Edgar Luevano wrote:
Hello again Greg,
I have a doubt about the meaming of pushdown,
what is this value used for?
It seems to me is something like the preroll time, but with the difference
that preroll is the neccesary time for buffering or load the data BEFORE
starting
to play, and pushdown is the neccesary time that need to be buffered AFTER
a decode has been done?
I found another value for PUSHDOWN in the audio renderer audrend.cpp.
#define MINIMAL_AUDIO_PUSHDOWN 120
The pushdown value in audio/device/pub/hxaudev.h is the amount of audio
needed to be pushed down into the physical audio hardware to ensure
smooth playback without running dry. Some systems have larger buffers,
threads, finer OS granularity that make them more or less resilient to
high CPU spikes or blocking events. So, this number is changed to reflect
that. The more audio you push down the longer you can go without writing
any before an underflow occurs. I just suggested you play with this on
the emulator because I know it has a 100ms granularity, which is very very
long. If this is not fixing the problem, then I enable logging, which should
work just fine on the PC emualator, and see if you can find out where the
dropout is happening with your AAC content.
As far as the audrend call to SetAudioPushdown, I would try removing that.
--greg.
Thank you
Edgar
-----Original Message-----
From: Greg Wright [mailto:[EMAIL PROTECTED]
Sent: Thursday, September 15, 2005 12:09 PM
To: Edgar Luevano
Cc: audio-dev
Subject: Re: [Audio-dev] aac on emulator
Edgar Luevano wrote:
Hello Greg,
The MINIMUM_AUDIO_PUSHDOWN was already set to 1000, I only uncommented
#define ENFORCE_MINIMUM_PUSHDOWN
but still it only sounds like a buzzer.
What another thing do you think occasionate this?
Thank you
Edgar
You are going to have to debug this then. See if the audio device
every runs out of data. Put print statements in CheckToPlayMoreAudio
and see how often it is getting called. Does this happen with all
content or just AAC? Check the output of GetCurrentAudioTime as well.
--greg.
-----Original Message-----
From: Greg Wright [mailto:[EMAIL PROTECTED]
Sent: Wednesday, September 14, 2005 12:52 PM
To: Edgar Luevano
Cc: audio-dev
Subject: Re: [Audio-dev] aac on emulator
Edgar Luevano wrote:
Thank you Greg.
The file hxaudev.cpp and hxaudev.h seems that are not used
for the build I'm doing (symbian 80 emulator),
Ah yes, we implement the audio stuff in symbian without inheriateing
from hxaudev.cpp. Try changing audsymbian.h:
#define MINIMUM_AUDIO_PUSHDOWN 1000
//#define ENFORCE_MINIMUM_PUSHDOWN
Just uncomment the ENFORCE_MINIMUM_PUSHDOWN and see if that helps. It
will if AAC is setting a very small audio pushdown.
--greg.
The sources that are compiled when I make a (make clean, make copy) in
audio/device
are : audsymbian.cpp, audio_svr.cpp, audio_svr_cntxt.cpp,
audio_session-mmf.cpp and fakeaudiodevice.cpp
so probably i need to make the change in fakedevice?
Thank you
Edgar
-----Original Message-----
From: Greg Wright [mailto:[EMAIL PROTECTED]
Sent: Wednesday, September 14, 2005 12:11 PM
To: Edgar Luevano
Cc: audio-dev
Subject: Re: [Audio-dev] aac on emulator
Edgar Luevano wrote:
Hello Greg,
I tried make it work by modifying MINIMUM_AUDIO_PUSHDOWN in audsymbian.h.
but still it does not sounds fine.
I did not understand what you mean with "Try doubling it for MIN_HEAP".
I did not see MIN_HEAP defined in the audio files.
Could you clarify this please.?
This code here:
#ifdef HELIX_CONFIG_MIN_PCM_PUSHDOWN_BYTES
#define MINIMUM_AUDIO_PUSHDOWN 100
#else
#define MINIMUM_AUDIO_PUSHDOWN 1000
#endif
instead of 100, make it 1000 lets say. If that fixes it, then you can
try to make it smaller if you want.
--greg.
Thank you.
Edgar
-----Original Message-----
From: Greg Wright [mailto:[EMAIL PROTECTED]
Sent: Tuesday, September 13, 2005 12:39 PM
To: Edgar Luevano
Cc: audio-dev
Subject: Re: [Audio-dev] aac on emulator
Edgar Luevano wrote:
Dear all,
I have found that aac files played on the symbian device sounds like
buzzing.
But when I play the same file in the device, it sounds fine.
You mean emulator?
Do you know why this happen? How can I make it sound fine in the
emulator?
thank you
One problem you have with the Symbian emulator is that its system
granularity
is only 100ms, while on the device it is 10ms (or what is 15ms??). So, it
is
possible that you are underflowing the audio with AAC on the emulator.
You
might try increasing the audio pushdown on the emulator only to see if
that
fixes it. Check in audio/device/pub/hxaudev.h and look for
MINIMUM_AUDIO_PUSHDOWN.
Try doubling it for MIN_HEAP. The important thing is that it works on the
device, which it does, so only increase this for your testing on the
emulator.
--greg.
Edgar
Edgar Luevano
Dextratech Technologies
Monterrey, N.L
Mexico
+52 82202010
www.dextratech.com
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