Can't fine tune with .3gp files

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  • lmrose
    Participant
    Post count: 20
    #637 |

    I’m aiming for smaller APKs by using .3gp audio files. However, I can’t fine tune with them because browsers do not support .3gp audio files. So, I have to work around this by:
    1. Start with MP3 files
    2. Synchronize
    3. Fine tune and import adjusted timing files
    4. Remove the MP3 files, and replace them with .3gps
    5. Build the app.

    Is there any hope for fine tuning with .3gps in the near future?

  • Chris Hubbard
    Participant
    Post count: 19
    #639 |

    Yes, .3gp files aren’t completely working. The problem is that SAB can’t determine the duration of the audio. I have to add some code to support this.

    One work-around is to add the MP3 and make adjustments to the timing files. Then edit the entry and rename the file to be the 3gp file (I believe this will work). The timing will be the same.

  • Peter Brassington
    Participant
    Post count: 2
    #93018 |

    Sounds promising. What kind of file size reduction have you managed with this?

  • Eric Pawley
    Participant
    Post count: 2
    #93020 |

    I’ve not worked with .3gp files before, so I did some research. According to the Wikipedia page, .3gp is based on MPEG-4, and “Some cell phones use the .mp4 extension for 3GP video.”

    Would renaming .3gp files to .mp4 work?
    If not, would converting the audio to .mp4 offer acceptable size/quality, or is .3gp using a superior codec?

  • Chris Hubbard
    Participant
    Post count: 19
    #93023 |

    3GP is a multimedia container format which can store MP4 video stream and AMR-NB audio streams. I don’t believe renaming the file will help. I need to add a library that can parse the container information to get the durations. You should be able to safely use MP3 files to adjust the timings and then replace the files with a lower file size encoding.

    The reason to consider 3GP is for the AMR-NB audio encoding. It is designed for speech encoding. If you have music in the background, then it might not work well.

    You (better, a native speaker) really need to listen to the content to see if it good. I have heard 3GP encoded files that (to me) are indistinguishable and others that were awful.

    If your original is FCBH recording, you could also change the MP3 parameters (re-encode) to reduce the file size.

  • Ian McQ
    Participant
    Post count: 2
    #93043 |

    I did some research on 3GP. I put some of what I learned here: https://github.com/SILAsiaPub/audio-to-3gp/blob/master/transform-info.md

    There is a preses.xml file to add small 3GP and mp3 outputs to WinFF. There is also a GUI for FFMPEG for geeks.

    Ian

  • LorenH
    Participant
    Post count: 27
    #93046 |

    I have found 3gp to be about 1/5 the size of 64kb encoded mp3 that we were using. I have had very few complaints about the quality. It is not as good, but generally considered acceptable. Every app that I make now that includes audio, includes at least on full book of audio encoded in 3gp. I normally include the Gospel of Mark audio in the apps that I put in the Play Store and set the app to open by default at Mark 1. That way the audio just works for that whole book. I am also making apps that have the whole NT audio embedd, using 3gp. These are too big for the play store, but I make them a download option on ScriptureEarth.org. I run ffmpeg from the command line in Linux to do the conversion. Chris Hubbard kindly gave me the parameters that work. –Loren

  • LorenH
    Participant
    Post count: 27
    #93047 |

    Being able to run the timing process on the 3gp files would be nice, but using mp3 for the timings and then using those timings with the 3gp audio files doesn’t slow you down very much. –Loren

  • Ian McQ
    Participant
    Post count: 2
    #93049 |

    Loren thanks for sharing your strategy, it sould like a good choice. Can you share your settings?
    Ian

  • LorenH
    Participant
    Post count: 27
    #93063 |

    Sorry it took awhile to get back and respond. This command should convert all the mp3 files in the current folder to 3gp. This is run in a Linux terminal:

    for i in *.mp3; do ffmpeg -i “$i” -ar 8000 -s 128×96 -ac 1 “${i%.mp3}.3gp”; done

    The resulting files seem to be adequate, even with the dramatized Hosanna recordings.

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