Highlights & Features:

• Smarter thread defaults based on the user's CPU for better performance
• Faster thumbnails with lower-resolution decoding for quicker preview generation
• Better FFmpeg support across FFmpeg 4.4, 6, and 8
• Audio crash fix when applying channel mappings concurrently
• Cleaner thumbnails with cropped preview images and no black bars

libopenshot Changelog (Version: 0.7.0, SO: 30)

• b9b5c882 2026-04-02 Jonathan Thomas Bumping version to 0.7.0, SO 30 (minimum libopenshot-audio has not changed) HEAD, origin/release-20260402
• 6152b2a9 2026-04-02 Jonathan Thomas Merge branch 'develop' into optimize-preview origin/optimize-preview
• 51a2d7c2 2026-03-30 Jonathan Thomas Merge pull request #1052 from OpenShot/omp-ffmpeg-thread-control origin/develop
• 6c67d762 2026-03-30 Jonathan Thomas Adding new MaxDecodeSize functionality to ReaderBase, which allows FFmpegReader and QtImageReaders to inspect and thumbnail clips much faster, and no longer be forced to do that a full resolution. Also refactoring CreateReader() inside Clip() constructor, so it can be called outside of the constructor, for example, when needing to create a reader for inspection or thumbnailing in openshot-qt.
• f64d56bc 2026-03-28 Jonathan Thomas Fixing bad assumption in Settings unit test which was failing on Windows builders now.
• 7abc3510 2026-03-28 Jonathan Thomas Fixing build failures on Benchmark args test
• bca37e04 2026-03-28 Jonathan Thomas - Default OMP/FF threads now come from the machine CPU count, with a minimum of 2. - Defaults exposed via DefaultOMPThreads() and DefaultFFThreads(). - User overrides are clamped to 2 .. 3x CPU count. - openshot-benchmark now supports --omp-threads and --ff-threads. - Tests cover the new settings and benchmark arg behavior.
• e63a3837 2026-03-28 Jonathan Thomas Merge pull request #1051 from OpenShot/fix-audio-crash
• 70166b81 2026-03-28 Jonathan Thomas Prevent crash with concurrent change_mapping. We need a mutex for protection when applying mappers to clips.
• 8b90d8af 2026-03-28 Jonathan Thomas Merge pull request #1050 from OpenShot/improved-zoom-resize
• 9f85ec41 2026-03-27 Jonathan Thomas Adding a new override (scale_mode) to thumbnail function, so we can crop thumbnails with no black bars for a more consistent look.
• d8d577bf 2026-03-26 Jonathan Thomas Merge pull request #1049 from OpenShot/vulkan-benchmark
• f31010b7 2026-03-26 Jonathan Thomas Fixing some Codacy nitpicks in the vulkan benchmark code
• 0c37eadc 2026-03-26 Jonathan Thomas Pipeline VulkanDirect benchmark by submitting GPU work before decoding next frame
• 31ae3613 2026-03-26 Jonathan Thomas Merge pull request #1048 from OpenShot/safe-clip-memory
• ed12e252 2026-03-25 Jonathan Thomas Fixing some Codacy nitpicks in our Vulkan benchmark code
• 51eba65c 2026-03-25 Jonathan Thomas Fixing deadlocks on RTX and cuda and fixing cmake to allow for better vulkan detection. Performance is not great though on the RTX gpu.
• 1414a4af 2026-03-25 Jonathan Thomas - Added an optional vulkan-benchmark executable without changing normal libopenshot builds. - Built a small benchmark matrix to compare CPU and GPU pipelines on the same video. - Added --row so each path can run by itself for debugging and stable testing. - Switched the benchmark to a more realistic preview-style workload instead of full-size-only transforms. - Added PNG dump support so rows can save sample output frames for visual verification. - The custom Vulkan path now does real preview scaling and alpha overlay, and can stay fully on-GPU for Vulkan decode. - Added runtime detection for VAAPI, CUDA, and Vulkan, so unsupported rows skip cleanly on different systems. - Added CUDA benchmark rows for NVIDIA systems, while keeping VAAPI and Vulkan conditional at runtime.
• 4a024fc3 2026-03-24 Jonathan Thomas Adding comment about disabled clip cache
• 19eee97f 2026-03-24 Jonathan Thomas Fixing unit test related to verifying clip cache, which obviously is disabled now.
• 2c6e1660 2026-03-24 Jonathan Thomas Disabling clip cache, since it's faster on the openshot-benchmark, and the benefits of clip cache don't seem obvious at this point (if caching is slower than not caching)
• 6dfc0c29 2026-03-24 Jonathan Thomas Fix FFmpegReader fallback frame ownership and restore timeline-safe clip compositing
• bad0ee5f 2026-03-24 Jonathan Thomas Slower, but safer memory access to Clip image - to prevent mutations from corrupting cached frame pixels
• d9ca3b5e 2026-03-22 Jonathan Thomas Merge pull request #1047 from OpenShot/ubuntu-1804-sidedata
• 6d1f07c0 2026-03-22 Jonathan Thomas Fixing build error on Ubuntu 18.04, with older version of FFmpeg (wrong signature for av_stream_get_side_data).
• 31aa84ae 2026-03-22 Jonathan Thomas Merge pull request #1046 from OpenShot/empty-keyframes
• 503bbcb7 2026-03-22 Jonathan Thomas Protect core clip keyframes from being empty after loading from JSON (scale_x/y, location_x/y, origin_x/y, shear_x/y, rotation)
• 77932332 2026-03-22 Jonathan Thomas Merge pull request #1045 from OpenShot/ffmpeg-8
• c1b56f7d 2026-03-21 Jonathan Thomas Fixing some FFmpeg 8 build and runtime issues with channel mappings for resampling, that caused audio to be lost when resampled (no audio playback) due to invalid channel layouts.
• 0bbb2fe3 2026-03-21 Jonathan Thomas Fix FFmpegReader side-data compatibility across FFmpeg 4.4, 6, and 8
• 040d2f05 2026-03-21 Jonathan Thomas - Fix FFmpegReader for FFmpeg 8 stream side-data API changes - Replace deprecated codec-context macro usage and clean build warnings
• dcc0d3e5 2026-03-20 Jonathan Thomas Merge pull request #1044 from OpenShot/release-20260316