fixed seek operation when not at eof

av/container/input.pxd

@@ -6,4 +6,6 @@ from av.stream cimport Stream
 
 cdef class InputContainer(Container):
 
+    cdef bint eof
+
     cdef flush_buffers(self)

av/container/input.pyx

@@ -173,6 +173,7 @@ cdef class InputContainer(Container):
                         ret = lib.av_read_frame(self.ptr, packet.ptr)
                     self.err_check(ret)
                 except EOFError:
+                    self.eof = True
                     break
 
                 if include_stream[packet.ptr.stream_index]:
@@ -276,7 +277,9 @@ cdef class InputContainer(Container):
             ret = lib.av_seek_frame(self.ptr, stream_index, c_offset, flags)
         err_check(ret)
 
-        self.flush_buffers()
+        # codec buffers must be cleared if file is at eof, 
+        if self.eof or lib.avio_feof(self.ptr.pb):
+            self.flush_buffers()
 
     cdef flush_buffers(self):
         self._assert_open()

include/libavformat/avformat.pxd

@@ -275,6 +275,8 @@ cdef extern from "libavformat/avformat.h" nogil:
 
     cdef int avio_closep(AVIOContext **s)
 
+    cdef int avio_feof(AVIOContext *s)
+
     cdef int avformat_find_stream_info(
         AVFormatContext *ctx,
         AVDictionary **options,  # Can be NULL.