gstreamer/gst/gstbuffer.override

/* -*- Mode: C; ; c-file-style: "python" -*- */
/* gst-python
 * Copyright (C) 2002 David I. Lehn
 * Copyright (C) 2004 Johan Dahlin
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 * 
 * Author: Johan Dahlin <johan@gnome.org>
 */
%%
headers

static int gst_buffer_getreadbuffer (PyGstMiniObject   *self,
				     int          index,
				     const void **ptr);
static int gst_buffer_getwritebuf   (PyGstMiniObject   *self,
				     int          index,
				     const void **ptr);
static int gst_buffer_getsegcount   (PyGstMiniObject   *self,
				     int         *lenp);
static int gst_buffer_getcharbuf    (PyGstMiniObject   *self,
				     int          index,
				     const char **ptr);
%%
override gst_buffer_new kwargs
static int
_wrap_gst_buffer_new(PyGBoxed *self, PyObject *args, PyObject *kwargs)
{
	static char *kwlist[] = { "data", "buffer_size", NULL };
	char *data = NULL;
	int size = 0;
	int buf_size = -1;

	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|z#i:GstBuffer.__init__", kwlist,
					 &data, &size, &buf_size))
		return -1;
	
	if (size < 0) {
		PyErr_SetString(PyExc_TypeError, "buffer size must be >= 0");
		return -1;
	}
	if (buf_size < 0)
		buf_size = size;
	if (buf_size < size) {
		PyErr_SetString(PyExc_TypeError, "buffer size must be >= data size");
		return -1;
	}
	self->gtype = GST_TYPE_BUFFER;
	self->free_on_dealloc = TRUE;
	
	self->boxed = gst_buffer_new_and_alloc(buf_size);
	
	if (!self->boxed) {
		PyErr_SetString(PyExc_RuntimeError, "could not create GstBuffer object");
		return -1;
	}

	if (data == NULL)
		return 0;

	memcpy (GST_BUFFER_DATA (self->boxed), data, size);
	GST_BUFFER_SIZE (self->boxed) = size;
	
	return 0;
}
%%
override gst_buffer_get_data
static PyObject*
_wrap_gst_buffer_get_data(PyObject *self)
{
	GstBuffer *buf = pyg_boxed_get(self, GstBuffer);
	return PyString_FromStringAndSize((gchar *) GST_BUFFER_DATA(buf),
					  GST_BUFFER_SIZE(buf));
}
%%
override gst_buffer_set_data kwargs
static PyObject*
_wrap_gst_buffer_set_data(PyObject *self, PyObject *args, PyObject *kwargs)
{
	static char *kwlist[] = {"data", NULL};
	PyObject *data;
	GstBuffer *buf;
	
	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O:GstBuffer:set_data", kwlist, &data))
	{
		return NULL;
	}
	if (!PyString_Check(data)) {
		PyErr_SetString(PyExc_TypeError, "data should be a string");
		return NULL;
	}
	buf = pyg_boxed_get(self, GstBuffer);
	if (GST_BUFFER_FLAGS(buf) & GST_BUFFER_READONLY) {
		PyErr_SetString(PyExc_TypeError, "set_data can't use a READONLY buffer");
		return NULL;
	}
	GST_BUFFER_SIZE(buf) = PyString_Size(data);
	GST_BUFFER_DATA(buf) = (guint8 *) g_new0(char, GST_BUFFER_SIZE(buf));

	memcpy(GST_BUFFER_DATA(buf),
	       PyString_AsString(data),
	       PyString_Size(data));

	Py_INCREF(Py_None);
	return Py_None;
}
%%
override-slot GstBuffer.tp_str
static PyObject *
_wrap_gst_buffer_tp_str(PyGstMiniObject *self)
{
	GstBuffer *buf = pyg_boxed_get(self, GstBuffer);

	return PyString_FromStringAndSize((const gchar*) GST_BUFFER_DATA(buf),
					  (gint) GST_BUFFER_SIZE(buf));
}
%%
override-slot GstBuffer.tp_as_buffer
static PyBufferProcs _wrap_gst_buffer_tp_as_buffer = {
        (getreadbufferproc)gst_buffer_getreadbuffer, /* bf_getreadbuffer */
	(getwritebufferproc)gst_buffer_getwritebuf,  /* bf_getwritebuffer */
	(getsegcountproc)gst_buffer_getsegcount,     /* bf_getsegcount */
	(getcharbufferproc)gst_buffer_getcharbuf,    /* bf_getcharbuffer */
};

static int
gst_buffer_getreadbuffer(PyGstMiniObject *self, int index, const void **ptr)
{
	GstBuffer *buf = pyg_boxed_get(self, GstBuffer);

	if ( index != 0 ) {
		PyErr_SetString(PyExc_SystemError,
				"accessing non-existent GstBuffer segment");
		return -1;
	}
	
	*ptr = GST_BUFFER_DATA(buf);
	return GST_BUFFER_SIZE(buf);
}

static int
gst_buffer_getsegcount(PyGstMiniObject *self, int *lenp)
{
	GstBuffer *buf = pyg_boxed_get(self, GstBuffer);

	if (lenp)
		*lenp = GST_BUFFER_SIZE(buf);
	return 1;
}

static int
gst_buffer_getcharbuf(PyGstMiniObject *self, int index, const char **ptr)
{
	return gst_buffer_getreadbuffer (self, index, (const void **) ptr);
}

static int
gst_buffer_getwritebuf(PyGstMiniObject *self, int index, const void **ptr)
{
	GstBuffer *buf = pyg_boxed_get(self, GstBuffer);

	if ( index != 0 ) {
		PyErr_SetString(PyExc_SystemError,
				"accessing non-existent GstBuffer segment");
		return -1;
	}
	
	if (!gst_buffer_is_writable (buf)) {
		PyErr_SetString(PyExc_TypeError,
				"buffer is not writable");
		return -1;
	}

	*ptr = GST_BUFFER_DATA(buf);
	return GST_BUFFER_SIZE(buf);
}

%%
override-slot GstBuffer.tp_as_sequence
/* FIXME: should buffer parts be buffers or strings? */

static int
pygst_buffer_length(PyObject *self)
{
	return GST_BUFFER_SIZE(pygobject_get (self));
}

static PyObject *
pygst_buffer_slice(PyObject *self, int start, int end)
{
  GstBuffer *buf = GST_BUFFER (pygobject_get (self));
  if (start < 0)
    start = 0;
  if (end < 0)
    end = 0;
  if (end > GST_BUFFER_SIZE(buf))
    end = GST_BUFFER_SIZE(buf);
    
  if (end <= start) {
    PyErr_SetString(PyExc_IndexError, "buffer index out of range");
    return NULL;
  }
  return PyString_FromStringAndSize((gchar *) GST_BUFFER_DATA (buf) + start, end - start);
}

static PyObject *
pygst_buffer_item(PyObject *self, int index)
{
  return pygst_buffer_slice (self, index, index + 1);
}

static int
pygst_buffer_ass_slice (PyObject *self, int start, int end, PyObject *val)
{
  GstBuffer *buf = GST_BUFFER (pygobject_get (self));
  const void *data;
  int len;

  if (!gst_buffer_is_writable (buf)) {
    PyErr_SetString(PyExc_TypeError, "buffer is not writable");
    return -1;
  }
  /* FIXME: policy? */
  if (start < 0 || end <= start || end > GST_BUFFER_SIZE (buf)) {
    PyErr_SetString(PyExc_IndexError, "buffer index out of range");
    return -1;
  }
  end -= start;
  if (PyObject_AsReadBuffer(val, &data, &len))
    return -1;
  if (len > end)
    len = end;
  memcpy (GST_BUFFER_DATA (buf) + start, data, len);
  return 0;
}

static int
pygst_buffer_ass_item (PyObject *self, int index, PyObject *val)
{
  GstBuffer *buf = GST_BUFFER (pygobject_get (self));
  const void *data;
  int len;

  if (!gst_buffer_is_writable (buf)) {
    PyErr_SetString(PyExc_TypeError, "buffer is not writable");
    return -1;
  }
  if (index < 0 || index > GST_BUFFER_SIZE (buf)) {
    PyErr_SetString(PyExc_IndexError, "buffer index out of range");
    return -1;
  }
  if (PyObject_AsReadBuffer(val, &data, &len))
    return -1;
  /* FIXME: how do we handle this? */
  if (len > GST_BUFFER_SIZE (buf) - index)
    len = GST_BUFFER_SIZE (buf) - index;
  memcpy (GST_BUFFER_DATA (buf) + index, data, len);
  return 0;
}

static PySequenceMethods _wrap_gst_buffer_tp_as_sequence = {
	pygst_buffer_length,                /* sq_length */
	NULL,                               /* sq_concat */
	NULL,                               /* sq_repeat */
	pygst_buffer_item,		    /* sq_item */
	pygst_buffer_slice,		    /* sq_slice */
	pygst_buffer_ass_item,              /* sq_ass_item */
	pygst_buffer_ass_slice,             /* sq_ass_slice */
	NULL,                               /* sq_contains */
	NULL,                               /* sq_inplace_concat */
	NULL,                               /* sq_inplace_repeat */
};
%%
define GstBuffer.copy_on_write
static PyObject *
_wrap_gst_buffer_copy_on_write (PyObject *self)
{
	GstBuffer *buf = pyg_boxed_get(self, GstBuffer);

	if (gst_buffer_is_writable (buf)) {
	  Py_INCREF (self);
	  return self;
	}
	buf = gst_buffer_copy (buf);
	self = pyg_boxed_new (GST_TYPE_BUFFER, buf, FALSE, TRUE);
	return self;
}
%%
define GstBuffer.flag_is_set
static PyObject *
_wrap_gst_buffer_flag_is_set(PyObject *self, PyObject *args)
{
	int flag;
	PyObject *retval;
	GstBuffer *buf;
	
	if (!PyArg_ParseTuple(args, "i:GstBuffer.flag_is_set", &flag))
		return NULL;

	buf = pyg_boxed_get(self, GstBuffer);
	g_assert(GST_IS_BUFFER(buf));
	
	retval = GST_BUFFER_FLAG_IS_SET(buf, flag) ? Py_True : Py_False;
	Py_INCREF(retval);
	return retval;
}
%%
define GstBuffer.flag_set
static PyObject *
_wrap_gst_buffer_flag_set(PyObject *self, PyObject *args)
{
	int flag;
	GstBuffer *buf;
	
	if (!PyArg_ParseTuple(args, "i:GstBuffer.set", &flag))
		return NULL;

	buf = pyg_boxed_get(self, GstBuffer);
	g_assert(GST_IS_BUFFER(buf));
	GST_BUFFER_FLAG_SET(buf, flag);

	Py_INCREF(Py_None);
	return Py_None;
}
%%
define GstBuffer.flag_unset
static PyObject *
_wrap_gst_buffer_flag_unset(PyObject *self, PyObject *args)
{
	int flag;
	GstBuffer *buf;
	
	if (!PyArg_ParseTuple(args, "i:GstBuffer.unset", &flag))
		return NULL;

	buf = pyg_boxed_get(self, GstBuffer);
	g_assert(GST_IS_BUFFER(buf));
	GST_BUFFER_FLAG_UNSET(buf, flag);

	Py_INCREF(Py_None);
	return Py_None;
}