Opened 11 years ago
Last modified 10 years ago
#1476 new defect
rtp pcm_alaw/pcm_mulaw streaming from ALSA
|Reported by:||Spideru||Owned by:|
|Blocking:||Reproduced by developer:||no|
|Analyzed by developer:||no|
- What I was trying to accomplish:
I am trying to stream ALSA audio in (one channel) over RTP, to a VLC server with pcm_alaw/pcm_mulaw format @8ksample/s.
- The problem I encountered:
After few seconds (from 5 to 100, randomly) of correct and audible sound on server (but with wrong stream speed), the program (ffmpeg) exit with "segmentation fault".
- Exact command line:
./ffmpeg -f alsa -ar 8000 -ac 1 -i hw:1,0 -ar 8000 -acodec pcm_alaw -ab 64k -f rtp rtp://127.0.0.1:1234
- Output of ffmpeg -v 9 -loglevel 99 -report:
- Output of debug as described here http://ffmpeg.org/bugreports.html :
- Summary of the bug:
Program exit with segmentation fault
- How to reproduce:
run command and wait few seconds
ffmpeg version N-41796-g1bb30d0
built on Jun 22 2012 10:56:44 with gcc 4.6.3
configuration: --enable-libx264 --enable-gpl
libavutil 51. 59.100 / 51. 59.100
libavcodec 54. 29.100 / 54. 29.100
libavformat 54. 10.100 / 54. 10.100
libavdevice 54. 0.100 / 54. 0.100
libavfilter 2. 82.100 / 2. 82.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
Change History (5)
comment:1 by , 11 years ago
comment:2 by , 11 years ago
I can not reproduce here. Please:
- try to determine what part of the command line are actually relevant for the bug, using successively
-f null, no
-acodec, input from a file rather than ALSA, etc.;
valgrindoutput of the minimal command line.
(It seems that ALSA is returning some unitialized data in the first packet, but that can probably not be related to a segfault in lavfi dozens of seconds later.)
comment:3 by , 11 years ago
I have done several tests, it seems that the problem appears only when using an external mic (USB type).
./ffmpeg -f alsa -ar 8000 -ac 1 -i default -ar 8000 -acodec pcm_alaw -f rtp rtp://127.0.0.1:1234
works perfectly (default is internal mic in)
./ffmpeg -f alsa -ar 8000 -ac 1 -i hw:1,0 -ar 8000 -acodec pcm_alaw -f rtp rtp://127.0.0.1:1234
generates a segmentation fault after a minute (hw:1,0 is external USB mic in).
comment:4 by , 10 years ago
|Component:||FFmpeg → undetermined|
|Keywords:||crash SIGSEGV added|
Is this problem still reproducible with current git head?
comment:5 by , 10 years ago
|Priority:||important → normal|
decreasing priority as clearly a bug that noone can or is willing to try to reproduce in 6month isnt "important"
I'll just copy/paste what's on pastebin, so it doesn't expire some time in the future..