This is a simple guide to getting the code and encoding a simple video.
- Standard build tools (autoconf, automake v1.11 or later, libtool, and a C compiler)
- libogg (v1.3 or later)
- libcheck (v0.9.8 or later, can be skipped if you pass --disable-unit-tests to ./configure)
- libsdl (can by skipped if you pass --disable-player to ./configure)
Instructions for installing these packages are OS-specific (feel free to contribute some here, especially if you tried installing these somewhere and ran into difficulties; you will likely save other people some pain). If you have a package manager that has separate -dev versions with the public headers, make sure you install those in addition to the actual libraries.
Just run these commands:
git clone https://git.xiph.org/daala.git cd daala ./autogen.sh ./configure make
Make sure you run the git clone operation on the same machine where you intend to use the code. Checking out a copy on Windows and then trying to use it on Linux will not work, as executable permissions and line-endings will not be set properly.
Encoding a Video
If you do not have one, get a sample video or two in .y4m format from media.xiph.org. We also maintain a set of still-image collections in .y4m format:
- Subset 1 (50 images, small training set)
- Subset 2 (1000 images, large training set)
- Subset 3 (50 images, small testing set)
- Subset 4 (1000 images, large testing set)
Encode the video:
./examples/encoder_example -v 30 -k 256 video.y4m -o video.ogv
- video.y4m is the input video you want to encode,
- video.ogv is the name of the encoded video file to output,
- -v specifies the quality (currently from 0 to 511, where 0 is lossless), and
- -k specifies the maximum keyframe interval (this is currently 1 by default, which makes every frame a keyframe).
Decoding a Video
Play the video:
./examples/player_example -p video.ogv
The -p option starts the player paused. Run
for information on the controls available while playing.
If you want to use a different player, you can decode the video back to .y4m with
./examples/dump_video video.ogv -o decoded_video.y4m
Many other players can play back these .y4m files, and other tools can convert them to various other formats.
Using PNG Images
To encode a series of images:
make tools ./tools/png2y4m video%05d.png -o video.y4m
where %05d means your input images are named video00000.png, video00001.png, etc. You can leave out the %05d tag if you only want to convert a single image (which does not need to be numbered).
To convert a y4m back to PNGs:
./tools/y4m2png video.y4m -o video%05d.png
If you are converting a .y4m file that only contains a single frame (e.g., from one of the still-image subsets linked above), you can leave out the %05d tag. Conversion from PNG to Y4M uses the Rec 709 matrix with video levels, a box filter for chroma subsampling, and a triangular dither. Conversion back from Y4M to PNG uses the same matrix, levels, and box filter, but does not dither.