[vlc-devel] [PATCH 14/18] Add KAI audio output module for OS/2

Rémi Denis-Courmont remi at remlab.net
Thu Oct 20 16:51:37 CEST 2011


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.

> +#define KAI_AUDIO_DEVICE_LONGTEXT N_( \
> +    "Select a proper audio device to be used by KAI" )

Sentence should end with a dot.

> +
> +#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.

> +
> +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.

> +    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.

> +
> +    psz_mode = var_CreateGetString( p_aout, "kai-audio-device" );

var_InheritString() should be enough here.

> +    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.

> +
> +    /* Support s16l only */
> +    p_aout->format.i_format = VLC_CODEC_S16L;

And again.

> +
> +    aout_FormatPrepare( &p_aout->format );

And lastly.

> +
> +    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.

> +
> +        /* 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.

> +
> +        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'. It should even break out of the loop if
i_len is non-zero, assuming KAI tolerates short reads.

> +            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_len += p_aout_buffer->i_buffer;
> +
> +            next_date += p_aout_buffer->i_length;
> +
> +            aout_BufferFree( p_aout_buffer );
> +        }
> +        else
> +        {
> +            vlc_memset( ( uint8_t * ) p_buffer + i_len, 0, i_buf_size -
> i_len );
> +
> +            i_len = i_buf_size;

Hmm, this is VLC audio output cargo cult programming. In practice, most
outputs do not need zeroes.

> +        }
> +    }
> +
> +    return i_buf_size;
> +}

-- 
Rémi Denis-Courmont
http://www.remlab.net/



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