media/gpu/test: Add documentation about the new video decoder perf tests.
This CL adds documentation for the new video decoder performance tests
(video_decode_accelerator_perf_tests).
TEST=None
BUG=925714
Change-Id: I04a6d5cd348cb05da92b0a4cc44721e3c58ea807
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1563530
Reviewed-by: Alexandre Courbot <[email protected]>
Commit-Queue: David Staessens <[email protected]>
Cr-Commit-Position: refs/heads/master@{#651076}diff --git a/docs/README.md b/docs/README.md
index 41387ed..5e1a56e 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -291,6 +291,8 @@
use the accelerated video decoder/encoder test programs.
* [Video Decoder Tests](media/gpu/video_decoder_test_usage.md) - Running the
new video decoder tests.
+* [Video Decoder Performance Tests](media/gpu/video_decoder_perf_test_usage.md) -
+ Running the new video decoder performance tests.
### Accessibility
* [Accessibility Overview](accessibility/overview.md) - Overview of
diff --git a/docs/media/gpu/video_decoder_perf_test_usage.md b/docs/media/gpu/video_decoder_perf_test_usage.md
new file mode 100644
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@@ -0,0 +1,66 @@
+# Video Decoder performance tests
+The video decoder performance tests are a set of tests used to measure the
+performance of various video decoder implementations. These tests run directly
+on top of the video decoder implementation, and don't require the full Chrome
+browser stack. They are build on top of the
+[GoogleTest](https://github.com/google/googletest/blob/master/README.md)
+framework.
+
+[TOC]
+
+## Running from Tast
+__Note:__ The video decoder performance tests are in the progress of being added
+to the Tast framework. This section will be updated once this is done.
+
+## Running manually
+To run the video decoder performance tests manually the
+_video_decode_accelerator_perf_tests_ target needs to be built and deployed to
+the device being tested. Running the video decoder performance tests can be done
+by executing:
+
+ ./video_decode_accelerator_perf_tests [<video path>] [<video metadata path>]
+
+e.g.: `./video_decode_accelerator_perf_tests test-25fps.h264`
+
+__Test videos:__ Test videos are present for multiple codecs in the
+[_media/test/data_](https://cs.chromium.org/chromium/src/media/test/data/)
+folder in Chromium's source tree (e.g.
+[_test-25fps.vp8_](https://cs.chromium.org/chromium/src/media/test/data/test-25fps.vp8)).
+If no video is specified _test-25fps.h264_ will be used.
+
+__Video Metadata:__ These videos also have an accompanying metadata _.json_ file
+that needs to be deployed alongside the test video. They can also be found in
+the _media/test/data_ folder (e.g.
+[_test-25fps.h264.json_](https://cs.chromium.org/chromium/src/media/test/data/test-25fps.h264.json)).
+If no metadata file is specified _\<video path\>.json_ will be used. The video
+metadata file contains info about the video such as its codec profile,
+dimensions and number of frames.
+
+__Note:__ Various CPU scaling and thermal throttling mechanisms might be active
+on the device (e.g. _scaling_governor_, _intel_pstate_). As these can influence
+test results it's advised to disable them.
+
+## Performance metrics
+Currently uncapped decoder performance is measured by playing the specified test
+video from start to finish. Various performance metrics (e.g. the number of
+frames decoded per second) are collected, and written to a file called
+_perf_metrics/<test_name>.txt_. Individual frame decode times can be found in
+_perf_metrics/<test_name>.frame_times.txt_.
+
+__Note:__ A capped performance test is in the process of being added. This test
+will simulate a more realistic real-time decoding environment.
+
+## Command line options
+Multiple command line arguments can be given to the command:
+
+ -v enable verbose mode, e.g. -v=2.
+ --vmodule enable verbose mode for the specified module,
+ e.g. --vmodule=*media/gpu*=2.
+ --use_vd use the new VD-based video decoders, instead of
+ the default VDA-based video decoders.
+ --gtest_help display the gtest help and exit.
+ --help display this help and exit.
+
+## Source code
+See the video decoder performance tests [source code](https://cs.chromium.org/chromium/src/media/gpu/video_decode_accelerator_perf_tests.cc).
+
