Re: [Swftools-common] How can I mix a series of audio files into a SWF/FLV file?

[Matthias Kramm]

On Mon, Sep 08, 2008 at 03:56:00PM -0500, David Trusty <address@hidden> wrote:
> I have a FLV file which contains video only.  I want to insert a series of 
> audio files
> into it and create a combined audio and video file.  I need to do it using a 
> script.
> 
> Suppose I know that the FLV file was started at time T1 and the audio files
> were started at times T1+x and T1+y, etc.  How can I mix the audio in at 
> certain times of video?

Hm. Tricky.
Try to convert the audio files to raw first:
    sox -r 44100 -c 1 -b file1.wav file1.raw
    sox -r 44100 -c 1 -b file2.wav file2.raw
    ...

Then, you can patch in the starting points using something like this:
    dd if=/dev/zero of=silence01.raw bs=D1 count=1
    dd if=/dev/zero of=silence12.raw bs=D2 count=1
    ...

with D1 the time between start of video and start of sound 1 (multiplied
by 44100), and D2 the time between sound 1 and sound 2 (etc.).

Concatenate everything:
    cat silence01.raw file1.raw silence12.raw file2.raw ... > sound.raw
   
Convert back to WAV, and then to SWF:
    sox sound.raw -c 1 -b -r 44100 sound.wav
    wav2swf -r <fps> sound.wav -o sound.swf

with <fps> the frames per second of your video file.

Then, you can combine video+audio:
    swfcombine -Tm video.swf sound.swf

Greetings

Matthias