Stream ID using Pipeline with Resolution Preservation

General
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1

Hi,

I’m implementing a GStreamer pipeline similar to what is used on the example pipeline with resolution preservation (tappas/docs/pipelines/single_network.rst at 0f4813c7683f388886b9900ceaeeb0c4ec49a3f0 · hailo-ai/tappas · GitHub).
For my app, I need to catch also the stream_id. However, when I use “tee” in the pipeline the stream_id is always empty. If I remove the tee the stream_id appears as an SHA256 code :slight_smile:

There is any solution for that?

The pipeline:

source_element = f"rtspsrc location={self.video_source} name=src  message-forward=true ! "
source_element += "rtph264depay !"
source_element += QUEUE(f"queue_rtsp", max_size_buffers=30)
source_element += "decodebin ! queue leaky=downstream max-size-buffers=5 max-size-bytes=0 max-size-time=0 ! "
source_element += "video/x-raw, format=I420 ! "

source_element += QUEUE("queue_src_convert", max_size_buffers=5)
source_element += f"videoconvert n-threads=3 name=src_convert ! "

pipeline_string = source_element

pipeline_string += "tee name=t hailomuxer name=hmux "

pipeline_string += "t. ! "
pipeline_string += QUEUE("bypass_queue", max_size_buffers=20)
pipeline_string += "hmux.sink_0 "

pipeline_string += "t. ! "
pipeline_string += "videoscale ! "
pipeline_string += QUEUE("queue_hailonet", max_size_buffers=5)
pipeline_string += f"hailonet hef-path={self.hef_path} batch-size=1 {thresholds_str} ! "
pipeline_string += QUEUE("queue_hailofilter", max_size_buffers=5)
pipeline_string += f"hailofilter function-name={self.default_network_name} so-path={self.default_postprocess_so} qos=false ! "
pipeline_string += "queue leaky=no max-size-buffers=30 max-size-bytes=0 max-size-time=0 ! "
pipeline_string += "hailotracker name=hailo_tracker class-id=-1 keep-past-metadata=true kalman-dist-thr=.5 iou-thr=.6 keep-tracked-frames=2 keep-lost-frames=2 ! "

pipeline_string += QUEUE("queue_hmuc")
pipeline_string += "hmux.sink_1 "
pipeline_string += "hmux. ! "

pipeline_string += QUEUE("queue_hailopython", max_size_buffers=5)
pipeline_string += f"hailopython qos=false module={self.options_menu.python_module} ! "
pipeline_string += QUEUE("queue_hailooverlay", max_size_buffers=5)
pipeline_string += f"hailooverlay ! "
pipeline_string += QUEUE("queue_videoconvert", max_size_buffers=5)
pipeline_string += f"videoconvert n-threads=3 ! "
pipeline_string += f"fpsdisplaysink vide

The callback function:

def run(video_frame: VideoFrame):
    stream_id = video_frame.roi.get_stream_id()
    width = video_frame.video_info.width
    height = video_frame.video_info.height
    

    print(stream_id, width, height)

    return Gst.FlowReturn.OK
2

Hey @diulhio

The empty stream_id issue when using the tee element in your GStreamer pipeline might be related to metadata handling. Here’s a potential solution and explanation:

  • Metadata Preservation with Identity Elements

To ensure metadata (including stream_id) is correctly preserved and passed through the pipeline, add identity elements after the tee. Here’s how to modify your pipeline string:

python

pipeline_string += "tee name=t hailomuxer name=hmux "

# First branch
pipeline_string += "t. ! identity name=identity_1 ! "
pipeline_string += QUEUE("bypass_queue", max_size_buffers=20)
pipeline_string += "hmux.sink_0 "

# Second branch
pipeline_string += "t. ! identity name=identity_2 ! "
pipeline_string += "videoscale ! "
pipeline_string += QUEUE("queue_hailonet", max_size_buffers=5)
pipeline_string += f"hailonet hef-path={self.hef_path} batch-size=1 {thresholds_str} ! "
# ... (rest of the pipeline remains unchanged)

Key changes:

  • Added identity name=identity_1 after the first t.
  • Added identity name=identity_2 after the second t.

These identity elements act as passthrough elements that help maintain metadata consistency across pipeline branches. This should address the stream_id preservation issue you’re experiencing.

If you implement this change and still face issues, please provide more details about your specific setup and any error messages you encounter.

1 Like
3

Hi,

 Please search "STREAM_ID_SO" in Hailo-Application-Code-Examples, you will find how to use the stream-id.

BR

2 Likes
4

@omria Unfortunately the addition of the two “identity” didn’t work.

@chrysler.chen That worked like a charm!! I wish I had seen this before, I spent a few hours to understand how GStreamer generate the SHA256 id for RTSP streams, in order to identify multiple streamings data. Thank you very much!

1 Like