py: Add cam.py

Add cam.py, which mimics the 'cam' tool. Four rendering backends are
added:

* null - Do nothing
* kms - Use KMS with dmabufs
* qt - SW render on a Qt window
* qtgl - OpenGL render on a Qt window

All the renderers handle only a few pixel formats, and especially the GL
renderer is just a prototype.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

6 files changed, 1516 insertions, 0 deletions

diff --git a/src/py/cam/cam.py b/src/py/cam/cam.py
new file mode 100755
index 00000000..012b191c
--- /dev/null
+++ b/src/py/cam/cam.py
@@ -0,0 +1,475 @@
+#!/usr/bin/env python3
+
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+
+# \todo Convert ctx and state dicts to proper classes, and move relevant
+#       functions to those classes.
+
+import argparse
+import binascii
+import libcamera as libcam
+import os
+import sys
+
+
+class CustomAction(argparse.Action):
+    def __init__(self, option_strings, dest, **kwargs):
+        super().__init__(option_strings, dest, default={}, **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        if len(namespace.camera) == 0:
+            print(f'Option {option_string} requires a --camera context')
+            sys.exit(-1)
+
+        if self.type == bool:
+            values = True
+
+        current = namespace.camera[-1]
+
+        data = getattr(namespace, self.dest)
+
+        if self.nargs == '+':
+            if current not in data:
+                data[current] = []
+
+            data[current] += values
+        else:
+            data[current] = values
+
+
+def do_cmd_list(cm):
+    print('Available cameras:')
+
+    for idx, c in enumerate(cm.cameras):
+        print(f'{idx + 1}: {c.id}')
+
+
+def do_cmd_list_props(ctx):
+    camera = ctx['camera']
+
+    print('Properties for', ctx['id'])
+
+    for name, prop in camera.properties.items():
+        print('\t{}: {}'.format(name, prop))
+
+
+def do_cmd_list_controls(ctx):
+    camera = ctx['camera']
+
+    print('Controls for', ctx['id'])
+
+    for name, prop in camera.controls.items():
+        print('\t{}: {}'.format(name, prop))
+
+
+def do_cmd_info(ctx):
+    camera = ctx['camera']
+
+    print('Stream info for', ctx['id'])
+
+    roles = [libcam.StreamRole.Viewfinder]
+
+    camconfig = camera.generate_configuration(roles)
+    if camconfig is None:
+        raise Exception('Generating config failed')
+
+    for i, stream_config in enumerate(camconfig):
+        print('\t{}: {}'.format(i, stream_config))
+
+        formats = stream_config.formats
+        for fmt in formats.pixel_formats:
+            print('\t * Pixelformat:', fmt, formats.range(fmt))
+
+            for size in formats.sizes(fmt):
+                print('\t  -', size)
+
+
+def acquire(ctx):
+    camera = ctx['camera']
+
+    camera.acquire()
+
+
+def release(ctx):
+    camera = ctx['camera']
+
+    camera.release()
+
+
+def parse_streams(ctx):
+    streams = []
+
+    for stream_desc in ctx['opt-stream']:
+        stream_opts = {'role': libcam.StreamRole.Viewfinder}
+
+        for stream_opt in stream_desc.split(','):
+            if stream_opt == 0:
+                continue
+
+            arr = stream_opt.split('=')
+            if len(arr) != 2:
+                print('Bad stream option', stream_opt)
+                sys.exit(-1)
+
+            key = arr[0]
+            value = arr[1]
+
+            if key in ['width', 'height']:
+                value = int(value)
+            elif key == 'role':
+                rolemap = {
+                    'still': libcam.StreamRole.StillCapture,
+                    'raw': libcam.StreamRole.Raw,
+                    'video': libcam.StreamRole.VideoRecording,
+                    'viewfinder': libcam.StreamRole.Viewfinder,
+                }
+
+                role = rolemap.get(value.lower(), None)
+
+                if role is None:
+                    print('Bad stream role', value)
+                    sys.exit(-1)
+
+                value = role
+            elif key == 'pixelformat':
+                pass
+            else:
+                print('Bad stream option key', key)
+                sys.exit(-1)
+
+            stream_opts[key] = value
+
+        streams.append(stream_opts)
+
+    return streams
+
+
+def configure(ctx):
+    camera = ctx['camera']
+
+    streams = parse_streams(ctx)
+
+    roles = [opts['role'] for opts in streams]
+
+    camconfig = camera.generate_configuration(roles)
+    if camconfig is None:
+        raise Exception('Generating config failed')
+
+    for idx, stream_opts in enumerate(streams):
+        stream_config = camconfig.at(idx)
+
+        if 'width' in stream_opts and 'height' in stream_opts:
+            stream_config.size = (stream_opts['width'], stream_opts['height'])
+
+        if 'pixelformat' in stream_opts:
+            stream_config.pixel_format = stream_opts['pixelformat']
+
+    stat = camconfig.validate()
+
+    if stat == libcam.CameraConfiguration.Status.Invalid:
+        print('Camera configuration invalid')
+        exit(-1)
+    elif stat == libcam.CameraConfiguration.Status.Adjusted:
+        if ctx['opt-strict-formats']:
+            print('Adjusting camera configuration disallowed by --strict-formats argument')
+            exit(-1)
+
+        print('Camera configuration adjusted')
+
+    r = camera.configure(camconfig)
+    if r != 0:
+        raise Exception('Configure failed')
+
+    ctx['stream-names'] = {}
+    ctx['streams'] = []
+
+    for idx, stream_config in enumerate(camconfig):
+        stream = stream_config.stream
+        ctx['streams'].append(stream)
+        ctx['stream-names'][stream] = 'stream' + str(idx)
+        print('{}-{}: stream config {}'.format(ctx['id'], ctx['stream-names'][stream], stream.configuration))
+
+
+def alloc_buffers(ctx):
+    camera = ctx['camera']
+
+    allocator = libcam.FrameBufferAllocator(camera)
+
+    for idx, stream in enumerate(ctx['streams']):
+        ret = allocator.allocate(stream)
+        if ret < 0:
+            print('Cannot allocate buffers')
+            exit(-1)
+
+        allocated = len(allocator.buffers(stream))
+
+        print('{}-{}: Allocated {} buffers'.format(ctx['id'], ctx['stream-names'][stream], allocated))
+
+    ctx['allocator'] = allocator
+
+
+def create_requests(ctx):
+    camera = ctx['camera']
+
+    ctx['requests'] = []
+
+    # Identify the stream with the least number of buffers
+    num_bufs = min([len(ctx['allocator'].buffers(stream)) for stream in ctx['streams']])
+
+    requests = []
+
+    for buf_num in range(num_bufs):
+        request = camera.create_request(ctx['idx'])
+
+        if request is None:
+            print('Can not create request')
+            exit(-1)
+
+        for stream in ctx['streams']:
+            buffers = ctx['allocator'].buffers(stream)
+            buffer = buffers[buf_num]
+
+            ret = request.add_buffer(stream, buffer)
+            if ret < 0:
+                print('Can not set buffer for request')
+                exit(-1)
+
+        requests.append(request)
+
+    ctx['requests'] = requests
+
+
+def start(ctx):
+    camera = ctx['camera']
+
+    camera.start()
+
+
+def stop(ctx):
+    camera = ctx['camera']
+
+    camera.stop()
+
+
+def queue_requests(ctx):
+    camera = ctx['camera']
+
+    for request in ctx['requests']:
+        camera.queue_request(request)
+        ctx['reqs-queued'] += 1
+
+    del ctx['requests']
+
+
+def capture_init(contexts):
+    for ctx in contexts:
+        acquire(ctx)
+
+    for ctx in contexts:
+        configure(ctx)
+
+    for ctx in contexts:
+        alloc_buffers(ctx)
+
+    for ctx in contexts:
+        create_requests(ctx)
+
+
+def capture_start(contexts):
+    for ctx in contexts:
+        start(ctx)
+
+    for ctx in contexts:
+        queue_requests(ctx)
+
+
+# Called from renderer when there is a libcamera event
+def event_handler(state):
+    cm = state['cm']
+    contexts = state['contexts']
+
+    os.read(cm.efd, 8)
+
+    reqs = cm.get_ready_requests()
+
+    for req in reqs:
+        ctx = next(ctx for ctx in contexts if ctx['idx'] == req.cookie)
+        request_handler(state, ctx, req)
+
+    running = any(ctx['reqs-completed'] < ctx['opt-capture'] for ctx in contexts)
+    return running
+
+
+def request_handler(state, ctx, req):
+    if req.status != libcam.Request.Status.Complete:
+        raise Exception('{}: Request failed: {}'.format(ctx['id'], req.status))
+
+    buffers = req.buffers
+
+    # Compute the frame rate. The timestamp is arbitrarily retrieved from
+    # the first buffer, as all buffers should have matching timestamps.
+    ts = buffers[next(iter(buffers))].metadata.timestamp
+    last = ctx.get('last', 0)
+    fps = 1000000000.0 / (ts - last) if (last != 0 and (ts - last) != 0) else 0
+    ctx['last'] = ts
+    ctx['fps'] = fps
+
+    for stream, fb in buffers.items():
+        stream_name = ctx['stream-names'][stream]
+
+        crcs = []
+        if ctx['opt-crc']:
+            with fb.mmap() as mfb:
+                plane_crcs = [binascii.crc32(p) for p in mfb.planes]
+                crcs.append(plane_crcs)
+
+        meta = fb.metadata
+
+        print('{:.6f} ({:.2f} fps) {}-{}: seq {}, bytes {}, CRCs {}'
+              .format(ts / 1000000000, fps,
+                      ctx['id'], stream_name,
+                      meta.sequence, meta.bytesused,
+                      crcs))
+
+        if ctx['opt-metadata']:
+            reqmeta = req.metadata
+            for ctrl, val in reqmeta.items():
+                print(f'\t{ctrl} = {val}')
+
+        if ctx['opt-save-frames']:
+            with fb.mmap() as mfb:
+                filename = 'frame-{}-{}-{}.data'.format(ctx['id'], stream_name, ctx['reqs-completed'])
+                with open(filename, 'wb') as f:
+                    for p in mfb.planes:
+                        f.write(p)
+
+    state['renderer'].request_handler(ctx, req)
+
+    ctx['reqs-completed'] += 1
+
+
+# Called from renderer when it has finished with a request
+def request_prcessed(ctx, req):
+    camera = ctx['camera']
+
+    if ctx['reqs-queued'] < ctx['opt-capture']:
+        req.reuse()
+        camera.queue_request(req)
+        ctx['reqs-queued'] += 1
+
+
+def capture_deinit(contexts):
+    for ctx in contexts:
+        stop(ctx)
+
+    for ctx in contexts:
+        release(ctx)
+
+
+def do_cmd_capture(state):
+    capture_init(state['contexts'])
+
+    renderer = state['renderer']
+
+    renderer.setup()
+
+    capture_start(state['contexts'])
+
+    renderer.run()
+
+    capture_deinit(state['contexts'])
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    # global options
+    parser.add_argument('-l', '--list', action='store_true', help='List all cameras')
+    parser.add_argument('-c', '--camera', type=int, action='extend', nargs=1, default=[], help='Specify which camera to operate on, by index')
+    parser.add_argument('-p', '--list-properties', action='store_true', help='List cameras properties')
+    parser.add_argument('--list-controls', action='store_true', help='List cameras controls')
+    parser.add_argument('-I', '--info', action='store_true', help='Display information about stream(s)')
+    parser.add_argument('-R', '--renderer', default='null', help='Renderer (null, kms, qt, qtgl)')
+
+    # per camera options
+    parser.add_argument('-C', '--capture', nargs='?', type=int, const=1000000, action=CustomAction, help='Capture until interrupted by user or until CAPTURE frames captured')
+    parser.add_argument('--crc', nargs=0, type=bool, action=CustomAction, help='Print CRC32 for captured frames')
+    parser.add_argument('--save-frames', nargs=0, type=bool, action=CustomAction, help='Save captured frames to files')
+    parser.add_argument('--metadata', nargs=0, type=bool, action=CustomAction, help='Print the metadata for completed requests')
+    parser.add_argument('--strict-formats', type=bool, nargs=0, action=CustomAction, help='Do not allow requested stream format(s) to be adjusted')
+    parser.add_argument('-s', '--stream', nargs='+', action=CustomAction)
+    args = parser.parse_args()
+
+    cm = libcam.CameraManager.singleton()
+
+    if args.list:
+        do_cmd_list(cm)
+
+    contexts = []
+
+    for cam_idx in args.camera:
+        camera = next((c for i, c in enumerate(cm.cameras) if i + 1 == cam_idx), None)
+
+        if camera is None:
+            print('Unable to find camera', cam_idx)
+            return -1
+
+        contexts.append({
+                        'camera': camera,
+                        'idx': cam_idx,
+                        'id': 'cam' + str(cam_idx),
+                        'reqs-queued': 0,
+                        'reqs-completed': 0,
+                        'opt-capture': args.capture.get(cam_idx, False),
+                        'opt-crc': args.crc.get(cam_idx, False),
+                        'opt-save-frames': args.save_frames.get(cam_idx, False),
+                        'opt-metadata': args.metadata.get(cam_idx, False),
+                        'opt-strict-formats': args.strict_formats.get(cam_idx, False),
+                        'opt-stream': args.stream.get(cam_idx, ['role=viewfinder']),
+                        })
+
+    for ctx in contexts:
+        print('Using camera {} as {}'.format(ctx['camera'].id, ctx['id']))
+
+    for ctx in contexts:
+        if args.list_properties:
+            do_cmd_list_props(ctx)
+        if args.list_controls:
+            do_cmd_list_controls(ctx)
+        if args.info:
+            do_cmd_info(ctx)
+
+    if args.capture:
+
+        state = {
+            'cm': cm,
+            'contexts': contexts,
+            'event_handler': event_handler,
+            'request_prcessed': request_prcessed,
+        }
+
+        if args.renderer == 'null':
+            import cam_null
+            renderer = cam_null.NullRenderer(state)
+        elif args.renderer == 'kms':
+            import cam_kms
+            renderer = cam_kms.KMSRenderer(state)
+        elif args.renderer == 'qt':
+            import cam_qt
+            renderer = cam_qt.QtRenderer(state)
+        elif args.renderer == 'qtgl':
+            import cam_qtgl
+            renderer = cam_qtgl.QtRenderer(state)
+        else:
+            print('Bad renderer', args.renderer)
+            return -1
+
+        state['renderer'] = renderer
+
+        do_cmd_capture(state)
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/src/py/cam/cam_kms.py b/src/py/cam/cam_kms.py
new file mode 100644
index 00000000..ae6be277
--- /dev/null
+++ b/src/py/cam/cam_kms.py
@@ -0,0 +1,183 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+
+import pykms
+import selectors
+import sys
+
+FMT_MAP = {
+    'RGB888': pykms.PixelFormat.RGB888,
+    'YUYV': pykms.PixelFormat.YUYV,
+    'ARGB8888': pykms.PixelFormat.ARGB8888,
+    'XRGB8888': pykms.PixelFormat.XRGB8888,
+}
+
+
+class KMSRenderer:
+    def __init__(self, state):
+        self.state = state
+
+        self.cm = state['cm']
+        self.contexts = state['contexts']
+        self.running = False
+
+        card = pykms.Card()
+
+        res = pykms.ResourceManager(card)
+        conn = res.reserve_connector()
+        crtc = res.reserve_crtc(conn)
+        mode = conn.get_default_mode()
+        modeb = mode.to_blob(card)
+
+        req = pykms.AtomicReq(card)
+        req.add_connector(conn, crtc)
+        req.add_crtc(crtc, modeb)
+        r = req.commit_sync(allow_modeset=True)
+        assert(r == 0)
+
+        self.card = card
+        self.resman = res
+        self.crtc = crtc
+        self.mode = mode
+
+        self.bufqueue = []
+        self.current = None
+        self.next = None
+        self.cam_2_drm = {}
+
+    # KMS
+
+    def close(self):
+        req = pykms.AtomicReq(self.card)
+        for s in self.streams:
+            req.add_plane(s['plane'], None, None, dst=(0, 0, 0, 0))
+        req.commit()
+
+    def add_plane(self, req, stream, fb):
+        s = next(s for s in self.streams if s['stream'] == stream)
+        idx = s['idx']
+        plane = s['plane']
+
+        if idx % 2 == 0:
+            x = 0
+        else:
+            x = self.mode.hdisplay - fb.width
+
+        if idx // 2 == 0:
+            y = 0
+        else:
+            y = self.mode.vdisplay - fb.height
+
+        req.add_plane(plane, fb, self.crtc, dst=(x, y, fb.width, fb.height))
+
+    def apply_request(self, drmreq):
+
+        buffers = drmreq['camreq'].buffers
+
+        for stream, fb in buffers.items():
+            drmfb = self.cam_2_drm.get(fb, None)
+
+            req = pykms.AtomicReq(self.card)
+            self.add_plane(req, stream, drmfb)
+            req.commit()
+
+    def handle_page_flip(self, frame, time):
+        old = self.current
+        self.current = self.next
+
+        if len(self.bufqueue) > 0:
+            self.next = self.bufqueue.pop(0)
+        else:
+            self.next = None
+
+        if self.next:
+            drmreq = self.next
+
+            self.apply_request(drmreq)
+
+        if old:
+            req = old['camreq']
+            ctx = old['camctx']
+            self.state['request_prcessed'](ctx, req)
+
+    def queue(self, drmreq):
+        if not self.next:
+            self.next = drmreq
+            self.apply_request(drmreq)
+        else:
+            self.bufqueue.append(drmreq)
+
+    # libcamera
+
+    def setup(self):
+        self.streams = []
+
+        idx = 0
+        for ctx in self.contexts:
+            for stream in ctx['streams']:
+
+                cfg = stream.configuration
+                fmt = cfg.pixel_format
+                fmt = FMT_MAP[fmt]
+
+                plane = self.resman.reserve_generic_plane(self.crtc, fmt)
+                assert(plane is not None)
+
+                self.streams.append({
+                    'idx': idx,
+                    'stream': stream,
+                    'plane': plane,
+                    'fmt': fmt,
+                    'size': cfg.size,
+                })
+
+                for fb in ctx['allocator'].buffers(stream):
+                    w, h = cfg.size
+                    stride = cfg.stride
+                    fd = fb.fd(0)
+                    drmfb = pykms.DmabufFramebuffer(self.card, w, h, fmt,
+                                                    [fd], [stride], [0])
+                    self.cam_2_drm[fb] = drmfb
+
+                idx += 1
+
+    def readdrm(self, fileobj):
+        for ev in self.card.read_events():
+            if ev.type == pykms.DrmEventType.FLIP_COMPLETE:
+                self.handle_page_flip(ev.seq, ev.time)
+
+    def readcam(self, fd):
+        self.running = self.state['event_handler'](self.state)
+
+    def readkey(self, fileobj):
+        sys.stdin.readline()
+        self.running = False
+
+    def run(self):
+        print('Capturing...')
+
+        self.running = True
+
+        sel = selectors.DefaultSelector()
+        sel.register(self.card.fd, selectors.EVENT_READ, self.readdrm)
+        sel.register(self.cm.efd, selectors.EVENT_READ, self.readcam)
+        sel.register(sys.stdin, selectors.EVENT_READ, self.readkey)
+
+        print('Press enter to exit')
+
+        while self.running:
+            events = sel.select()
+            for key, mask in events:
+                callback = key.data
+                callback(key.fileobj)
+
+        print('Exiting...')
+
+    def request_handler(self, ctx, req):
+
+        drmreq = {
+            'camctx': ctx,
+            'camreq': req,
+        }
+
+        self.queue(drmreq)
diff --git a/src/py/cam/cam_null.py b/src/py/cam/cam_null.py
new file mode 100644
index 00000000..a6da9671
--- /dev/null
+++ b/src/py/cam/cam_null.py
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+
+import selectors
+import sys
+
+
+class NullRenderer:
+    def __init__(self, state):
+        self.state = state
+
+        self.cm = state['cm']
+        self.contexts = state['contexts']
+
+        self.running = False
+
+    def setup(self):
+        pass
+
+    def run(self):
+        print('Capturing...')
+
+        self.running = True
+
+        sel = selectors.DefaultSelector()
+        sel.register(self.cm.efd, selectors.EVENT_READ, self.readcam)
+        sel.register(sys.stdin, selectors.EVENT_READ, self.readkey)
+
+        print('Press enter to exit')
+
+        while self.running:
+            events = sel.select()
+            for key, mask in events:
+                callback = key.data
+                callback(key.fileobj)
+
+        print('Exiting...')
+
+    def readcam(self, fd):
+        self.running = self.state['event_handler'](self.state)
+
+    def readkey(self, fileobj):
+        sys.stdin.readline()
+        self.running = False
+
+    def request_handler(self, ctx, req):
+        self.state['request_prcessed'](ctx, req)
diff --git a/src/py/cam/cam_qt.py b/src/py/cam/cam_qt.py
new file mode 100644
index 00000000..5753f0b2
--- /dev/null
+++ b/src/py/cam/cam_qt.py
@@ -0,0 +1,354 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+#
+# Debayering code from PiCamera documentation
+
+from io import BytesIO
+from numpy.lib.stride_tricks import as_strided
+from PIL import Image
+from PIL.ImageQt import ImageQt
+from PyQt5 import QtCore, QtGui, QtWidgets
+import numpy as np
+import sys
+
+
+def rgb_to_pix(rgb):
+    img = Image.frombuffer('RGB', (rgb.shape[1], rgb.shape[0]), rgb)
+    qim = ImageQt(img).copy()
+    pix = QtGui.QPixmap.fromImage(qim)
+    return pix
+
+
+def separate_components(data, r0, g0, g1, b0):
+    # Now to split the data up into its red, green, and blue components. The
+    # Bayer pattern of the OV5647 sensor is BGGR. In other words the first
+    # row contains alternating green/blue elements, the second row contains
+    # alternating red/green elements, and so on as illustrated below:
+    #
+    # GBGBGBGBGBGBGB
+    # RGRGRGRGRGRGRG
+    # GBGBGBGBGBGBGB
+    # RGRGRGRGRGRGRG
+    #
+    # Please note that if you use vflip or hflip to change the orientation
+    # of the capture, you must flip the Bayer pattern accordingly
+
+    rgb = np.zeros(data.shape + (3,), dtype=data.dtype)
+    rgb[r0[1]::2, r0[0]::2, 0] = data[r0[1]::2, r0[0]::2]  # Red
+    rgb[g0[1]::2, g0[0]::2, 1] = data[g0[1]::2, g0[0]::2]  # Green
+    rgb[g1[1]::2, g1[0]::2, 1] = data[g1[1]::2, g1[0]::2]  # Green
+    rgb[b0[1]::2, b0[0]::2, 2] = data[b0[1]::2, b0[0]::2]  # Blue
+
+    return rgb
+
+
+def demosaic(rgb, r0, g0, g1, b0):
+    # At this point we now have the raw Bayer data with the correct values
+    # and colors but the data still requires de-mosaicing and
+    # post-processing. If you wish to do this yourself, end the script here!
+    #
+    # Below we present a fairly naive de-mosaic method that simply
+    # calculates the weighted average of a pixel based on the pixels
+    # surrounding it. The weighting is provided b0[1] a b0[1]te representation of
+    # the Bayer filter which we construct first:
+
+    bayer = np.zeros(rgb.shape, dtype=np.uint8)
+    bayer[r0[1]::2, r0[0]::2, 0] = 1  # Red
+    bayer[g0[1]::2, g0[0]::2, 1] = 1  # Green
+    bayer[g1[1]::2, g1[0]::2, 1] = 1  # Green
+    bayer[b0[1]::2, b0[0]::2, 2] = 1  # Blue
+
+    # Allocate an array to hold our output with the same shape as the input
+    # data. After this we define the size of window that will be used to
+    # calculate each weighted average (3x3). Then we pad out the rgb and
+    # bayer arrays, adding blank pixels at their edges to compensate for the
+    # size of the window when calculating averages for edge pixels.
+
+    output = np.empty(rgb.shape, dtype=rgb.dtype)
+    window = (3, 3)
+    borders = (window[0] - 1, window[1] - 1)
+    border = (borders[0] // 2, borders[1] // 2)
+
+    # rgb_pad = np.zeros((
+    #    rgb.shape[0] + borders[0],
+    #    rgb.shape[1] + borders[1],
+    #    rgb.shape[2]), dtype=rgb.dtype)
+    # rgb_pad[
+    #    border[0]:rgb_pad.shape[0] - border[0],
+    #    border[1]:rgb_pad.shape[1] - border[1],
+    #    :] = rgb
+    # rgb = rgb_pad
+    #
+    # bayer_pad = np.zeros((
+    #    bayer.shape[0] + borders[0],
+    #    bayer.shape[1] + borders[1],
+    #    bayer.shape[2]), dtype=bayer.dtype)
+    # bayer_pad[
+    #    border[0]:bayer_pad.shape[0] - border[0],
+    #    border[1]:bayer_pad.shape[1] - border[1],
+    #    :] = bayer
+    # bayer = bayer_pad
+
+    # In numpy >=1.7.0 just use np.pad (version in Raspbian is 1.6.2 at the
+    # time of writing...)
+    #
+    rgb = np.pad(rgb, [
+        (border[0], border[0]),
+        (border[1], border[1]),
+        (0, 0),
+    ], 'constant')
+    bayer = np.pad(bayer, [
+        (border[0], border[0]),
+        (border[1], border[1]),
+        (0, 0),
+    ], 'constant')
+
+    # For each plane in the RGB data, we use a nifty numpy trick
+    # (as_strided) to construct a view over the plane of 3x3 matrices. We do
+    # the same for the bayer array, then use Einstein summation on each
+    # (np.sum is simpler, but copies the data so it's slower), and divide
+    # the results to get our weighted average:
+
+    for plane in range(3):
+        p = rgb[..., plane]
+        b = bayer[..., plane]
+        pview = as_strided(p, shape=(
+            p.shape[0] - borders[0],
+            p.shape[1] - borders[1]) + window, strides=p.strides * 2)
+        bview = as_strided(b, shape=(
+            b.shape[0] - borders[0],
+            b.shape[1] - borders[1]) + window, strides=b.strides * 2)
+        psum = np.einsum('ijkl->ij', pview)
+        bsum = np.einsum('ijkl->ij', bview)
+        output[..., plane] = psum // bsum
+
+    return output
+
+
+def to_rgb(fmt, size, data):
+    w = size[0]
+    h = size[1]
+
+    if fmt == 'YUYV':
+        # YUV422
+        yuyv = data.reshape((h, w // 2 * 4))
+
+        # YUV444
+        yuv = np.empty((h, w, 3), dtype=np.uint8)
+        yuv[:, :, 0] = yuyv[:, 0::2]                    # Y
+        yuv[:, :, 1] = yuyv[:, 1::4].repeat(2, axis=1)  # U
+        yuv[:, :, 2] = yuyv[:, 3::4].repeat(2, axis=1)  # V
+
+        m = np.array([
+            [1.0, 1.0, 1.0],
+            [-0.000007154783816076815, -0.3441331386566162, 1.7720025777816772],
+            [1.4019975662231445, -0.7141380310058594, 0.00001542569043522235]
+        ])
+
+        rgb = np.dot(yuv, m)
+        rgb[:, :, 0] -= 179.45477266423404
+        rgb[:, :, 1] += 135.45870971679688
+        rgb[:, :, 2] -= 226.8183044444304
+        rgb = rgb.astype(np.uint8)
+
+    elif fmt == 'RGB888':
+        rgb = data.reshape((h, w, 3))
+        rgb[:, :, [0, 1, 2]] = rgb[:, :, [2, 1, 0]]
+
+    elif fmt == 'BGR888':
+        rgb = data.reshape((h, w, 3))
+
+    elif fmt in ['ARGB8888', 'XRGB8888']:
+        rgb = data.reshape((h, w, 4))
+        rgb = np.flip(rgb, axis=2)
+        # drop alpha component
+        rgb = np.delete(rgb, np.s_[0::4], axis=2)
+
+    elif fmt.startswith('S'):
+        bayer_pattern = fmt[1:5]
+        bitspp = int(fmt[5:])
+
+        # TODO: shifting leaves the lowest bits 0
+        if bitspp == 8:
+            data = data.reshape((h, w))
+            data = data.astype(np.uint16) << 8
+        elif bitspp in [10, 12]:
+            data = data.view(np.uint16)
+            data = data.reshape((h, w))
+            data = data << (16 - bitspp)
+        else:
+            raise Exception('Bad bitspp:' + str(bitspp))
+
+        idx = bayer_pattern.find('R')
+        assert(idx != -1)
+        r0 = (idx % 2, idx // 2)
+
+        idx = bayer_pattern.find('G')
+        assert(idx != -1)
+        g0 = (idx % 2, idx // 2)
+
+        idx = bayer_pattern.find('G', idx + 1)
+        assert(idx != -1)
+        g1 = (idx % 2, idx // 2)
+
+        idx = bayer_pattern.find('B')
+        assert(idx != -1)
+        b0 = (idx % 2, idx // 2)
+
+        rgb = separate_components(data, r0, g0, g1, b0)
+        rgb = demosaic(rgb, r0, g0, g1, b0)
+        rgb = (rgb >> 8).astype(np.uint8)
+
+    else:
+        rgb = None
+
+    return rgb
+
+
+class QtRenderer:
+    def __init__(self, state):
+        self.state = state
+
+        self.cm = state['cm']
+        self.contexts = state['contexts']
+
+    def setup(self):
+        self.app = QtWidgets.QApplication([])
+
+        windows = []
+
+        for ctx in self.contexts:
+            camera = ctx['camera']
+
+            for stream in ctx['streams']:
+                fmt = stream.configuration.pixel_format
+                size = stream.configuration.size
+
+                window = MainWindow(ctx, stream)
+                window.setAttribute(QtCore.Qt.WA_ShowWithoutActivating)
+                window.show()
+                windows.append(window)
+
+        self.windows = windows
+
+    def run(self):
+        camnotif = QtCore.QSocketNotifier(self.cm.efd, QtCore.QSocketNotifier.Read)
+        camnotif.activated.connect(lambda x: self.readcam())
+
+        keynotif = QtCore.QSocketNotifier(sys.stdin.fileno(), QtCore.QSocketNotifier.Read)
+        keynotif.activated.connect(lambda x: self.readkey())
+
+        print('Capturing...')
+
+        self.app.exec()
+
+        print('Exiting...')
+
+    def readcam(self):
+        running = self.state['event_handler'](self.state)
+
+        if not running:
+            self.app.quit()
+
+    def readkey(self):
+        sys.stdin.readline()
+        self.app.quit()
+
+    def request_handler(self, ctx, req):
+        buffers = req.buffers
+
+        for stream, fb in buffers.items():
+            wnd = next(wnd for wnd in self.windows if wnd.stream == stream)
+
+            wnd.handle_request(stream, fb)
+
+        self.state['request_prcessed'](ctx, req)
+
+    def cleanup(self):
+        for w in self.windows:
+            w.close()
+
+
+class MainWindow(QtWidgets.QWidget):
+    def __init__(self, ctx, stream):
+        super().__init__()
+
+        self.ctx = ctx
+        self.stream = stream
+
+        self.label = QtWidgets.QLabel()
+
+        windowLayout = QtWidgets.QHBoxLayout()
+        self.setLayout(windowLayout)
+
+        windowLayout.addWidget(self.label)
+
+        controlsLayout = QtWidgets.QVBoxLayout()
+        windowLayout.addLayout(controlsLayout)
+
+        windowLayout.addStretch()
+
+        group = QtWidgets.QGroupBox('Info')
+        groupLayout = QtWidgets.QVBoxLayout()
+        group.setLayout(groupLayout)
+        controlsLayout.addWidget(group)
+
+        lab = QtWidgets.QLabel(ctx['id'])
+        groupLayout.addWidget(lab)
+
+        self.frameLabel = QtWidgets.QLabel()
+        groupLayout.addWidget(self.frameLabel)
+
+        group = QtWidgets.QGroupBox('Properties')
+        groupLayout = QtWidgets.QVBoxLayout()
+        group.setLayout(groupLayout)
+        controlsLayout.addWidget(group)
+
+        camera = ctx['camera']
+
+        for k, v in camera.properties.items():
+            lab = QtWidgets.QLabel()
+            lab.setText(k + ' = ' + str(v))
+            groupLayout.addWidget(lab)
+
+        group = QtWidgets.QGroupBox('Controls')
+        groupLayout = QtWidgets.QVBoxLayout()
+        group.setLayout(groupLayout)
+        controlsLayout.addWidget(group)
+
+        for k, (min, max, default) in camera.controls.items():
+            lab = QtWidgets.QLabel()
+            lab.setText('{} = {}/{}/{}'.format(k, min, max, default))
+            groupLayout.addWidget(lab)
+
+        controlsLayout.addStretch()
+
+    def buf_to_qpixmap(self, stream, fb):
+        with fb.mmap() as mfb:
+            cfg = stream.configuration
+            w, h = cfg.size
+            pitch = cfg.stride
+
+            if cfg.pixel_format == 'MJPEG':
+                img = Image.open(BytesIO(mfb.planes[0]))
+                qim = ImageQt(img).copy()
+                pix = QtGui.QPixmap.fromImage(qim)
+            else:
+                data = np.array(mfb.planes[0], dtype=np.uint8)
+                rgb = to_rgb(cfg.pixel_format, cfg.size, data)
+
+                if rgb is None:
+                    raise Exception('Format not supported: ' + cfg.pixel_format)
+
+                pix = rgb_to_pix(rgb)
+
+        return pix
+
+    def handle_request(self, stream, fb):
+        ctx = self.ctx
+
+        pix = self.buf_to_qpixmap(stream, fb)
+        self.label.setPixmap(pix)
+
+        self.frameLabel.setText('Queued: {}\nDone: {}\nFps: {:.2f}'
+                                .format(ctx['reqs-queued'], ctx['reqs-completed'], ctx['fps']))
diff --git a/src/py/cam/cam_qtgl.py b/src/py/cam/cam_qtgl.py
new file mode 100644
index 00000000..8a95994e
--- /dev/null
+++ b/src/py/cam/cam_qtgl.py
@@ -0,0 +1,383 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+
+from PyQt5 import QtCore, QtWidgets
+from PyQt5.QtCore import Qt
+
+import math
+import numpy as np
+import os
+import sys
+
+os.environ['PYOPENGL_PLATFORM'] = 'egl'
+
+import OpenGL
+# OpenGL.FULL_LOGGING = True
+
+from OpenGL import GL as gl
+from OpenGL.EGL.EXT.image_dma_buf_import import *
+from OpenGL.EGL.KHR.image import *
+from OpenGL.EGL.VERSION.EGL_1_0 import *
+from OpenGL.EGL.VERSION.EGL_1_2 import *
+from OpenGL.EGL.VERSION.EGL_1_3 import *
+
+from OpenGL.GLES2.OES.EGL_image import *
+from OpenGL.GLES2.OES.EGL_image_external import *
+from OpenGL.GLES2.VERSION.GLES2_2_0 import *
+from OpenGL.GLES3.VERSION.GLES3_3_0 import *
+
+from OpenGL.GL import shaders
+
+from gl_helpers import *
+
+# libcamera format string -> DRM fourcc
+FMT_MAP = {
+    'RGB888': 'RG24',
+    'XRGB8888': 'XR24',
+    'ARGB8888': 'AR24',
+    'YUYV': 'YUYV',
+}
+
+
+class EglState:
+    def __init__(self):
+        self.create_display()
+        self.choose_config()
+        self.create_context()
+        self.check_extensions()
+
+    def create_display(self):
+        xdpy = getEGLNativeDisplay()
+        dpy = eglGetDisplay(xdpy)
+        self.display = dpy
+
+    def choose_config(self):
+        dpy = self.display
+
+        major, minor = EGLint(), EGLint()
+
+        b = eglInitialize(dpy, major, minor)
+        assert(b)
+
+        print('EGL {} {}'.format(
+              eglQueryString(dpy, EGL_VENDOR).decode(),
+              eglQueryString(dpy, EGL_VERSION).decode()))
+
+        check_egl_extensions(dpy, ['EGL_EXT_image_dma_buf_import'])
+
+        b = eglBindAPI(EGL_OPENGL_ES_API)
+        assert(b)
+
+        def print_config(dpy, cfg):
+
+            def getconf(a):
+                value = ctypes.c_long()
+                eglGetConfigAttrib(dpy, cfg, a, value)
+                return value.value
+
+            print('EGL Config {}: color buf {}/{}/{}/{} = {}, depth {}, stencil {}, native visualid {}, native visualtype {}'.format(
+                getconf(EGL_CONFIG_ID),
+                getconf(EGL_ALPHA_SIZE),
+                getconf(EGL_RED_SIZE),
+                getconf(EGL_GREEN_SIZE),
+                getconf(EGL_BLUE_SIZE),
+                getconf(EGL_BUFFER_SIZE),
+                getconf(EGL_DEPTH_SIZE),
+                getconf(EGL_STENCIL_SIZE),
+                getconf(EGL_NATIVE_VISUAL_ID),
+                getconf(EGL_NATIVE_VISUAL_TYPE)))
+
+        if False:
+            num_configs = ctypes.c_long()
+            eglGetConfigs(dpy, None, 0, num_configs)
+            print('{} configs'.format(num_configs.value))
+
+            configs = (EGLConfig * num_configs.value)()
+            eglGetConfigs(dpy, configs, num_configs.value, num_configs)
+            for config_id in configs:
+                print_config(dpy, config_id)
+
+        config_attribs = [
+            EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+            EGL_RED_SIZE, 8,
+            EGL_GREEN_SIZE, 8,
+            EGL_BLUE_SIZE, 8,
+            EGL_ALPHA_SIZE, 0,
+            EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+            EGL_NONE,
+        ]
+
+        n = EGLint()
+        configs = (EGLConfig * 1)()
+        b = eglChooseConfig(dpy, config_attribs, configs, 1, n)
+        assert(b and n.value == 1)
+        config = configs[0]
+
+        print('Chosen Config:')
+        print_config(dpy, config)
+
+        self.config = config
+
+    def create_context(self):
+        dpy = self.display
+
+        context_attribs = [
+            EGL_CONTEXT_CLIENT_VERSION, 2,
+            EGL_NONE,
+        ]
+
+        context = eglCreateContext(dpy, self.config, EGL_NO_CONTEXT, context_attribs)
+        assert(context)
+
+        b = eglMakeCurrent(dpy, EGL_NO_SURFACE, EGL_NO_SURFACE, context)
+        assert(b)
+
+        self.context = context
+
+    def check_extensions(self):
+        check_gl_extensions(['GL_OES_EGL_image'])
+
+        assert(eglCreateImageKHR)
+        assert(eglDestroyImageKHR)
+        assert(glEGLImageTargetTexture2DOES)
+
+
+class QtRenderer:
+    def __init__(self, state):
+        self.state = state
+
+    def setup(self):
+        self.app = QtWidgets.QApplication([])
+
+        window = MainWindow(self.state)
+        window.setAttribute(QtCore.Qt.WA_ShowWithoutActivating)
+        window.show()
+
+        self.window = window
+
+    def run(self):
+        camnotif = QtCore.QSocketNotifier(self.state['cm'].efd, QtCore.QSocketNotifier.Read)
+        camnotif.activated.connect(lambda x: self.readcam())
+
+        keynotif = QtCore.QSocketNotifier(sys.stdin.fileno(), QtCore.QSocketNotifier.Read)
+        keynotif.activated.connect(lambda x: self.readkey())
+
+        print('Capturing...')
+
+        self.app.exec()
+
+        print('Exiting...')
+
+    def readcam(self):
+        running = self.state['event_handler'](self.state)
+
+        if not running:
+            self.app.quit()
+
+    def readkey(self):
+        sys.stdin.readline()
+        self.app.quit()
+
+    def request_handler(self, ctx, req):
+        self.window.handle_request(ctx, req)
+
+    def cleanup(self):
+        self.window.close()
+
+
+class MainWindow(QtWidgets.QWidget):
+    def __init__(self, state):
+        super().__init__()
+
+        self.setAttribute(Qt.WA_PaintOnScreen)
+        self.setAttribute(Qt.WA_NativeWindow)
+
+        self.state = state
+
+        self.textures = {}
+        self.reqqueue = {}
+        self.current = {}
+
+        for ctx in self.state['contexts']:
+
+            self.reqqueue[ctx['idx']] = []
+            self.current[ctx['idx']] = []
+
+            for stream in ctx['streams']:
+                fmt = stream.configuration.pixel_format
+                size = stream.configuration.size
+
+                if fmt not in FMT_MAP:
+                    raise Exception('Unsupported pixel format: ' + str(fmt))
+
+                self.textures[stream] = None
+
+        num_tiles = len(self.textures)
+        self.num_columns = math.ceil(math.sqrt(num_tiles))
+        self.num_rows = math.ceil(num_tiles / self.num_columns)
+
+        self.egl = EglState()
+
+        self.surface = None
+
+    def paintEngine(self):
+        return None
+
+    def create_surface(self):
+        native_surface = c_void_p(self.winId().__int__())
+        surface = eglCreateWindowSurface(self.egl.display, self.egl.config,
+                                         native_surface, None)
+
+        b = eglMakeCurrent(self.egl.display, self.surface, self.surface, self.egl.context)
+        assert(b)
+
+        self.surface = surface
+
+    def init_gl(self):
+        self.create_surface()
+
+        vertShaderSrc = '''
+            attribute vec2 aPosition;
+            varying vec2 texcoord;
+
+            void main()
+            {
+                gl_Position = vec4(aPosition * 2.0 - 1.0, 0.0, 1.0);
+                texcoord.x = aPosition.x;
+                texcoord.y = 1.0 - aPosition.y;
+            }
+        '''
+        fragShaderSrc = '''
+            #extension GL_OES_EGL_image_external : enable
+            precision mediump float;
+            varying vec2 texcoord;
+            uniform samplerExternalOES texture;
+
+            void main()
+            {
+                gl_FragColor = texture2D(texture, texcoord);
+            }
+        '''
+
+        program = shaders.compileProgram(
+            shaders.compileShader(vertShaderSrc, GL_VERTEX_SHADER),
+            shaders.compileShader(fragShaderSrc, GL_FRAGMENT_SHADER)
+        )
+
+        glUseProgram(program)
+
+        glClearColor(0.5, 0.8, 0.7, 1.0)
+
+        vertPositions = [
+            0.0, 0.0,
+            1.0, 0.0,
+            1.0, 1.0,
+            0.0, 1.0
+        ]
+
+        inputAttrib = glGetAttribLocation(program, 'aPosition')
+        glVertexAttribPointer(inputAttrib, 2, GL_FLOAT, GL_FALSE, 0, vertPositions)
+        glEnableVertexAttribArray(inputAttrib)
+
+    def create_texture(self, stream, fb):
+        cfg = stream.configuration
+        fmt = cfg.pixel_format
+        fmt = str_to_fourcc(FMT_MAP[fmt])
+        w, h = cfg.size
+
+        attribs = [
+            EGL_WIDTH, w,
+            EGL_HEIGHT, h,
+            EGL_LINUX_DRM_FOURCC_EXT, fmt,
+            EGL_DMA_BUF_PLANE0_FD_EXT, fb.fd(0),
+            EGL_DMA_BUF_PLANE0_OFFSET_EXT, 0,
+            EGL_DMA_BUF_PLANE0_PITCH_EXT, cfg.stride,
+            EGL_NONE,
+        ]
+
+        image = eglCreateImageKHR(self.egl.display,
+                                  EGL_NO_CONTEXT,
+                                  EGL_LINUX_DMA_BUF_EXT,
+                                  None,
+                                  attribs)
+        assert(image)
+
+        textures = glGenTextures(1)
+        glBindTexture(GL_TEXTURE_EXTERNAL_OES, textures)
+        glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
+        glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
+        glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
+        glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
+        glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, image)
+
+        return textures
+
+    def resizeEvent(self, event):
+        size = event.size()
+
+        print('Resize', size)
+
+        super().resizeEvent(event)
+
+        if self.surface is None:
+            return
+
+        glViewport(0, 0, size.width() // 2, size.height())
+
+    def paintEvent(self, event):
+        if self.surface is None:
+            self.init_gl()
+
+        for ctx_idx, queue in self.reqqueue.items():
+            if len(queue) == 0:
+                continue
+
+            ctx = next(ctx for ctx in self.state['contexts'] if ctx['idx'] == ctx_idx)
+
+            if self.current[ctx_idx]:
+                old = self.current[ctx_idx]
+                self.current[ctx_idx] = None
+                self.state['request_prcessed'](ctx, old)
+
+            next_req = queue.pop(0)
+            self.current[ctx_idx] = next_req
+
+            stream, fb = next(iter(next_req.buffers.items()))
+
+            self.textures[stream] = self.create_texture(stream, fb)
+
+        self.paint_gl()
+
+    def paint_gl(self):
+        b = eglMakeCurrent(self.egl.display, self.surface, self.surface, self.egl.context)
+        assert(b)
+
+        glClear(GL_COLOR_BUFFER_BIT)
+
+        size = self.size()
+
+        for idx, ctx in enumerate(self.state['contexts']):
+            for stream in ctx['streams']:
+                if self.textures[stream] is None:
+                    continue
+
+                w = size.width() // self.num_columns
+                h = size.height() // self.num_rows
+
+                x = idx % self.num_columns
+                y = idx // self.num_columns
+
+                x *= w
+                y *= h
+
+                glViewport(x, y, w, h)
+
+                glBindTexture(GL_TEXTURE_EXTERNAL_OES, self.textures[stream])
+                glDrawArrays(GL_TRIANGLE_FAN, 0, 4)
+
+        b = eglSwapBuffers(self.egl.display, self.surface)
+        assert(b)
+
+    def handle_request(self, ctx, req):
+        self.reqqueue[ctx['idx']].append(req)
+        self.update()
diff --git a/src/py/cam/gl_helpers.py b/src/py/cam/gl_helpers.py
new file mode 100644
index 00000000..ac5e6889
--- /dev/null
+++ b/src/py/cam/gl_helpers.py
@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+
+from OpenGL.EGL.VERSION.EGL_1_0 import EGLNativeDisplayType, eglGetProcAddress, eglQueryString, EGL_EXTENSIONS
+
+from OpenGL.raw.GLES2 import _types as _cs
+from OpenGL.GLES2.VERSION.GLES2_2_0 import *
+from OpenGL.GLES3.VERSION.GLES3_3_0 import *
+from OpenGL import GL as gl
+
+from ctypes import c_int, c_char_p, c_void_p, cdll, POINTER, util, \
+    pointer, CFUNCTYPE, c_bool
+
+
+def getEGLNativeDisplay():
+    _x11lib = cdll.LoadLibrary(util.find_library('X11'))
+    XOpenDisplay = _x11lib.XOpenDisplay
+    XOpenDisplay.argtypes = [c_char_p]
+    XOpenDisplay.restype = POINTER(EGLNativeDisplayType)
+
+    return XOpenDisplay(None)
+
+
+# Hack. PyOpenGL doesn't seem to manage to find glEGLImageTargetTexture2DOES.
+def getglEGLImageTargetTexture2DOES():
+    funcptr = eglGetProcAddress('glEGLImageTargetTexture2DOES')
+    prototype = CFUNCTYPE(None, _cs.GLenum, _cs.GLeglImageOES)
+    return prototype(funcptr)
+
+
+glEGLImageTargetTexture2DOES = getglEGLImageTargetTexture2DOES()
+
+# \todo This can be dropped when we have proper PixelFormat bindings
+def str_to_fourcc(str):
+    assert(len(str) == 4)
+    fourcc = 0
+    for i, v in enumerate([ord(c) for c in str]):
+        fourcc |= v << (i * 8)
+    return fourcc
+
+
+def get_gl_extensions():
+    n = GLint()
+    glGetIntegerv(GL_NUM_EXTENSIONS, n)
+    gl_extensions = []
+    for i in range(n.value):
+        gl_extensions.append(gl.glGetStringi(GL_EXTENSIONS, i).decode())
+    return gl_extensions
+
+
+def check_gl_extensions(required_extensions):
+    extensions = get_gl_extensions()
+
+    if False:
+        print('GL EXTENSIONS: ', ' '.join(extensions))
+
+    for ext in required_extensions:
+        if ext not in extensions:
+            raise Exception(ext + ' missing')
+
+
+def get_egl_extensions(egl_display):
+    return eglQueryString(egl_display, EGL_EXTENSIONS).decode().split(' ')
+
+
+def check_egl_extensions(egl_display, required_extensions):
+    extensions = get_egl_extensions(egl_display)
+
+    if False:
+        print('EGL EXTENSIONS: ', ' '.join(extensions))
+
+    for ext in required_extensions:
+        if ext not in extensions:
+            raise Exception(ext + ' missing')