Hi Stefan,
The problem describe below appears to be linked to knotify. It appears to crash on
startup. Once I start it up
manually and then start up artsd, it appears to work. However, the sounds appear to be
delayed and the system's
response is very, very slow. The testaudiosubsys is working fine.
Nikolaus
"Nikolaus J. Sucher" wrote:
> Hi Stefan,
>
> So I finally got the sound to work on my Sparc Ultra 5! There is still a lot to be
>done though! Artsd does
> not seem to start up automatically on starting kde. When I start it manually as
>artsd, the sound effects
> work, when I start artswrapper they don't work. Do you have any suggestions what I
>might to have to look
> for???
>
> Tx again, things are looking up!
>
> Nikolaus
>
> Stefan Westerfeld wrote:
>
> > Hi!
> >
> > The routine that does float -> integer conversion is defined in convert.cc
> > and looks like this (it's called from Synth_PLAY):
> >
> > void Arts::convert_stereo_2float_i16le(unsigned long samples, float *left, float
>*right, unsigned char *to)
> > {
> > float *end = left+samples;
> > long syn;
> >
> > while(left < end)
> > {
> > syn = QRound((*left++)*32767);
> >
> > if(syn < -32768) syn = -32768; /* clipping */
> > if(syn > 32767) syn = 32767;
> >
> > *to++ = syn & 0xff;
> > *to++ = (syn >> 8) & 0xff;
> > [...]
> >
> > The signal as float is between -1.0 and 1.0 - after the multiplication
> > and conversion to integer it is between -32767 and 32767. You see that it
> > is signed there, i.e.
> >
> > 0x7fff (represents 1.0)
> > 0x7ffe
> > ...
> > 0x0001
> > 0x0000 (represents 0.0)
> > 0xffff
> > ...
> > 0x8002
> > 0x8001 (represents -1.0)
> >
> > Then, the *to++ lines take the least significant byte first, and then the
> > most significant byte - no further conversion is done. That means that
> > a value which is a tad bit larger than -1.0 would be written as
> >
> > fragment_buffer[i] = 0x02; fragment_buffer[i+1] = 0x80;
> >
> > This is called little endian because the number 0x1234 would be represented
> > as 0x34 0x12, that is, the endian gets little - it is confusing, because the
> > endian still holds the most significant byte.
> >
> > Cu... Stefan
> >
> > On Sat, Dec 02, 2000 at 12:29:07AM +0800, Nikolaus J. Sucher wrote:
> > > Stefan,
> > >
> > > Ok, after having read through the OSS programmers guide
>(http://www.opensound.com/pguide/oss.pdf),
> > > I am now convinced that the problems stem from the big endian nature of the
>Sparc while you send
> > > little endian data down to audiosubsystem. If I understand this right, you add
>the data from
> > > wBuffer to the fragment buffer. The type of the fragment buffer is char. Does
>this mean that you
> > > split the 16 bit data in two parts that you add to the fragment_buffer (i.e. big
>byte into
> > > fragment_buffer[i], small byte into fragment_buffer[i+1])? What is happening
>with sign? Can you
> > > elaborate on this, please?
> > >
> > > Tx,
> > > Nikolaus
> > >
> > >
> > > "Nikolaus J. Sucher" wrote:
> > >
> > > > Hi Stefan,
> > > >
> > > > I did what ;you suggested and compiled the testasubsystem program. Using this
>program, Ihave
> > > > ascertained that the audiosubsystem gets data, it reads the data, puts the
>data into the
> > > > fragment buffer and writes the data to the sound card. HOWEVER, for some
>mysterious reason, I
> > > > don't get the sine wave sound on my audio output but more like a hammering. I
>checked all the
> > > > parameters (encoding, sample rate, bits/sample etc), everything appears to be
>allright. Byte
> > > > swapping doesn't make any difference either. Do you have any suggestion or
>idea what might be
> > > > missing here???
> > > >
> > > > Have a great weekend,
> > > > Nikolaus
> > > >
> > > > Stefan Westerfeld wrote:
> > > >
> > > > > Hi!
> > > > >
> > > > > On Fri, Dec 01, 2000 at 12:55:26AM +0800, Nikolaus J. Sucher wrote:
> > > > > > Stefan Westerfeld wrote:
> > > > > >
> > > > > > > Hi!
> > > > > > >
> > > > > > > On Thu, Nov 30, 2000 at 11:00:25AM +0800, Nikolaus J. Sucher wrote:
> > > > > > > > > 2. reimplement handleIO(), call needMore() exactly once
> > > > > > > >
> > > > > > > > OK!
> > > > > > > >
> > > > > > > > > and write through
> > > > > > > > > the result to the audio device (the encoding aRts produces is
>signed,
> > > > > > > > > 16bit, little endian)
> > > > > > > >
> > > > > > > > I am very close. One more question: what is the name of the buffer
>where the data goes
> > > > > > > > that comes from the producer (producer->needMore();). How do I "write
>through"? I am
> > > > > > > > not sufe yet if I have to convert from little endian to bigendian or
>not. I will check
> > > > > > > > on that.
> > > > > > >
> > > > > > > producer->needMore will lead to a call of AudioSubSystem::write - the OSS
> > > > > > > implementation puts the data in wBuffer, and later (in handleIO) gets it
> > > > > > > from there and writes it to the audio device.
> > > > > > >
> > > > > > > So you can either keep that mechanism, then you can write what is in
> > > > > > > wBuffer after calling needMore, or reimplement AudioSubSystem::write to
> > > > > > > "write through" directly.
> > > > > >
> > > > > > Sorry, that I keep bothering about this but I am still learning...
> > > > > > I am stuck here. I don't know how to actually read what is in the
>wBuffer. I only get
> > > > > > click, click, click from my audio, no matter what I try. When I check
>the OSS
> > > > > > implementation, it appears as if I never get anything into the
>fragment_buffer except
> > > > > > zeroes????
> > > > > > I very much appreciate your help and patience!!
> > > > >
> > > > > What might be helpful is if you don't try to get artsd working at first, but
> > > > > testasubsys (which is in kdelibs/arts/examples - you need to do make check
> > > > > to get it compiled). It plays a 2 seconds sine wave. That should be suitable
> > > > > for testing.
> > > > >
> > > > > With artsd, the normal thing you should expect when you start it is getting
> > > > > zeros, and only if you use applications, like artsplay, kaiman, artsbuilder
> > > > > or similar, you'll get some sound.
> > > > >
> > > > > Cu... Stefan
> > > > > --
> > > > > -* Stefan Westerfeld, [EMAIL PROTECTED] (PGP!), Hamburg/Germany
> > > > > KDE Developer, project infos at http://space.twc.de/~stefan/kde *-
> >
> > Content-Description: Card for Nikolaus J. Sucher
> >
> > --
> > -* Stefan Westerfeld, [EMAIL PROTECTED] (PGP!), Hamburg/Germany
> > KDE Developer, project infos at http://space.twc.de/~stefan/kde *-
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