| from cpython cimport PyBUF_WRITABLE, PyBuffer_FillInfo |
| from libc.string cimport memcpy |
|
|
| from av.bytesource cimport ByteSource, bytesource |
|
|
|
|
| cdef class Buffer: |
| """A base class for PyAV objects which support the buffer protocol, such |
| as :class:`.Packet` and :class:`.Plane`. |
|
|
| """ |
|
|
| cdef size_t _buffer_size(self): |
| return 0 |
|
|
| cdef void* _buffer_ptr(self): |
| return NULL |
|
|
| cdef bint _buffer_writable(self): |
| return True |
|
|
| def __getbuffer__(self, Py_buffer *view, int flags): |
| if flags & PyBUF_WRITABLE and not self._buffer_writable(): |
| raise ValueError("buffer is not writable") |
|
|
| PyBuffer_FillInfo(view, self, self._buffer_ptr(), self._buffer_size(), 0, flags) |
|
|
| @property |
| def buffer_size(self): |
| """The size of the buffer in bytes.""" |
| return self._buffer_size() |
|
|
| @property |
| def buffer_ptr(self): |
| """The memory address of the buffer.""" |
| return <size_t>self._buffer_ptr() |
|
|
| def update(self, input): |
| """Replace the data in this object with the given buffer. |
|
|
| Accepts anything that supports the `buffer protocol <https://docs.python.org/3/c-api/buffer.html>`_, |
| e.g. bytes, Numpy arrays, other :class:`Buffer` objects, etc.. |
|
|
| """ |
| if not self._buffer_writable(): |
| raise ValueError("buffer is not writable") |
|
|
| cdef ByteSource source = bytesource(input) |
| cdef size_t size = self._buffer_size() |
|
|
| if source.length != size: |
| raise ValueError(f"got {source.length} bytes; need {size} bytes") |
|
|
| memcpy(self._buffer_ptr(), source.ptr, size) |
|
|
