[FFmpeg-trac] #692(undetermined:new): Audio is not in sync with video, webcam capturing

[FFmpeg]

#692: Audio is not in sync with video, webcam capturing
-------------------------------------+-------------------------------------
             Reporter:  burek        |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:               |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by burek):

 This is also producing the same issue
 {{{
 ffmpeg \
         -f video4linux2 -r 25 -s vga -i /dev/video0 \
         -f alsa -ar 44100 -ac 1 -i front:CARD=U0x46d0x809,DEV=0 \
         -f mpegts udp://burek:10001

 }}}
 And now, I guess, you will say don't use udp, try to save to a file, so
 here it is:

 {{{
 ffmpeg \
         -f video4linux2 -r 25 -s vga -i /dev/video0 \
         -f alsa -ar 44100 -ac 1 -i front:CARD=U0x46d0x809,DEV=0 \
         out.ts
 }}}


 {{{
 root at bla:~# ffmpeg -f video4linux2 -r 25 -s vga -i /dev/video0 -f alsa -ar
 44100 -ac 1 -i front:CARD=U0x46d0x809,DEV=0 out.ts
 ffmpeg version N-35149-g3880b45, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Nov 25 2011 02:16:49 with gcc 4.6.2
   configuration: --enable-static --enable-shared --enable-gpl --enable-
 nonfree --enable-postproc --enable-libx264 --enable-libaacplus --enable-
 libmp3lame --e
 nable-libv4l2 --enable-libvo-aacenc --enable-version3
   libavutil    51. 28. 0 / 51. 28. 0
   libavcodec   53. 37. 0 / 53. 37. 0
   libavformat  53. 21. 0 / 53. 21. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 49. 0 /  2. 49. 0
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 [video4linux2,v4l2 @ 0xf46a20] Estimating duration from bitrate, this may
 be inaccurate
 Input #0, video4linux2,v4l2, from '/dev/video0':
   Duration: N/A, start: 136.366416, bitrate: 92160 kb/s
     Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 640x480,
 92160 kb/s, 25 tbr, 1000k tbn, 25 tbc
 [alsa @ 0xf47a00] Estimating duration from bitrate, this may be inaccurate
 Input #1, alsa, from 'front:CARD=U0x46d0x809,DEV=0':
   Duration: N/A, start: 1322479771.473944, bitrate: N/A
     Stream #1:0: Audio: pcm_s16le, 48000 Hz, 1 channels, s16, 768 kb/s
 [buffer @ 0xf48ee0] w:640 h:480 pixfmt:yuv420p tb:1/1000000 sar:0/1
 sws_param:
 [mpegts @ 0xf49040] muxrate VBR, pcr every 2 pkts, sdt every 200, pat/pmt
 every 40 pkts
 Output #0, mpegts, to 'out.ts':
   Metadata:
     encoder         : Lavf53.21.0
     Stream #0:0: Video: mpeg2video, yuv420p, 640x480, q=2-31, 200 kb/s,
 90k tbn, 25 tbc
     Stream #0:1: Audio: mp2, 48000 Hz, 1 channels, s16, 128 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (rawvideo -> mpeg2video)
   Stream #1:0 -> #0:1 (pcm_s16le -> mp2)
 Press [q] to stop, [?] for help
 frame=  264 fps= 26 q=9.7 Lsize=     712kB time=00:00:10.15 bitrate=
 574.5kbits/s dup=111 drop=0
 video:468kB audio:159kB global headers:0kB muxing overhead 13.596405%
 }}}
 The problem still exists.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/692#comment:6>
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