Fixes#1550 - Docker builds were broken after PR #1535 switched from
vendored GPAC to system GPAC.
Changes:
- Switch from Alpine to Debian Bookworm (Alpine's musl libc has issues
with Rust bindgen's libclang dynamic loading)
- Support three build variants via BUILD_TYPE argument:
- minimal: No OCR support
- ocr (default): Tesseract OCR for bitmap subtitles
- hardsubx: OCR + FFmpeg for burned-in subtitle extraction
- Support dual source modes via USE_LOCAL_SOURCE argument:
- 0 (default): Clone from GitHub (standalone Dockerfile)
- 1: Use local source (faster for developers)
- Add .dockerignore to exclude build artifacts (~2.7GB -> ~900KB context)
- Update README.md with comprehensive build instructions
Tested all three variants successfully:
- minimal: ~130MB image
- ocr: ~215MB image
- hardsubx: ~610MB image
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
GPAC renamed its libraries to `libgpac.so.13` causing image build to fail:
```
Error: building at STEP "COPY --from=builder /usr/local/lib/libgpac.so.12 /usr/local/lib/": checking on sources under "/home/pszemus/.local/share/containers/storage/overlay/faa4f2b5c39251a5cf42a97234d2d5652336a2388c96a64d85fc1922c4c43a71/merged": copier: stat: "/usr/local/lib/libgpac.so.12": no such file or directory
```
so let's fix the gpac version to the latest release (2.4.0)
* [FIX] Corrected bitness check for 64-bit systems
* Improve Dockerfile: cleanup, parallel build, and remove redundancies
- Replaced cd with WORKDIR for clarity and Docker best practices.
- Removed unused LIB_CLANG_PATH export, as it only affected a single build layer; the library is automatically detected during build.
- Parallelized the GPAC build using make -j$(nproc).
- Removed redundant CMD instruction, as ENTRYPOINT already defines the container's execution command.
* [DOCS] Update CHANGES.TXT for Dockerfile improvements
---------
Co-authored-by: AhmedYasserrr <ahmdyasrj@gamil.com>
