From: Roman Shaposhnik <rvs@sun.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] audio standards -- too many to choose from
Date: Wed, 12 Aug 2009 19:16:14 -0700 [thread overview]
Message-ID: <97C5540D-6FE2-4587-9F05-8799E0056622@sun.com> (raw)
In-Reply-To: <Pine.BSI.4.64.0908112221450.20861@malasada.lava.net>
On Aug 12, 2009, at 1:28 AM, Tim Newsham wrote:
>>> I agree wrt. "mp3". I'm considering the possibility of supporting
>>> alaw, ulaw, pcm8, pcm16 in big/little and signed/unsigned formats,
>>> and adpcm, using the hardware features...
>>
>>
>> Here's a complete list of audio formats that one can make hardware
>> either generate or accept. Where do you draw the line?
>> $ ffmpeg -formats | grep DEA | egrep -v "wmav|vorbis|flac"
>> DEA adpcm_4xm
>> DEA adpcm_adx
>> DEA adpcm_ct
> [...]
>
> Draw the line at what the hardware can be told to decode
> with a flip of a register?
Pretty much all of the above.
> The driver interface can easily
> accomodate arbitrary encoding names (see inferno's driver
> for an example). The rest is just mapping strings to register
> values. With the appropriate API, supporting 30 audio formats
> is hardly harder than supporting 3....
My list was only there to try and prove the point that Russ has
made -- pick a most common format and stick with it. Convert
everything else into it. Forget about the fact that hardware
can/could do gazillion variations. At least forget about it for
the time being while you're getting basics right.
> One thing that strikes me is that if the device interface is
> designed in a flexible way that allows for arbitrary codings, then
> it will be easy to layer a userland driver on top of it that
> extends the API with more encodings that arent supported in hardware.
> If the interface isnt flexible in this way, then a separate
> interface will have to be made for such a userland driver...
> I'm not sure what the value of unifying those two interface is...
I don't think I buy this point of view. Gratuitous flexibility is not
something Plan 9 is known for, nor should it. IMHO.
Thanks,
Roman.
next prev parent reply other threads:[~2009-08-13 2:16 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-12 1:08 Tim Newsham
2009-08-12 1:14 ` erik quanstrom
2009-08-12 1:31 ` Tim Newsham
2009-08-12 1:45 ` erik quanstrom
2009-08-12 2:07 ` Tim Newsham
2009-08-12 3:14 ` ron minnich
2009-08-12 3:24 ` erik quanstrom
2009-08-12 4:49 ` Charles Forsyth
2009-08-12 4:24 ` Russ Cox
2009-08-12 4:35 ` Charles Forsyth
2009-08-12 15:12 ` Russ Cox
2009-08-12 4:36 ` Roman Shaposhnik
2009-08-12 15:36 ` hiro
2009-08-14 2:45 ` Roman V. Shaposhnik
2009-08-14 13:56 ` hiro
2009-08-12 5:15 ` Tim Newsham
2009-08-12 5:39 ` Roman Shaposhnik
2009-08-12 8:28 ` Tim Newsham
2009-08-12 9:30 ` Steve Simon
2009-08-13 2:16 ` Roman Shaposhnik [this message]
2009-08-13 3:17 ` erik quanstrom
2009-08-13 22:48 ` James Tomaschke
2009-08-13 22:52 ` erik quanstrom
2009-08-13 23:19 ` Christopher Nielsen
2009-08-13 23:47 ` James Tomaschke
2009-08-14 0:00 ` erik quanstrom
2009-08-14 1:13 ` James Tomaschke
2009-08-14 1:41 ` Anthony Sorace
2009-08-14 2:30 ` James Tomaschke
2009-08-14 1:42 ` Devon H. O'Dell
2009-08-14 1:51 ` Devon H. O'Dell
2009-08-14 2:22 ` James Tomaschke
2009-08-14 3:16 ` Charles Forsyth
2009-08-14 3:42 ` James Tomaschke
2009-08-14 7:04 ` Charles Forsyth
2009-08-14 20:43 ` James Tomaschke
2009-08-15 9:26 ` Steve Simon
2009-08-14 13:16 ` matt
2009-08-14 4:51 ` Devon H. O'Dell
2009-08-14 5:01 ` Devon H. O'Dell
2009-08-14 5:56 ` James Tomaschke
2009-08-19 9:58 ` matt
2009-08-14 5:18 ` James Tomaschke
2009-08-14 14:39 ` Devon H. O'Dell
2009-08-14 9:16 ` Paul Donnelly
2009-08-14 13:47 ` hiro
2009-08-14 20:03 ` Tim Newsham
2009-08-14 21:24 ` sqweek
2009-08-14 21:54 ` Skip Tavakkolian
2009-08-15 12:23 ` hiro
2009-08-14 22:05 ` Bakul Shah
2009-08-12 5:43 ` Anthony Sorace
2009-08-12 5:59 ` Roman Shaposhnik
2009-08-12 6:11 ` Roman Shaposhnik
2009-08-12 11:18 ` erik quanstrom
2009-08-13 2:06 ` Roman Shaposhnik
2009-08-12 22:11 ` James Tomaschke
2009-08-13 7:45 ` Skip Tavakkolian
2009-08-12 4:20 ` Roman Shaposhnik
2009-08-12 4:25 ` erik quanstrom
2009-08-12 4:50 ` Roman Shaposhnik
2009-08-12 5:10 ` Tim Newsham
2009-08-12 5:25 ` Roman Shaposhnik
2009-08-12 15:42 ` David Leimbach
2009-08-12 5:15 ` Anthony Sorace
2009-08-13 6:42 ` Skip Tavakkolian
2009-08-13 13:07 ` erik quanstrom
2009-08-13 13:30 ` Skip Tavakkolian
2009-08-13 13:31 ` Devon H. O'Dell
2009-08-13 14:31 ` Anthony Sorace
2009-08-13 14:41 ` Devon H. O'Dell
2009-08-13 17:20 ` hiro
2009-08-12 15:30 ` hiro
2009-08-12 5:54 ` Lawrence E. Bakst
2009-08-12 6:13 ` Roman Shaposhnik
2009-08-12 19:50 ` Tim Newsham
2009-08-12 20:57 ` Bakul Shah
2009-08-13 2:18 ` Roman Shaposhnik
2009-08-13 3:46 ` Tim Newsham
2009-08-13 17:00 ` Devon H. O'Dell
2009-08-13 19:13 ` Christopher Nielsen
2009-08-15 0:44 erik quanstrom
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