can't seek in swf

[hxuanyu]

I'm building a video player using ffmpeg, when seek to the beginning of a swf file(av_seek_frame to 0), ffmpeg throws lots of FFMPEG: Unknown tag,

and subsequent call of av_read_frame returns false.

the version I use is ffmpeg 1.1.3

and this can be reproduced with ffplay

$ gdb ffplay
GNU gdb (GDB) 7.5.50.20120815-cvs (cygwin-special)
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <​http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-cygwin".
For bug reporting instructions, please see:
<​http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /cygdrive/c/Users/Alex/Downloads/ffmpeg-latest-win32-static/ffmpeg-20130217-git-b8bb661-win32-static/bin/ffplay...(no debugging symbols found)...done.
(gdb) r -ss 0 c:/20051210.swf
Starting program: /cygdrive/c/Users/Alex/Downloads/ffmpeg-latest-win32-static/ffmpeg-20130217-git-b8bb661-win32-static/bin/ffplay -ss 0 c:/20051210.swf
[New Thread 8364.0x27f0]
[New Thread 8364.0x2748]
[New Thread 8364.0x172c]
[New Thread 8364.0x2520]
[New Thread 8364.0x2780]A-V: 0.000 fd= 0 aq= 0KB vq= 0KB sq= 0B f=0/0
[New Thread 8364.0x15c4]
[New Thread 8364.0x23c8]
[New Thread 8364.0x1698]
[New Thread 8364.0x2078]
[New Thread 8364.0x20c4]
[New Thread 8364.0x1c14]
[New Thread 8364.0x1b74]

1.75 A-V: 0.000 fd= 0 aq= 0KB vq= 0KB sq= 0B f=0/0

there's no video playback window pops up

[Carl Eugen Hoyos]

Related to ticket #2496.

For future tickets: Please always test current git head and please only provide ffplay output if a problem is not reproducible with ffmpeg (the application).