On Mar 13, 2013, at 3:30 PM, Oleg <[email protected]> wrote:

> And about solving your problem, first find where is the problem: In mic? In 
> QTKit API? In ffmpeg API? Don't try to "repair" whole system when you don't 
> know what exactly doesn't work.

Understood, in fact, that's the motivation for posting the example. At this 
point, there are no errors being returned anywhere along the way -- all works, 
the audio is just junk. My belief is that the problem is not with the capture 
or the streaming, but rather likely with the conversion of the audio from its 
source sample format. 

I've finally gotten a runnable app w/source -- I tried to put some time into 
this so as to deliver a UI and source that would clearly demonstrate the 
problem I'm experiencing. I would really appreciate it if someone could take a 
look and let me know what the problem with it is, which most certainly is 
centered in the audio processing. Here's the source to a runnable Mac app on 
GitHub: 

https://github.com/BigHillSoftware/QTFFmpeg

WHAT THE APP DOES: 

- The app presents a UI that shows a video preview and audio level for 
video/audio being captured by QTKit. Clicking the "Start Streaming" button will 
open an output format context and will write an FLV file (my target format) to 
your Desktop. ***NOTE: This app also outputs a log file to the Application 
Support directory -- I am outputting this log for ease in log storage/exchange 
-- I just thought I'd mention that in case someone who helps out wants to get 
rid of the leftovers once removing this app. 

WHAT IS HAPPENING WHEN THE APP IS RUN: 

- If I write *only* video frames using the av_write_frame call, the resulting 
FLV video seems fine (no audio of course, which I need). 

- If I write both audio and video, the resulting FLV when played gives me audio 
that is ear-piercing junk, and the video seems to stream fine for about 15 
seconds, and then just freezes. 

- If I write *only* audio, the resulting audio in the FLV is ear-piercing junk. 

I would be very grateful if any experts out there could just pull this thing 
and run it, and then take a look at the source. The crux of the FFmpeg API 
usage is in the class called QTFFAVStreamer. Please do not hesitate to ask me 
any questions, and feel free to contact me either with a reply to this thread, 
or offline at my email address of [email protected]. 

Again, thank you very much for your help. 

Regards, 

Brad

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