[libavg-devel] Audio patch

[Ulrich von Zadow]

Nick Hebner wrote:
> On Mon, Mar 24, 2008 at 6:33 AM, Ulrich von Zadow <uzadow at libavg.de> wrote:
> 
>> Hi,
>>
>> I just merged the changes in the trunk to Nick's audio branch. All went
>> well, tests still pass :-).
> 
> 
> Thanks for doing this. I had done the same thing recently, but didn't get a
> chance to commit it. Adding a parameter entry to the video node
> NodeDefinition for speedfactor killed me for about 5 hours :). I am glad you
> didn't have trouble.

Yeah, the speedfactor parameter was uninitialized after the first merge 
here too ;-).

> Also, in creating a layout containing videos with audio, I experienced some
> stability issues, so we have some work to do. I also have not had the chance
> to write any formal tests, and would appreciate input (again) on the best
> way to accomplish this.

Er - I didn't answer that request when you first asked for input? Oops.

Anyway:

A colleague at Archimedes (where I work) is making some very simple 
audio test files now:
- 440 Hz sine waves in 48, 44.1 and 22.05 KHz in mono
- Stereo versions with one side at 441 Hz (so you can hear cancellations 
if they're played back in mono :-) )
- 0.1 and 2 seconds in length so we have quick automatic test files and 
longer ones for listening.

Initial test ideas:
1) In /src/video/testvideo.cpp, decode audio files at different Hz and 
assert that there are no clicks/discontinuities. If the difference 
between two adjacent samples is too large, that's a click :-).
2) Same as 1), just with looping audio files.
3) Decode video files with audio in testvideo.cpp. Check for clicks and 
for frame contents.

These all need to work using synchronous and asynchronous operation.

Then, we can start adding tests that exercise the python interface 
(src/test/Test.py).

Cheers,

   Uli


-- 
Any technology distinguishable from magic is insufficiently advanced.

Ulrich von Zadow | +49-172-7872715
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