Make MSE buffer sizes configurable via command line

media/base/media_switches.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Defines all the "media" command-line switches.
 
 #ifndef MEDIA_BASE_MEDIA_SWITCHES_H_
 #define MEDIA_BASE_MEDIA_SWITCHES_H_
 
 #include "base/feature_list.h"
@@ skipping 49 matching lines @@
 MEDIA_EXPORT extern const char kRequireAudioHardwareForTesting[];
 
 MEDIA_EXPORT extern const char kVideoUnderflowThresholdMs[];
 
 MEDIA_EXPORT extern const char kDisableRTCSmoothnessAlgorithm[];
 
 MEDIA_EXPORT extern const char kEnableVp9InMp4[];
 
 MEDIA_EXPORT extern const char kForceVideoOverlays[];
 
+MEDIA_EXPORT extern const char kMSEAudioBufferSize[];

[wolenetz, 2016/07/28 17:55:08]

IIUC, these need to be propogated from browser to renderer process (e.g., in
https://cs.chromium.org/chromium/src/content/browser/renderer_host/render_pro...).

Have you tested these flags? Can such test be automated?

[servolk, 2016/07/28 21:46:46]

Good point, yeah, I'll add the new flags to that list. I haven't done much
testing on this yet, I first wanted to see if you would be ok with making this
configurable via command-line in the first place.
As for the automated testing - I guess we could append those switches to the
command line, but that will affect all media tests. I'm not sure if that's a
good idea. On the other hand we do already have test coverage for the
DemuxerStream::SetStreamMemoryLimit being invoked through
MediaSourceState::SetMemoryLimits in chunk demuxer, SourceStreamBuffer and
pipeline integration tests, so perhaps that's enough and we don't need to cover
the command line switches specifically. WDYT?

[wolenetz, 2016/07/28 23:02:15]

Let's not do this for all media tests. There is a VirtualTestSuite layout test
functionality which could be used to run a test with a special set of flags and
mark it [ Skip ] in TestExpectations to keep it from running on any but the
intended platform+flag virtual variant. See
https://codereview.chromium.org/1644763002/diff/160001 for an example. (Would
probably require a subfolder under http/tests/media/media-source/ to contain
this specific "test-memory-limit-command-line" test, but seems doable and
valuable to automate.)

[servolk, 2016/07/29 21:03:25]

Ok, yeah, I'll look into adding a virtual test suite-based test.

[servolk, 2016/07/29 23:16:39]

TBH I find the virtual test suites a bit confusing, not sure if I got it right,
so I've uploaded the test changes in a separate CL, so that this one is not
blocked on the test changes (which might take a few more iterations to get
right):
https://codereview.chromium.org/2195933002/

+MEDIA_EXPORT extern const char kMSEVideoBufferSize[];
+
 }  // namespace switches
 
 namespace media {
 
 // All features in alphabetical order. The features should be documented
 // alongside the definition of their values in the .cc file.
 
 #if defined(ENABLE_PLUGINS)
 MEDIA_EXPORT extern const base::Feature kFlashJoinsMediaSession;
 #endif  // defined(ENABLE_PLUGINS)
 
 MEDIA_EXPORT extern const base::Feature kNewAudioRenderingMixingStrategy;
 MEDIA_EXPORT extern const base::Feature kUseNewMediaCache;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MEDIA_SWITCHES_H_