Files
ffmpeg-builder/lib/readme.sh
2025-11-28 13:36:24 -06:00

140 lines
6.5 KiB
Bash

#!/usr/bin/env bash
make_bullet_points() {
for arg in "$@"; do
echo "- ${arg}"
done
}
gen_function_info() {
local funcName="$1"
echo "${FB_FUNC_DESCS[${funcName}]} using \`./scripts/${funcName}.sh\`"
}
gen_compile_opts_info() {
for opt in "${FB_COMP_OPTS[@]}"; do
echo "- \`${opt}\`: ${FB_COMP_OPTS_DESC[${opt}]}"
done
}
FB_FUNC_NAMES+=('gen_readme')
FB_FUNC_DESCS['gen_readme']='generate project README.md'
gen_readme() {
local readme="${REPO_DIR}/README.md"
echo "
# ffmpeg-builder
A collection of scripts for building \`ffmpeg\` and encoding content with the built \`ffmpeg\`.
Tested on:
- linux x86_64/aarch64 on:
$(printf ' - %s\n' "${VALID_DOCKER_IMAGES[@]}")
- darwin aarch64
With these scripts you can:
1. $(gen_function_info install_deps)
2. $(gen_function_info build)
3. $(gen_function_info encode)
4. $(gen_function_info efg)
# Building
This project supports multiple ways to build.
## Configuration
Configuration is done through environment variables.
By default, this project will build a static \`ffmpeg\` binary in \`./gitignore/sysroot/bin/ffmpeg\`.
The default enabled libraries included in the \`ffmpeg\` build are:
$(make_bullet_points ${DEFAULT_ENABLE})
The user-overridable compile options are:
$(gen_compile_opts_info)
Examples:
- only build libsvtav1_psy and libopus: \`ENABLE='libsvtav1_psy libopus' ./scripts/build.sh\`
- build shared libraries in custom path: \`PREFIX=/usr/local STATIC=OFF ./scripts/build.sh\`
- build without LTO at O1: \`LTO=OFF OPT=1 ./scripts/build.sh\`
### Native build
Make sure to $(gen_function_info install_deps). Then $(gen_function_info build).
### Docker build
1. choose a given distro from: \`${VALID_DOCKER_IMAGES[*]}\`.
2. $(gen_function_info docker_build_image) \`<distro>\`.
3. $(gen_function_info docker_run_image) \`<distro>\` \`./scripts/build.sh\`
Docker builds support the same configuration options as native builds. For example to build \`ffmpeg\` on ubuntu with only \`libdav1d\` enabled:
\`\`\`bash
./scripts/docker_build_image.sh ubuntu
ENABLE='libdav1d' ./scripts/docker_run_image.sh ubuntu ./scripts/build.sh
\`\`\`
# Encoding scripts
The encoding scripts are designed to be installed to system paths for re-use via symbolic links back to this repo using the \`-I\` flag.
## Encoding with svtav1-psy and opus
\`\`\`bash
$(encode)
\`\`\`
- Uses svtav1-psy for the video encoder.
- Uses libopus for the audio encoder.
- Skips re-encoding av1/opus streams.
- Only maps audio streams that match the video stream language if the video stream has a defined language.
- Only maps english subtitle streams.
- Adds track statistics to the output mkv file and embeds the encoder versions to the output metadata. For example:
\`\`\`
ENCODE : aa4d7e6
FFMPEG : 8.0
LIBOPUS : 1.5.2
LIBSVTAV1_PSY : 3.0.2-B
SVTAV1_PARAMS : film-grain=8:film-grain-denoise=1:tune=0:...
VIDEO_PARAMS : -crf 25 -preset 3 -g 240
\`\`\`
Example usage:
- standard usage: \`encode -i input.mkv output.mkv\`
- print out what will be executed without starting encoding: \`encode -i input.mkv -p\`
- encode with film-grain synthesis value of 20 with denoising: \`encode -g 20 -i input.mkv\`
## Estimate film-grain
\`\`\`bash
$(efg)
\`\`\`
- Provides a way to estimate the ideal film-grain amount by encoding from low-high given values and the step amount.
- Observing the point of diminishing returns, one can make an informed decision for a given film-grain value to choose.
Example usage:
- \`efg -i input.mkv -p\`
\`\`\`
1 +------------------------------------------------------------------------------------------------------+
| *****G***** + + + |
| *****G** '/tmp/plot.dat' ***G*** |
0.95 |-+ ***** +-|
| **G* |
| *** |
| **** |
0.9 |-+ *G* +-|
| **** |
| **** |
0.85 |-+ *G* +-|
| *** |
| **** |
0.8 |-+ *G* +-|
| *** |
| **** |
| *G* |
0.75 |-+ *** +-|
| **** |
| *G* |
0.7 |-+ *** +-|
| ** |
| *** |
| *G* |
0.65 |-+ *** +-|
| **** |
| + + + *|
0.6 +------------------------------------------------------------------------------------------------------+
\`\`\`
" >"${readme}"
}