OpusTodo: Difference between revisions
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== For 1.2 == | |||
== | * Low bitrate quality improvements | ||
* | * AVX optimizations | ||
* Fix compilation as a single module for gecko | |||
* | |||
* | |||
== Spec == | == Spec == | ||
* Matroska mapping. See: [[MatroskaOpus]] And firefox/ffmpeg implementation | |||
* RTP payload format. Mono/stereo mapping is complete [[https://tools.ietf.org/html/rfc7587 RFC 7587]], no multichannel mapping yet. | |||
* mp4 mapping. See [[https://opus-codec.org/docs/opus_in_isobmff.html ISO Base Media File Format draft]] | |||
* | == 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?) | ||
** [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, ...) | |||
** 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 == | == Other == | ||
* Oggz-validate (should also validate opus toc) | * Oggz-validate (should also validate opus toc) | ||
== Opus-tools == | == Opus-tools == | ||
* | * Port opusdec to libopusfile/libopusurl. | ||
* A simple real time streaming example tool | * A simple real time streaming example tool | ||
* < | ** Start with opusrtp.c in [https://git.xiph.org/?p=opus-tools.git opus-tools] | ||
* Replaygain (half done— needs a gain tool) | ** 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 | |||
== Optimisations == | |||
* Vectorising comb_filter() | |||
* Use 16-bit mul plus shift in denormalise_bands() | |||
* Optimise MDCT somehow | |||
== 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] | |||
== 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 | |||
[[Category:Opus]] | |||
Latest revision as of 18:59, 19 July 2016
For 1.2
- Low bitrate quality improvements
- AVX optimizations
- Fix compilation as a single module for gecko
Spec
- Matroska mapping. See: MatroskaOpus And firefox/ffmpeg implementation
- RTP payload format. Mono/stereo mapping is complete [RFC 7587], no multichannel mapping yet.
- mp4 mapping. See [ISO Base Media File Format draft]
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