AirPlay video playback causes MythFrontend to segfault

[Mark Canup <markcanup@…>]

I am running Mythbuntu 12.04 with MythTV v0.25.1-49-g65913e7. I am attempting to playing video from an iPhone 4 with iOS 5.1.1 (9B206) on Verizon.

I have MYTHTV_AIRPLAY set and can play video fine through AirPlay if initiated from the YouTube app. However, when I attempt to play a video I recorded from my "Camera Roll" in the Photos app, it causes MythTV to segfault. Near as I can tell this is related to not being able to decode QuickTime/MOV files but I haven't been able to find any documentation on how to enable that, and it seems like it shouldn't cause a segfault regardless.

To recreate the issue, I start /usr/bin/mythfrontend from the command line (with "export MYTHTV_AIRPLAY=1" already set in my .profile). I leave MythTV on the main menu. Then, on my iPhone, I go to "Camera Roll" and select a video to play. I can see my MythTV system as an output location from my iPhone, and choose it. The iPhone says it is playing through AirPlay, but the MythTV frontend hangs and eventually crashes after about 10 seconds.

I'm attaching three files (1) the console output from when I was running mythfrontend until the segfault occurred, (2) the log in /var/log/mythtv/mythfrontend.log for the same time period, which is similar but not exactly the same, and (3) the output of mythfrontend --version.

[Mark Canup <markcanup@…>]

I also noticed the following in dmesg:

[ 672.751310] mythfrontend.re[3047]: segfault at 128c ip 00007f02cec2ff17 sp 00007fff2d0ccfa8 error 4 in libmythtv-0.25.so.0.25.0[7f02ce7a5000+944000]

[beirdo]

Please attach the full backtrace of the coredump created. (as in thread apply all bt full)

[JYA]

no further info provided, and it works fine for me

[mike@…]

GDB output with backtrace

[mike@…]

AirPlay on MythTV cannot play this file

[mike@…]

MythTV will crash if this file is played after playing sample.3gp

[mike@…]

I've attached three files:

mythfrontend_gdb.log.zip: This is the output from GDB from startup to the crash with a backtrace. I'm running Mythbuntu and just updated 8/18/2012 7am EDT. Version information is in the log. The backtrace has whatever symbol information is provided in the binary from the Mythbuntu distribution.

sample.3gp: After startup, I attempted to play this file through AirPlay first. It didn't crash, but it failed to play. The frontend's log shows repeated attempts to play it.

sample_sorenson.mov: Attempting to play this file after sample.3gp results in the crash.

Note that other types of video files play fine. Please let me know if you need more information.

[JYA]

Provide a backtrace using master/0.26

This code is no longer relevant in 0.26

[mike@…]

Are no more fixes going into version 0.25?

[JYA]

No

[mike@…]

Then my work is done here.

[kalifg@…]

I have the same exact problem using 0.26 on a 12.04 Mythbuntu system (upgraded to latest mythfrontend in the PPA).

[JYA]

Then provide a backtrace and logs.

[kalifg@…]

Crashes immediately

[kalifg@…]

Pauses then crashes

[kalifg@…]

There seem to be three different failure modes, all with the same file.

1. Sometimes the frontend doesn't log any connection at all
2. Sometimes the frontend crashes immediately
3. Sometimes the frontend pauses before crashing. This one at least logs some info about not having the proper decoder.

I have attached the logs of running mythfrontend.real from startup to segfault for 2 & 3. The file I am using is 174MB; if it would be helpful I can try to create a file small enough to upload that still triggers the segfault.

Please let me know if there's any other information I can provide. I really appreciate your work.

[JYA]

did you install the debugging symbols? the backtrace is very incomplete..