But if you want to be able to play that video recording with sound using any media player, I found three programs that are capable of converting a video file with QCELP audio to a different video format.
- FormatFactory
- Handbrake
- XMediaRecode
I'll give directions on how to use Handbrake
(link) to convert the file to an mp4/MPEG4 file; the version on my computer is v0.9.4. I haven't used the newest version v0.9.5. I haven't tried to give directions before for using it, so I hope these steps will make sense. I didn't try to give an in-depth explanation of the video settings in Handbrake. I'll leave it to you to research that.
Drag and drop the .3g2 phone video recording anywhere onto the main screen of Handbrake.
On the main screen, I have "Container" set to "MP4 File"; "Large file size", "Web optimized", "iPod 5G support" are unchecked; and on the right side of the screen the Preset is set to "Regular: Normal"
Click on the tab "Video". Change "Video Codec" to "MPEG-4 (FFmpeg)". I kept "Framerate (FPS)" set to "Same as source". Under "Quality" are three choices -- Target Size, Avg Bitrate, and Constant Quality. Each setting has advantages and disadvantages.
I don't have experience using Target Size, so I can tell you what setting worked for me for "Avg Bitrate" and "Constant Quality".
For "Avg Bitrate", I opened MediaInfo (mentioned earlier in my first post) and dragged and dropped the file name of the video recording onto it. Media Info has information about the bitrate under "First video stream" listed as [...] Kbps. Type that number into Handbrake for the "Avg Bitrate"; if we typed a number lower than that, we'd just be downgrading the video quality.
For Constant Quality, try "3" or "4". A value of "3" will give us a converted file that is very close in quality to the original video recording. "2" is too high a value. If you want a better understanding of the affect on video quality by using these different numbers, you can use MediaInfo to get detailed information. How is "Constant Quality" different from "Avg Bitrate" ? You specify a quality level and HandBrake adjusts the bitrate to meet it during the converting. By comparison, when you convert using "Avg Bitrate" setting in Handbrake, Handbrake creates a file whose bit rate hovers around that size. I don't think using "Constant Quality" will pose a problem for converting a video recorded by the phone. But if you were using "Constant Quality" for a (much) higher quality source material than a phone recording, then in some places of the converted file the bitrate can spike high enough that some rudimentary media players might not be capable of playing back the converted file.
The last thing to do is click the "Audio" tab. For "Source", select "1 English (QCELP)". For "Audio Codec", make sure "AAC (faac)" is selected. For "Mixdown", select "Mono". When you use MediaInfo to examine that video recording, click "View" and then "Tree" to get detailed information about the recording. This information will show that the audio bitrate and audio sampling rate are very low. So, for "Samplerate" and "Bitrate", select the lowest matching values which for my u370 video recording were 22.05 and 32, respectively.
At the top of the screen, click the green "Start" button to convert the phone recording.
If the converted file has an extension of ".m4v", change it to ".mp4"
