demuxer

mp4/context.py

@@ -0,0 +1,54 @@
+# RozK
+
+from . import libav
+from .codec import Codec
+from .stream import NullStream, Stream
+from .packet import Packet
+
+class Context:
+    __slots__ = '_ref'
+
+    def __init__(self):
+        self._ref = libav.alloc_context()
+        if not self._ref:
+            raise MemoryError
+
+    def __del__(self):
+        if self._ref:
+            libav.free_context(self._ref)
+
+    @property
+    def _as_parameter_(self):
+        return self._ref
+
+    def open_input(self, url):
+        if not self._ref:
+            return
+        errcode = libav.open_input(self._ref, url)
+        if errcode < 0:
+            raise Exception(f"Failed to open: {url}")
+        errcode = libav.find_stream_info(self._ref)
+        if errcode < 0:
+            libav.close_input(self._ref)
+            raise Exception("Failed to find stream info")
+
+    def close_input(self):
+        if self._ref:
+            libav.close_input(self._ref)
+
+    def find_stream(self, type):
+        if not self._ref:
+            return NullStream()
+        index, codec_ref = libav.find_best_stream(self._ref, type)
+        if index < 0 or not codec_ref:
+            return NullStream()
+        return Stream(index, Codec(codec_ref))
+
+    def read_packet(self):
+        if not self._ref:
+            return None
+        packet = Packet()
+        errcode = libav.read_frame(self._ref, packet)
+        if errcode < 0:
+            return None
+        return packet