libva-dump/README

# libva-dump

libva-dump allows dumping metadata and slices from videos.

## Usage

To get started with libva-dump, a video player that supports VAAPI is required,
such as VLC. Specific environment variables need to be set in order to use and
configure the backend:
* LIBVA_DRIVER_NAME: the libVA backend to use, must be set to "dump"
* DUMP_COUNT: the number of frames to dump (defaults to 3 if unspecified)

## Example script

An example script that takes the video to dump as first argument follows:
```
#!/bin/sh

export LIBVA_DRIVER_NAME=dump
export DUMP_COUNT=250
vlc "$1" > frames.h
```

## Output

libva-dump will save dumped slices in the current directory, named following the
"slice-%d.dump" format. This can be modified in `src/dump.c` if needed.