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pyobjc / pyobjc-framework-Quartz / Modules / _CVPixelBuffer.m

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/*
 * Customer wrappers for a number of CoreVideo APIs.
 */
#include <Python.h>
#include "pyobjc-api.h"

#if PyObjC_BUILD_RELEASE >= 1005
  /* WITH_COREVIDEO  */

#import <CoreVideo/CoreVideo.h>

static void 
mod_CVPixelBufferReleaseBytesCallback(
	void *releaseRefCon, const void *baseAddress)
{
	PyObject* info = (PyObject*)releaseRefCon;
	PyGILState_STATE state = PyGILState_Ensure();

	if (PyTuple_GET_ITEM(info, 0) != Py_None) {
		PyObject* r = PyObject_CallFunction(
			PyTuple_GET_ITEM(info, 0),
			"O",
			PyTuple_GET_ITEM(info, 1));
		if  (r == NULL) {
			Py_XDECREF(info);
			PyObjCErr_ToObjCWithGILState(&state);
		}

		Py_DECREF(r);
	}

	Py_DECREF(info);
	PyGILState_Release(state);
}

static PyObject*
mod_CVPixelBufferCreateWithBytes(
	PyObject* self __attribute__((__unused__)),
	PyObject* args)
{
	CFAllocatorRef allocator;
	size_t	       width;
	size_t	       height;
	OSType         pixelFormatType;
	void*          baseAddress;
	size_t         bytesPerRow;
	CFDictionaryRef pixelBufferAttributes;
	CVPixelBufferRef pixelBuffer;
	PyObject* py_allocator;
	PyObject* py_width;
	PyObject* py_height;
	PyObject* py_pixelFormatType;
	PyObject* py_buffer;
	Py_ssize_t buflen;
	PyObject* py_bytesPerRow;
	PyObject* releaseCallback;
	PyObject* info;
	PyObject* py_pixelBufferAttributes;
	PyObject* py_pixelBuffer = Py_None;

	if (!PyArg_ParseTuple(args, "OOOOOOOOO|O",
		&py_allocator, &py_width, &py_height, &py_pixelFormatType,
		&py_buffer, &py_bytesPerRow, &releaseCallback, &info,
		&py_pixelBufferAttributes, &py_pixelBuffer)) {

		return NULL;
	}

	if (PyObjC_PythonToObjC(@encode(CFAllocatorRef), py_allocator, &allocator) < 0) {
		return NULL;
	}
	if (PyObjC_PythonToObjC(@encode(size_t), py_width, &width) < 0) {
		return NULL;
	}
	if (PyObjC_PythonToObjC(@encode(size_t), py_height, &height) < 0) {
		return NULL;
	}
	if (PyObjC_PythonToObjC(@encode(OSType), py_pixelFormatType, &pixelFormatType) < 0) {
		return NULL;
	}
	if (PyObjC_PythonToObjC(@encode(size_t), py_bytesPerRow, &bytesPerRow) < 0) {
		return NULL;
	}
	if (PyObjC_PythonToObjC(@encode(CFDictionaryRef), py_pixelBufferAttributes, &pixelBufferAttributes) < 0) {
		return NULL;
	}

	if (py_pixelBuffer != Py_None) {
		PyErr_SetString(PyExc_ValueError, "pixelBufferOut must be None");
		return NULL;
	}
	
	if (PyObject_AsWriteBuffer(py_buffer, &baseAddress, &buflen) < 0) {
		return NULL;
	}

	PyObject* real_info = Py_BuildValue("OOO",
		releaseCallback, info, py_buffer);
	if (real_info == NULL) {
		return NULL;
	}

	CVReturn rv;

	PyObjC_DURING
		rv = CVPixelBufferCreateWithBytes(
			allocator,
			width,
			height,
			pixelFormatType,
			baseAddress,
			bytesPerRow,
			mod_CVPixelBufferReleaseBytesCallback,
			real_info,
			pixelBufferAttributes,
			&pixelBuffer);

	PyObjC_HANDLER
		rv = 0;
		PyObjCErr_FromObjC(localException);
	
	PyObjC_ENDHANDLER
	
	if (PyErr_Occurred()) {
		Py_DECREF(real_info);
		return NULL;
	}

	if (pixelBuffer == NULL) {
		Py_DECREF(real_info);
		Py_INCREF(Py_None);
		return Py_None;
	}

	py_pixelBuffer = PyObjC_ObjCToPython(
				@encode(CVPixelBufferRef),
				&pixelBuffer);
	CFRelease(pixelBuffer); /* Compensate for create rule */
	return py_pixelBuffer;
}



static PyMethodDef mod_methods[] = {
	{
		"CVPixelBufferCreateWithBytes",
		(PyCFunction)mod_CVPixelBufferCreateWithBytes,
		METH_VARARGS,
		NULL
	},

	{ 0, 0, 0, 0 }
};

#else /* ! WITH_CORE_VIDEO */

static PyMethodDef mod_methods[] = {
	{ 0, 0, 0, 0 }
};

#endif /* ! WITH_CORE_VIDEO */



PyObjC_MODULE_INIT(_CVPixelBuffer)
{
	PyObject* m = PyObjC_MODULE_CREATE(_CVPixelBuffer);
	if (!m) PyObjC_INITERROR();

	if (PyObjC_ImportAPI(m) < 0) PyObjC_INITERROR();

	PyObjC_INITDONE();
}