168505 2017-02-17 04:35:31 -0800 [GStreamer] Fast replay on video hide/unhide on platforms with limited video buffer pools 2017-02-17 06:52:21 -0800 1 1 1 Unclassified WebKit Media WebKit Local Build Unspecified Unspecified RESOLVED FIXED P2 Normal --- 1 eocanha eocanha commit-queue oldest_to_newest 1278201 0 eocanha 2017-02-17 04:35:31 -0800 Some platforms have limited video buffer pools. For instance, OMX on Raspberry Pi 2 when using EGL buffers and zero copy. On those platforms, the fact of returning all the video buffers to the pool is critical to avoid stalling the video pipeline waiting for available buffers. When a video is hidden by setting "display: none", a special early return codepath triggering an early return[1] is activated on MediaPlayerGStreamerBase::pushTextureToCompositor(). This causes that the texture in the video sample is never consumed and therefore never released. This causes a stall of the video stream in the aforementioned platforms, as the video pool runs out of buffers. At the same time, the audio stream doesn't suffer from that problem and the audio keeps being decoded and "rendered" at a normal rate. When the video is shown again, the buffers are returned and the decoder tries to catch up, quickly producing all the pending samples and sending them for display to the video sink. As a result, the user sees the video "on fast forward" until the catching up is complete. IMHO, the proper solution would be to consume the video buffer in some way even when the layer is hidden, so it's returned to the pool and the video stream keeps flowing. I haven't been able to reproduce the issue on desktop Linux because the software decoder used on this platform uses the regular allocator, which can provide a virtually unlimited amount of new buffers. There's no buffer pool to exhaust. [1] https://github.com/WebKit/webkit/blob/9fced9a00615b3ee7a5ff82485e92440a1f4d030/Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamerBase.cpp#L677 1278208 1 301915 eocanha 2017-02-17 05:36:38 -0800 Created attachment 301915 Patch 1278240 2 301915 commit-queue 2017-02-17 06:52:18 -0800 Comment on attachment 301915 Patch Clearing flags on attachment: 301915 Committed r212549: <http://trac.webkit.org/changeset/212549> 1278241 3 commit-queue 2017-02-17 06:52:21 -0800 All reviewed patches have been landed. Closing bug. 301915 2017-02-17 05:36:38 -0800 2017-02-17 06:52:18 -0800 Patch bug-168505-20170217133359.patch text/plain 2829 eocanha U3VidmVyc2lvbiBSZXZpc2lvbjogMjEyMjgyCmRpZmYgLS1naXQgYS9Tb3VyY2UvV2ViQ29yZS9D aGFuZ2VMb2cgYi9Tb3VyY2UvV2ViQ29yZS9DaGFuZ2VMb2cKaW5kZXggMjdkZjRkZTdmZjFlOWM2 ODQzNzk5NWExZWEwNmFjODRkODlmYzMxNS4uNGZiYjY3OGM3YjEyYTg5OGQ4MDE1ZWYzNjA0MTg2 NTliOTE3NWI4NyAxMDA2NDQKLS0tIGEvU291cmNlL1dlYkNvcmUvQ2hhbmdlTG9nCisrKyBiL1Nv dXJjZS9XZWJDb3JlL0NoYW5nZUxvZwpAQCAtMSwzICsxLDIzIEBACisyMDE3LTAyLTE3ICBFbnJp cXVlIE9jYcOxYSBHb256w6FsZXogIDxlb2NhbmhhQGlnYWxpYS5jb20+CisKKyAgICAgICAgW0dT dHJlYW1lcl0gRmFzdCByZXBsYXkgb24gdmlkZW8gaGlkZS91bmhpZGUgb24gcGxhdGZvcm1zIHdp dGggbGltaXRlZCB2aWRlbyBidWZmZXIgcG9vbHMKKyAgICAgICAgaHR0cHM6Ly9idWdzLndlYmtp dC5vcmcvc2hvd19idWcuY2dpP2lkPTE2ODUwNQorCisgICAgICAgIFJldmlld2VkIGJ5IE5PQk9E WSAoT09QUyEpLgorCisgICAgICAgIFRoZSBXZWJLaXQgY29kZSBpc24ndCBjb25zdW1pbmcgdGhl IHZpZGVvIHNhbXBsZXMgd2hlbiB0aGUgdmlkZW8gbGF5ZXIgaXMgaGlkZGVuLAorICAgICAgICBz byB0aGUgYnVmZmVycyBhcmVuJ3QgYmVpbmcgcmV0dXJuZWQgdG8gdGhlIHBvb2wgYW5kIHN0YXJ2 ZSB0aGUgZGVjb2RlciB3aGVuIHRoZQorICAgICAgICBidWZmZXIgcG9vbCBydW5zIG91dCBvZiBi dWZmZXJzIChvbiBwbGF0Zm9ybXMgdXNpbmcgYSBidWZmZXIgcG9vbCBhbmQgYSBjdXN0b20KKyAg ICAgICAgYWxsb2NhdG9yLCBzdWNoIGFzIE9NWCBvbiB0aGUgUmFzcGJlcnJ5IFBpIDIpLiBXaGVu IHRoZSB2aWRlbyBsYXllciBpcyByZXN0b3JlZCwKKyAgICAgICAgdGhlIHBpcGVsaW5lIHRyaWVz IHRvIGNhdGNoIHVwIGFuZCB0aGUgdXNlciBzZWVzIHRoZSB2aWRlbyAiZ29pbmcgZmFzdCBmb3J3 YXJkIi4KKworICAgICAgICBUaGUgYWRkZWQgY29kZSAiY29uc3VtZXMiIChyZW1vdmVzIGFuZCB1 bnJlZnMpIHRoZSBidWZmZXIgaW4gdGhhdCBjYXNlLiBIb3dldmVyLAorICAgICAgICB0aGUgc2Ft cGxlIGlzbid0IGNvbXBsZXRlbHkgcmVtb3ZlZCBiZWNhdXNlIGl0IHN0aWxsIGhvbGRzIGltcG9y dGFudCBpbmZvIChlZzoKKyAgICAgICAgY2FwcykgbmVlZGVkIGZvciB0aGUgcHJvcGVyIG9wZXJh dGlvbiBvZiB0aGUgdmlkZW8gZWxlbWVudC4KKworICAgICAgICAqIHBsYXRmb3JtL2dyYXBoaWNz L2dzdHJlYW1lci9NZWRpYVBsYXllclByaXZhdGVHU3RyZWFtZXJCYXNlLmNwcDoKKyAgICAgICAg KFdlYkNvcmU6Ok1lZGlhUGxheWVyUHJpdmF0ZUdTdHJlYW1lckJhc2U6OnB1c2hUZXh0dXJlVG9D b21wb3NpdG9yKToKKwogMjAxNy0wMi0xMyAgQW50b2luZSBRdWludCAgPGdyYW91dHNAYXBwbGUu Y29tPgogCiAgICAgICAgIFJFR1JFU1NJT046IFVwZGF0ZSB2b2x1bWUgYW5kIHNjcnViYmluZyBz bGlkZXIgdG8gbWF0Y2ggSEkgZGVzaWducwpkaWZmIC0tZ2l0IGEvU291cmNlL1dlYkNvcmUvcGxh dGZvcm0vZ3JhcGhpY3MvZ3N0cmVhbWVyL01lZGlhUGxheWVyUHJpdmF0ZUdTdHJlYW1lckJhc2Uu Y3BwIGIvU291cmNlL1dlYkNvcmUvcGxhdGZvcm0vZ3JhcGhpY3MvZ3N0cmVhbWVyL01lZGlhUGxh eWVyUHJpdmF0ZUdTdHJlYW1lckJhc2UuY3BwCmluZGV4IGE3ZWRmODNmYTU4NzBkNjdhMDIyYzFm NzQ4Y2ZhODU1MWEzOTc4MjEuLjdlY2I0ZTg1NTg1M2VlMzI2ZDcwZWM4YWNlZmY1YmZkMzY1MGUx MjQgMTAwNjQ0Ci0tLSBhL1NvdXJjZS9XZWJDb3JlL3BsYXRmb3JtL2dyYXBoaWNzL2dzdHJlYW1l ci9NZWRpYVBsYXllclByaXZhdGVHU3RyZWFtZXJCYXNlLmNwcAorKysgYi9Tb3VyY2UvV2ViQ29y ZS9wbGF0Zm9ybS9ncmFwaGljcy9nc3RyZWFtZXIvTWVkaWFQbGF5ZXJQcml2YXRlR1N0cmVhbWVy QmFzZS5jcHAKQEAgLTY3NCw4ICs2NzQsMTYgQEAgdm9pZCBNZWRpYVBsYXllclByaXZhdGVHU3Ry ZWFtZXJCYXNlOjpwdXNoVGV4dHVyZVRvQ29tcG9zaXRvcigpCiAKICAgICBMb2NrSG9sZGVyIGhv bGRlcihtX3BsYXRmb3JtTGF5ZXJQcm94eS0+bG9jaygpKTsKIAotICAgIGlmICghbV9wbGF0Zm9y bUxheWVyUHJveHktPmlzQWN0aXZlKCkpCisgICAgaWYgKCFtX3BsYXRmb3JtTGF5ZXJQcm94eS0+ aXNBY3RpdmUoKSkgeworICAgICAgICAvLyBDb25zdW1lIHRoZSBidWZmZXIgKHNvIGl0IGdldHMg ZXZlbnR1YWxseSB1bnJlZmZlZCkgYnV0IGtlZXAgdGhlIHJlc3Qgb2YgdGhlIGluZm8uCisgICAg ICAgIGNvbnN0IEdzdFN0cnVjdHVyZSogaW5mbyA9IGdzdF9zYW1wbGVfZ2V0X2luZm8obV9zYW1w bGUuZ2V0KCkpOworICAgICAgICBHc3RTdHJ1Y3R1cmUqIGluZm9Db3B5ID0gbnVsbHB0cjsKKyAg ICAgICAgaWYgKGluZm8pCisgICAgICAgICAgICBpbmZvQ29weSA9IGdzdF9zdHJ1Y3R1cmVfY29w eShpbmZvKTsKKyAgICAgICAgbV9zYW1wbGUgPSBhZG9wdEdSZWYoZ3N0X3NhbXBsZV9uZXcobnVs bHB0ciwgZ3N0X3NhbXBsZV9nZXRfY2FwcyhtX3NhbXBsZS5nZXQoKSksCisgICAgICAgICAgICBn c3Rfc2FtcGxlX2dldF9zZWdtZW50KG1fc2FtcGxlLmdldCgpKSwgaW5mb0NvcHkpKTsKICAgICAg ICAgcmV0dXJuOworICAgIH0KIAogI2lmIFVTRShHU1RSRUFNRVJfR0wpCiAgICAgc3RkOjp1bmlx dWVfcHRyPEdzdFZpZGVvRnJhbWVIb2xkZXI+IGZyYW1lSG9sZGVyID0gc3RkOjptYWtlX3VuaXF1 ZTxHc3RWaWRlb0ZyYW1lSG9sZGVyPihtX3NhbXBsZS5nZXQoKSwgdGV4TWFwRmxhZ0Zyb21Pcmll bnRhdGlvbihtX3ZpZGVvU291cmNlT3JpZW50YXRpb24pKTsK