From 4786b6aae34bf375a37962b3379e24725bb8badb Mon Sep 17 00:00:00 2001 From: David Staessens Date: Tue, 27 Aug 2019 07:40:50 +0000 Subject: [PATCH] media/gpu/test: Update video decoder performance tests usage documentation. This CL updates the video decoder performance tests usage documentation, with a description of the capped performance test recently added to the video_decode_accelerator_perf_tests. TEST=None BUG=953114 Change-Id: Ibbc367b49c62e31a865870004eeaf31044c8acdc Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1638307 Commit-Queue: David Staessens Reviewed-by: Alexandre Courbot Cr-Commit-Position: refs/heads/master@{#690654} --- .../gpu/video_decoder_perf_test_usage.md | 32 ++++++++++++++----- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/docs/media/gpu/video_decoder_perf_test_usage.md b/docs/media/gpu/video_decoder_perf_test_usage.md index be6b64e0198609..b270d7edf936d6 100644 --- a/docs/media/gpu/video_decoder_perf_test_usage.md +++ b/docs/media/gpu/video_decoder_perf_test_usage.md @@ -41,14 +41,30 @@ 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/.txt_. Individual frame decode times can be found in -_perf_metrics/.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. +To measure decoder performance two different test scenarios are used. + +__Uncapped decoder performance:__ In this scenario the specified test video is +decoded from start to finish as fast as possible. This test scenario provides an +estimate of the decoder's maximum performance (e.g. the maximum FPS). + +__Capped decoder performance:__ This scenario simulates a more realistic +environment by decoding a video from start to finish at its actual frame rate, +while simulating real-time rendering. Frames that are not decoded by the time +they should be rendered will be dropped. + +Various performance metrics are collected by these tests: +* FPS: The average number of frames the decoder was able to decode per second. +* Frames Dropped: The number of frames that were dropped during playback, only +relevant for the capped performance test. +* Dropped frame percentage: The percentage of frames dropped, only relevant for +the capped performance test. +* Frame delivery time: The time between subsequent frame deliveries. The average +frame delivery time and 25/50/75 percentiles are calculated. +* Frame decode time: The time between scheduling a frame to be decoded and +getting the decoded frame. This metric provides a measure of the decoder's +latency. The average decode time and 25/50/75 percentiles are calculated. + +All performance metrics are written to _perf_metrics/.json_. ## Command line options Multiple command line arguments can be given to the command: