#615: ALSA buffer xrun
--------------------------------------+---------------------------------
Reporter: burek | Owner: michael
Type: defect | Status: new
Priority: normal | Component: FFmpeg
Version: git-master | Keywords:
Blocked By: | Blocking:
Reproduced by developer: 0 | Analyzed by developer: 0
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when grabbing video+audio from usb webcam, this error always appear, no
matter what output muxer format is chosen: "ALSA buffer xrun"
i've tried with .avi, .ts, .flv, .mkv, and all give the similar output:
{{{
ffmpeg -y -re \
-f video4linux2 -r 30 -s qvga -i /dev/v4l/by-id/usb-
046d_0809_33A881A3-video-index0 \
-f alsa -ar 44100 -ac 2 -i default:CARD=Intel \
out.flv
ffmpeg version N-34519-g54a09f1, Copyright (c) 2000-2011 the FFmpeg
developers
built on Nov 6 2011 12:46:05 with gcc 4.6.1
configuration: --enable-static --enable-shared --enable-gpl --enable-
nonfree --enable-postproc --enable-libx264 --enable-libaacplus --enable-
libmp3lame --enable-libv4l2 --enable-libvo-aacenc --enable-version3
libavutil 51. 23. 0 / 51. 23. 0
libavcodec 53. 28. 0 / 53. 28. 0
libavformat 53. 19. 0 / 53. 19. 0
libavdevice 53. 4. 0 / 53. 4. 0
libavfilter 2. 47. 0 / 2. 47. 0
libswscale 2. 1. 0 / 2. 1. 0
libpostproc 51. 2. 0 / 51. 2. 0
[video4linux2,v4l2 @ 0x2247980] Estimating duration from bitrate, this may
be inaccurate
Input #0, video4linux2,v4l2, from '/dev/v4l/by-id/usb-046d_0809_33A881A3
-video-index0':
Duration: N/A, start: 27263.653187, bitrate: 27648 kb/s
Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 320x240,
27648 kb/s, 30 tbr, 1000k tbn, 30 tbc
[alsa @ 0x2242040] Estimating duration from bitrate, this may be
inaccurate
Input #1, alsa, from 'default:CARD=Intel':
Duration: N/A, start: 1320593764.890759, bitrate: N/A
Stream #1:0: Audio: pcm_s16le, 44100 Hz, 2 channels, s16, 1411 kb/s
[buffer @ 0x2297f20] w:320 h:240 pixfmt:yuv420p tb:1/1000000 sar:0/1
sws_param:
Output #0, flv, to 'out.flv':
Metadata:
encoder : Lavf53.19.0
Stream #0:0: Video: flv1 ([2][0][0][0] / 0x0002), yuv420p, 320x240,
q=2-31, 200 kb/s, 1k tbn, 30 tbc
Stream #0:1: Audio: mp3 ([2][0][0][0] / 0x0002), 44100 Hz, 2 channels,
s16, 128 kb/s
Stream mapping:
Stream #0.0 -> #0.0 (rawvideo -> flv)
Stream #1.0 -> #0.1 (pcm_s16le -> libmp3lame)
Press [q] to stop, [?] for help
[alsa @ 0x2242040] ALSA buffer xrun.
ALSA buffer xrun. 6 q=2.6 size= 34kB time=00:00:01.48 bitrate=
185.4kbits/s
ALSA buffer xrun. 8 q=2.6 size= 103kB time=00:00:03.52 bitrate=
240.2kbits/s
frame= 78 fps= 8 q=2.8 Lsize= 252kB time=00:00:04.91 bitrate=
421.2kbits/s
video:171kB audio:77kB global headers:0kB muxing overhead 1.801323%
root@strumf:~/videos/tests/mpegts# ^C
}}}
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/615>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker
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