Difference between revisions of "OpusTodo"

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(update for 1.1.3)
 
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== Code ==
+
== For 1.2 ==
 +
* Low bitrate quality improvements
 +
* AVX optimizations
 +
* Fix compilation as a single module for gecko
  
=== For IETF draft ===
+
== Spec ==
* Code cleanup
+
* Matroska mapping. See: [[MatroskaOpus]] And firefox/ffmpeg implementation
** Remove SKP_ prefixes
+
* RTP payload format. Mono/stereo mapping is complete [[https://tools.ietf.org/html/rfc7587 RFC 7587]], no multichannel mapping yet.
** remove silk_ prefixes in file names
+
* mp4 mapping. See [[https://opus-codec.org/docs/opus_in_isobmff.html ISO Base Media File Format draft]]
** s/libcelt/celt/ ?
 
* Multi-channel signalling (done, needs more testing)
 
* Implement OPUS_RESET (done, untested)
 
* remove unnecessary float<->int conversions
 
  
== SILK issues ==
+
== Website ==
* PLC buffer not fully initialized (fix needs verifying)
+
* De-uglify webpage - some suggestions:
* Mid and side using different sampling rates (fix needs verifying)
+
** write about codecs obsoleted by OPUS (Speex, CELT, Vorbis(?) and the proprietary ones)
* <s>LLBR stereo issue (has a proposed fix)</s>
+
** write about implementations (libopus encoder/decoder, libavcodec decoder, any others?)
** <s>Introduces prefill bug (fixed on greg's tree)</s>
+
** [https://en.wikipedia.org/wiki/Comparison_of_audio_coding_formats audio codec comparison table] (Opus, Vorbis, Speex, ..., MP5) of features (channels, freq, bits per sample, license, language (C89), integer impl. (Vorbis decoder only, Opus YES, ...)
* Artefacts on SILK mono<->stereo switching
+
** future use in video files (Theora? Dirac? WebM? other future codecs...)
* Artefacts on SILK frame size switching (e.g. 960,480 glitches)
+
** audio files for storage (like Vorbis, no raw Opus defined, only inside OGG), ...  
* Use of signed overflow (undefined in C), intentionally and otherwise.  
+
* Promotional material (some nice free/public-domain sounds/radio stations in Opus format)
* Encoder triggers DTX randomly (even if not enabled) for 40/60 ms stereo frames
 
  
=== Later ===
+
== Other ==
* <strike>Exposed CELT constrained VBR</strike>
+
 
* <strike>Fixed-point build</strike>
+
* Oggz-validate (should also validate opus toc)
* <strike>Fix build system (right now it fails to build shared libraries, drops .o files all over)</strike>
+
 
* <strike>Floating point API</strike>
+
== Opus-tools ==
* Usable command-line tools (opus is a major regression from libcelt right now)
+
* Port opusdec to libopusfile/libopusurl.
* Smart automatic mode decision
+
* A simple real time streaming example tool
* psymodel based VBR
+
** Start with opusrtp.c in [https://git.xiph.org/?p=opus-tools.git opus-tools]
* Remove copy in inverse MDCT
+
** Make <code>opusrtp rtp://example.com:5431/</code> listen to that host and port and mux packets from there. Generalize the cpac bases --sniff implementation
 +
** Make sending similarly generic. Maybe just <code>opusrtp source.opus -o rtp://example.com:5431/</code> to send source.opus out to the destination?
 +
** Make --sniff save one file per
 +
** Implement DTLS-SRTP. See webrtc.
 +
** audio capture/encode, decode/playback?
 +
** Parse and act on sdp for convenience and testing.
 +
 
 +
* EBU R128/Replaygain (half done— needs a gain tool)
 +
 
 +
== Surround work ==
 +
 
 +
* Apply spreading to energy masking
 +
* More conservative energy masking (not just mean difference) and dynalloc
 +
* Allow SILK/hybrid on center channel for voice?
 +
 
 +
== Psychoacoustic stuff ==
 +
 
 +
* Adaptive width narrowing and forced intensity stereo bands
  
== Spec ==
+
== Optimisations ==
  
* Finish codec draft
+
* Vectorising comb_filter()
* Ogg mapping (including multi-channel). See: [[OggOpus]]
+
* Use 16-bit mul plus shift in denormalise_bands()
* RTP payload format
+
* Optimise MDCT somehow
  
== Other ==
+
== Third-Party tool enhancements ==
 +
* mutagen: [https://bitbucket.org/lazka/mutagen/issue/202/oggopus-support-in-place-rewrites-for support padding in comments header], [https://bitbucket.org/lazka/mutagen/issue/203/oggopus-allow-updating-the-output_gain allow updating output gain in ID header]
  
* Logo
+
== Future work ==
* Test vectors
+
* psymodel based VBR
* Listening tests
+
* Remove copy in inverse MDCT
* Documentation (at a minimum every exported symbol should have complete and accurate documentation)
+
* Save some float<->int conversions
* Add content to opus-codec.org
+
* Improvements to LP mode CBR (greg has some code)
* Oggz-validate (should also validate opus toc)
+
* Unconstrained SILK VBR
** The above documentation
+
* Better handling for the case where FEC has a different bandwidth than the current mode
** Presentations
+
* PLC transitions on unprotected SILK-SILK bandwidth changes?
** Examples and test results  (hyperlink to Monty's demo, gmaxwell's HA results page, etc)
+
* Figure out how to use speech/music detection optimally
* Useful example software (e.g. streaming software that works correctly) (opus-tools in xiph git)
+
** find optimal switching time (low energy/tonality)
** <s>Support for resampling in tools</s>
+
* Improve variable frame size
  
== Third party software ==
+
[[Category:Opus]]
* Support in ekiga
 
* Support in mumble
 
* Support in asterisk
 
* Support in firefox (rtcweb and in ogg)
 
* Support in VLC
 
* Support in ogg123
 
* Support in ffmpeg
 
* Support in rockbox
 
* Support in foobar2000
 
* Support in gstreamer
 
* Support in mplayer
 
* Support in xmms
 
* Support in oggdsf
 
* Support in xiphqt
 

Latest revision as of 19:59, 19 July 2016

For 1.2

  • Low bitrate quality improvements
  • AVX optimizations
  • Fix compilation as a single module for gecko

Spec

Website

  • De-uglify webpage - some suggestions:
    • write about codecs obsoleted by OPUS (Speex, CELT, Vorbis(?) and the proprietary ones)
    • write about implementations (libopus encoder/decoder, libavcodec decoder, any others?)
    • audio codec comparison table (Opus, Vorbis, Speex, ..., MP5) of features (channels, freq, bits per sample, license, language (C89), integer impl. (Vorbis decoder only, Opus YES, ...)
    • future use in video files (Theora? Dirac? WebM? other future codecs...)
    • audio files for storage (like Vorbis, no raw Opus defined, only inside OGG), ...
  • Promotional material (some nice free/public-domain sounds/radio stations in Opus format)

Other

  • Oggz-validate (should also validate opus toc)

Opus-tools

  • Port opusdec to libopusfile/libopusurl.
  • A simple real time streaming example tool
    • Start with opusrtp.c in opus-tools
    • Make opusrtp rtp://example.com:5431/ listen to that host and port and mux packets from there. Generalize the cpac bases --sniff implementation
    • Make sending similarly generic. Maybe just opusrtp source.opus -o rtp://example.com:5431/ to send source.opus out to the destination?
    • Make --sniff save one file per
    • Implement DTLS-SRTP. See webrtc.
    • audio capture/encode, decode/playback?
    • Parse and act on sdp for convenience and testing.
  • EBU R128/Replaygain (half done— needs a gain tool)

Surround work

  • Apply spreading to energy masking
  • More conservative energy masking (not just mean difference) and dynalloc
  • Allow SILK/hybrid on center channel for voice?

Psychoacoustic stuff

  • Adaptive width narrowing and forced intensity stereo bands

Optimisations

  • Vectorising comb_filter()
  • Use 16-bit mul plus shift in denormalise_bands()
  • Optimise MDCT somehow

Third-Party tool enhancements

Future work

  • psymodel based VBR
  • Remove copy in inverse MDCT
  • Save some float<->int conversions
  • Improvements to LP mode CBR (greg has some code)
  • Unconstrained SILK VBR
  • Better handling for the case where FEC has a different bandwidth than the current mode
  • PLC transitions on unprotected SILK-SILK bandwidth changes?
  • Figure out how to use speech/music detection optimally
    • find optimal switching time (low energy/tonality)
  • Improve variable frame size