Would /tests/examples/pylon/howto_decode_meta.py be filled?

[Dueta]

Currently the file howto_decode_meta.py and gstpylonmeta.py are both empty. I'm trying to fetch FrameCounter from gst buf meta and here's my probe placing between 'jpegenc' and 'multifilesink'

def on_buffer_probe(self, pad, info, camera_index):
        buf = info.get_buffer()
        if buf:
            meta = pygstpylon.gst_buffer_get_pylon_meta(hash(buf))
            if meta:
                frame_count = meta.chunks.get("FrameCounter")
                if frame_count is not None:
                    print(f"Camera {camera_index} Frame Counter: {frame_count}")
                else:
                    print('no count!')
            else:
                print('no meta!')
        else:
            print('no buf!')
        return Gst.PadProbeReturn.OK

It seems that cannot fetch meta from pygstpylon.gst_buffer_get_pylon_meta(hash(buf)) and printing 'no meta' in terminal. Appreciate for any suggestion!

[thiesmoeller]

here is some sample code:

import gi
gi.require_version('Gst', '1.0')
gi.require_version('GstVideo', '1.0')  # Import GstVideo
from gi.repository import Gst, GObject, GstVideo

import pygstpylon

# Initialize GStreamer
Gst.init(None)

# Define the probe function
def probe_callback(pad, info):
    # Get the buffer from the probe info
    buffer = info.get_buffer()

    if buffer:
        # Print buffer metadata
        print("Buffer Metadata:")

        # Get buffer duration
        duration = buffer.duration
        print(f"  Duration: {duration} nanoseconds")

        # Get buffer size
        size = buffer.get_size()
        print(f"  Size: {size} bytes")

        # Print any additional metadata (e.g., timestamps)
        pts = buffer.pts
        dts = buffer.dts
        print(f"  PTS: {pts} nanoseconds")
        print(f"  DTS: {dts} nanoseconds")

        # Access GstVideoMeta
        video_meta = GstVideo.buffer_get_video_meta(buffer)
        if video_meta:
            print("GstVideoMeta:")
            print(f"  Width: {video_meta.width}")
            print(f"  Height: {video_meta.height}")
            print(f"  Format: {video_meta.format}")
            print(f"  Number of Planes: {video_meta.n_planes}")
            print(f"  Stride: {video_meta.stride}")
            print(f"  Offsets: {video_meta.offset}")

        # Extract Pylon chunk data (if available)
        pylon_meta = pygstpylon.gst_buffer_get_pylon_meta(hash(buffer))
        if pylon_meta:
            print("Pylon Chunk Metadata:")
            print(f"   BlockID: {pylon_meta.block_id}")
            print(f"   Image Number: {pylon_meta.image_number}")
            print(f"   Offset X: {pylon_meta.offset_x}")
            print(f"   Offset Y: {pylon_meta.offset_y}")
            print(f"   Skipped Images: {pylon_meta.skipped_images}")
            print(f"   Stride: {pylon_meta.stride}")
            print(f"   Timestamp: {pylon_meta.timestamp}")
            print(f"   Chunks: {pylon_meta.chunks}")

    return Gst.PadProbeReturn.OK

# Create the GStreamer elements
pylon_source = Gst.ElementFactory.make('pylonsrc', 'source')
fake_sink = Gst.ElementFactory.make('fakesink', 'sink')

# Check if elements were created successfully
if not pylon_source or not fake_sink:
    print("Not all elements could be created.")
    exit(-1)

# Create an empty pipeline
pipeline = Gst.Pipeline.new('test-pipeline')

# Add elements to the pipeline
pipeline.add(pylon_source)
pipeline.add(fake_sink)

# Link the elements
pylon_source.link(fake_sink)

# Add a probe to the source pad of the pylonsrc element
src_pad = pylon_source.get_static_pad('src')
if src_pad:
    src_pad.add_probe(Gst.PadProbeType.BUFFER, probe_callback)

# Start the pipeline
pipeline.set_state(Gst.State.PLAYING)

# Wait for a while to allow the pipeline to process
try:
    # Run the pipeline for a certain period (e.g., 10 seconds)
    GObject.MainLoop().run()
except KeyboardInterrupt:
    pass

# Stop the pipeline
pipeline.set_state(Gst.State.NULL)