ndistreamer 2.0: reengineered real-time pipeline

.github/workflows/ci.yml

@@ -0,0 +1,54 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+    tags: ["v*"]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  build-and-test:
+    name: ${{ matrix.name }}
+    runs-on: ubuntu-24.04
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: GCC release
+            cxx: g++
+            build_type: Release
+            sanitize: OFF
+          - name: Clang release
+            cxx: clang++
+            build_type: Release
+            sanitize: OFF
+          - name: GCC ASan+UBSan
+            cxx: g++
+            build_type: Debug
+            sanitize: ON
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            cmake ninja-build pkg-config g++ clang libgtest-dev ffmpeg \
+            libavformat-dev libavcodec-dev libavfilter-dev libavdevice-dev \
+            libavutil-dev libswscale-dev libswresample-dev
+
+      - name: Configure
+        run: >
+          cmake -S . -B build -G Ninja
+          -DCMAKE_CXX_COMPILER=${{ matrix.cxx }}
+          -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
+          -DNDISTREAMER_SANITIZE=${{ matrix.sanitize }}
+          -DNDISTREAMER_WERROR=ON
+
+      - name: Build
+        run: cmake --build build
+
+      - name: Test
+        run: ctest --test-dir build --output-on-failure --timeout 120

CHANGELOG.md

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+# Changelog
+
+## 2.0.0
+
+A ground-up rewrite. The goal is unchanged (stream media as an NDI source from Linux), but the
+architecture, timing model and feature set are all new.
+
+### Highlights
+
+- **One pipeline for every decoder.** The three duplicated applications (software, VAAPI, CUDA) are
+  replaced by a single threaded pipeline: demux → decode → process → present. Bounded queues connect
+  the stages and a shared presentation clock drives the output.
+- **Accurate A/V timing.** Frames are sent at their presentation timestamps, and audio is the master
+  clock while it plays. NDI timecodes are derived from media timestamps, so receivers that
+  synchronize on timecode get exact alignment. Variable frame rates, late-starting streams, long
+  pauses and inputs without timestamps are handled.
+- **Graceful overload.** When the machine can't keep up, video sheds work in stages while audio
+  keeps playing. In order: drop late frames, skip processing of late frames, then decode keyframes
+  only. Live sources tolerate clock drift and mid-GOP joins.
+- **Generic hardware decoding.** `-t auto|vaapi|cuda|vdpau|...` accepts any FFmpeg device type.
+  When the device can't handle a stream, that stream falls back to software. GPU frames are
+  downloaded directly into NDI's buffer layout.
+- **Lower CPU use.** Formats NDI accepts natively are passed through instead of always being
+  converted to UYVY as 1.x did. Video is submitted with NDI's asynchronous API, and software
+  decoding now uses multiple threads. For 1080p60 H.264, passthrough cut sender CPU from 66 % of a
+  core (forcing UYVY) to 36 % with software decoding and 22 % with VAAPI.
+- **No NDI SDK needed to build.** The NDI runtime is loaded at start-up from the usual locations,
+  `NDI_RUNTIME_DIR_V6`, or `--ndi-lib`. The previous `/opt/ndi` SDK location is still searched.
+
+### New features
+
+- Seamless looping (`--loop`) with a continuous timeline. MP3 encoder delay and padding are
+  accounted for.
+- Any FFmpeg input: network streams (RTSP, SRT, HLS, ...), capture devices (`-f v4l2`, `x11grab`,
+  `pulse`, ...) and protocol options (`-o key=value`).
+- FFmpeg video filters (`--vf`), including GPU filters on hardware frames.
+- Output pixel format choice (`-p auto|uyvy|nv12|i420|bgra|rgba`).
+- Multichannel audio is preserved and sent as 32-bit float. Optional `--audio-rate` and
+  `--audio-channels`.
+- Stream selection (`--video-stream`, `--audio-stream`, `--no-video`, `--no-audio`), NDI groups
+  (`-g`), and audio-only or video-only inputs.
+- Interlaced content is flagged correctly for NDI.
+- Clean shutdown on Ctrl+C or SIGTERM, levelled logging (`-v`/`-q`), `--stats`, `--version`, and
+  meaningful exit codes.
+
+### Fixes compared to 1.x
+
+- Files without an audio stream no longer crash (the stream-count check was wrong and the code
+  dereferenced a missing audio stream).
+- The NDI frame rate is no longer taken from `codecpar->framerate`, which is often 0/0. It now comes
+  from the container's real frame rate.
+- Decoders are drained at the end of the input, so the last frames are no longer lost.
+- Audio is no longer forced to 16-bit stereo, so no precision or channels are lost.
+- Corrupt packets are skipped instead of stopping the stream.
+- The CPU no longer busy-waits on queues, and a per-frame NV12 allocation and copy is gone.
+- Builds with current FFmpeg: `avcodec_close` was removed upstream.
+
+### Compatibility notes
+
+- The command line is backward compatible: `-i`, `-s` and `-t software|vaapi|cuda` still work.
+- Debug builds no longer produce a separately named `ndistreamer_debug` binary.
+- Requires FFmpeg 6.0 or newer and a C++20 compiler (GCC 13+, Clang 17+).
+
+### Development
+
+- 85 automated tests, including whole-pipeline tests against a fake `libndi.so`. These check
+  pacing, A/V alignment, loop continuity and frame lifetime. Tests also verify the NDI ABI against
+  the official SDK headers and stream end to end to a real NDI receiver when the SDK is available.
+- CI on Ubuntu 24.04 (FFmpeg 6.1) with GCC, Clang, and ASan/UBSan.

CMakeLists.txt

@@ -1,58 +1,102 @@
+cmake_minimum_required(VERSION 3.20)
 
-cmake_minimum_required(VERSION 3.14)
-project(NDIStreamer)
+project(ndistreamer
+    VERSION 2.0.0
+    DESCRIPTION "Stream any media file, network stream or capture device as an NDI source"
+    HOMEPAGE_URL "https://github.com/lowlevelmetal/ndi-streamer"
+    LANGUAGES CXX)
 
-# C++ Standard
-set(CMAKE_CXX_STANDARD 20)  # Or 20 for C++20
-set(CMAKE_CXX_STANDARD_REQUIRED True)  # Ensure the compiler respects the version
-set(CMAKE_CXX_EXTENSIONS OFF)  # Disable compiler-specific extensions like gnu++17
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+    set(CMAKE_BUILD_TYPE Release CACHE STRING "Build type" FORCE)
+endif()
 
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
-set(CMAKE_EXPORT_COMPILE_COMMANDS "ON")
-
-message(STATUS "CMAKE_MODULE_PATH: ${CMAKE_MODULE_PATH}")
-
-# Set debug flags
-set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g -D_DEBUG")
-
-# Find NDI SDK
-find_package(NDISDK REQUIRED)
-
-# Find FFMPEG
-find_package(FFMPEG REQUIRED)
-
-# Include NDI SDK headers
-include_directories(${NDI_INCLUDE_DIR} ${FFMPEG_INCLUDE_DIRS})
-
-# Define sources
-set(SOURCES
-    src/averror.cpp
-    src/demuxer.cpp
-    src/decoder.cpp
-    src/audioresampler.cpp
-    src/ndi.cpp
-    src/frametimer.cpp
-    src/frame.cpp
-    src/asyncndisource.cpp
-    src/softwareapp.cpp
-    src/vaapiapp.cpp
-    src/cudaapp.cpp
-    src/simplefilter.cpp
-    src/ndistreamer.cpp
-    src/cudadecoder.cpp
-    src/vaapidecoder.cpp)
-
-# Set executable name
-if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-    add_executable(ndistreamer_debug ${SOURCES})
-    target_link_libraries(ndistreamer_debug ${NDI_LIB} ${FFMPEG_LIBRARIES})
-else()
-    add_executable(ndistreamer ${SOURCES})
-    target_link_libraries(ndistreamer ${NDI_LIB} ${FFMPEG_LIBRARIES})
+
+option(NDISTREAMER_BUILD_TESTS "Build the test suite (requires GoogleTest)" ${PROJECT_IS_TOP_LEVEL})
+option(NDISTREAMER_SANITIZE "Build with AddressSanitizer and UndefinedBehaviorSanitizer" OFF)
+option(NDISTREAMER_WERROR "Treat compiler warnings as errors" OFF)
+set(NDI_SDK_DIR "" CACHE PATH
+    "Optional NDI SDK root. Not needed to build; enables ABI verification and end-to-end tests")
+
+# Dependencies ---------------------------------------------------------------
+
+find_package(PkgConfig REQUIRED)
+# FFmpeg 6.0 or newer.
+pkg_check_modules(FFMPEG REQUIRED IMPORTED_TARGET
+    libavformat>=60
+    libavcodec>=60
+    libavfilter>=9
+    libavdevice>=60
+    libavutil>=58
+    libswscale>=7
+    libswresample>=4)
+find_package(Threads REQUIRED)
+
+# Newer FFmpeg lets filter sources carry color properties.
+include(CheckCXXSourceCompiles)
+set(CMAKE_REQUIRED_INCLUDES ${FFMPEG_INCLUDE_DIRS})
+check_cxx_source_compiles([[
+    #include <cstdint>
+    extern "C" {
+    #include <libavfilter/buffersrc.h>
+    }
+    int main() { AVBufferSrcParameters p{}; p.color_space = AVCOL_SPC_BT709; p.color_range = AVCOL_RANGE_MPEG; return 0; }
+]] NDISTREAMER_HAVE_BUFFERSRC_COLOR)
+unset(CMAKE_REQUIRED_INCLUDES)
+
+# Compiler settings ----------------------------------------------------------
+
+add_library(ndistreamer_warnings INTERFACE)
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+    target_compile_options(ndistreamer_warnings INTERFACE -Wall -Wextra -Wpedantic -Wshadow -Wnon-virtual-dtor
+        $<$<BOOL:${NDISTREAMER_WERROR}>:-Werror>)
 endif()
 
-# Enable testing
-enable_testing()
+if(NDISTREAMER_SANITIZE)
+    add_compile_options(-fsanitize=address,undefined -fno-omit-frame-pointer -fno-sanitize-recover=undefined)
+    add_link_options(-fsanitize=address,undefined)
+endif()
+
+# Targets --------------------------------------------------------------------
+
+configure_file(src/version.hpp.in ${CMAKE_CURRENT_BINARY_DIR}/generated/version.hpp @ONLY)
+
+add_library(ndistreamer_core STATIC
+    src/av/audio_processor.cpp
+    src/av/decoder.cpp
+    src/av/ffmpeg.cpp
+    src/av/input.cpp
+    src/av/video_processor.cpp
+    src/frames.cpp
+    src/ndi/runtime.cpp
+    src/ndi/sender.cpp
+    src/options.cpp
+    src/streamer.cpp
+    src/util/clock.cpp
+    src/util/log.cpp)
+target_include_directories(ndistreamer_core PUBLIC
+    ${CMAKE_CURRENT_SOURCE_DIR}/src
+    ${CMAKE_CURRENT_BINARY_DIR}/generated)
+target_link_libraries(ndistreamer_core
+    PUBLIC PkgConfig::FFMPEG Threads::Threads ${CMAKE_DL_LIBS}
+    PRIVATE ndistreamer_warnings)
+target_compile_definitions(ndistreamer_core PRIVATE
+    $<$<BOOL:${NDISTREAMER_HAVE_BUFFERSRC_COLOR}>:NDISTREAMER_HAVE_BUFFERSRC_COLOR>)
 
-# Add tests directory
-add_subdirectory(tests)
+add_executable(ndistreamer src/main.cpp)
+target_link_libraries(ndistreamer PRIVATE ndistreamer_core ndistreamer_warnings)
+
+include(GNUInstallDirs)
+install(TARGETS ndistreamer RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+
+# Tests ----------------------------------------------------------------------
+
+if(NDISTREAMER_BUILD_TESTS)
+    enable_testing()
+    add_subdirectory(tests)
+endif()