[alsa-devel] [ALSA-UTILS][PATCH] Add support for cplay and crecord

[Vinod Koul]

On Thu, Mar 05, 2015 at 08:43:18AM +0100, Jaroslav Kysela wrote:
> Dne 5.3.2015 v 08:00 Vinod Koul napsal(a):
> > On Wed, Mar 04, 2015 at 04:34:41PM +0000, Qais Yousef wrote:
> >> On 03/04/2015 04:10 PM, Vinod Koul wrote:
> >>> On Wed, Mar 04, 2015 at 03:36:00PM +0000, Qais Yousef wrote:
> >>>> cplay and crecord use compress offload API to play and record compressed audio.
> >>>>
> >>>> They're based on cplay and crec from tinycompress library using LGPL license.
> >>>>
> >>>> For now cplay only supports playing mp3 files.
> >>>>
> >>>> Signed-off-by: Qais Yousef <qais.yousef at imgtec.com>
> >>>> Cc: Takashi Iwai <tiwai at suse.de>
> >>>> Cc: Vinod Koul <vinod.koul at intel.com>
> >>>> Cc: Mark Brown <broonie at kernel.org>
> >>>> ---
> >>>> I renamed crec to crecord also to match aplay and arecord, hopefully
> >>>> you don't mind Vinod.
> >>> No thats fine..
> >>>
> >>>> This patch is dependent on my other patch that adds support for compress offload
> >>>> to alsa-lib.
> >>> And where is that, should have preceded this
> >>
> >> Hmm not sure what went wrong. I resent it. Seems I have some emailer
> >> issues as I had this problem before.
> >> Hopefully you received it now.
> >>
> >>>> I needed to include <sound/compress_params.h> in cplay.c and crec.c
> >>>> but I couldn't find an example of any C file which directly includes <sound/*.h>
> >>>> The norm seems to be to just include <alsa/asoundlib.h>. Do I need to
> >>>> redefine structs from <sound/compress_params.h> to newly added <alsa/compress.h>?
> >>>> <alsa/pcm.h> seems to redefine structs from <sound/asound.h>.
> >>> These are kernel headers and should be in your include path if you have
> >>> those installed
> >>>> I could only test cplay but have no means to test crecord at the moment.
> >>>>
> >>>>  Makefile.am       |   3 +
> >>>>  configure.ac      |   6 +-
> >>>>  cplay/Makefile.am |  14 ++
> >>>>  cplay/cplay.c     | 294 +++++++++++++++++++++++++++++++++++
> >>>>  cplay/crec.c      | 449 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>>>  cplay/tinymp3.h   |  72 +++++++++
> >>>>  6 files changed, 837 insertions(+), 1 deletion(-)
> >>>>  create mode 100644 cplay/Makefile.am
> >>>>  create mode 100644 cplay/cplay.c
> >>>>  create mode 100644 cplay/crec.c
> >>>>  create mode 100644 cplay/tinymp3.h
> >>> Okay here is where we need discussion on the future course. If we do this
> >>> then we end up in two code bases, something I would not encourage!
> >>>
> >>> On the other hand if we add the make file changes to tinycompress or if
> >>> required split this into two, lib and tools and then package lib part into
> >>> alsa-lib and players into tools, that way we can have single code base. That
> >>> was my intent behind ensuring that this is dual licensed.
> >>
> >> I'm not sure I follow you completely here. You mean keep cplay and
> >> crec in tinycompress with the dual licensing but only merge the lib
> >> part (which my other patch does) into alsa-lib? For me having this
> >> lib part into alsa-lib is the important bit. Moving crec and cplay
> >> to alsa-utils was something I thought would be useful but maybe not.
> > Not that
> > 
> > Since alsa splits lib and tools, in order to take this into alsa-libs we
> > need to split tinycompress, to something like lib and tool part.
> > 
> > Then alsa-lib can import the lib part of tinycompress. Please note I am not
> > saying we should copy or move code into alsa-lib.
> > The reason for that is
> > 1. copying code will cause more maintaince of same code in two places :(
> > 2. moving into alsa-lib is not an option as existing users like android will
> > suffer as they dont use alsa-lib
> > 
> > So I think, while building and packaging alsa-library and tools we can
> > import the tinycompress using LGPL license and use that to give complete
> > library on Linux to users
> > 
> > Takashi, can we get you blessing for this approach before we embark on this,
> > or any other better ideas?
> 
> The problem is if the code is not duplicated, then the parts of the
> alsa-lib binary will be dual-licenced. I don't think that it's the right
> way.
> 
> And if the code is duplicated, then patch authors for all next updates
> in both libraries (alsa-lib, tinycompress) must be asked for permissions
> to change code licence for the merge to the second library.
> 
> I think that a plugin-style extension should be created here (so
> tinycompress will be used at runtime as the dynamic library).
> 
> compress API -> tinycompress plugin -> tinycompress .so functions
> 
> This will allow us also to create another plugins in future.
That does solve the issue for me as well. The intent is to provide
compressed functionality within alsa-libs so asa plugin that can work very
well...

Any other thoughts... ?

-- 
~Vinod