[vlc-devel] vlc wmv start playing time control and key frame position do not tally
zhu shi song
zhushisongzhu at yahoo.com
Sun Jan 15 11:20:19 CET 2012
I have hzvideo.wmv video file, first I use asfbin to see its key frames.
<<<<<<
C:\videotools\asfbin1.8.2.903>asfbin -infokf -i hzvideo.wmv
.....
Parsing file C:\videotools\hzvideo.wmv:
0-100%:.....10.....20.....30.....40.....50.....60.....70.....80.....90.....100
File C:\videotools\hzvideo.wmv key samples:
Video Stream Numbers
Time [ms] HH.MM.SS.MMM 1
0 00:00:00.000 X
10000 00:00:10.000 X
20000 00:00:20.000 X
30000 00:00:30.000 X
>>>>>>>>
From asfbin output info, there is one keyframe for every 10s.
Then I test the video using ffplay, when I set to play from 11s, we can see that it starts playing from 10s(key frame point). Seeking of ffplay is correct. See the following output:
<<<<<<
[root at bogon ~]# ffplay -ss 11 hzvideo.wmv
ffplay version N-34849-g07c7ffc, Copyright (c) 2003-2011 the FFmpeg developers
......
input #0, asf, from 'hzvideo.wmv':
Metadata:
WM/Writer :
WMFSDKVersion : 10.00.00.4072
WMFSDKNeeded : 0.0.0.0000
IsVBR : 0
Duration: 00:00:37.99, start: 0.000000, bitrate: 755 kb/s
Stream #0:0(chi): Video: wmv2 (WMV2 / 0x32564D57), yuv420p, 704x576, 700 kb/s, 25 tbr, 1k tbn, 1k tbc
[asf @ 0xb2101320] freeing incomplete packet size 3598, new 3421
[wmv2 @ 0xb21079c0] warning: first frame is no keyframe
10.80 A-V: 0.000 fd= 0 aq= 0KB vq= 14KB sq= 0B f=0/0 0/0
>>>>>
I try hard to play the video using every version of vlc(vlc-1.1.11, vlc-1.2.0-rc1, vlc-1.3.0-git), every of them has the same problem. They all can't seek to correct keyframe point. For example, I seek to 13s, player should play from 10s, but vlc starts playing from 0s. When I seek to 16s, vlc then seeks to 10s. VLC does start-time control wrongly. The error causes that the length of partially transcoded video is not correct.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/vlc-devel/attachments/20120115/b2975953/attachment.html>
More information about the vlc-devel
mailing list