[vlc-devel] [PATCH 14/18] Add KAI audio output module for OS/2
Rémi Denis-Courmont
remi at remlab.net
Fri Oct 21 17:14:49 CEST 2011
Le vendredi 21 octobre 2011 17:22:22 KO Myung-Hun, vous avez écrit :
> Rémi Denis-Courmont wrote:
> > On Thu, 20 Oct 2011 21:30:21 +0900, KO Myung-Hun <komh at chollian.net>
> >
> > wrote:
> >> ---
> >>
> >> configure.ac | 23 +++
> >> modules/audio_output/Modules.am | 8 +
> >> modules/audio_output/kai.c | 327
> >> +++++++++++++++++++++++++++++++++++++++
> >> 3 files changed, 358 insertions(+), 0 deletions(-)
> >> create mode 100644 modules/audio_output/kai.c
> >>
> >> diff --git a/configure.ac b/configure.ac
> >> index 4687149..4fcca19 100644
> >> --- a/configure.ac
> >> +++ b/configure.ac
> >> @@ -3591,6 +3591,29 @@ dnl
> >>
> >> PKG_ENABLE_MODULES_VLC([SAMPLERATE], [], [samplerate], [Resampler with
> >> libsamplerate], [auto])
> >>
> >> dnl
> >>
> >> +dnl OS/2 KAI plugin
> >> +dnl
> >> +AC_ARG_ENABLE(kai,
> >> + [AS_HELP_STRING([--enable-kai],
> >> + [support the K Audio Interface KAI (default enabled on OS/2)])],, [
> >> + AS_IF([test "$SYS" = "os2"], [
> >> + enable_kai="yes"
> >> + ])
> >> +])
> >> +have_kai="no"
> >> +KAI_LIBS=""
> >> +AS_IF([test "$enable_kai" != "no"], [
> >> + AC_CHECK_HEADERS([kai.h], [
> >> + have_kai="yes"
> >> + AC_CHECK_LIB(kai, main, [
> >> + KAI_LIBS="-lkai"
> >> + ])
> >> + ])
> >> +])
> >> +AC_SUBST(KAI_LIBS)
> >> +AM_CONDITIONAL([HAVE_KAI], [test "${have_kai}" = "yes"])
> >> +
> >> +dnl
> >>
> >> dnl Interface plugins
> >> dnl
> >>
> >> diff --git a/modules/audio_output/Modules.am
> >> b/modules/audio_output/Modules.am
> >> index 0cbbbb7..c7d7cca 100644
> >> --- a/modules/audio_output/Modules.am
> >> +++ b/modules/audio_output/Modules.am
> >> @@ -45,3 +45,11 @@ libpulse_plugin_la_DEPENDENCIES =
> >>
> >> if HAVE_PULSE
> >> libvlc_LTLIBRARIES += libpulse_plugin.la
> >> endif
> >>
> >> +
> >> +libkai_plugin_la_SOURCES = kai.c
> >> +libkai_plugin_la_CFLAGS = $(AM_CFLAGS)
> >> +libkai_plugin_la_LIBADD = $(AM_LIBADD) $(KAI_LIBS)
> >> +libkai_plugin_la_DEPENDENCIES =
> >> +if HAVE_KAI
> >> +libvlc_LTLIBRARIES += libkai_plugin.la
> >> +endif
> >> diff --git a/modules/audio_output/kai.c b/modules/audio_output/kai.c
> >> new file mode 100644
> >> index 0000000..d691410
> >> --- /dev/null
> >> +++ b/modules/audio_output/kai.c
> >> @@ -0,0 +1,327 @@
> >
> > +/***********************************************************************
> > ******
> >
> >> + * kai.c : KAI audio output plugin for vlc
> >> +
> >
> > *************************************************************************
> > ****
> >
> >> + * Copyright (C) 2010 the VideoLAN team
> >> + *
> >> + * Authors: KO Myung-Hun <komh at chollian.net>
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License as published by
> >> + * the Free Software Foundation; either version 2 of the License, or
> >> + * (at your option) any later version.
> >> + *
> >> + * This program is distributed in the hope that it will be useful,
> >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> >> + * GNU General Public License for more details.
> >> + *
> >> + * You should have received a copy of the GNU General Public License
> >> + * along with this program; if not, write to the Free Software
> >> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA
> >> 02110-1301, USA.
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * Preamble
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +#ifdef HAVE_CONFIG_H
> >> +# include "config.h"
> >> +#endif
> >> +
> >> +#include <vlc_common.h>
> >> +#include <vlc_plugin.h>
> >> +#include <vlc_aout.h>
> >> +
> >> +#include <float.h>
> >> +
> >> +#include <kai.h>
> >> +
> >> +#define FRAME_SIZE 2048
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * aout_sys_t: KAI audio output method descriptor
> >> +
> >
> > *************************************************************************
> > ****
> >
> >> + * This structure is part of the audio output thread descriptor.
> >> + * It describes the specific properties of an audio device.
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +struct aout_sys_t
> >> +{
> >> + aout_packet_t packet;
> >> + HKAI hkai;
> >> +};
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * Local prototypes
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +static int Open ( vlc_object_t * );
> >> +static void Close ( vlc_object_t * );
> >> +static void Play ( audio_output_t *_p_aout, block_t *block );
> >> +
> >> +static ULONG APIENTRY KaiCallback ( PVOID, PVOID, ULONG );
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * Module descriptor
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +#define KAI_AUDIO_DEVICE_TEXT N_( \
> >> + "Device:" )
> >
> > Should not have trailing semicolon.
>
> Colon ? If so, fixed.
>
> >> +#define KAI_AUDIO_DEVICE_LONGTEXT N_( \
> >> + "Select a proper audio device to be used by KAI" )
> >
> > Sentence should end with a dot.
>
> Ok.
>
> >> +
> >> +#define KAI_AUDIO_EXCLUSIVE_MODE_TEXT N_( \
> >> + "Open audio in exclusive mode" )
> >> +#define KAI_AUDIO_EXCLUSIVE_MODE_LONGTEXT N_( \
> >> + "Enable this option if you want your audio not to be interrupted by
> >> the " \
> >> + "other audio" )
> >
> > Same here.
>
> Fixed.
>
> >> +
> >> +static const char *const ppsz_kai_audio_device[] = {
> >> + "auto", "dart", "uniaud" };
> >> +static const char *const ppsz_kai_audio_device_text[] = {
> >> + N_("Auto"), "DART", "UNIAUD" };
> >> +
> >> +vlc_module_begin ()
> >> + set_shortname( "KAI" )
> >> + set_description( N_("K Audio Interface audio output") )
> >> + set_capability( "audio output", 100 )
> >> + set_category( CAT_AUDIO )
> >> + set_subcategory( SUBCAT_AUDIO_AOUT )
> >> + add_string( "kai-audio-device", ppsz_kai_audio_device[0],
> >> + KAI_AUDIO_DEVICE_TEXT, KAI_AUDIO_DEVICE_LONGTEXT, false
> >
> > )
> >
> >> + change_string_list( ppsz_kai_audio_device,
> >> ppsz_kai_audio_device_text,
> >> + 0 )
> >> + add_bool( "kai-audio-exclusive-mode", false,
> >> + KAI_AUDIO_EXCLUSIVE_MODE_TEXT,
> >> KAI_AUDIO_EXCLUSIVE_MODE_LONGTEXT,
> >> + true )
> >> + add_shortcut( "kai" )
> >
> > This should be superfluous since the module is called kai already.
>
> Fixed.
>
> >> + set_callbacks( Open, Close )
> >> +vlc_module_end ()
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * Open: open the audio device
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +static int Open ( vlc_object_t *p_this )
> >> +{
> >> + audio_output_t *p_aout = (audio_output_t *)p_this;
> >> + aout_sys_t *p_sys;
> >> + char *psz_mode;
> >> + ULONG i_kai_mode;
> >> + KAISPEC ks_wanted, ks_obtained;
> >> + int i_nb_channels;
> >> + int i_bytes_per_frame;
> >> + vlc_value_t val, text;
> >> +
> >> + /* Allocate structure */
> >> + p_aout->sys = calloc( 1, sizeof( aout_sys_t ) );
> >> +
> >> + if( p_aout->sys == NULL )
> >> + return VLC_ENOMEM;
> >> +
> >> + p_sys = p_aout->sys;
> >> +
> >> + if( var_Get( p_aout, "audio-device", &val ) != VLC_ENOVAR )
> >> + {
> >> + /* The user has selected an audio device. */
> >> + if ( val.i_int == AOUT_VAR_STEREO )
> >> + {
> >> + p_aout->format.i_physical_channels
> >> + = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
> >> + }
> >> + else if ( val.i_int == AOUT_VAR_MONO )
> >> + {
> >> + p_aout->format.i_physical_channels = AOUT_CHAN_CENTER;
> >> + }
> >> + }
> >
> > This will corrupt p_aout->format.i_physical_channels for the next plug-in
> > if kaiOpen() fails afterward.
>
> Fixed.
>
> >> +
> >> + psz_mode = var_CreateGetString( p_aout, "kai-audio-device" );
> >
> > var_InheritString() should be enough here.
>
> Ok.
>
> >> + if( !psz_mode )
> >> + psz_mode = ppsz_kai_audio_device[ 0 ]; // "auto"
> >> +
> >> + i_kai_mode = KAIM_AUTO;
> >> + if( strcmp( psz_mode, "dart" ) == 0 )
> >> + i_kai_mode = KAIM_DART;
> >> + else if( strcmp( psz_mode, "uniaud" ) == 0 )
> >> + i_kai_mode = KAIM_UNIAUD;
> >> + msg_Dbg( p_aout, "selected mode = %s", psz_mode );
> >> +
> >> + if( psz_mode != ppsz_kai_audio_device[ 0 ])
> >> + free( psz_mode );
> >> +
> >> + i_nb_channels = aout_FormatNbChannels( &p_aout->format );
> >> + if ( i_nb_channels > 2 )
> >> + {
> >> + /* KAI doesn't support more than two channels. */
> >> + i_nb_channels = 2;
> >> + p_aout->format.i_physical_channels
> >> + = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
> >> + }
> >
> > Same problem as earlier.
>
> Fixed.
>
> >> +
> >> + /* Support s16l only */
> >> + p_aout->format.i_format = VLC_CODEC_S16L;
> >
> > And again.
>
> Fixed.
>
> >> +
> >> + aout_FormatPrepare( &p_aout->format );
> >
> > And lastly.
>
> Fixed.
>
> >> +
> >> + i_bytes_per_frame = p_aout->format.i_bytes_per_frame;
> >> +
> >> + /* Initialize library */
> >> + if( kaiInit( i_kai_mode ))
> >> + {
> >> + msg_Err( p_aout, "cannot initialize KAI");
> >> +
> >> + goto exit_free_sys;
> >> + }
> >> +
> >> + ks_wanted.usDeviceIndex = 0;
> >> + ks_wanted.ulType = KAIT_PLAY;
> >> + ks_wanted.ulBitsPerSample = BPS_16;
> >> + ks_wanted.ulSamplingRate = p_aout->format.i_rate;
> >> + ks_wanted.ulDataFormat = MCI_WAVE_FORMAT_PCM;
> >> + ks_wanted.ulChannels = i_nb_channels;
> >> + ks_wanted.ulNumBuffers = 2;
> >> + ks_wanted.ulBufferSize = FRAME_SIZE * i_bytes_per_frame;
> >> + ks_wanted.fShareable = !var_CreateGetBool( p_aout,
> >> +
> >> "kai-audio-exclusive-mode");
> >> + ks_wanted.pfnCallBack = KaiCallback;
> >> + ks_wanted.pCallBackData = p_aout;
> >> + msg_Dbg( p_aout, "requested ulBufferSize = %ld",
> >> ks_wanted.ulBufferSize );
> >> +
> >> + /* Open the sound device. */
> >> + if( kaiOpen( &ks_wanted, &ks_obtained, &p_sys->hkai ))
> >> + {
> >> + msg_Err( p_aout, "cannot open KAI device");
> >> +
> >> + goto exit_kai_done;
> >> + }
> >> +
> >> + msg_Dbg( p_aout, "open in %s mode",
> >> + ks_obtained.fShareable ? "shareable" : "exclusive" );
> >> + msg_Dbg( p_aout, "obtained i_nb_samples = %lu",
> >> + ks_obtained.ulBufferSize / i_bytes_per_frame );
> >> + msg_Dbg( p_aout, "obtained i_bytes_per_frame = %d",
> >> + p_aout->format.i_bytes_per_frame );
> >> +
> >> + p_aout->pf_play = Play;
> >> + p_aout->pf_pause = aout_PacketPause;
> >> + p_aout->pf_flush = aout_PacketFlush;
> >> +
> >> + aout_PacketInit( p_aout, &p_sys->packet,
> >> + ks_obtained.ulBufferSize / i_bytes_per_frame );
> >> + aout_VolumeSoftInit( p_aout );
> >> +
> >> + if ( var_Type( p_aout, "audio-device" ) == 0 )
> >> + {
> >> + /* First launch. */
> >> + var_Create( p_aout, "audio-device",
> >> + VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
> >> + text.psz_string = _("Audio Device");
> >> + var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text,
> >
> > NULL
> >
> >> );
> >> +
> >> + val.i_int = AOUT_VAR_STEREO;
> >> + text.psz_string = _("Stereo");
> >> + var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val,
> >> &text );
> >> + val.i_int = AOUT_VAR_MONO;
> >> + text.psz_string = _("Mono");
> >> + var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val,
> >> &text );
> >> + if ( i_nb_channels == 2 )
> >> + {
> >> + val.i_int = AOUT_VAR_STEREO;
> >> + }
> >> + else
> >> + {
> >> + val.i_int = AOUT_VAR_MONO;
> >> + }
> >> + var_Change( p_aout, "audio-device", VLC_VAR_SETDEFAULT, &val,
> >> NULL );
> >> + var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart,
> >> NULL );
> >> + }
> >> +
> >> + var_TriggerCallback( p_aout, "intf-change" );
> >> +
> >> + /* Prevent SIG_FPE */
> >> + _control87(MCW_EM, MCW_EM);
> >> +
> >> + return VLC_SUCCESS;
> >> +
> >> +exit_kai_done :
> >> + kaiDone();
> >> +
> >> +exit_free_sys :
> >> + free( p_sys );
> >> +
> >> + return VLC_EGENERIC;
> >> +}
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * Play: play a sound samples buffer
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +static void Play (audio_output_t *p_aout, block_t *block)
> >> +{
> >> + aout_sys_t *p_sys = p_aout->sys;
> >> +
> >> + kaiPlay( p_sys->hkai );
> >> +
> >> + aout_PacketPlay( p_aout, block );
> >> +}
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * Close: close the audio device
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +static void Close ( vlc_object_t *p_this )
> >> +{
> >> + audio_output_t *p_aout = (audio_output_t *)p_this;
> >> + aout_sys_t *p_sys = p_aout->sys;
> >> +
> >> + kaiClose( p_sys->hkai );
> >> + kaiDone();
> >> +
> >> + aout_PacketDestroy( p_aout );
> >> + free( p_sys );
> >> +}
> >> +
> >
> > +/***********************************************************************
> > ******
> >
> >> + * KaiCallback: what to do once KAI has played sound samples
> >> +
> >
> > *************************************************************************
> > ****/
> >
> >> +static ULONG APIENTRY KaiCallback( PVOID p_cb_data,
> >> + PVOID p_buffer,
> >> + ULONG i_buf_size )
> >> +{
> >> + audio_output_t *p_aout = (audio_output_t *)p_cb_data;
> >> + aout_buffer_t *p_aout_buffer;
> >> + mtime_t next_date;
> >> + ULONG i_len = 0;
> >> +
> >> + next_date = mdate();
> >> + while ( i_len < i_buf_size )
> >> + {
> >> + if( next_date < mdate())
> >> + next_date = mdate();
> >
> > mdate() should be cached.
>
> Ok.
>
> >> +
> >> + /* Get the next audio data buffer */
> >> + p_aout_buffer = aout_PacketNext( p_aout, next_date );
> >
> > next_date should include the (estimated) latency of the audio hardware
> > output and buffer. Otherwise lip sync will not work.
>
> What is 'lip sync' ?
http://en.wikipedia.org/wiki/Audio_to_video_synchronization
> >> +
> >> + if(!p_aout_buffer)
> >> + {
> >> + // means we are too early to request a new buffer?
> >> + mwait( next_date - AOUT_MAX_PTS_ADVANCE/4 );
> >
> > This should probably 'continue'.
>
> Just 'continue' ? I think, it will cause CPU load to 99.9% unless we
> give up time slice.
You're calling mwait(). If you mean to say that using mwait() is a bad idea, I
agree, but it's your code not mine.
> > It should even break out of the loop if
> > i_len is non-zero, assuming KAI tolerates short reads.
>
> Do you mean that i_len shorter than i_buf_size should be return ?
If it works.
> KAI recognizes a shorter return value than i_buf_size as a end signature
> of a stream.
Then not.
But then aout_Packet*() is not appropriate.
> >> + next_date = mdate();
> >> + p_aout_buffer = aout_PacketNext( p_aout, next_date );
> >> + }
> >> +
> >> + if ( p_aout_buffer != NULL )
> >> + {
> >> + vlc_memcpy( ( uint8_t * ) p_buffer + i_len,
> >> + p_aout_buffer->p_buffer,
> >> + p_aout_buffer->i_buffer );
> >
> > I don't understand how you ensure that
> > i_len + p_aout_buffer->i_buffer <= i_buf_size
>
> I think the following codes ensures this.
>
> aout_PacketInit( p_aout, &p_sys->packet,
> ks_obtained.ulBufferSize / i_bytes_per_frame );
This ensures that:
p_aout_buffer->i_buffer == ks_obtained.ulBufferSize / i_bytes_per_frame
Maybe:
i_buf_size == ks_obtained.ulBufferSize / i_bytes_per_frame
Though this is not obvious. But even then, this proves:
p_aout_buffer->i_buffer <= i_buf_size
So this assumes i_len == 0. Then the loop is not designed correctly.
> > Hmm, this is VLC audio output cargo cult programming. In practice, most
> > outputs do not need zeroes.
>
> Even if we could not get any packets from VLC, there is no need to fill
> the audio buffers for audio output such as KAI with zeros ?
That depends on the audio API. Most will just play zeroes implicitly if they
underrun, which is OK. Some will instead replay the buffer again, which is
bad.
--
Rémi Denis-Courmont
http://www.remlab.net/
http://fi.linkedin.com/in/remidenis
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