Opened 16 years ago
Closed 15 years ago
#4621 closed patch (fixed)
dropped frames in MPEG4 AVC (H.264) streams due to non monotone dts
| Reported by: | anonymous | Owned by: | Janne Grunau |
|---|---|---|---|
| Priority: | minor | Milestone: | 0.22 |
| Component: | mythtv | Version: | head |
| Severity: | medium | Keywords: | |
| Cc: | Ticket locked: | no |
Description
I was running svn with a patch found on the dev list some time ago that enabled 2 cores on my on my core2 duo. After Changeset 15816 it no longer applies and i guess it would not be needed any more since that changeset allows for 2 or more cores in ffmpeg. I have always been running with "Standard" and XV in my profile and that has been working ok with the attached patch. I have no skills at all when it comes to programming so i can't tell what it does differently. I can get it to play smoothly in latest SVN for a while if i fast forward for a while and then hit play, but after about 20 seconds a NVP buffer Pause appears and it starts to stutter. this never happened with before. Cores are running about 50% each so there is plenty left.
Attachments (3)
Change History (13)
Changed 16 years ago by
| Attachment: | bbchd.diff added |
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comment:1 Changed 16 years ago by
| Owner: | changed from Isaac Richards to Janne Grunau |
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| Status: | new → assigned |
| Type: | defect → patch |
| Version: | unknown → head |
comment:2 Changed 16 years ago by
| Milestone: | unknown → 0.21 |
|---|---|
| Status: | assigned → accepted |
nah, there is unfortunately a problem with the timestamps of h264 frames. Using the dts as we do now in avformatdecoder does unfortunately no longer work. Replacement with calculated pts for the next frame is almost finished. It's a pity that libavcodec's decoder don't set AVFrame.pts.
comment:3 Changed 16 years ago by
I had 2 cores enabled. Let me know if there is anything you want me to provide or test. Would be really nice to get this going again before 0.21 is released. Great job on all the new stuff implemented it works like a charm for me.
Changed 16 years ago by
| Attachment: | mythtv-h264_threading2.patch added |
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Updated BBC HD patch (svn 15826)
comment:4 Changed 16 years ago by
I too was using the patch floating around the list that made BBC HD playback work. I've updated it against svn15826 and can now watch BBC HD again (need to enable 2 cores in mythfrontend now). The patch enables the skip loop filter otherwise my E6600 can't keep up. I guess its not the right fix otherwise it would have been applied previously, but it fixes things for me for now.
Good to see the h264 multi cpu bits being added to myth!!
comment:5 Changed 16 years ago by
| Summary: | 720P50 no longer plays smothly → dropped frames in MPEG4 AVC (H.264) streams due to non monotone dts |
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comment:6 Changed 16 years ago by
(In [15910]) assure strictly monotonic increasing video pts
For some/all h.264 streams our libav* copies report broken dts. Since we used the dts as video pts, non monotone dts causes playback issues resulting in dropped frames. This change calculates the next video pts if it detects non monotonicity. Refs #4621
comment:7 Changed 16 years ago by
| Milestone: | 0.21 → 0.22 |
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comment:8 Changed 16 years ago by
Janne,
Just to confirm that together 15910 and 15816 allow smooth playback of BBC_HD. Only patch still needed to SVN is the skip_loop_filter statement, (unless you have a really monster dual core cpu)
Changed 16 years ago by
| Attachment: | skip_loop_r15913.patch added |
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skip_loop_filter, reduced h264 processor load
comment:9 Changed 16 years ago by
comment:10 Changed 15 years ago by
| Resolution: | → fixed |
|---|---|
| Status: | accepted → closed |
Skip loop filter will be handled in #4653. closing this as fixed since the original problem is fixed.
anonymous probably just needs to enable the use of two cores, but I'm assigning this to Janne as there is a patch attached...