Displaying 20 results from an estimated 10000 matches similar to: "preskip and seeking suing Opus"
2013 Aug 15
2
preskip and seeking suing Opus
Yes, that's a start.
Ultimately, though, I'm hoping to reduce the 80ms requirement, and am
trying to get a handle on what state in the decoder must converge and what
complications I might be up against. I'm also only considering CELT-based
encodings if that simplifies things.
I know that Opus can do inter-frame energy envelope prediction, but that
dependency can be eliminated by
2013 Aug 15
0
preskip and seeking suing Opus
On 13-08-14 10:09 PM, Bob Estes wrote:
> I've been studying the Opus code and documentation for a while and have
> seen it mentioned several times that Opus uses pre-skip to allow the
> codec to converge. What convergence are they referring to? Rate
> control? Energy envelope prediction after seeking?
Not rate control, but there are a number of predictors running in the
2019 Aug 16
4
MetaData Update for FLAC and OPUS
I am a software developer myself. We develop a Radio Automation System/Broadcasting. Hence we are using the reference encoders.
For OGG there is LUCKILY still the admin interface working to update meta data mid-stream.
That is why my post is related to the other ogg based formats: FLAC and OPUS!
Tractor Pro is btw not supporting FLAC or OPUS and alao uses the admin update interface!
As such
2014 Jun 03
1
Question about FEC and ogg/opus
Hello,
We have a use case where we want to record an opus RTP stream to a .opus
file. We want to fill in any gaps in the stream, and we also want to
take advantage of inband FEC whenever possible.
The ogg/opus draft describes[1] how to fill in gaps by generating
zero-byte frames, but I do not understand how (and if) FEC can be used.
Is this possible, and if so, what is the recommended way of
2017 Nov 16
2
Gapless concatenation of Opus frames
Hi all,
I finally understand how lipopusenc is capable of producing chainable
Opus files (in contrast to my program), and I managed to successfully
implement the method [1].
Essentially, the last frame of a file is marked as a "keyframe" by
disabling prediction for this frame in libopus. This encoded keyframe
frame is then copied in verbatim to the next file, with the pre-skip
set to
2014 Jan 21
1
Opus in WebM
It does not; Vorbis needs only lap consecutive frames, and the timing was
constructed so that the 'timestamp' of a vorbis frame actually points to
the middle of the frame data. When you combine a starting frame with the
subsequent frame, the data you get back is from the starting timestamp
forward. Because Opus needs to preroll a larger amount, that trick wouldn't
work with Opus.
2013 Oct 18
7
AM335x ARM Cortex-A8 performance drop opus 1.1
Hello!,
i've just compared the 1.0.3 release with the master branch
on a BeagleBone Black (AM335x 1GHz ARM Cortex-A8 with NEON
floating-point accelerator) and Arch Linux ARM.
At the moment I dont no why, but I see that 1.1 is much slower
in encoding. Are there any default changes, that I missed and could
explain this? Normaly I suggested a better performance with 1.1 and
the ARM
2008 Aug 12
7
New Ogg Dirac mapping draft
David Flynn has proposed a new Ogg Dirac mapping. The draft is here:
http://davidf.woaf.net/dirac-mapping-ogg.pdf
This is a much bigger break from other codecs than my draft (at
http://wiki.xiph.org/index.php/OggDirac). We talked a bit about it on
IRC today. Below is my summary; hopefully David can correct anything
I got wrong or misleading. Comments?
There are two main differences
2006 Dec 30
5
Theora encoding in FFmpeg
(Cross posted to theora-dev@xiph.org and ffmpeg-devel@mplayerhq.hu)
I am working towards adding Theora encoding support to libavcodec in
FFmpeg. I am doing this by simply calling libtheora from libavcodec.
I am at the point where I can execute:
"./ffmpeg -v 100 -i test.wmv -f avi -an -vcodec theora -b 1000000 -y test.avi"
I get some whirring and an output file written. My calls to
2017 Nov 13
3
Gapless concatenation of Opus frames
Hi Jean-Mark,
thank you for your answer!
Yes, you understood my question correctly. I was just about to compose
a reply to my original question, where I described how I solved my
problem. As you've already suggested, I've switched to Ogg/Opus, which
is better supported, but does not work with the Media Source Extensions.
I'll have a look whether disabling prediction will help with
2020 Feb 13
2
opus-codec.org/comparison: Mono or Stereo?
Looking at the Opus comparison page[1], I can't figure out whether the
Opus/AAC/Vorbis/MP3 lines are meant to imply a mono or stereo
encoding. Could someone please update the caption to clarify this?
The single dot for G.711 is clearly mono, but for stereo music, are
the codecs at the top meant to converge near 128 kbps, or 256 kbps?
[1] http://opus-codec.org/comparison/
2014 Apr 14
3
Opus on MIPS performance
Hi All,
First time poster to this group, please ignore my ignorance?
I?m trying to use Opus 1.1 on a 400MHz MIPS 24k CPU (AR9331, specifically, like in the Arduino Yun).
I?ve successfully built (I think) opus-1.1 and opus-tools-1.8 and they run, but are dog slow.
opus-1.1 does have the ?enable-fixed-point option set, as this chip only has soft-float.
My short test file (less than one
2004 Aug 06
1
Speex, what container?
But is there any sound player for windows that plays speex in an ogg container?
One more question, besides the source code found in the speex site (like speexenc.c) can you tell me where to find source code developed in C++ (using object oriented programing) that makes it easier to write ogg files with speex content?
Miguel Gomes
-----Mensagem original-----
De:
2017 Feb 06
2
libvorbis without encapulsation
L'octidi 18 pluviôse, an CCXXV, Miscellaneous a écrit :
> > The RLP draft mentioned on the libvorbis docs page, are there sample
> > implementations (in C) of this yet anywhere?
> Sorry that should say RTP, not RLP
I am not sure I understand exactly what you are asking, but libavformat
has a RTP packetizer that works for both Vorbis and Theora, implemented
in rtpenc_xiph.c.
2018 Oct 25
2
Possible bug in Opus 1.3 (opus-tools-0.2-opus-1.3)?
Hi!
Playing with Opus 1.3 I converted a tone sweep with a sample rate of 96kHz (just for fun). Before I had converted that from WAV to FLAC, and to Vorbis without problems.
With Opus I noticed that the file size for 48kHz and 48 kbps compared to 96kHz Vorbis at 31kbps is about double the size and it sounds even worse (than Vorbis) (there is a lot of noise in the lower frequencies when a low
2013 May 15
2
Info OPUS encoder
Hello,
I am testing the command line based opus encoder/decoder tools and I have some questions regarding the information given by the encoder (see below as an example).
Encoding using libopus 1.0.2 (audio)
-----------------------------------------------------
Input: 48kHz 1 channel
Output: 1 channel (1 uncoupled)
20ms packets, 64kbit/sec VBR
Preskip: 312
Encoding complete
2013 Jul 22
2
Encoder state management - 'chunked' Opus?
Hi,
I'm playing around using Opus in a 'chunked' streaming context, where
chunks of media are served in separate HTTP responses.
I am trying to hunt down the source of some clicks-and-pops during
playback, and while it is very likely that these glitches are due to the
low quality of my code, I wanted to ask if the admonition in the API
docs[1] that "encoder state *must*
2017 Nov 15
2
Gapless concatenation of Opus frames
Hi Jean-Marc (and everyone else who replied),
> Considering you're switching to Ogg, I think you should give libopusenc> a try. It does a really good job at getting rid of *all*
discontinuities> -- to the point where you can chop a song into files
less than one> millisecond each and it still sounds good. It's also
pretty simple to> use. You just feed it audio and tell it
2015 Oct 17
1
Why does this code not generate a valid opus file?
Hi.
I assume that I am deeply stupid and have missed something obvious, but why does this bare-bones code not generate a valid (If trivial) opus file?
Running opusinfo I ge the following which I interpret this to mean that not even the first packet gets a pass:
New logical stream (#1, serial: 1f0cce42): type opus
WARNING: Could not decode Opus header packet 0 - invalid Opus stream (1)
WARNING:
2013 May 11
2
Javascript source client
Thomas,
Thank you for your interest in this, you description is as accurate as I
can see.
> From my perspective your challenges will be to get the containers right.
> WebM for audio+video
> Ogg for audio
>
> Also (I'm not that familiar with webRTC) you might need to reencode
> to Opus and VP8 in some cases?
here is the great news