I have some old 3GP (mp4v codec)videos from my HTC desire S and when I try to drop them into Vegas they won't open so I decided to convert them to a format that would open. However when I convert to a standard mp4 template h.254 at a frame rate of 30, the video converts and plays back at twice the speed but the audio is original.

I cannot figure out the frame rate for the original video according to Gspot it is 16.393 and other videos its 9.901 etc

Here is the information from the container 3gp4: 3GPP Media (.3GP) Release 4

  • mp41: MP4 v1 [ISO 14496-1:ch13]
  • 3gp6: 3GPP Media (.3GP) Release 6 Basic Profile
  • Recommended Display Size: 800 x 480

How would I convert such videos to play back normally?

Format                                   : MPEG-4  
Format profile                           : 3GPP Media Release 4  
Codec ID                                 : 3gp4  
File size                                : 208 MiB  
Duration                                 : 3mn 55s  
Overall bit rate                         : 7 430 Kbps  
Law rating                               : (empty)  
Released date                            : 0  
Encoded date                             : UTC 2012-04-29 18:18:23  
Tagged date                              : UTC 2012-04-29 18:18:23  
Classification                           : (empty)  

ID                                       : 1  
Format                                   : MPEG-4 Visual  
Format profile                           : Simple@L6  
Format settings, BVOP                    : Yes  
Format settings, QPel                    : No
Format settings, GMC                     : No warppoints  
Format settings, Matrix                  : Default (H.263)  
Codec ID                                 : 20  
Duration                                 : 3mn 55s  
Bit rate mode                            : Constant  
Bit rate                                 : 7 416 Kbps  
Nominal bit rate                         : 8 000 Kbps  
Width                                    : 1 280 pixels  
Height                                   : 720 pixels  
Display aspect ratio                     : 16:9  
Frame rate mode                          : Variable  
Frame rate                               : 13.033 fps 
Minimum frame rate                       : 3.906 fps  
Maximum frame rate                       : 58.824 fps  
Color space                              : YUV  
Bit depth                                : 8 bits  
Scan type                                : Progressive  
Compression mode                         : Lossy 
Bits/(Pixel*Frame)                       : 0.617  
Stream size                              : 208 MiB (100%)  
Language                                 : English  
Encoded date                             : UTC 2012-04-29 18:18:23  
Tagged date                              : UTC 2012-04-29 18:18:23  

ID                                       : 2  
Format                                   : AMR  
Format/Info                              : Adaptive Multi-Rate  
Format profile                           : Narrow band  
Codec ID                                 : samr  
Duration                                 : 3mn 55s  
Bit rate mode                            : Constant  
Bit rate                                 : 12.8 Kbps  
Channel(s)                               : 1 channel  
Sampling rate                            : 8 000 Hz  
Bit depth                                : 13 bits  
Stream size                              : 367 KiB (0%)  
Writing library                          : pvmm  
Language                                 : English  
Encoded date                             : UTC 2012-04-29 18:18:23  
Tagged date                              : UTC 2012-04-29 18:18:23  
  • Usually there is information about the original framerate in the details tab of the properties of the video. What are you using to convert your videos? Jan 14, 2013 at 23:40
  • You say that if you convert it at a framerate of 30 fps it plays at twice the speed. Have you tried converting it with a framerata of 30/2 = 15 fps? And to make the question more complete: what software are you using for the conversion? Jan 15, 2013 at 11:26
  • Yes I tried to convert it 15 too, but it didn't work. The only converter I used was the free version of Any Video Converter
    – Aasim Azam
    Jan 15, 2013 at 11:28
  • Could you run MediaInfo on your footage and post it here? This will show all relevant information about your video. As I see it now it boils down to using AviSynth scripts. I'm looking into what exact script will help you, but you can of course take a look at the program yourself. Jan 15, 2013 at 11:41
  • 1
    Here's someone with the same problem who has a solution through with Avisynth. Jan 15, 2013 at 20:10

2 Answers 2


Have you tried using Quicktime Pro version 7? It's what I usually use for file conversions. It costs about £20 / $30.


Open your file.

Go to the file menu, and select Export Choose your format, e.g. Quicktime Movie with ProRes 422 codec at 30 fps.


This is an excellent use case for gstreamer and the MKV format. gstreamer was written to tackle this problem nicely. It can be used and accompanied by ffmpeg to transcode a video into a constant or variable rate video format.

Here is a link to a great resource on solving this problem: https://www.linuxtv.org/wiki/index.php/V4L_capturing

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