# gstreamer-python

**Repository Path**: pande1/gstreamer-python

## Basic Information

- **Project Name**: gstreamer-python
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2024-04-07
- **Last Updated**: 2024-04-07

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

## gstreamer-python
### Purpose
- abstraction over [PyGOBJECT API](https://lazka.github.io/pgi-docs/) for Gstreamer
- work with Gstreamer metadata
- common tools for Gstreamer pipeline management
- easy [gst-python](https://github.com/GStreamer/gst-python) installation

### Install
#### Install OS packages
- [How to install Gstreamer on Ubuntu](http://lifestyletransfer.com/how-to-install-gstreamer-on-ubuntu/)
- [How to install Gstreamer Python Bindings](http://lifestyletransfer.com/how-to-install-gstreamer-python-bindings/)

#### in-place
```bash
python3 -m venv venv

source venv/bin/activate
pip install --upgrade wheel pip setuptools
pip install --upgrade --requirement requirements.txt

./build-3rd-party.sh
./build-gst-python.sh
```

#### pip-package
```bash

pip install git+https://github.com/jackersson/gstreamer-python.git@{tag_name}#egg=gstreamer-python

### to skip ./build-gst-python.sh
pip install . -v --install-option "build_py" --install-option "--skip-gst-python"

### to set specific gstreamer version
export GST_VERSION=1.14.5
```
### Test
```bash
PYTHONPATH=. pytest tests/ -s --verbose
```

### Tools

#### Setup
- By default Gstreamer tools use **libgstreamer-1.0.so.0**
```bash
export LIB_GSTREAMER_PATH=libgstreamer-1.0.so.0
```
Export **LIB_GSTREAMER_PATH** with custom path to **libgstreamer.so**

##### Setup Log Level
```bash
export GST_PYTHON_LOG_LEVEL=0, 1, 2, 3, 4, 5
```

#### [Make Gst.Buffer writable](http://lifestyletransfer.com/how-to-make-gstreamer-buffer-writable-in-python/)
    from gstreamer import map_gst_buffer
    with map_gst_buffer(pbuffer, Gst.MapFlags.READ | Gst.MapFlags.WRITE) as mapped:
                // do_something with mapped

#### Make Gst.Memory writable
    from gstreamer import map_gst_memory
    with map_gst_memory(memory, Gst.MapFlags.READ | Gst.MapFlags.WRITE) as mapped:
                // do_something with mapped

#### Get Gst.Buffer shape (width,height) from Gst.Caps
    from gstreamer import get_buffer_size
    ret, (width, height) = get_buffer_size(Gst.Caps)

#### Convert Gst.Buffer to np.ndarray
    from gstreamer import gst_buffer_to_ndarray, gst_buffer_with_pad_to_ndarray

    array = gst_buffer_to_ndarray(Gst.Buffer, width, height, channels)
    # or
    array = gst_buffer_with_pad_to_ndarray(Gst.Buffer, Gst.Pad, channels)

### GstPipeline
- With **GstPipeline** run any **gst-launch** pipeline in Python
```bash
from gstreamer import GstPipeline

command = "videotestsrc num-buffers=100 ! fakesink sync=false"
with GstPipeline(command) as pipeline:
    ...
```


#### GstVideoSource based on AppSink
- With **GstVideoSource** run any **gst-launch** pipeline and receive buffers in Python
```bash
from gstreamer import GstVideoSource

width, height, num_buffers = 1920, 1080, 100
caps_filter = 'capsfilter caps=video/x-raw,format=RGB,width={},height={}'.format(width, height)
command = 'videotestsrc num-buffers={} ! {} ! appsink emit-signals=True sync=false'.format(
num_buffers, caps_filter)
with GstVideoSource(command) as pipeline:
    buffers = []
    while len(buffers) < num_buffers:
        buffer = pipeline.pop()
        if buffer:
            buffers.append(buffer)
    print('Got: {} buffers'.format(len(buffers)))
```

#### GstVideoSink based on AppSrc
- With **GstVideoSink** push buffers in Python to any **gst-launch** pipeline
```bash
from gstreamer import GstVideoSink

width, height = 1920, 1080
command = "appsrc emit-signals=True is-live=True ! videoconvert ! fakesink sync=false"
with GstVideoSink(command, width=width, height=height) as pipeline:
    for _ in range(10):
        pipeline.push(buffer=np.random.randint(low=0, high=255, size=(height, width, 3), dtype=np.uint8))
```

### Metadata

#### [Object Info MedataData](https://github.com/jackersson/gstreamer-python/blob/master/gstreamer/gst_objects_info_meta.py)

       x
       y
       width
       height
       confidence
       class_name
       track_id


### Examples
#### Run Gstreamer pipeline in Python using Gst.ElementFactory
```bash
python examples/pipeline_with_factory.py
```

#### Run Gstreamer pipeline in Python using Gst.parse_launch
```bash
python examples/pipeline_with_parse_launch.py -p "videotestsrc num-buffers=100 pattern=1 ! autovideosink"
```

#### Capture frames (np.ndarray) from any Gstreamer pipeline
```bash
PYTHONPATH=. python examples/run_appsink.py -p "videotestsrc num-buffers=100 ! capsfilter caps=video/x-raw,format=RGB,width=640,height=480 ! appsink emit-signals=True"
```

#### Push images (np.ndarray) to any Gstreamer pipeline
```bash
PYTHONPATH=. python examples/run_appsrc.py -p "appsrc emit-signals=True is-live=True caps=video/x-raw,format=RGB,width=640,height=480 ! queue ! videoconvert ! autovideosink"  -n 1000
```