[opus] Ogg Format

[Amit Ashara]

Hello Jean-Marc,

The structure of the Ogg-Opus format is clear. That part of the thread is
closed

This is a second discussion I wanted to open on simplification of the
Ogg-Opus to a simpler format for micro-controllers irrespective of vendor
which could be supported by tools on PC as well.

Regards
Amit

On Wed, May 11, 2016 at 5:54 PM, Jean-Marc Valin <jmvalin at jmvalin.ca> wrote:

> Hi Amit,
>
> I'm not sure what you're trying to ask, but the reserved space in the
> header is an optional thing. Encoders are free to do it, but are not
> required to do so.
>
>         Jean-Marc
>
> On 05/11/2016 01:32 PM, Amit Ashara wrote:
> > Hello Jean-Marc,
> >
> > So for the moment we can assume that this method is also OK to use?
> >
> > On Embedded Systems, both SRAM and Flash can be a restricting factor
> > besides the compute time. To optimize the utilization of embedded
> > resources, may I suggest a simplification of the Ogg-Opus format and can
> > this be considered by the Opus org and IETF as an addition?
> >
> > Regards
> > Amit
> >
> > On Wed, May 11, 2016 at 12:09 PM, Jean-Marc Valin <jmvalin at jmvalin.ca
> > <mailto:jmvalin at jmvalin.ca>> wrote:
> >
> >     On 05/11/2016 12:35 PM, Amit Ashara wrote:
> >     > I ran the opusenc.exe on a wave file and checked the OpusTag
> section. My
> >     > concern is on Total Segment Size being >> than the actual data
> being
> >     > put. Is this just an example of implementation or does a size of
> 764
> >     > BYTES kept as a place holder for putting more data?
> >
> >     Yes, opusenc does reserve some space in the header so that tags can
> >     later be modified "in place", without having to rewrite the entire
> file.
> >
> >             Jean-Marc
> >
> >
> >     > 4f 67 67 53 = Oggs
> >     > 00 = Version
> >     > 00 = Header
> >     > 00 00 00 00 00 00 00 00 = Granule Position
> >     > a5 73 00 00 = Bit Stream Serial Number
> >     > 01 00 00 00 = Page Sequence Numner
> >     > 90 a9 36 42 = Checksum
> >     > 03 = Page Segments
> >     > ff ff fe = Each Segment Size (TOTAL SIZE IS 764 BYTES)
> >     > 4f 70 75 73 54 61 67 73 = OpusTags
> >     > 0b 00 00 00 = Vendor String Length of 11
> >     > 6c 69 62 6f 70 75 73 20 31 2e 31 = "libopus 1.1"
> >     > 03 00 00 00 = User Comment List Length of 3
> >     > 25 00 00 00 = User Comment #0 String Length of 37
> >     > 45 4e 43 4f 44 45 52 3d 6f 70 75 73 65 6e 63 20 66 72 6f 6d 20 6f
> >     70 75
> >     > 73 2d 74 6f 6f 6c 73 20 30 2e 31 2e 39 = "ENCODER=opusenc from
> >     > opus-tools 0.1.9"
> >     > 0a 00 00 00 = User Comment #1 String Length of 10
> >     > 74 69 74 6c 65 3d 48 4f 4c 41 = "title=HOLA"
> >     > 1e 00 00 00 = User Comment #2 String Length of 30
> >     > 45 4e 43 4f 44 45 52 5f 4f 50 54 49 4f 4e 53 3d 2d 2d 6d 61 78 2d
> >     64 65
> >     > 6c 61 79 20 32 30 = "ENCODER_OPTIONS=--max-delay 20"
> >     > 00 00 00... ALL THE WAY TO THE NEXT Oggs Container
> >     >
> >     > Regards
> >     > Amit
> >     >
> >     > On Tue, May 10, 2016 at 10:47 PM, Ralph Giles <giles at thaumas.net
> >     <mailto:giles at thaumas.net>
> >     > <mailto:giles at thaumas.net <mailto:giles at thaumas.net>>> wrote:
> >     >
> >     >     On 10/05/16 02:37 PM, Amit Ashara wrote:
> >     >
> >     >     > Is there a format document on the OpusTag structure? Search
> always shows
> >     >     > up Vorbis but not Opus.
> >     >
> >     >     The basic format is shared with Vorbis, but the 'magic
> signature' is
> >     >     different ('OpusTags' instead of '0x05vorbis') and vorbis puts
> a 0x01
> >     >     value in an extra byte after the last tag.
> >     >
> >     >     The OpusTag packet layout is described in
> >     >     https://tools.ietf.org/html/rfc7845.html#section-5.2
> >     >
> >     >     Common tag names used for interoperability are described in
> the Vorbis
> >     >     documentation. See
> https://www.xiph.org/vorbis/doc/v-comment.html
> >     >     There are more extensive tag lists on some other sites.
> >     >
> >     >
> >     >
> >     >
> >     > _______________________________________________
> >     > opus mailing list
> >     > opus at xiph.org <mailto:opus at xiph.org>
> >     > http://lists.xiph.org/mailman/listinfo/opus
> >     >
> >
> >
>
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