Displaying 20 results from an estimated 6000 matches similar to: "Fwd: [codec] Last proposal for the update draft"
2014 Jun 18
0
Alleged bug in Silk codec
Hi Marcello,
It turns out that the problem has a much simpler explanation. As far as
I can tell, it's actually a bug in silk_sum_sqr_shift() and this trivial
patch appears to fix the problem:
http://jmvalin.ca/misc_stuff/sum_sqr_shift_fix.patch
It would still require some testing to check that the fix doesn't have
any bad side effect. Let me know how well the fix works for you. Again,
2014 Jun 20
0
Alleged bug in Silk codec
Hi Marcello,
Actually, we were careful to avoid the undefined behaviour here. In
fact, we are specifically running a clang test detecting undefined
behaviour. If you look at the silk_SMLABB_ovflw() macro, you will see it
is based on silk_ADD32_ovflw(), which is defined as:
#define silk_ADD32_ovflw(a, b) ((opus_int32)((opus_uint32)(a) +
(opus_uint32)(b)))
By casting to unsigned, all the cases
2014 Jun 20
2
Alleged bug in Silk codec
Right, there shouldn't be a problem with undefined behavior.
That said, a 64 bit implementation will work very well - in fact that's how
it was done originally.
The reason for the current implementation is to minimize 64-bit operations
in order to improve performance on limited-width architectures. This
functions gets used extensively, and I think the current implementation is
faster on
2014 Jun 20
2
Alleged bug in Silk codec
Hi Jean-Marc,
well spotted! The patch provided fixes the issue for me.
Nevertheless, in my code (and I would suggest doing the same in libopus) I
am going to replace the function with one that accumulates on 64 bits and
then calculates the shift, for at least 4 reasons:
- It is less and simpler code
- The result is likely to be slightly more accurate in case big numbers
come early in the
2017 Nov 13
1
libopusenc 0.1.1 released
Hi Drew,
On 11/13/2017 03:34 PM, Drew Allen wrote:
> Does your encoder support ch253/254?
Not at this point. Only families 0 and 1 are supported. I think adding
family 2 shouldn't be relatively straightforward, but adding family 3
would require some thought.
Cheers,
Jean-Marc
> Cheers,
> Drew
> On Mon, Nov 13, 2017 at 12:33 PM Jean-Marc Valin <jmvalin at jmvalin.ca
>
2017 Nov 16
0
Gapless concatenation of Opus frames
Hi Andreas,
So I encoded your file in chunks with a slightly modified version of
opusenc_example and I can't hear anything wrong. Maybe there's a problem
in the tools you used? I uploaded the files at:
https://jmvalin.ca/misc_stuff/continuous.opus (one file)
https://jmvalin.ca/misc_stuff/continuous.wav (one file, decoded)
https://jmvalin.ca/misc_stuff/chained.opus (many small files)
2017 Nov 13
3
libopusenc 0.1.1 released
Hi,
Just to let everyone know that I released libopusenc version 0.1.1. It
does not change the API/ABI compared to 0.1, but fixes a few bad bugs.
You can get it from https://www.opus-codec.org/downloads/
For those interested in testing it, there's an experimental patch to
make opus-tools use libopusenc for the encoder:
2017 Nov 16
1
Gapless concatenation of Opus frames
Hi Jean-Marc,
thank you for looking into this. I'm using the current release version
of libopus (1.2.1) and version 0.1.10 of opus-tools, both built from
source. Libopusenc is the current git master.
Indeed I cannot hear any glitches in continuous.opus, continuous.wav,
and chained.wav. chained.opus decodes just fine with opusdec as well,
but doesn't play properly in any standard audio
2017 Nov 13
0
libopusenc 0.1.1 released
Hey Jean-Marc,
Does your encoder support ch253/254?
Cheers,
Drew
On Mon, Nov 13, 2017 at 12:33 PM Jean-Marc Valin <jmvalin at jmvalin.ca> wrote:
> Hi,
>
> Just to let everyone know that I released libopusenc version 0.1.1. It
> does not change the API/ABI compared to 0.1, but fixes a few bad bugs.
> You can get it from https://www.opus-codec.org/downloads/
>
> For
2014 Jun 13
3
Alleged bug in Silk codec
Hi Jean Marc,
please find attached the audio file (mono 16khz). I shortened it to about
10 seconds. I also add 2 patches that worked for me. Further info that
might help:
- The problem seems to be related to silk_burg_modified not reaching the
maximum gain, so the actual filter order is 16 rather than 2 (which is
what would be expected with a sine wave).
- The problem seems to happen when
2017 Oct 30
0
OPUS vs MP3
Hi,
Before I comment on the graphics you posted to visualize the difference
between two audio signals, I'd like to ask for your help in evaluating
my JPEG encoder. I've encoded an image with JPEG and then computed the
difference with the original. I then converted the difference to sound.
You can listen to the image difference on this clip:
https://jmvalin.ca/misc_stuff/diff.wav
Can you
2018 Dec 28
1
[PATCH nbdkit] common: Improve pseudo-random number generation.
Currently we use non-cryptographically secure random numbers in two
places, the error filter (to inject errors at random) and the random
plugin. For this we have used either random_r or a home-brew-ish
Linear Congruential Generator. Use of random_r is problematic on BSDs
because it doesn't exist there. Use of the LCG is simply a bad
choice.
Replace both uses with a better quality and
2018 Dec 28
0
[PATCH v2 nbdkit] common: Improve pseudo-random number generation.
Currently we use non-cryptographically secure random numbers in two
places, the error filter (to inject errors at random) and the random
plugin. For this we have used either random_r or a home-brew-ish
Linear Congruential Generator. Use of random_r is problematic on BSDs
because it doesn't exist there. Use of the LCG is simply a bad
choice.
Replace both uses with a better quality and
2017 Oct 31
0
OPUS vs MP3
Just to be clear, my goal here wasn't to make fun of anyone, but to
drive the point that spectrograms should *never* be used to demonstrate
quality. The only case where they can sometimes be useful is for
diagnostic purposes. If you hear something and you're not sure what
you're hearing exactly, then sometimes a spectrogram can help you figure
out what it is. That's pretty much it.
2017 Oct 31
3
OPUS vs MP3
Jean-Mark sarkasm.
Jean-Markasm.
(Bonus points for providing an actual noisy WAV! ^_^)
On 30/10/2017 20:28, Jean-Marc Valin wrote:
Hi,
Before I comment on the graphics you posted to visualize the difference
between two audio signals, I'd like to ask for your help in evaluating
my JPEG encoder. I've encoded an image with JPEG and then computed the
difference with the original. I then
2016 Jun 13
0
Patches for adding 120 ms encoding
Hi Mark, Jean-Marc,
Thanks for your comments.
On Sun, Jun 12, 2016 at 6:34 AM Mark Harris <mark.hsj at gmail.com> wrote:
> Hi Felicia,
>
> A few comments:
>
> > - /* CELT can only support up to 20 ms */
> > subframe_size = st->Fs/50;
> > - nb_subframes = frame_size > st->Fs/25 ? 3 : 2;
> > + nb_subframes =
2017 Oct 31
3
Antw: Re: OPUS vs MP3
Hi guys,
as MP3 and Opus have very similar objectives, I think the original poster's
question was a valid one: Why does Opus have more artefacts in the lower
frequency ranges than MP3 has? The spontaneous suspect that lower frequency
artefacts may be more noticeably than higher frequency artefacts seems
plausible, also. Is it a matter of energy (which is higher for higher
frequencies)?
When
2016 Jun 27
0
Antw: Re: Patches for adding 120 ms encoding
Hi!
A note on style: Looking at this chunk of the patch
--
@@ -382,9 +382,15 @@ int main(int argc, char *argv[])
frame_size = sampling_rate/25;
else if (strcmp(argv[ args + 1 ], "60")==0)
frame_size = 3*sampling_rate/50;
+ else if (strcmp(argv[ args + 1 ], "80")==0)
+ frame_size = 4*sampling_rate/50;
+
2009 Jul 06
2
CELT 0.6.0 released, submitted as IETF draft
Hi everyone,
I'm pleased to announce version 0.6.0 of CELT, with many quality
improvements. This includes better stereo coupling, better handling of
transients, and better handling of highly tonal signals. In addition,
packet loss robustness has been improved through the optional use of
independent (intra) frames. CELT now supports a larger dynamic range,
suitable for encoding 24-bit audio
2017 Jan 27
0
FEC and Stereo
Thank you. Very helpful.
> On Jan 27, 2017, at 12:40 PM, Jean-Marc Valin <jmvalin at jmvalin.ca> wrote:
>
> On 27/01/17 12:29 PM, Jon Lederman wrote:
>> Thank you. Yes, we do need both channels independent. So, if we
>> encode each channel separately, we will be sacrificing the
>> compression ratio we would achieve with stereo encoding, correct?
>
> Not