:right-sidebar: True Adapter =================================================================== .. currentmodule:: gi.repository.GstBase .. class:: Adapter(**properties: ~typing.Any) :no-contents-entry: Superclasses: :class:`~gi.repository.GObject.Object` :Constructors: :: Adapter(**properties) new() -> GstBase.Adapter Constructors ------------ .. rst-class:: interim-class .. class:: Adapter :no-index: .. classmethod:: new() -> ~gi.repository.GstBase.Adapter Creates a new :obj:`~gi.repository.GstBase.Adapter`. Free with :func:`~gi.repository.GObject.GObject.Object.unref`. Methods ------- .. rst-class:: interim-class .. class:: Adapter :no-index: .. method:: available() -> int Gets the maximum amount of bytes available, that is it returns the maximum value that can be supplied to :func:`~gi.repository.GstBase.Adapter.map` without that function returning :const:`None`. .. method:: available_fast() -> int Gets the maximum number of bytes that are immediately available without requiring any expensive operations (like copying the data into a temporary buffer). .. method:: clear() -> None Removes all buffers from ``adapter``. .. method:: distance_from_discont() -> int Get the distance in bytes since the last buffer with the ``%GST_BUFFER_FLAG_DISCONT`` flag. The distance will be reset to 0 for all buffers with ``%GST_BUFFER_FLAG_DISCONT`` on them, and then calculated for all other following buffers based on their size. .. versionadded:: 1.10 .. method:: dts_at_discont() -> int Get the DTS that was on the last buffer with the GST_BUFFER_FLAG_DISCONT flag, or GST_CLOCK_TIME_NONE. .. versionadded:: 1.10 .. method:: flush(flush: int) -> None Flushes the first ``flush`` bytes in the ``adapter``. The caller must ensure that at least this many bytes are available. See also: :func:`~gi.repository.GstBase.Adapter.map`, :func:`~gi.repository.GstBase.Adapter.unmap` :param flush: the number of bytes to flush .. method:: get_buffer(nbytes: int) -> ~gi.repository.Gst.Buffer | None Returns a :obj:`~gi.repository.Gst.Buffer` containing the first ``nbytes`` of the ``adapter``, but does not flush them from the adapter. See :func:`~gi.repository.GstBase.Adapter.take_buffer` for details. Caller owns a reference to the returned buffer. gst_buffer_unref() after usage. Free-function: gst_buffer_unref .. versionadded:: 1.6 :param nbytes: the number of bytes to get .. method:: get_buffer_fast(nbytes: int) -> ~gi.repository.Gst.Buffer | None Returns a :obj:`~gi.repository.Gst.Buffer` containing the first ``nbytes`` of the ``adapter``, but does not flush them from the adapter. See :func:`~gi.repository.GstBase.Adapter.take_buffer_fast` for details. Caller owns a reference to the returned buffer. gst_buffer_unref() after usage. Free-function: gst_buffer_unref .. versionadded:: 1.6 :param nbytes: the number of bytes to get .. method:: get_buffer_list(nbytes: int) -> ~gi.repository.Gst.BufferList | None Returns a :obj:`~gi.repository.Gst.BufferList` of buffers containing the first ``nbytes`` bytes of the ``adapter`` but does not flush them from the adapter. See :func:`~gi.repository.GstBase.Adapter.take_buffer_list` for details. Caller owns the returned list. Call gst_buffer_list_unref() to free the list after usage. .. versionadded:: 1.6 :param nbytes: the number of bytes to get .. method:: get_list(nbytes: int) -> list[~gi.repository.Gst.Buffer] | None Returns a ``GList`` of buffers containing the first ``nbytes`` bytes of the ``adapter``, but does not flush them from the adapter. See :func:`~gi.repository.GstBase.Adapter.take_list` for details. Caller owns returned list and contained buffers. gst_buffer_unref() each buffer in the list before freeing the list after usage. .. versionadded:: 1.6 :param nbytes: the number of bytes to get .. method:: map() -> bytes | None Gets the first ``size`` bytes stored in the ``adapter``. The returned pointer is valid until the next function is called on the adapter. Note that setting the returned pointer as the data of a :obj:`~gi.repository.Gst.Buffer` is incorrect for general-purpose plugins. The reason is that if a downstream element stores the buffer so that it has access to it outside of the bounds of its chain function, the buffer will have an invalid data pointer after your element flushes the bytes. In that case you should use :func:`~gi.repository.GstBase.Adapter.take`, which returns a freshly-allocated buffer that you can set as :obj:`~gi.repository.Gst.Buffer` memory or the potentially more performant :func:`~gi.repository.GstBase.Adapter.take_buffer`. Returns :const:`None` if ``size`` bytes are not available. .. method:: masked_scan_uint32(mask: int, pattern: int, offset: int, size: int) -> int Scan for pattern ``pattern`` with applied mask ``mask`` in the adapter data, starting from offset ``offset``. The bytes in ``pattern`` and ``mask`` are interpreted left-to-right, regardless of endianness. All four bytes of the pattern must be present in the adapter for it to match, even if the first or last bytes are masked out. It is an error to call this function without making sure that there is enough data (offset+size bytes) in the adapter. This function calls :func:`~gi.repository.GstBase.Adapter.masked_scan_uint32_peek` passing :const:`None` for value. :param mask: mask to apply to data before matching against ``pattern`` :param pattern: pattern to match (after mask is applied) :param offset: offset into the adapter data from which to start scanning, returns the last scanned position. :param size: number of bytes to scan from offset .. method:: masked_scan_uint32_peek(mask: int, pattern: int, offset: int, size: int) -> tuple[int, int] Scan for pattern ``pattern`` with applied mask ``mask`` in the adapter data, starting from offset ``offset``. If a match is found, the value that matched is returned through ``value``, otherwise ``value`` is left untouched. The bytes in ``pattern`` and ``mask`` are interpreted left-to-right, regardless of endianness. All four bytes of the pattern must be present in the adapter for it to match, even if the first or last bytes are masked out. It is an error to call this function without making sure that there is enough data (offset+size bytes) in the adapter. :param mask: mask to apply to data before matching against ``pattern`` :param pattern: pattern to match (after mask is applied) :param offset: offset into the adapter data from which to start scanning, returns the last scanned position. :param size: number of bytes to scan from offset .. method:: offset_at_discont() -> int Get the offset that was on the last buffer with the GST_BUFFER_FLAG_DISCONT flag, or GST_BUFFER_OFFSET_NONE. .. versionadded:: 1.10 .. method:: prev_dts() -> tuple[int, int] Get the dts that was before the current byte in the adapter. When ``distance`` is given, the amount of bytes between the dts and the current position is returned. The dts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when the adapter is first created or when it is cleared. This also means that before the first byte with a dts is removed from the adapter, the dts and distance returned are GST_CLOCK_TIME_NONE and 0 respectively. .. method:: prev_dts_at_offset(offset: int) -> tuple[int, int] Get the dts that was before the byte at offset ``offset`` in the adapter. When ``distance`` is given, the amount of bytes between the dts and the current position is returned. The dts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when the adapter is first created or when it is cleared. This also means that before the first byte with a dts is removed from the adapter, the dts and distance returned are GST_CLOCK_TIME_NONE and 0 respectively. .. versionadded:: 1.2 :param offset: the offset in the adapter at which to get timestamp .. method:: prev_offset() -> tuple[int, int] Get the offset that was before the current byte in the adapter. When ``distance`` is given, the amount of bytes between the offset and the current position is returned. The offset is reset to GST_BUFFER_OFFSET_NONE and the distance is set to 0 when the adapter is first created or when it is cleared. This also means that before the first byte with an offset is removed from the adapter, the offset and distance returned are GST_BUFFER_OFFSET_NONE and 0 respectively. .. versionadded:: 1.10 .. method:: prev_pts() -> tuple[int, int] Get the pts that was before the current byte in the adapter. When ``distance`` is given, the amount of bytes between the pts and the current position is returned. The pts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when the adapter is first created or when it is cleared. This also means that before the first byte with a pts is removed from the adapter, the pts and distance returned are GST_CLOCK_TIME_NONE and 0 respectively. .. method:: prev_pts_at_offset(offset: int) -> tuple[int, int] Get the pts that was before the byte at offset ``offset`` in the adapter. When ``distance`` is given, the amount of bytes between the pts and the current position is returned. The pts is reset to GST_CLOCK_TIME_NONE and the distance is set to 0 when the adapter is first created or when it is cleared. This also means that before the first byte with a pts is removed from the adapter, the pts and distance returned are GST_CLOCK_TIME_NONE and 0 respectively. .. versionadded:: 1.2 :param offset: the offset in the adapter at which to get timestamp .. method:: pts_at_discont() -> int Get the PTS that was on the last buffer with the GST_BUFFER_FLAG_DISCONT flag, or GST_CLOCK_TIME_NONE. .. versionadded:: 1.10 .. method:: push(buf: ~gi.repository.Gst.Buffer) -> None Adds the data from ``buf`` to the data stored inside ``adapter`` and takes ownership of the buffer. :param buf: a :obj:`~gi.repository.Gst.Buffer` to add to queue in the adapter .. method:: take() -> bytes | None Returns a freshly allocated buffer containing the first ``nbytes`` bytes of the ``adapter``. The returned bytes will be flushed from the adapter. Caller owns returned value. g_free after usage. Free-function: g_free .. method:: take_buffer(nbytes: int) -> ~gi.repository.Gst.Buffer | None Returns a :obj:`~gi.repository.Gst.Buffer` containing the first ``nbytes`` bytes of the ``adapter``. The returned bytes will be flushed from the adapter. This function is potentially more performant than :func:`~gi.repository.GstBase.Adapter.take` since it can reuse the memory in pushed buffers by subbuffering or merging. This function will always return a buffer with a single memory region. Note that no assumptions should be made as to whether certain buffer flags such as the DISCONT flag are set on the returned buffer, or not. The caller needs to explicitly set or unset flags that should be set or unset. Since 1.6 this will also copy over all GstMeta of the input buffers except for meta with the ``%GST_META_FLAG_POOLED`` flag or with the "memory" tag. Caller owns a reference to the returned buffer. gst_buffer_unref() after usage. Free-function: gst_buffer_unref :param nbytes: the number of bytes to take .. method:: take_buffer_fast(nbytes: int) -> ~gi.repository.Gst.Buffer | None Returns a :obj:`~gi.repository.Gst.Buffer` containing the first ``nbytes`` of the ``adapter``. The returned bytes will be flushed from the adapter. This function is potentially more performant than :func:`~gi.repository.GstBase.Adapter.take_buffer` since it can reuse the memory in pushed buffers by subbuffering or merging. Unlike :func:`~gi.repository.GstBase.Adapter.take_buffer`, the returned buffer may be composed of multiple non-contiguous :obj:`~gi.repository.Gst.Memory` objects, no copies are made. Note that no assumptions should be made as to whether certain buffer flags such as the DISCONT flag are set on the returned buffer, or not. The caller needs to explicitly set or unset flags that should be set or unset. This will also copy over all GstMeta of the input buffers except for meta with the ``%GST_META_FLAG_POOLED`` flag or with the "memory" tag. This function can return buffer up to the return value of :func:`~gi.repository.GstBase.Adapter.available` without making copies if possible. Caller owns a reference to the returned buffer. gst_buffer_unref() after usage. Free-function: gst_buffer_unref .. versionadded:: 1.2 :param nbytes: the number of bytes to take .. method:: take_buffer_list(nbytes: int) -> ~gi.repository.Gst.BufferList | None Returns a :obj:`~gi.repository.Gst.BufferList` of buffers containing the first ``nbytes`` bytes of the ``adapter``. The returned bytes will be flushed from the adapter. When the caller can deal with individual buffers, this function is more performant because no memory should be copied. Caller owns the returned list. Call gst_buffer_list_unref() to free the list after usage. .. versionadded:: 1.6 :param nbytes: the number of bytes to take .. method:: take_list(nbytes: int) -> list[~gi.repository.Gst.Buffer] | None Returns a ``GList`` of buffers containing the first ``nbytes`` bytes of the ``adapter``. The returned bytes will be flushed from the adapter. When the caller can deal with individual buffers, this function is more performant because no memory should be copied. Caller owns returned list and contained buffers. gst_buffer_unref() each buffer in the list before freeing the list after usage. :param nbytes: the number of bytes to take .. method:: unmap() -> None Releases the memory obtained with the last :func:`~gi.repository.GstBase.Adapter.map`.