capturing mpeg2 DVB-T stream in F15/16 creates stream with floating audio

[belegdol+mplayer@…]

This was originally reported into RPM fusion bugzilla:
​https://bugzilla.rpmfusion.org/show_bug.cgi?id=2068

According to the report it is a regression between 20100703 and 20110816:

"I was using F14 to capture mpeg2 DVB-T stream using mencoder without problems.
After upgrade to F15 the captured mpg file has audio completely out of sync. I
tried that also on F16 and it is the same. I was not able to find a constant
delay in audio, it just looks like it is floating randomly when I play the
video with mplayer or vlc.

mencoder -ovc copy -oac copy -endpos 00:01:00 -vf harddup -of mpeg -mpegopts
format=dvd:tsaf -o test.mpg ​http://stream:8080

The stream from ​http://stream:8080 is perfectly playable directly with both
mplayer and vlc."

I have asked the user to re-test with latest SVN using internal ffmpeg, and the problem is still there - so the packaging issue seems unlikely:

"With the DVBT stream it is still the same. The only difference is it prints
whole time it is capturing a message about duplicate frames.

I'll try to get other stream to test this against, but the DVBT stream can be
directly played with mplayer or vlc without complains.

Beside that I found (and it is not new to this version) the mencoder will stuck
when Ctrl+C is pressed during capture... but it is different bug.

Here is the output:
libavformat version 54.2.100 (internal)
TS file format detected.
VIDEO MPEG2(pid=101) AUDIO MPA(pid=111) SUB Teletext(pid=121) PROGRAM N. 513
Stream not seekable!
VIDEO: MPEG2 720x576 (aspect 2) 25.000 fps 15000.0 kbps (1875.0 kbyte/s)
[V] filefmt:29 fourcc:0x10000002 size:720x576 fps:25.000 ftime:=0.0400
==========================================================================
Opening audio decoder: [mpg123] MPEG 1.0/2.0/2.5 layers I, II, III
AUDIO: 48000 Hz, 2 ch, s16le, 192.0 kbit/12.50% (ratio: 24000->192000)
Selected audio codec: [mpg123] afm: mpg123 (MPEG 1.0/2.0/2.5 layers I, II, III)
==========================================================================
PACKET SIZE: 2048 bytes, deltascr: 43885
videocodec: framecopy (720x576 24bpp fourcc=10000002)
audiocodec: framecopy (format=50 chans=2 rate=48000 bits=16 B/s=24000 sample-1)
Limiting audio preload to 0.4s.
Increasing audio density to 4.
Writing header...
INITV: 0.200, 0.160, fps: 25.000
Pos: 0.8s 22f ( 0%) 18.90fps Trem: 0min 0mb A-V:-0.084 [0:192]

1 duplicate frame(s)!
Pos: 1.3s 32f ( 0%) 18.22fps Trem: 0min 0mb A-V:-0.084 [3867:192]
..."