demuxer

mp4/libav.py

@@ -0,0 +1,112 @@
+# RozK
+# https://www.ffmpeg.org/doxygen/trunk/group__libavf.html
+
+import ctypes
+
+_avformat = ctypes.cdll.LoadLibrary('libavformat.so')
+_avcodec = ctypes.cdll.LoadLibrary('libavcodec.so')
+
+class AVFormatContext(ctypes.Structure):
+    pass
+
+AVFormatContext_p = ctypes.POINTER(AVFormatContext)
+AVFormatContext_pp = ctypes.POINTER(AVFormatContext_p)
+
+_avformat.avformat_alloc_context.restype = AVFormatContext_p
+_avformat.avformat_alloc_context.argtypes = None
+
+def alloc_context():
+    return _avformat.avformat_alloc_context()
+
+_avformat.avformat_free_context.restype = None
+_avformat.avformat_free_context.argtypes = [AVFormatContext_p] # context
+
+def free_context(context):
+    _avformat.avformat_free_context(context)
+
+_avformat.avformat_open_input.restype = ctypes.c_int
+_avformat.avformat_open_input.argtypes = [
+    AVFormatContext_pp, # context
+    ctypes.c_char_p, # url
+    ctypes.c_void_p, # format
+    ctypes.POINTER(ctypes.c_void_p)] # options
+
+def 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] # context
+
+def 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, # context
+    ctypes.POINTER(ctypes.c_void_p)] # options
+
+def find_stream_info(context):
+    return _avformat.avformat_find_stream_info(context, None)
+
+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 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)
+
+_avformat.av_find_best_stream.restype = ctypes.c_int
+_avformat.av_find_best_stream.argtypes = [
+    AVFormatContext_p, # context
+    ctypes.c_int, # type
+    ctypes.c_int, # wanted stream
+    ctypes.c_int, # related stream
+    AVCodec_pp, # decoder
+    ctypes.c_int] # flags
+
+def 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
+
+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)
+
+_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] # packet
+
+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, # context
+    AVPacket_p] # packet
+
+def read_frame(context, packet):
+    return _avformat.av_read_frame(context, packet)