feat: Add GStreamer video recorder with comprehensive sample application

- Implements GstVideoRecorderOperator for encoding video streams to file
- Adds RAII GStreamer wrapper classes (Buffer, Caps, Memory, etc.)
- Supports zero-copy tensor-to-buffer conversion for host/CUDA memory
- Auto-detects video parameters, encoders, parsers, and muxers
- Includes comprehensive sample app with animated test patterns
- Provides flexible CLI with encoder properties and format support
- Handles H.264/H.265 encoding with MP4/MKV container formats

Author: GilShpr

.devcontainer/devcontainer.json

@@ -33,6 +33,7 @@
     },
     "runArgs": [
         "--net=host",
+        "--runtime=nvidia"
         //"<env>"
     ],
     "containerEnv": {

applications/CMakeLists.txt

@@ -56,6 +56,8 @@ add_holohub_application(endoscopy_tool_tracking DEPENDS
                                   yuan_qcap
                                   vtk_renderer)
 
+add_subdirectory(gstreamer)
+
 add_subdirectory(h264)
 
 add_holohub_application(isaac_sim_holoscan_bridge)

applications/gstreamer/CMakeLists.txt

@@ -0,0 +1,17 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+add_holohub_application(gst_video_recorder)
+

applications/gstreamer/gst_video_recorder/CMakeLists.txt

@@ -0,0 +1,34 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+project(gst_video_recorder CXX)
+
+find_package(holoscan REQUIRED CONFIG
+             PATHS "/opt/nvidia/holoscan" "/workspace/holoscan-sdk/install")
+
+add_executable(gst-video-recorder
+  gst_video_recorder.cpp
+)
+
+target_link_libraries(gst-video-recorder
+  PRIVATE
+  holoscan::core
+  holoscan_gstreamer_bridge
+)
+
+# Install target
+install(TARGETS gst-video-recorder DESTINATION bin/gst_video_recorder)
+
+

applications/gstreamer/gst_video_recorder/Dockerfile

@@ -0,0 +1,99 @@
+# syntax=docker/dockerfile:1
+
+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+ARG GPU_TYPE
+ARG BASE_SDK_VERSION
+ARG BASE_IMAGE=nvcr.io/nvidia/clara-holoscan/holoscan:v${BASE_SDK_VERSION}-${GPU_TYPE}
+FROM ${BASE_IMAGE} AS base
+
+ARG DEBIAN_FRONTEND=noninteractive
+ARG CMAKE_BUILD_TYPE=Release
+
+# --------------------------------------------------------------------------
+#
+# Set up prerequisites to run HoloHub CLI
+#
+# --------------------------------------------------------------------------
+FROM base AS holohub-cli-prerequisites
+
+# Install python3 if not present (needed for holohub CLI)
+ARG PYTHON_VERSION=python3
+RUN if ! command -v python3 >/dev/null 2>&1; then \
+        apt-get update \
+        && apt-get install --no-install-recommends -y \
+            software-properties-common curl gpg-agent \
+        && add-apt-repository ppa:deadsnakes/ppa \
+        && apt-get update \
+        && apt-get install --no-install-recommends -y \
+            ${PYTHON_VERSION} \
+        && apt purge -y \
+            python3-pip \
+            software-properties-common \
+        && apt-get autoremove --purge -y \
+        && rm -rf /var/lib/apt/lists/* \
+        && update-alternatives --install /usr/bin/python python /usr/bin/${PYTHON_VERSION} 100 \
+        && if [ "${PYTHON_VERSION}" != "python3" ]; then \
+            update-alternatives --install /usr/bin/python3 python3 /usr/bin/${PYTHON_VERSION} 100 \
+            ; fi \
+    ; fi
+ENV PIP_BREAK_SYSTEM_PACKAGES=1
+RUN if ! python3 -m pip --version >/dev/null 2>&1; then \
+        curl -sS https://bootstrap.pypa.io/get-pip.py | ${PYTHON_VERSION} \
+    ; fi
+
+# --------------------------------------------------------------------------
+#
+# Set up GStreamer-specific dependencies for gst_video_recorder
+#
+# --------------------------------------------------------------------------
+FROM holohub-cli-prerequisites AS holohub-cli
+
+RUN mkdir -p /tmp/scripts
+COPY holohub /tmp/scripts/
+RUN mkdir -p /tmp/scripts/utilities
+COPY utilities /tmp/scripts/utilities/
+RUN chmod +x /tmp/scripts/holohub
+RUN /tmp/scripts/holohub setup && rm -rf /var/lib/apt/lists/*
+
+# Install GStreamer development packages and pkg-config
+RUN apt-get update \
+    && apt-get install --no-install-recommends -y \
+        pkg-config \
+        libgstreamer1.0-dev \
+        libgstreamer-plugins-base1.0-dev \
+        libgstreamer-plugins-bad1.0-dev \
+        gstreamer1.0-plugins-base \
+        gstreamer1.0-plugins-bad \
+        gstreamer1.0-plugins-good \
+        gstreamer1.0-plugins-ugly \
+        gstreamer1.0-libav \
+    && apt-get autoremove -y \
+    && apt-get clean -y \
+    && rm -rf /var/lib/apt/lists/*
+
+# Enable autocomplete
+RUN echo ". /etc/bash_completion.d/holohub_autocomplete" >> /etc/bash.bashrc
+
+# Set default Holohub data directory
+ENV HOLOSCAN_INPUT_PATH=/workspace/holohub/data
+
+# --------------------------------------------------------------------------
+#
+# Default development stage for GStreamer applications
+#
+# --------------------------------------------------------------------------
+FROM holohub-cli AS holohub-dev

applications/gstreamer/gst_video_recorder/README.md

@@ -0,0 +1,181 @@
+# GStreamer Video Recorder
+
+A Holoscan application that demonstrates video recording using the GStreamer encoding pipeline.
+
+## Description
+
+This application showcases how to:
+- Generate video frames in Holoscan using the pattern generator
+- Feed video frames to GStreamer for encoding
+- Record encoded video to files in various formats (MP4, MKV)
+- Use different video codecs (H.264, H.265, and other GStreamer-supported codecs)
+- Support both host and CUDA device memory for zero-copy operation
+
+## Requirements
+
+- NVIDIA Holoscan SDK
+- GStreamer 1.0 with the following plugins:
+  - gstreamer1.0-plugins-base (videoconvert for host memory support)
+  - gstreamer1.0-plugins-bad (cudaconvert, nvh264enc, nvh265enc for NVIDIA hardware encoding)
+  - gstreamer1.0-plugins-good (mp4mux, matroskamux for container formats)
+  - gstreamer1.0-plugins-ugly (x264enc for CPU-based H.264 encoding)
+  - Additional codecs available through gstreamer1.0-libav if needed
+
+## Building
+
+### Option 1: Containerized Build (Recommended)
+No setup required - all dependencies are included in the container:
+
+```bash
+./holohub build gst_video_recorder
+```
+
+### Option 2: Local Build
+For faster builds and easier debugging. First install dependencies:
+
+```bash
+# From the gst_video_recorder directory
+./install_deps.sh
+
+# Then build locally
+./holohub build --local gst_video_recorder
+```
+
+The `install_deps.sh` script installs:
+- pkg-config (required for CMake)
+- GStreamer development libraries
+- All necessary GStreamer plugins for encoding
+
+## Usage
+
+```bash
+gst-video-recorder [OPTIONS]
+```
+
+### Options
+
+- `-o, --output <filename>` - Output video filename (default: output.mp4)
+  - Supported formats: .mp4, .mkv
+  - If no extension, defaults to .mp4
+- `-e, --encoder <name>` - Encoder base name (default: nvh264)
+  - Examples: nvh264, nvh265, x264, x265
+  - Note: 'enc' suffix is automatically appended
+- `-c, --count <number>` - Number of frames to generate (default: unlimited)
+- `-w, --width <pixels>` - Frame width (default: 1920)
+- `-h, --height <pixels>` - Frame height (default: 1080)
+- `-f, --framerate <rate>` - Frame rate as fraction or decimal (default: 30/1)
+  - Examples: '30/1', '30000/1001', '29.97', '60'
+  - Use '0/1' for live mode (no throttling, real-time timestamps)
+- `--pattern <type>` - Pattern type (default: 0)
+  - 0 = animated gradient
+  - 1 = animated checkerboard
+  - 2 = color bars (SMPTE style)
+- `--storage <type>` - Memory storage type (default: 1)
+  - 0 = host memory
+  - 1 = device/CUDA memory
+- `--property <key=value>` - Set encoder property (can be used multiple times)
+  - Examples: --property bitrate=8000 --property preset=1
+  - Property types are automatically detected and converted
+- `--help` - Show help message
+
+### Examples
+
+#### Record 10 seconds of video at 30fps (300 frames)
+
+```bash
+gst-video-recorder --count 300 -o video.mp4
+```
+
+#### Record high quality H.265 video
+
+```bash
+gst-video-recorder --count 300 --encoder nvh265 --property bitrate=10000 -o video.mp4
+```
+
+#### Record 720p video
+
+```bash
+gst-video-recorder --count 300 --width 1280 --height 720 -o video_720p.mp4
+```
+
+#### Record using host memory (CPU)
+
+```bash
+gst-video-recorder --count 300 --storage 0 --encoder x264 -o video.mp4
+```
+
+#### Record with H.265 to MKV container
+
+```bash
+gst-video-recorder --count 300 --encoder nvh265 -o video.mkv
+```
+
+#### Record animated checkerboard pattern
+
+```bash
+gst-video-recorder --count 300 --pattern 1 -o checkerboard.mp4
+```
+
+#### Record with custom encoder properties
+
+```bash
+gst-video-recorder --count 300 --property bitrate=8000 --property preset=1 --property gop-size=30 -o custom.mp4
+```
+
+#### Record with NTSC framerate (29.97 fps)
+
+```bash
+gst-video-recorder --count 300 --framerate 30000/1001 -o ntsc.mp4
+```
+
+## Architecture
+
+The application consists of two main components:
+
+1. **PatternGenOperator**: Generates animated test patterns as Holoscan entities with tensors
+2. **GstVideoRecorderOperator**: Receives video frames, manages the GStreamer pipeline, and handles encoding
+
+### Pipeline Flow
+
+```
+PatternGenOperator → GstVideoRecorderOperator → GStreamer Encoding Pipeline → File
+```
+
+The GStreamer encoding pipeline is automatically constructed based on the encoder and file format:
+
+- **Pipeline structure**: `[converter] ! [encoder]enc ! [parser] ! [muxer] ! filesink`
+- **Converter**: Automatically selected based on memory type (videoconvert for host, cudaconvert for device)
+- **Encoder**: Specified via `--encoder` option (nvh264, nvh265, x264, x265, etc.)
+- **Parser**: Automatically determined from encoder (h264parse, h265parse, etc.)
+- **Muxer**: Automatically determined from file extension (mp4mux for .mp4, matroskamux for .mkv)
+
+Example pipelines:
+
+- **NVIDIA H.264 to MP4**: `cudaconvert ! nvh264enc ! h264parse ! mp4mux ! filesink`
+- **NVIDIA H.265 to MKV**: `cudaconvert ! nvh265enc ! h265parse ! matroskamux ! filesink`
+- **CPU x264 to MP4**: `videoconvert ! x264enc ! h264parse ! mp4mux ! filesink`
+
+## Performance
+
+The application supports both host and device (CUDA) memory:
+
+- **Device memory** (`--storage 1`, default): Zero-copy operation for better performance when using NVIDIA hardware encoders (nvh264enc, nvh265enc)
+- **Host memory** (`--storage 0`): Required for CPU encoders (x264, x265) but involves memory copies
+
+## Notes
+
+- The pattern generator supports three test patterns:
+  - Animated gradient (default): Colorful sine wave patterns
+  - Animated checkerboard: Moving checkerboard with variable square size
+  - Color bars: SMPTE-style color bars (7 colors)
+- To use your own video source, replace `PatternGenOperator` with your video capture operator
+- The application waits for encoding to complete before exiting to ensure proper file finalization
+- EOS (End-Of-Stream) signal is sent automatically when recording completes
+- Video parameters (width, height, format, storage) are automatically detected from incoming frames
+
+## See Also
+
+- `holopattern_to_gst` - Similar application that can output to any GStreamer pipeline
+- GStreamer documentation: https://gstreamer.freedesktop.org/documentation/
+
+