Displaying 20 results from an estimated 400 matches similar to: "A few questions about libvorbis from a newbie"
2015 Dec 04
1
A few questions about libvorbis from a newbie
Sorry about the personal reply Ian. I hope keeping the subject the same is
the way to reply to the list (I have never used a mailing list before).
The last thing I am not grasping is how *pcm_total *works without a concept
of sample size?
If the sample size is whatever I decide to read it as, how does it
calculate the number of samples (of one channel I'm assuming because we
have to multiply
2005 Nov 05
1
buffer overruns for small files
I wonder if anyone would have a comment on an experiment I have pretty much completed in my MFC/C++ project. With my simple libvorbis implementation, ogg decoding works just fine for files that are 10kb or larger. For anything smaller (actually, I don't have a 9kb file, so <= 8), it seems that I get an inaccurate value for ov_pcm_total. Though ov_read returns zero, I overflow the buffer
2002 Aug 03
1
vbr / cbr / abr API calls
Hi,
Maybe this is documented somewhere, if so, please send me a link to the
documentation.
My question is: how to set up different (VBR, CBR, ABR) modes when
calling the Ogg Vorbis API?
Currently I do:
CBR:
ret = vorbis_encode_setup_managed( &vorbisInfo,
getInChannel(),
getOutSampleRate(),
2002 Jan 16
2
Problem with ov_read_float()
Greetings,
I'm having some sort of problem using ov_read_float(). Everything looks
good to me, but I'm trashing memory somehow, so clearly I'm screwing
something up. What confuses me is why it takes a ***float for the
buffer.
I call it like so:
float **buffer
bytes_read = ov_read_float(&vf, &buffer, 0)
memcpy (b, *buffer, 0);
This compiles fine, but after a few reads,
2002 Jan 03
3
Suggestion for libvorbisfile: scaling
I've been experimenting with the ideas of Replay Gain[1] and find that
ogg123 doesn't have a way of specifying the scaling applied to
replayed samples (like -f in mpg123).
Looking at libvorbisfile, I see no function exactly matching this
possibly desirable behaviour.
ov_read() scales by either 128 (byte output) or 32768 (word output),
but there's nothing in between.
ov_read_float()
2004 Jun 16
2
ogg123 volume?
Hi,
I need to adjust the output volume from ogg123 the same way that
mpg123 has the "-f n change scalefactor [32768]" option. I need to
do this within ogg123, instead of alternatives that involve pipes,
such as piping the output to sox.
I do not believe that this is currently possible in ogg123, and I'm
looking for some suggestions as to how it can be accomplished by
modifying
2004 Jun 16
2
ogg123 volume?
Hi,
I need to adjust the output volume from ogg123 the same way that
mpg123 has the "-f n change scalefactor [32768]" option. I need to
do this within ogg123, instead of alternatives that involve pipes,
such as piping the output to sox.
I do not believe that this is currently possible in ogg123, and I'm
looking for some suggestions as to how it can be accomplished by
modifying
2003 Feb 02
1
Observations about the floating point data in vorbisfile
Hello.
I noticed that when reading data with ov_read_float(), you can get
values outside [-1..1] when the stream is encoded at lower quality, but
with higher quality, the values trim down to inside [-1..1].
Looking at the plot from -q10, the data from ov_read_float seems
clipped.
I've made some plots of encoding the start of Rammsteins Feuer from the
xXx soundtrack (it's a pretty loud
2002 Jul 29
1
Where ov_read_float?
Subj!.
Kind Regards,
Michail.
_________________________________
Michail A.Baikov,
Linderdaum Team
http://www.gamedot.ru
http://linderdaum.gamedot.ru
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containing only the word
2002 Jul 20
1
small mistake in docs
Hi,
in ov_read_float.html there is a small mistake:
long ov_read(OggVorbis_File *vf, float ***pcm_channels, int
*bitstream);
hould read:
long ov_read_float(OggVorbis_File *vf, float ***pcm_channels, int
samples, int *bitstream);
It seems this function has been changed (compared to the RC3). Anything
else worked fine for me with the 1.0 release.
Olaf
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2002 Sep 03
1
tremor relicensed as BSD
For those of you not of the commit mailing list, I wanted to point out
that monty has checked the fixed-point 'tremor' vorbis decoder into
xiph.org cvs, under the usual (free) xiph license. This was developed
for use in embedded devices, so if you've been waiting for an
interger-only (no fpu) implementation, you might want to give it a try.
The code is in the 'Tremor' cvs
2003 Apr 30
1
float to PCM packing in libvorbisfile
Is there any particular reason why ov_read() packs floats to integer PCM
inline, rather than being implemented in terms of ov_read_float() and a
separate packing fucntion?
There are obviously many advantages doing audio manipulation on the floats
before packing, but right now you have to reinvent the packing stage yourself
- in a replaygain backend that I'm working on, I ended up copying
2002 Apr 09
1
Replay Gain for vorbis
I had completely forgotten about Replay Gain until Mr. Seibert reminded
me. Wasn't there talk of adding this to vorbis-tools?
Anyway, I went here:
http://sjeng.sourceforge.net/ftp/vorbis/
And downloaded the source for the replay gain tool. Unfortunately, I
cannot compile it. The errors regard parameters to ov_read_float. Is
there updated source somewhere else?
--
-:-:-
2004 Aug 06
4
vorbis bitrates - offtopic
Hi,
I'm experimenting with IceCast2, using DarkIce to generate the stream. I
have found some peculiarities with the vorbis bitrates.
In DarkIce, I call vorbis_encode_init() with about the following values:
vorbis_encode_init( &vorbisInfo, 2, 44100, 96, 96, 96);
which by all reasons should generate a 96 kb/s stream, as all
max_bitrate, nominal_bitrate and min_bitrate are set to 96.
2005 Oct 09
1
ov_read_float vs. ov_read
Hello,
Am I missing something?
float** pcm_channels;
int bitstream;
int where = ov_pcm_tell(&vf);
-> The Result is "0";
ov_read_float(&vf, &pcm_channels, 1, &bitstream);
-> pcm_channels[0][0] is "0.000338580"
ov_pcm_seek(&vf, 0);
char* buffer = new char[2];
ov_read(&vf, buffer, sizeof(buffer), 0, 2, 1, &bitstream);
short temp =
2015 Dec 04
1
A few questions about libvorbis from a newbie
I am deeply sorry about the corrupt message just being sent; there seems to have been a compatibility issue with my mailer and my browser.
This is an identical copy of the previous message:
Hello Martin,
Vorbis encoders are lossy, which is in a sense equivalent to converting the sample size of the raw PCM stream into something that would result in the desired bitrate.
The "sample size"
2002 Aug 20
1
managed mode / max bitrate doesn't have effect
Hi,
I'm experimenting with managed mode encoding with specifying maximum
bitrate. I call:
vorbis_encode_init( &vorbisInfo,
2,
44100,
-1,
96000,
96000);
to initialize the encoding. To my surprise, it seems the maxbitrate
value of 96000 doesn't have an effect, the bitrate of the
2006 May 11
1
Speed up?
Hello,
hope you're fine.
And hopefully someone can help me.
I wrote a short demonstration to show you my problem (see below). I'm
asking always for 64 samples. When "ov_read_float()" is finished, I
want to seek back to sample 1, and ask immediately for the next 64
samples.
But when I run this small app, I get an totally high CPU load.
Is there a way to it speed up?
Or do I
2004 Aug 06
2
vorbis_encode_init() bitrate arguments - offtopic
Hi,
It's a bit offtopic for this list, but you might be able to help. For
libvorbis rc3, what is the correct bitrate parametrization for the call
vorbis_encode_init()?
For rc2, it worked calling it the following way:
vorbis_encode_init( &vorbisInfo,
2, // two channels
44100, // 44.1kHz
2002 Jul 21
1
Vorbis 1.0 DLLs
My compiler isn't locating 'ov_read_float' from the prebuilt vorbisfile.dll.
Was that function missed from vorbisfile.def before compilation of the
Windows SDK files?
<p><p>J.
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