[MEncoder-users] Encoding h264 mov 50 fps to flv - loosing of frames and seconds

[belcampo]

Raffaele Gambelli wrote:
> Hi all,
> 
> I'm quite a newbie of video editing and I would like to receive your 
> opinion about my problem.
> My app internally makes use of mencoder to convert video of any formats 
> to flv videos.
> 
> My problem is that output video is less than original of 23 seconds, so 
> the original is 3.53 and flv is 3.30
> 
> Here there are input video characteristics, and then my command line 
> statement:
> 
> Format : MPEG-4
> Format profile : QuickTime
> Codec ID : qt
> File size : 91.0 MiB
> Duration :*3mn 53s *
> Overall bit rate : 3 269 Kbps
> Writing library : Apple QuickTime
> 
> *Video*
> ID                               : 2
> Format                           : *AVC*
> Format/Info                      : Advanced Video Codec
> Format profile                   : Main at L2.1
> Format settings, CABAC           : No
> Format settings, ReFrames        : 2 frames
> Codec ID                         : avc1
> Codec ID/Info                    : Advanced Video Coding
> Duration                         : 3mn 53s
> Bit rate mode                    : Variable
> Bit rate                         : 1 853 Kbps
> Width                            : 512 pixels
> Height                           : 288 pixels
> Display aspect ratio             : 16:9
> Frame rate mode                  : Constant
> Frame rate                       : *50.000 fps*
> Color space                      : YUV
> Chroma subsampling               : 4:2:0
> Bit depth                        : 8 bits
> 
> *Audio*
> ID                               : 1
> Format                           : PCM
> Format settings, Endianness      : Little
> Format settings, Sign            : Signed
> Codec ID                         : sowt
> Duration                         : 3mn 53s
> Bit rate mode                    : Constant
> Bit rate                         : 1 411.2 Kbps
> Channel(s)                       : 2 channels
> Sampling rate                    : 44.1 KHz
> Bit depth                        : 16 bits
> Stream size                      : 39.3 MiB (43%)
> Language                         : English
> 
> */usr/bin/mencoder* /test/test02_h264.mov -o 
> /tmp/no_meta_lXYcUz_test02_h264.mov.flv -of lavf -vf 
> scale=0:0,expand=0:0 -oac mp3lame -lameopts abr:br=56 -srate 22050 -ovc 
> lavc -lavcopts vcodec=flv:vbitrate=500:mbd=2:mv0:trell:v4mv:cbp:last_pred=3
> 
> The resulting video is 3.30 rather than 3.53 and in fact, this 
> difference is really visible and ugly when playing video.
> 
> My mencoder version is *SVN-r1.0~rc3+svn20090426-4.4.3* and I'm running 
> on Ubuntu 10.04
Maybe start with trying a recent, not this one which is more than a year 
old, version.
Use mediainfo on the original and the converted file, to check how many 
frames each have, from that maybe one can find the reason what is going 
wrong.
> 
> I would like to receive some hints about flv generation of these kinds 
> of video.
> *Consider that I tried with many others h264 video and they always 
> worked fine*, the only difference is the fps, all these successfully 
> converted video have less than 30 fps while the above described video 
> has 50 fps.
> 
> Thanks in advance and best regards
>