musickit-users

[Musickit-users] Quicktime Sound Access in SndKit (Mac OS X)

[John R. <jri...@cs...>]

Hi There,

I'm writing a Mac OS X Application (in Cocoa) that involves Quicktime
movies, and I'm trying to integrate SndKit, particularly the SndView
stuff  (which looks terrifically useful).

Does anyone out there have experience getting SndKit to deal with
Quicktime Sound files?  The movies I'm dealing with all have 16 bit mono
uncompressed soundtracks...

Thanks!
jr

[Musickit-users] Re: Quicktime Sound Access in SndKit (Mac OS X)

[Yves de C. <yv...@gn...>]

The format is well documented on developer.apple.com
and there is also an article at www.macdevcenter.com
that describes a java parser for QT.

yves

Le Jeudi, 12 juin 2003, =E0 11:21 America/Montreal, John Rieffel a =E9crit=
 :

>
> Hi There,
>
> I'm writing a Mac OS X Application (in Cocoa) that involves Quicktime
> movies, and I'm trying to integrate SndKit, particularly the SndView
> stuff  (which looks terrifically useful).
>
> Does anyone out there have experience getting SndKit to deal with
> Quicktime Sound files?  The movies I'm dealing with all have 16 bit=20
> mono
> uncompressed soundtracks...
>
> Thanks!
> jr
>
>
>
> -------------------------------------------------------
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>

[Musickit-users] Re: Quicktime Sound Access in SndKit (Mac OS X)

[John R. <jri...@cs...>]

Yves,

Thanks. Yes, I'm (mostly) familiar with the Quicktime format.  I'm very f=
amiliar
with the Quicktime Developer API.  I'm also a big fan of orielly and the
macdevcenter.  I've used the C-based movie toolbox as well as the
(paltry) Cocoa Quicktime tools.

But I'm stumped on how to get SndKit to "look" at the quicktime sound
data.  The only method I've thought of so far is to export the quicktime
sound as wav or aiff, then read the saved file via the Snd interface.
But, obviously, this is a horrible idea.

Granted, I'm still relatively new to all of this, and I'm not suggesting
that the process isn't obvious, simply that it hasn't dawned on me yet!

;)

jr



------- snip snip -------
> The format is well documented on developer.apple.com
> and there is also an article at www.macdevcenter.com
> that describes a java parser for QT.
>=20
> yves
>=20
> Le Jeudi, 12 juin 2003, =E0 11:21 America/Montreal, John Rieffel a =E9c=
rit :
>=20
> >
> > Hi There,
> >
> > I'm writing a Mac OS X Application (in Cocoa) that involves Quicktime
> > movies, and I'm trying to integrate SndKit, particularly the SndView
> > stuff  (which looks terrifically useful).
> >
> > Does anyone out there have experience getting SndKit to deal with
> > Quicktime Sound files?  The movies I'm dealing with all have 16 bit=20
> > mono
> > uncompressed soundtracks...
> >
> > Thanks!
> > jr
> >
> >
> >
> > -------------------------------------------------------
> > This SF.NET email is sponsored by: eBay
> > Great deals on office technology -- on eBay now! Click here:
> > http://adfarm.mediaplex.com/ad/ck/711-11697-6916-5
> > _______________________________________________
> > Musickit-users mailing list
> > Mus...@li...
> > https://lists.sourceforge.net/lists/listinfo/musickit-users
> >

Re: [Musickit-users] Re: Quicktime Sound Access in SndKit (Mac OS X)

[Leigh S. <le...@le...>]

> But I'm stumped on how to get SndKit to "look" at the quicktime sound
> data.  The only method I've thought of so far is to export the 
> quicktime
> sound as wav or aiff, then read the saved file via the Snd interface.
> But, obviously, this is a horrible idea.

If you can get access to a pointer to sample data that is formatted 
conventionally in frames, i.e for stereo:

sample 0, channel 0; sample 0, channel 1; sample 1, channel 0; sample 
1, channel 1; etc

You can initialise a SndAudioBuffer with:

SndAudioBuffer *qtAudioBuffer = [[SndAudioBuffer alloc] initWithFormat: 
sndSoundStructHoldingRateChannelsEtc data: dataPointer];

and then the Snd itself:

Snd *snd = [[Snd alloc] initWithAudioBuffer: qtAudioBuffer];

At the moment Snd and SndAudioBuffer hold their sample data 
differently, due to the original requirement to be compatible with 
SndSoundStructs. This will be unified such that you will probably be 
able to just initialise a Snd from a memory pointer.

SndSoundStruct will be soon modified such that it becomes a struct just 
holding sample format data named SndFormat probably:

typedef struct {
	int dataFormat;
	long frameCount;
	int channelCount;
	double sampleRate;
} SndFormat

Getting rid of the unused info, magic and troublesome dataLocation (and 
the crufty arrangement of data following the struct itself) fields. 
This will still make it easier to pass around formats of sound data 
than having to pass each parameter and move entirely to NSData based 
sample data manipulation. If we then want an higher efficiency VM 
sample data managing class than NSData provides, we can probably 
introduce SndSampleData.
--
Leigh Smith
mailto:le...@le...
http://www.leighsmith.com

[Musickit-users] Quicktime Sound to Sndkit Snd, take two

[John R. <jri...@ma...>]

Hi Folks,

Last time I checked in I was trying to import Quicktime sound into
SndKit.  I'm pleased to say that, thanks largely to help from Leigh's
and the quicktime-api mailing list, I've had a moderate amount of success.

To access the movie sound, I first put the movie intoa typed handle
(PutMovieIntoTypedHandle), using the following sound description:

 outDesc[0]->descSize = sizeof(SoundDescription);
 outDesc[0]->dataFormat = 'raw';
 outDesc[0]->numChannels = 1;
 outDesc[0]->sampleSize = 8;
 outDesc[0]->sampleRate = inDesc[0]->sampleRate;

and then creating a SndSoundStruct of the following format:

 mySS.magic = SND_MAGIC;
 mySS.dataSize = actualSamples;
 mySS.dataFormat = SND_FORMAT_LINEAR_8;
 mySS.samplingRate = 8000;
 mySS.channelCount = 1;

and then creating a SndAudioBuffer with the format above, and then
creating a Snd via initWithAudioBuffer.

There are several points of confusion:

- I'm not sure that the apple sound format 'raw' corresponds to
SND_FORMAT_LINEAR_8.  'raw' is described in the apple docs (references
below) as "k8BitOffsetBinary".  As far as I can tell, this is the only 8
bit format.

http://developer.apple.com/documentation/QuickTime/APIREF/SOURCESIV/soundformats.htm

Obviously I'm must misunderstand _something_, because when I plot the
data in a SubSndView, it looks like "stalagtites and stalagmites" as
opposed to a waveform. (I have the soundView display mode set to
"NX_SOUNDVIEW_WAVE"

Does anyone understand the relationship between quicktime sound data
formats and SndKit sound data formats?  

Thanks!
jr

Re: [Musickit-users] Quicktime Sound Access in SndKit (Mac OS X)

[Leigh S. <le...@le...>]

Not to put a dampener on SndView, but while it will definitely do the 
job, it can probably do with a bit of an update, it's probably the 
oldest code in the SndKit. This should all be behind the scenes, so you 
should be able to get it working now and have improvements benefit you 
later. Certainly it works well enough for Spectro. I've ear-marked it 
to be overhauled as part of an impending SndSoundStruct purge, fixing 
recording and myriad other improvements that I don't remember. I think 
we can introduce some better scrolling and viewing behaviour (I have an 
overridden NSScroller class that implements scaling as well as 
position). Feel free to compile a wish list for SndView (and/or 
implement some of these features). This will happen post 2.3 release 
however :-)

Do you want to read QuickTime sound files with the SndKit or do you 
want to read the QT files using the QuickTime framework and then create 
a Snd object from a data pointer, pasteboard or other memory operation? 
I did a QuickTime project using the QT framework and it is devilishly 
buggy, particularly with retrieving sound tracks. Perhaps QT 6.3 has 
fixed those problems. Otherwise, libsndfile/sox doesn't handle QT files 
directly. Other options include subclassing Snd in a similar fashion to 
SndMP3 to read sound tracks from QT movies using the QT framework.

I now have on the fly resampling working. I should be committing that 
code tonight sometime...
--
Leigh Smith
mailto:le...@le...
http://www.leighsmith.com