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Video freezes on step back - Aug 1 at 12:46AM
Steve Draper
2 Posts

Hi Doug/everyone.

Awesome software!

I'm using Tracker 5.0.1 (and have been using it since early 4.x) on Windows 10 with my Physics classes.

We have Casio Exilim High Speed cameras that record in .mov format. Mediainfo software says they are MPEG-4 Quicktime AVC format.

I can load them into Tracker fine. They play and step forward ok. But if I try to step back (one frame), the video freezes. The message log says this (multiple times):

'CONSOLE: 14:41:02.893 [AWT-EventQueue-0] ERROR org.ffmpeg - [h264 @ 0x179fa330] number of reference frames exceeds max (probably corrupt input), discarding one'

I noticed in Mediainfo that the frame rate of the MOV file says '29.970 (30000/1001) FPS'.

So I tried using a media converter to just change the frame rate to 30 fps (nothing else - still Quicktime MPEG4 AVC mov file).

And hey presto - the video is fine. I can step back without an issue, and nothing untoward in the message log.

The problem is that the Casio Exilim only saves as the 29.970 MOV file, so I would have to get my students to convert the file to 30fps every time they wanted to analyse anything. Can Tracker address this issue?

Cheers,
Steve


Replies to Video freezes on step back

Re: Video freezes on step back - Aug 01 11:56AM
Douglas Brown Avatar
Douglas Brown
208 Posts

I don't know why Xuggle (which uses ffmpeg) can't handle your video format (it may be a newer codec than the ffmpeg version) but there is probably no solution except to convert. However, the problem is probably not the frame rate and if you convert to a different frame rate the time data will not be accurate (29.97 fps is indeed a standard). I suggest you convert but change some other property than the frame rate. One possibility is to convert to FLV, a format that Xuggle handles well.

Hope this helps.  Doug



>
> We have Casio
> Exilim High Speed cameras that record in .mov format.
> Mediainfo software says they are MPEG-4 Quicktime
> AVC format.
>
> I can load them into Tracker fine. They
> play and step forward ok. But if I try to step back
> (one frame), the video freezes. The message log says
> this (multiple times):
>
> 'CONSOLE: 14:41:02.893 [AWT-EventQueue-0]
> ERROR org.ffmpeg - [h264 @ 0x179fa330] number of reference
> frames exceeds max (probably corrupt input), discarding
> one'
>
> I noticed in Mediainfo that the frame rate of
> the MOV file says '29.970 (30000/1001) FPS'.
>
> So I
> tried using a media converter to just change the frame
> rate to 30 fps (nothing else - still Quicktime MPEG4
> AVC mov file).
>
> And hey presto - the video is fine.
> I can step back without an issue, and nothing untoward
> in the message log.
>
> The problem is that the Casio
> Exilim only saves as the 29.970 MOV file, so I would
> have to get my students to convert the file to 30fps
> every time they wanted to analyse anything. Can Tracker
> address this issue?
>
> Cheers,
> Steve



Re: Re: Video freezes on step back - Aug 02 7:39PM
Steve Draper
2 Posts

Thanks for your reply, Doug.

OK. I tried converting to FLV instead without changing frame rate (or anything else). It works! Going back a frame is fine now.

Out of curiosity I opened the original 29.97fps MOV file with MediaInfo and compared to working 29.97fps FLV file. I have pasted both here in case you can shed any light on the cause. I noticed that the MOV file frame rate is reported as '29.970 (30000/1001) FPS', but the FLV is '29.970 FPS' without the bracketed part.

Cheers,
Steve

MOV file (freezes)
---------

General
Complete name                            : C:\Users\steve\Desktop\aaaa.MOV
Format                                   : MPEG-4
Format profile                           : QuickTime
Codec ID                                 : qt   2010.08 (qt  /caqv)
File size                                : 26.6 MiB
Duration                                 : 21 s 755 ms
Overall bit rate mode                    : Variable
Overall bit rate                         : 10.3 Mb/s
Encoded date                             : UTC 2012-03-28 01:26:39
Tagged date                              : UTC 2012-03-28 01:26:39
Writing application                      : Casio Digital Camera

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L3.1
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 1 frame
Format settings, GOP                     : N=1
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 21 s 755 ms
Bit rate mode                            : Variable
Bit rate                                 : 10.3 Mb/s
Width                                    : 640 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate mode                          : Constant
Frame rate                               : 29.970 (30000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 1.115
Stream size                              : 26.6 MiB (100%)
Language                                 : English
Encoded date                             : UTC 2012-03-28 01:26:39
Tagged date                              : UTC 2012-03-28 01:26:39

---------------------

FLV file (works)
---------

General
Complete name                            : C:\Users\steve\Desktop\aaaa.flv
Format                                   : Flash Video
File size                                : 3.08 MiB
Duration                                 : 21 s 755 ms
Overall bit rate                         : 1 188 kb/s
Writing application                      : Lavf57.19.100

Video
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L3
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames
Codec ID                                 : 7
Duration                                 : 21 s 755 ms
Bit rate                                 : 1 134 kb/s
Width                                    : 640 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate mode                          : Constant
Frame rate                               : 29.970 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.123
Stream size                              : 2.94 MiB (95%)
Writing library                          : x264 core 148
Encoding settings                        : cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=12 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=crf / mbtree=1 / crf=24.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00



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