._ref:
+            raise MemoryError
+
+    def __del__(self):
+        if self._ref:
+            libav.frame_free(self._ref)
+
+    @property
+    def _as_parameter_(self):
+        return self._ref

mp4/libav.py

@@ -0,0 +1,243 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+import errno
+import ctypes
+
+_avutil = ctypes.cdll.LoadLibrary('libavutil.so')
+_avformat = ctypes.cdll.LoadLibrary('libavformat.so')
+_avcodec = ctypes.cdll.LoadLibrary('libavcodec.so')
+
+def _errtag(a, b, c, d):
+    return -(ord(a) | (ord(b) << 8) | (ord(c) << 16) | (ord(d) << 24))
+
+if errno.EAGAIN < 0:
+    AVERROR_EAGAIN = errno.EAGAIN
+else:
+    AVERROR_EAGAIN = -errno.EAGAIN
+
+AVERROR_EOF = _errtag('E', 'O', 'F', ' ')
+
+_AV_ERROR_MAX_STRING_SIZE = 64
+
+AVMEDIA_TYPE_UNKNOWN = -1
+AVMEDIA_TYPE_VIDEO = 0
+AVMEDIA_TYPE_AUDIO = 1
+AVMEDIA_TYPE_DATA = 2
+AVMEDIA_TYPE_SUBTITLE = 3
+AVMEDIA_TYPE_ATTACHMENT = 4
+
+class AVFrame(ctypes.Structure):
+    pass
+
+AVFrame_p = ctypes.POINTER(AVFrame)
+AVFrame_pp = ctypes.POINTER(AVFrame_p)
+
+class AVCodecParameters(ctypes.Structure):
+    pass
+
+AVCodecParameters_p = ctypes.POINTER(AVCodecParameters)
+
+class AVRational(ctypes.Structure):
+    _fields_ = [
+        ("num", ctypes.c_int),
+        ("den", ctypes.c_int)]
+
+class AVStream(ctypes.Structure):
+    _fields_ = [
+        ("av_class", ctypes.c_void_p),
+        ("index", ctypes.c_int),
+        ("id", ctypes.c_int),
+        ("codecpar", AVCodecParameters_p),
+        ("priv_data", ctypes.c_void_p),
+        ("time_base", AVRational)]
+        # ...
+
+AVStream_p = ctypes.POINTER(AVStream)
+AVStream_pp = ctypes.POINTER(AVStream_p)
+
+class AVFormatContext(ctypes.Structure):
+    _fields_ = [
+        ("av_class", ctypes.c_void_p),
+        ("iformat", ctypes.c_void_p),
+        ("oformat", ctypes.c_void_p),
+        ("priv_data", ctypes.c_void_p),
+        ("pb", ctypes.c_void_p),
+        ("ctx_flags", ctypes.c_int),
+        ("nb_streams", ctypes.c_uint),
+        ("streams", AVStream_pp)]
+        # ...
+
+AVFormatContext_p = ctypes.POINTER(AVFormatContext)
+AVFormatContext_pp = ctypes.POINTER(AVFormatContext_p)
+
+class AVPacket(ctypes.Structure):
+    _fields_ = [
+        ("buf", ctypes.c_void_p),
+        ("pts", ctypes.c_int64),
+        ("dts", ctypes.c_int64),
+        ("data", ctypes.c_void_p),
+        ("size", ctypes.c_int),
+        ("stream_index", ctypes.c_int)]
+        # ...
+
+AVPacket_p = ctypes.POINTER(AVPacket)
+AVPacket_pp = ctypes.POINTER(AVPacket_p)
+
+class AVCodec(ctypes.Structure):
+    _fields_ = [
+        ("name", ctypes.c_char_p),
+        ("long_name", ctypes.c_char_p)]
+        # ...
+
+AVCodec_p = ctypes.POINTER(AVCodec)
+AVCodec_pp = ctypes.POINTER(AVCodec_p)
+
+class AVCodecContext(ctypes.Structure):
+    pass
+
+AVCodecContext_p = ctypes.POINTER(AVCodecContext)
+AVCodecContext_pp = ctypes.POINTER(AVCodecContext_p)
+
+_avutil.av_strerror.restype = ctypes.c_int
+_avutil.av_strerror.argtypes = [
+    ctypes.c_int, # errno
+    ctypes.c_char_p, # errbuf
+    ctypes.c_size_t] # errbuff_size
+
+def strerror(errno):
+    errbuf = ctypes.create_string_buffer(_AV_ERROR_MAX_STRING_SIZE)
+    _avutil.av_strerror(errno, errbuf, _AV_ERROR_MAX_STRING_SIZE)
+    return errbuf.value.decode("utf-8")
+
+_avutil.av_frame_alloc.restype = AVFrame_p
+_avutil.av_frame_alloc.argtypes = None
+
+def frame_alloc():
+    return _avutil.av_frame_alloc()
+
+_avutil.av_frame_free.restype = None
+_avutil.av_frame_free.argtypes = [AVFrame_pp]
+
+def frame_free(frame):
+    _avutil.av_frame_free(ctypes.byref(frame))
+
+_avformat.avformat_alloc_context.restype = AVFormatContext_p
+_avformat.avformat_alloc_context.argtypes = None
+
+def format_alloc_context():
+    return _avformat.avformat_alloc_context()
+
+_avformat.avformat_free_context.restype = None
+_avformat.avformat_free_context.argtypes = [AVFormatContext_p]
+
+def format_free_context(context):
+    _avformat.avformat_free_context(context)
+
+_avformat.avformat_open_input.restype = ctypes.c_int
+_avformat.avformat_open_input.argtypes = [
+    AVFormatContext_pp,
+    ctypes.c_char_p, # url
+    ctypes.c_void_p, # format
+    ctypes.POINTER(ctypes.c_void_p)] # options
+
+def format_open_input(context, url):
+    return _avformat.avformat_open_input(ctypes.byref(context), url.encode('ascii', 'ignore'), None, None)
+
+_avformat.avformat_close_input.restype = None
+_avformat.avformat_close_input.argtypes = [AVFormatContext_pp]
+
+def format_close_input(context):
+    _avformat.avformat_close_input(ctypes.byref(context))
+
+_avformat.avformat_find_stream_info.restype = ctypes.c_int
+_avformat.avformat_find_stream_info.argtypes = [
+    AVFormatContext_p,
+    ctypes.POINTER(ctypes.c_void_p)] # options
+
+def format_find_stream_info(context):
+    return _avformat.avformat_find_stream_info(context, None)
+
+_avformat.av_find_best_stream.restype = ctypes.c_int
+_avformat.av_find_best_stream.argtypes = [
+    AVFormatContext_p,
+    ctypes.c_int, # type
+    ctypes.c_int, # wanted stream
+    ctypes.c_int, # related stream
+    AVCodec_pp,
+    ctypes.c_int] # flags
+
+def format_find_best_stream(context, type):
+    codec = AVCodec_p()
+    index = _avformat.av_find_best_stream(context, type, -1, -1, ctypes.byref(codec), 0)
+    return index, codec
+
+_avformat.av_packet_alloc.restype = AVPacket_p
+_avformat.av_packet_alloc.argtypes = None
+
+def packet_alloc():
+    return _avformat.av_packet_alloc()
+
+_avformat.av_packet_free.restype = None
+_avformat.av_packet_free.argtypes = [AVPacket_pp]
+
+def packet_free(packet):
+    _avformat.av_packet_free(ctypes.byref(packet))
+
+_avformat.av_read_frame.restype = ctypes.c_int
+_avformat.av_read_frame.argtypes = [AVFormatContext_p, AVPacket_p]
+
+def read_frame(context, packet):
+    return _avformat.av_read_frame(context, packet)
+
+_avcodec.avcodec_alloc_context3.restype = AVCodecContext_p
+_avcodec.avcodec_alloc_context3.argtypes = [AVCodec_p]
+
+def codec_alloc_context(codec):
+    return _avcodec.avcodec_alloc_context3(codec)
+
+_avcodec.avcodec_free_context.restype = None
+_avcodec.avcodec_free_context.argtypes = [AVCodecContext_pp]
+
+def codec_free_context(context):
+    _avcodec.avcodec_free_context(ctypes.byref(context))
+
+_avcodec.avcodec_parameters_to_context.restype = ctypes.c_int
+_avcodec.avcodec_parameters_to_context.argtypes = [AVCodecContext_p, AVCodecParameters_p]
+
+def codec_parameters_to_context(context, parameters):
+    return _avcodec.avcodec_parameters_to_context(context, parameters)
+
+_avcodec.avcodec_open2.restype = ctypes.c_int
+_avcodec.avcodec_open2.argtypes = [
+    AVCodecContext_p,
+    AVCodec_p,
+    ctypes.POINTER(ctypes.c_void_p)] # options
+
+def codec_open(context, codec):
+    return _avcodec.avcodec_open2(context, codec, None)
+
+_avcodec.avcodec_send_packet.restype = ctypes.c_int
+_avcodec.avcodec_send_packet.argtypes = [AVCodecContext_p, AVPacket_p]
+
+def codec_send_packet(context, packet):
+    return _avcodec.avcodec_send_packet(context, packet)
+
+_avcodec.avcodec_receive_frame.restype = ctypes.c_int
+_avcodec.avcodec_receive_frame.argtypes = [AVCodecContext_p, AVFrame_p]
+
+def codec_receive_frame(context, frame):
+    return _avcodec.avcodec_receive_frame(context, frame)

mp4/packet.py

@@ -0,0 +1,39 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+from . import libav
+
+class Packet:
+    __slots__ = '_ref'
+
+    def __init__(self):
+        self._ref = libav.packet_alloc()
+        if not self._ref:
+            raise MemoryError
+
+    def __del__(self):
+        if self._ref:
+            libav.packet_free(self._ref)
+
+    @property
+    def _as_parameter_(self):
+        return self._ref
+
+    @property
+    def stream_index(self):
+        if self._ref:
+            return self._ref.contents.stream_index
+        return -1

mp4/stream.py

@@ -0,0 +1,26 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+class Stream:
+    __slots__ = 'index', 'codec', 'parameters'
+
+    def __init__(self, index, codec, parameters):
+        self.index = index
+        self.codec = codec
+        self.parameters = parameters
+
+    def contains(self, packet):
+        return (self.index == packet.stream_index)

pve.py

@@ -0,0 +1,39 @@
+# People's Video Editor: high quality, GPU accelerated mp4 editor
+# Copyright (C) 2025 Roz K <roz@rozk.net>
+#
+# This file is part of People's Video Editor.
+#
+# People's Video Editor is free software: you can redistribute it and/or modify it under the terms of the
+# GNU General Public License as published by the Free Software Foundation, either version 3 of the License,
+# or (at your option) any later version.
+#
+# People's Video Editor is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with People's Video Editor.
+# If not, see <https://www.gnu.org/licenses/>.
+
+from mp4.demuxer import Demuxer
+from mp4.decoder import Decoder
+
+demuxer = Demuxer('test.mp4')
+
+print(f"nb_streams  = {demuxer.nb_streams}")
+print(f"video codec = {demuxer.video_stream.codec.name}")
+print(f"audio codec = {demuxer.audio_stream.codec.name}")
+
+video_decoder = Decoder(demuxer.video_stream)
+audio_decoder = Decoder(demuxer.audio_stream)
+
+while True:
+    packet = demuxer.read_packet()
+    eof = (packet is None)
+    if eof or demuxer.video_stream.contains(packet):
+        video_frames = video_decoder.decode(packet)
+        print(f"decoded {len(video_frames)} video frames")
+    if eof or demuxer.audio_stream.contains(packet):
+        audio_frames = audio_decoder.decode(packet)
+        print(f"decoded {len(audio_frames)} audio frames")
+    if eof:
+        break