Opened 8 years ago

Closed 8 years ago

Last modified 8 years ago

#9755 closed Bug Report - General (fixed)

segfault when using time stretch with passthrough

Reported by: mybobmy@… Owned by:
Priority: minor Milestone: 0.25
Component: MythTV - General Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no

Description (last modified by sphery)

I am seeing an immediate crash as soon as I enable time stretch with passthrough enabled. I was not seeing this on a build from 3/26. Have not had a chance to try reverting the recent patches for fixing passthrough with time stretch to see if those are the cause.

Am attaching my attempt at a backtrace. Hopefully it got what was needed. Please let me know if you need anything else.

mythfrontend[8981] trap divide error ip:7f0b7c874935 sp:7f0b41a3a730 error:0 in libmyth-0.24.so.0.24.0[7f0b7c7e3000+444000]

Attachments (1)

crash.txt (172.4 KB) - added by anonymous 8 years ago.
gdb log

Download all attachments as: .zip

Change History (7)

Changed 8 years ago by anonymous

Attachment: crash.txt added

gdb log

comment:1 Changed 8 years ago by JYA

Can you provide the full output for playback with -v audio thanks.

And what version of master are you running?

comment:2 in reply to:  1 Changed 8 years ago by mybobmy@…

Replying to jyavenard:

Time stretch might have been a red herring on this. It is more likely related to creating the AC3 stream. I have a similar problem if I enable upconverting to 5.1 with a stereo recording.

As for version, I'm dense when it comes to GIT. 'svn info' is so simple... Best answer I've found is either :

git rev-parse HEAD: 8ed63e5222e81e711945815154eeec8a0dead83d OR

git describe: v0.25pre-1866-g8ed63e5

There were no audio patches between when I built and when I posted the bug.

2011-04-30 00:43:24.901 Using protocol version 65
2011-04-30 00:43:41.647 Pulse: PulseAudio not running
2011-04-30 00:43:41.654 ALSA: OpenDevice iec958:CARD=SB,DEV=0
2011-04-30 00:43:41.655 AO: Sample rate 44100 is supported
2011-04-30 00:43:41.655 AO: Sample rate 48000 is supported
2011-04-30 00:43:41.655 AO: Sample rate 88200 is supported
2011-04-30 00:43:41.655 AO: Sample rate 96000 is supported
2011-04-30 00:43:41.656 AO: Sample rate 192000 is supported
2011-04-30 00:43:41.656 AO: 2 channel(s) are supported
2011-04-30 00:43:41.667 AO: may be AC3 or DTS capable
2011-04-30 00:43:41.667 AO: 6 channel(s) are supported
2011-04-30 00:43:41.669 AudioPlayer: Enabling Audio
2011-04-30 00:43:41.797 AFD: Audio Track #1 is A/V stream #1 and has 6 channels in the English language(6647399).
2011-04-30 00:43:41.798 AFD: Selected track 1: English AC3 5.1ch (A/V Stream #1)
2011-04-30 00:43:41.798 AFD: Initializing audio parms from audio track #1
2011-04-30 00:43:41.798 AFD: Audio format changed 
			from id(NONE)     -1Hz -1ch -1bps     (profile 0) to id( AC3)  48000Hz  6ch 16bps  pt (profile 0)
2011-04-30 00:43:41.798 AO: Setting AC3 passthrough
2011-04-30 00:43:41.800 SPDIFEncoder: Creating spdif encoder (for AC3)
2011-04-30 00:43:41.800 AO: Killing AudioOutputDSP
2011-04-30 00:43:41.801 AO: Original codec was AC3, signed 16 bit, 48 kHz, 6 channels
2011-04-30 00:43:41.801 AO: enc(0), passthru(1), features (AC3,DTS) configured_channels(6), 6 channels supported(1)
2011-04-30 00:43:41.801 ALSA: OpenDevice iec958:CARD=SB,DEV=0,AES0=6,AES1=0x82,AES2=0x00,AES3=0x01 for passthrough
2011-04-30 00:43:41.802 ALSA: SetParameters(format=2, channels=2, rate=48000, buffer_time=500000, period_time=16)
2011-04-30 00:43:41.802 ALSA: Buffer size range from 64 to 1048576
2011-04-30 00:43:41.802 ALSA: Period size range from 32 to 524288
2011-04-30 00:43:41.802 ALSA: Buffer time = 500000 us
2011-04-30 00:43:41.803 ALSA: Period time = 15 periods
2011-04-30 00:43:41.813 ALSA: Buffer size = 24000 | Period size = 1600
2011-04-30 00:43:41.833 AO: Audio fragment size: 3200
2011-04-30 00:43:41.833 AO: Audio Stretch Factor: 1
2011-04-30 00:43:41.834 AO: Ending Reconfigure()
2011-04-30 00:43:41.834 AO: kickoffOutputAudioLoop: pid = 16597
2011-04-30 00:43:41.834 AO: OutputAudioLoop: Play Event
2011-04-30 00:43:42.413 Player(0): Forcing decode extra audio option on (Video method requires it).
2011-04-30 00:43:42.451 Player(0): Video sync method can't support double framerate (refresh rate too low for 2x deint)
2011-04-30 00:43:42.460 AO: OutputAudioLoop: Play Event
2011-04-30 00:43:48.579 AO: Pause 0
2011-04-30 00:43:48.582 AFD: Disabling pass through
2011-04-30 00:43:48.582 AFD: Initializing audio parms from audio track #1
2011-04-30 00:43:48.582 AFD: Audio format changed 
			from id( AC3)  48000Hz  6ch 16bps  pt (profile 0) to id( AC3)  48000Hz  6ch 16bps     (profile 0)
2011-04-30 00:43:48.582 AO: Killing AudioOutputDSP
2011-04-30 00:43:48.583 AO: OutputAudioLoop: Stop Event
2011-04-30 00:43:48.583 AO: kickoffOutputAudioLoop exiting
2011-04-30 00:43:48.584 AO: Original codec was AC3, signed 16 bit, 48 kHz, 6 channels
2011-04-30 00:43:48.584 AO: enc(1), passthru(0), features (AC3,DTS) configured_channels(6), 6 channels supported(1)
2011-04-30 00:43:48.584 AO: Reencoding decoded AC-3/DTS to AC-3
2011-04-30 00:43:48.584 AO: Creating AC-3 Encoder with sr = 48000, ch = 6
2011-04-30 00:43:48.584 DEnc: Init codecid=AC3, br=448000, sr=48000, ch=6
2011-04-30 00:43:48.586 DigitalEncoder::Init fs=0, bpf=12 ofb=0
2011-04-30 00:43:48.586 ALSA: OpenDevice iec958:CARD=SB,DEV=0,AES0=6,AES1=0x82,AES2=0x00,AES3=0x01 for passthrough
2011-04-30 00:43:48.587 ALSA: SetParameters(format=2, channels=2, rate=48000, buffer_time=500000, period_time=16)
2011-04-30 00:43:48.588 ALSA: Buffer size range from 64 to 1048576
2011-04-30 00:43:48.588 ALSA: Period size range from 32 to 524288
2011-04-30 00:43:48.588 ALSA: Buffer time = 500000 us
2011-04-30 00:43:48.588 ALSA: Period time = 15 periods
2011-04-30 00:43:48.613 ALSA: Buffer size = 24000 | Period size = 1600
2011-04-30 00:43:48.643 AO: Audio fragment size: 3200
2011-04-30 00:43:48.643 AO: Audio Stretch Factor: 1
2011-04-30 00:43:48.644 AO: Ending Reconfigure()
2011-04-30 00:43:48.644 AO: kickoffOutputAudioLoop: pid = 16597
2011-04-30 00:43:48.644 AO: OutputAudioLoop: Play Event

comment:3 Changed 8 years ago by JYA

Allright. The issue was introduced with the new ffmpeg re-sync. SHA:a63b62a34a3f67c0b33296ba804b594e6ff09ba5

the AC3 encoder is broken since

comment:4 Changed 8 years ago by Github

Milestone: unknown0.25
Resolution: fixed
Status: newclosed

Update AC3 encoder following ffmpeg resync.

AC3 encoder by default now use float ; use the older fixed S16 one. To do: check if working with float is any faster as most of the time will be already working internally with floats.

Fixes #9755.

Changeset: 5e94e9a445ab4d32895825039f319de0b9904cf7

comment:5 Changed 8 years ago by mybobmy@…

That fixed the issue. Thanks.

comment:6 Changed 8 years ago by sphery

Description: modified (diff)
version_output: Please attach all output as a file in bug reports. MythTV Version : v0.25pre-1866-g8ed63e5-dirty MythTV Branch : master Network Protocol : 65 Library API : 0.25.20110425-2 QT Version : 4.6.2 Options compiled in: linux release use_hidesyms using_alsa using_oss using_pulse using_pulseoutput using_backend using_bindings_perl using_bindings_python using_bindings_php using_directfb using_dvb using_firewire using_frontend using_hdhomerun using_hdpvr using_iptv using_ivtv using_joystick_menu using_libxml2 using_lirc using_mheg using_opengl_video using_qtdbus using_qtwebkit using_v4l using_x11 using_xrandr using_xv using_bindings_perl using_bindings_python using_bindings_php using_mythtranscode using_opengl using_vdpau using_ffmpeg_threads using_live using_mheg using_libxml2
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