Using the Video Encode Accelerator Unittests Manually

The VEAtest (or video_encode_accelerator_unittest) is a set of unit tests that embeds the Chrome video encoding stack without requiring the whole browser, meaning they can work in a headless environment. It includes a variety of tests to validate the encoding stack with h264, vp8 and vp9.

Running this test manually can be very useful when bringing up a new codec, or in order to make sure that new code does not break hardware encoding. This document is a walk though the prerequisites for running this program, as well as the most common options.


The required kernel drivers should be loaded, and there should exist a /dev/video-enc0 symbolic link pointing to the encoder device node (e.g. /dev/video-enc0/dev/video0).

The unittests can be built by specifying the video_encode_accelerator_unittest target to ninja. If you are building for an ARM board that is not yet supported by the simplechrome workflow, use arm-generic as the board. It should work across all ARM targets.

For unlisted Intel boards, any other Intel target (preferably with the same chipset) should be usable with libva. AMD targets can use amd64-generic.

Basic VEA usage

The VEA test takes raw YUV files in I420 format as input and produces e.g. an H.264 Annex-B byte stream. Sample raw YUV files can be found at the following locations:

It is recommended to rename these files after downloading them to e.g. crowd1080.yuv and bear-320x180.yuv.

The VEA can then be tested as follows:

./video_encode_accelerator_unittest --single-process-tests --disable_flush --gtest_filter=SimpleEncode/VideoEncodeAcceleratorTest.TestSimpleEncode/0 --test_stream_data=bear-320x180.yuv:320:180:1:bear.mp4:100000:30

for the bear file, and

./video_encode_accelerator_unittest --single-process-tests --disable_flush --gtest_filter=SimpleEncode/VideoEncodeAcceleratorTest.TestSimpleEncode/0 --test_stream_data=crowd1080.yuv:1920:1080:1:crowd.mp4:4000000:30

for the larger crowd file. These commands will put the encoded output into bear.mp4 and crowd.mp4 respectively. They can then be copied on the host and played with mplayer -fps 25.

Test filtering options

./video_encode_accelerator_unittest --help will list all valid options.

The list of available tests can be retrieved using the --gtest_list_tests option.

By default, all tests are run, which can be a bit too much, especially when bringing up a new codec. The --gtest_filter option can be used to specify a pattern of test names to run.

Verbosity options

The --vmodule options allows to specify a set of source files that should be more verbose about what they are doing. For basic usage, a useful set of vmodule options could be:


Source code

The VEAtest's source code can be consulted here:

V4L2 support:

VAAPI support: