[PATCH] work with ALSA 1.0 API
Jeffrey W. Baker
jwbaker at acm.org
Thu May 10 07:17:40 CEST 2001
Hello,
I have finished my patch for vlc to use the latest ALSA API. The output
of "cvs diff -u" in plugins/alsa is attached. I have tested it on a
couple of streams and it works fine. I hope you will apply it.
Regards,
Jeffrey
-- Attached file included as plaintext by Listar --
-- File: vlc-alsa-patch
-- Desc: Patch to plugins/alsa/aout_alsa.c
Index: aout_alsa.c
===================================================================
RCS file: /var/cvs/videolan/vlc/plugins/alsa/aout_alsa.c,v
retrieving revision 1.14
diff -u -r1.14 aout_alsa.c
--- aout_alsa.c 2001/05/06 04:32:02 1.14
+++ aout_alsa.c 2001/05/10 05:14:45
@@ -4,7 +4,8 @@
* Copyright (C) 2000 VideoLAN
* $Id: aout_alsa.c,v 1.14 2001/05/06 04:32:02 sam Exp $
*
- * Authors: Henri Fallon <henri at videolan.org>
+ * Authors: Henri Fallon <henri at videolan.org> - Original Author
+ * Jeffrey Baker <jwbaker at acm.org> - Port to ALSA 1.0 API
*
* 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
@@ -64,37 +65,17 @@
typedef struct aout_sys_s
{
- snd_pcm_t * p_alsa_handle;
- alsa_device_t s_alsa_device;
- alsa_card_t s_alsa_card;
- snd_pcm_channel_params_t s_alsa_channel_params;
- snd_pcm_format_t s_alsa_format;
+ snd_pcm_t * p_alsa_handle;
+ unsigned long buffer_time;
+ unsigned long period_time;
+ unsigned long chunk_size;
+ unsigned long buffer_size;
+ unsigned long rate;
+ unsigned int bytes_per_sample;
+ unsigned int samples_per_frame;
+ unsigned int bytes_per_frame;
} aout_sys_t;
-/*****************************************************************************
- * Local prototypes
- *****************************************************************************/
-static int aout_Probe ( probedata_t *p_data );
-static int aout_Open ( aout_thread_t *p_aout );
-static int aout_SetFormat ( aout_thread_t *p_aout );
-static long aout_GetBufInfo ( aout_thread_t *p_aout, long l_buffer_info );
-static void aout_Play ( aout_thread_t *p_aout,
- byte_t *buffer, int i_size );
-static void aout_Close ( aout_thread_t *p_aout );
-
-/*****************************************************************************
- * Functions exported as capabilities. They are declared as static so that
- * we don't pollute the namespace too much.
- *****************************************************************************/
-void _M( aout_getfunctions )( function_list_t * p_function_list )
-{
- p_function_list->pf_probe = aout_Probe;
- p_function_list->functions.aout.pf_open = aout_Open;
- p_function_list->functions.aout.pf_setformat = aout_SetFormat;
- p_function_list->functions.aout.pf_getbufinfo = aout_GetBufInfo;
- p_function_list->functions.aout.pf_play = aout_Play;
- p_function_list->functions.aout.pf_close = aout_Close;
-}
/*****************************************************************************
* aout_Probe: probes the audio device and return a score
@@ -104,19 +85,11 @@
*****************************************************************************/
static int aout_Probe( probedata_t *p_data )
{
- int i_open_return,i_close_return;
+ int i_open_return, i_close_return;
aout_sys_t local_sys;
- /* This is the same as the beginning of the aout_Open */
- /* Initialize */
- local_sys.s_alsa_device.i_num = 0;
- local_sys.s_alsa_card.i_num = 0;
-
/* Open device */
- i_open_return = snd_pcm_open( &(local_sys.p_alsa_handle),
- local_sys.s_alsa_card.i_num,
- local_sys.s_alsa_device.i_num,
- SND_PCM_OPEN_PLAYBACK );
+ i_open_return = snd_pcm_open(&(local_sys.p_alsa_handle), "plug:0,0", SND_PCM_STREAM_PLAYBACK, 0);
if( i_open_return )
{
/* Score is zero */
@@ -124,9 +97,9 @@
}
/* Close it */
- i_close_return = snd_pcm_close ( local_sys.p_alsa_handle );
+ i_close_return = snd_pcm_close(local_sys.p_alsa_handle);
- if( i_close_return )
+ if (i_close_return)
{
intf_ErrMsg( "Error closing alsa device in aout_probe; exit=%i",
i_close_return );
@@ -162,20 +135,14 @@
return( 1 );
}
- /* Initialize */
- p_aout->p_sys->s_alsa_device.i_num = 0;
- p_aout->p_sys->s_alsa_card.i_num = 0;
- /* FIXME : why not other format ? */
- p_aout->i_format = AOUT_FMT_S16_LE;
- /* FIXME : why always 2 channels ?*/
- p_aout->i_channels = 2;
- p_aout->l_rate = main_GetIntVariable( AOUT_RATE_VAR, AOUT_RATE_DEFAULT );
-
+ p_aout->i_format = AOUT_FORMAT_DEFAULT;
+ p_aout->i_channels = 1 + main_GetIntVariable( AOUT_STEREO_VAR,
+ AOUT_STEREO_DEFAULT );
+ p_aout->l_rate = main_GetIntVariable( AOUT_RATE_VAR,
+ AOUT_RATE_DEFAULT );
+
/* Open device */
- if( ( i_open_returns = snd_pcm_open( &(p_aout->p_sys->p_alsa_handle),
- p_aout->p_sys->s_alsa_card.i_num,
- p_aout->p_sys->s_alsa_device.i_num,
- SND_PCM_OPEN_PLAYBACK ) ) )
+ if( ( i_open_returns = snd_pcm_open(&(p_aout->p_sys->p_alsa_handle), "plug:0,0", SND_PCM_STREAM_PLAYBACK, 0) ) )
{
intf_ErrMsg( "Could not open alsa device; exit = %i",
i_open_returns );
@@ -196,88 +163,119 @@
*****************************************************************************/
static int aout_SetFormat( aout_thread_t *p_aout )
{
+
+ int rv;
+ int format;
- int i_set_param_returns;
- int i_prepare_playback_returns;
- int i_playback_go_returns;
-
- /* Fill with zeros */
- memset( &p_aout->p_sys->s_alsa_channel_params,0,
- sizeof( p_aout->p_sys->s_alsa_channel_params ) );
-
- /* Fill the s_alsa_channel_params structure */
-
- /* Tranfer mode and direction*/
- p_aout->p_sys->s_alsa_channel_params.channel = SND_PCM_CHANNEL_PLAYBACK ;
- p_aout->p_sys->s_alsa_channel_params.mode = SND_PCM_MODE_STREAM;
-
- /* Format and rate */
- p_aout->p_sys->s_alsa_channel_params.format.interleave = 1;
- if( p_aout->i_format == AOUT_FMT_S16_LE )
- p_aout->p_sys->s_alsa_channel_params.format.format =
- SND_PCM_SFMT_S16_LE;
+ snd_pcm_hw_params_t *hw;
+ snd_pcm_sw_params_t *sw;
+
+ snd_pcm_hw_params_alloca(&hw);
+ snd_pcm_sw_params_alloca(&sw);
+
+ switch (p_aout->i_format) {
+ case AOUT_FMT_S16_LE:
+ format = SND_PCM_FORMAT_S16_LE;
+ p_aout->p_sys->bytes_per_sample = 2;
+ break;
+
+ default:
+ format = SND_PCM_FORMAT_S16_BE;
+ p_aout->p_sys->bytes_per_sample = 2;
+ break;
+ }
+
+ p_aout->p_sys->samples_per_frame = p_aout->i_channels;
+ p_aout->p_sys->bytes_per_frame = p_aout->p_sys->samples_per_frame * p_aout->p_sys->bytes_per_sample;
+
+ rv = snd_pcm_hw_params_any(p_aout->p_sys->p_alsa_handle, hw);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to retrieve initial parameters.");
+ return(-1);
+ }
+
+ rv = snd_pcm_hw_params_set_access(p_aout->p_sys->p_alsa_handle, hw, SND_PCM_ACCESS_RW_INTERLEAVED);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to set interleaved stream format.");
+ return(-1);
+ }
+
+ rv = snd_pcm_hw_params_set_format(p_aout->p_sys->p_alsa_handle, hw, format);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to set stream sample size and word order.");
+ return(-1);
+ }
+
+ rv = snd_pcm_hw_params_set_channels(p_aout->p_sys->p_alsa_handle, hw, p_aout->i_channels);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to set number of output channels.");
+ return(-1);
+ }
+
+ rv = snd_pcm_hw_params_set_rate_near(p_aout->p_sys->p_alsa_handle, hw, p_aout->l_rate, 0);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to set sample rate.");
+ return(-1);
+ }
+ else
+ p_aout->p_sys->rate = rv;
+
+ rv = snd_pcm_hw_params_set_buffer_time_near(p_aout->p_sys->p_alsa_handle, hw, AOUT_BUFFER_DURATION, 0);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to set buffer time.");
+ return(-1);
+ }
else
- p_aout->p_sys->s_alsa_channel_params.format.format =
- SND_PCM_SFMT_S16_BE;
- p_aout->p_sys->s_alsa_channel_params.format.rate = p_aout->l_rate;
- p_aout->p_sys->s_alsa_channel_params.format.voices = p_aout->i_channels ;
-
- /* When to start playing and when to stop */
- p_aout->p_sys->s_alsa_channel_params.start_mode = SND_PCM_START_DATA;
- p_aout->p_sys->s_alsa_channel_params.stop_mode = SND_PCM_STOP_STOP;
-
- /* Buffer information . I have chosen the stream mode here
- * instead of the block mode. I don't know whether i'm wrong
- * but it seemed more logical */
- /* TODO : find the best value to put here. Probably depending
- * on many parameters */
- p_aout->p_sys->s_alsa_channel_params.buf.stream.queue_size = 131072;
-
- p_aout->p_sys->s_alsa_channel_params.buf.stream.fill = SND_PCM_FILL_NONE ;
- p_aout->p_sys->s_alsa_channel_params.buf.stream.max_fill = 0 ;
-
- /* Now we pass this to the driver */
- i_set_param_returns = snd_pcm_channel_params(
- p_aout->p_sys->p_alsa_handle,
- &(p_aout->p_sys->s_alsa_channel_params) );
+ p_aout->p_sys->buffer_time = rv;
- if( i_set_param_returns )
- {
- intf_ErrMsg( "ALSA_PLUGIN : Unable to set parameters; exit = %i",
- i_set_param_returns );
- intf_ErrMsg( "This means : %s",
- snd_strerror( i_set_param_returns ) );
- return( -1 );
+ rv = snd_pcm_hw_params_set_period_time_near(p_aout->p_sys->p_alsa_handle, hw, p_aout->p_sys->buffer_time / p_aout->p_sys->bytes_per_frame, 0);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to set period time.");
+ return(-1);
+ }
+ else
+ p_aout->p_sys->period_time = rv;
+
+ rv = snd_pcm_hw_params(p_aout->p_sys->p_alsa_handle, hw);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to install configuration into hardware.");
+ return(-1);
}
+
+ p_aout->p_sys->chunk_size = snd_pcm_hw_params_get_period_size(hw, 0);
+ p_aout->p_sys->buffer_size = snd_pcm_hw_params_get_buffer_size(hw);
- /* we shall now prepare the channel */
- i_prepare_playback_returns =
- snd_pcm_playback_prepare( p_aout->p_sys->p_alsa_handle );
+ snd_pcm_sw_params_current(p_aout->p_sys->p_alsa_handle, sw);
+ rv = snd_pcm_sw_params_set_sleep_min(p_aout->p_sys->p_alsa_handle, sw, 0);
- if( i_prepare_playback_returns )
- {
- intf_ErrMsg( "ALSA_PLUGIN : Unable to prepare channel : exit = %i",
- i_prepare_playback_returns );
- intf_ErrMsg( "This means : %s",
- snd_strerror( i_set_param_returns ) );
+ rv = snd_pcm_sw_params_set_avail_min(p_aout->p_sys->p_alsa_handle, sw, p_aout->p_sys->chunk_size);
- return( -1 );
- }
-
- /* then we may go */
- i_playback_go_returns =
- snd_pcm_playback_go( p_aout->p_sys->p_alsa_handle );
- if( i_playback_go_returns )
- {
- intf_ErrMsg( "ALSA_PLUGIN : Unable to prepare channel (bis) : "
- "exit = %i", i_playback_go_returns );
- intf_ErrMsg( "This means : %s",
- snd_strerror( i_set_param_returns ) );
- return( -1 );
- }
+ rv = snd_pcm_sw_params_set_start_threshold(p_aout->p_sys->p_alsa_handle, sw, p_aout->p_sys->buffer_size);
+
+ rv = snd_pcm_sw_params_set_stop_threshold(p_aout->p_sys->p_alsa_handle, sw, p_aout->p_sys->buffer_size);
+
+ rv = snd_pcm_sw_params(p_aout->p_sys->p_alsa_handle, sw);
+ if (rv < 0) {
+ intf_ErrMsg("ALSA PLUGIN: Unable to install configuration into software.");
+ return(-1);
+ }
+
+
return( 0 );
}
+static void aout_HandleXrun(aout_thread_t *p_aout)
+{
+ int rv;
+
+ intf_ErrMsg("ALSA PLUGIN: resetting output after buffer underrun.");
+
+ rv = snd_pcm_prepare(p_aout->p_sys->p_alsa_handle);
+ if (rv < 0)
+ intf_ErrMsg("ALSA PLUGIN: Unable to recover from buffer underrun: %s", snd_strerror(rv));
+}
+
+
/*****************************************************************************
* aout_BufInfo: buffer status query
*****************************************************************************
@@ -288,14 +286,13 @@
*****************************************************************************/
static long aout_GetBufInfo( aout_thread_t *p_aout, long l_buffer_limit )
{
- snd_pcm_channel_status_t alsa_channel_status;
+ snd_pcm_status_t *status;
int i_alsa_get_status_returns;
- memset(&alsa_channel_status, 0, sizeof( alsa_channel_status ) );
-
- i_alsa_get_status_returns = snd_pcm_channel_status(
- p_aout->p_sys->p_alsa_handle, &alsa_channel_status );
+ snd_pcm_status_alloca(&status);
+ i_alsa_get_status_returns = snd_pcm_status(p_aout->p_sys->p_alsa_handle, status);
+
if( i_alsa_get_status_returns )
{
intf_ErrMsg ( "Error getting alsa buffer info; exit=%i",
@@ -305,25 +302,23 @@
return ( -1 );
}
- switch( alsa_channel_status.status )
+ switch(snd_pcm_status_get_state(status))
{
- case SND_PCM_STATUS_NOTREADY : intf_ErrMsg("Status NOT READY");
- break;
- case SND_PCM_STATUS_UNDERRUN : {
-
- int i_prepare_returns;
- intf_ErrMsg( "Status UNDERRUN ... reseting queue ");
- i_prepare_returns = snd_pcm_playback_prepare(
- p_aout->p_sys->p_alsa_handle );
- if ( i_prepare_returns )
- {
- intf_ErrMsg( "Error : could not flush : %i", i_prepare_returns );
- intf_ErrMsg( "This means : %s", snd_strerror(i_prepare_returns) );
- }
- break;
- }
+ case SND_PCM_STATE_XRUN :
+ aout_HandleXrun(p_aout);
+ break;
+
+ case SND_PCM_STATE_OPEN:
+ case SND_PCM_STATE_PREPARED:
+ case SND_PCM_STATE_RUNNING:
+ break;
+
+ default:
+ intf_ErrMsg("ALSA PLUGIN: Encountered unhandled condition %i!", snd_pcm_status_get_state(status));
+ break;
}
- return( alsa_channel_status.count );
+
+ return(snd_pcm_status_get_avail(status) * p_aout->p_sys->bytes_per_frame);
}
/*****************************************************************************
@@ -333,15 +328,24 @@
*****************************************************************************/
static void aout_Play( aout_thread_t *p_aout, byte_t *buffer, int i_size )
{
- int i_write_returns;
+ snd_pcm_uframes_t tot_frames;
+ snd_pcm_uframes_t frames_left;
+ snd_pcm_uframes_t rv;
+
+ tot_frames = i_size / p_aout->p_sys->bytes_per_frame;
+ frames_left = tot_frames;
+
+ while (frames_left > 0)
+ {
+ rv = snd_pcm_writei(p_aout->p_sys->p_alsa_handle, buffer + (tot_frames - frames_left) * p_aout->p_sys->bytes_per_frame, frames_left);
+
+ if ((signed int) rv < 0)
+ {
+ intf_ErrMsg("ALSA PLUGIN: error writing to output: %s", snd_strerror(rv));
+ return;
+ }
- i_write_returns = (int) snd_pcm_write (
- p_aout->p_sys->p_alsa_handle, (void *) buffer, (size_t) i_size );
-
- if( i_write_returns <= 0 )
- {
- intf_ErrMsg ( "Error writing blocks; exit=%i", i_write_returns );
- intf_ErrMsg ( "This means : %s", snd_strerror( i_write_returns ) );
+ frames_left -= rv;
}
}
@@ -364,3 +368,16 @@
intf_DbgMsg( "Alsa plugin : Alsa device closed");
}
+/*****************************************************************************
+ * Functions exported as capabilities. They are declared as static so that
+ * we don't pollute the namespace too much.
+ *****************************************************************************/
+void _M( aout_getfunctions )( function_list_t * p_function_list )
+{
+ p_function_list->pf_probe = aout_Probe;
+ p_function_list->functions.aout.pf_open = aout_Open;
+ p_function_list->functions.aout.pf_setformat = aout_SetFormat;
+ p_function_list->functions.aout.pf_getbufinfo = aout_GetBufInfo;
+ p_function_list->functions.aout.pf_play = aout_Play;
+ p_function_list->functions.aout.pf_close = aout_Close;
+}
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