635188 - Flash video is excessively dropping frames.

Status: RESOLVED INCOMPLETE

(Core Graveyard :: Plug-ins, defect)

Description

[Simon Howes]

User-Agent:       Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b12pre) Gecko/20110217 Firefox/4.0b12pre
Build Identifier: 

Carried over from bug 591687.

Flash video is dropping frames — while video is running and no user input, but really becomes excessive when data is streaming (loading), switching tab/window or opening a context menu.

To test for now, let's all use http://www.youtube.com/watch?v=XSGBVzeBUbk right click over the video, and choose "show video info".

I'm having 100-200 frames drop a minute with a 360p video when no user input in Minefield, Safari 4-5 frames dropped which only appear at initial load or switching between windowed and fullscreen.

Reproducible: Always

Comment 1

[chiklit]

At 360p I'm only seeing 8 frames dropped after a minute with the latest nightly and Flash 10.2.152.26. And all of those happened within the first second or so of opening the video.

At 1080p I'm seeing about 170 frames dropped after the first minute. This seems to be because while the video is loading Flash and Firefox are maxing out my CPU and leaving little left for video processing, once the video has finished loading CPU usage goes down significantly. I've also included the results doing the same thing in Safari as a reference.

At 1080p while loading (with movie playing):
Firefox - 65-75% CPU
Plugin container - 90-100% CPU

Safari - 45-50% CPU
Plugin container - 90-100% CPU

At 1080p while loading (with movie paused):
Firefox - 35-40% CPU
Plugin container - 80-90% CPU

Safari - 35-45% CPU
Plugin container - 25-30% CPU

Once loading is complete (movie playing):
Firefox - 18-20% CPU
Plugin container - 75-80% CPU

Safari - 3-4% CPU
Plugin container - 75-80% CPU

Comment 2

[Michael]

I'm getting dropped frames and corrupted video...

Comment 3

[Benoit Girard (:BenWa)]

Can you copy and attach the information from: about:support ? 

What kind of corrupted video are you seeing?

Comment 4

[u279076]

Attachment: Screenshot: Dropped Frames

I'm seeing 155 frames dropped after 1 minute of playback on Firefox 4.0rc1 on Mac OSX 10.6.6.

Comment 5

[u279076]

Attachment: about:support info

Here is my about:support info

Comment 6

[Simon Howes]

Attachment: Embedded YouTube video with Stage Video enabled

I have made an embedded video with Adobe's Stage Video enabled.

Comment 7

[dan]

I'm seeing upwards of 900 frames dropped after 2 minutes. What's up here? 

FF 9.0.1/ Mac OSX 10.6.8

Graphics
Adapter Description 0x21a00,0x20400
WebGL RendererATI Technologies Inc. -- ATI Radeon HD 2600 OpenGL Engine -- 2.1 ATI-1.6.36
GPU Accelerated Windows 2/2 OpenGL

Comment 8

[dan]

Attachment: Another screenshot showing > 900 dropped frames over 2min

Comment 9

[dan]

My bad. Firebug was causing the ridiculous amount of dropped frames. With Firebug disabled, I still get ~30 dropped frames per minute.

Comment 10

[Wayne Mery (:wsmwk)]

Simon, you had several other performance issues in the time frame this was reported. Do you still see this? (ahughes also)

Comment 11

[Emanuel Hoogeveen [:ehoogeveen]]

What chiklit reported in comment #1 is basically the same as what I found on my laptop in bug 870650, and I think the situation actually got worse due to Flash's new sandbox process (which causes even more inter-process churn).

My personal hypothesis is that it's a consequence of the way Flash, or perhaps Youtube's player, downloads and processes new data. If it's processing in a tight loop instead of limiting the throughput somehow, I can see how my laptop might have trouble keeping up with my 30 Mbps connection (especially with the data being exchanged between Firefox's main process, the plugin-container process and Flash's sandbox process).

I don't know if this is the same problem as what Simon was reporting, though.

Comment 12

[u279076]

No I can't reproduce this anymore but I suspect the original circumstances of this bug are largely irrelevant now. Flash, Firefox, OSX, and Youtube are all very different than they were in 2011. That's not to say the bug is irrelevant but a lot has changed since then.

Emanuel I don't think your bug report is the same issue as what was reported here over 2 years ago.

This bug should probably just be resolved INCOMPLETE and a new one filed if a modern reproducible use case can be identified.