1 /*****************************************************************************
2 * ac3_spdif.c: ac3 pass-through to external decoder with enabled soundcard
3 *****************************************************************************
4 * Copyright (C) 2001 VideoLAN
5 * $Id: ac3_spdif.c,v 1.5.2.1 2001/12/30 06:06:00 sam Exp $
7 * Authors: Stéphane Borel <stef@via.ecp.fr>
8 * Juha Yrjola <jyrjola@cc.hut.fi>
9 * German Gomez Garcia <german@piraos.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
24 *****************************************************************************/
26 #define MODULE_NAME ac3_spdif
27 #include "modules_inner.h"
29 /*****************************************************************************
31 *****************************************************************************/
36 #include <string.h> /* memcpy() */
45 #include "intf_msg.h" /* intf_DbgMsg(), intf_ErrMsg() */
49 #include "audio_output.h"
52 #include "modules_export.h"
54 #include "stream_control.h"
55 #include "input_ext-dec.h"
57 #include "ac3_spdif.h"
58 #include "ac3_iec958.h"
62 /****************************************************************************
64 ****************************************************************************/
65 static int decoder_Probe ( probedata_t * );
66 static int decoder_Run ( decoder_config_t * );
67 static int InitThread ( ac3_spdif_thread_t * );
68 static void EndThread ( ac3_spdif_thread_t * );
69 static void BitstreamCallback ( bit_stream_t *, boolean_t );
71 /*****************************************************************************
73 *****************************************************************************/
74 void _M( adec_getfunctions )( function_list_t * p_function_list )
76 p_function_list->pf_probe = decoder_Probe;
77 p_function_list->functions.dec.pf_run = decoder_Run;
80 /*****************************************************************************
81 * Build configuration tree.
82 *****************************************************************************/
84 ADD_WINDOW( "Configuration for ac3 spdif decoder module" )
85 ADD_COMMENT( "Nothing to configure" )
89 p_module->i_capabilities = MODULE_CAPABILITY_DEC;
90 p_module->psz_longname = "Ac3 SPDIF decoder for AC3 pass-through";
94 _M( adec_getfunctions )( &p_module->p_functions->dec );
97 MODULE_DEACTIVATE_START
98 MODULE_DEACTIVATE_STOP
100 /*****************************************************************************
101 * decoder_Probe: probe the decoder and return score
102 *****************************************************************************
103 * Tries to launch a decoder and return score so that the interface is able
105 *****************************************************************************/
106 static int decoder_Probe( probedata_t *p_data )
108 if( main_GetIntVariable( AOUT_SPDIF_VAR, 0 ) &&
109 p_data->i_type == AC3_AUDIO_ES )
116 /****************************************************************************
117 * decoder_Run: the whole thing
118 ****************************************************************************
119 * This function is called just after the thread is launched.
120 ****************************************************************************/
121 static int decoder_Run( decoder_config_t * p_config )
123 ac3_spdif_thread_t * p_spdif;
124 mtime_t i_frame_time;
126 /* PTS of the current frame */
127 mtime_t i_current_pts = 0;
129 intf_DbgMsg( "spdif debug: ac3_spdif thread created, initializing." );
131 /* Allocate the memory needed to store the thread's structure */
132 p_spdif = malloc( sizeof(ac3_spdif_thread_t) );
134 if( p_spdif == NULL )
136 intf_ErrMsg ( "spdif error: not enough memory "
137 "for spdif_CreateThread() to create the new thread");
138 DecoderError( p_config->p_decoder_fifo );
142 p_spdif->p_config = p_config;
144 if (InitThread( p_spdif ) )
146 intf_ErrMsg( "spdif error: could not initialize thread" );
147 DecoderError( p_config->p_decoder_fifo );
152 /* Compute the theorical duration of an ac3 frame */
153 i_frame_time = 1000000 * AC3_FRAME_SIZE /
154 p_spdif->ac3_info.i_sample_rate;
156 intf_DbgMsg( "spdif debug: ac3_spdif thread (%p) initialized", p_spdif );
158 while( !p_spdif->p_fifo->b_die && !p_spdif->p_fifo->b_error )
160 /* Handle the dates */
161 if( p_spdif->i_real_pts )
163 mtime_t i_delta = p_spdif->i_real_pts - i_current_pts -
165 if( i_delta > i_frame_time || i_delta < -i_frame_time )
167 intf_WarnMsg( 3, "spdif warning: date discontinuity (%d)",
170 i_current_pts = p_spdif->i_real_pts;
171 p_spdif->i_real_pts = 0;
175 i_current_pts += i_frame_time;
178 /* if we're late here the output won't have to play the frame */
179 if( i_current_pts > mdate() )
181 p_spdif->p_aout_fifo->date[p_spdif->p_aout_fifo->l_end_frame] =
184 /* Write in the first free packet of aout fifo */
185 p_spdif->p_iec = ((u8*)(p_spdif->p_aout_fifo->buffer) +
186 (p_spdif->p_aout_fifo->l_end_frame * SPDIF_FRAME_SIZE ));
188 /* Build burst to be sent to hardware decoder */
189 ac3_iec958_build_burst( p_spdif );
191 vlc_mutex_lock (&p_spdif->p_aout_fifo->data_lock);
192 p_spdif->p_aout_fifo->l_end_frame =
193 (p_spdif->p_aout_fifo->l_end_frame + 1 ) & AOUT_FIFO_SIZE;
194 vlc_mutex_unlock (&p_spdif->p_aout_fifo->data_lock);
197 /* Find syncword again in case of stream discontinuity */
198 /* Here we have p_spdif->i_pts == 0
199 * Therefore a non-zero value after a call to GetBits() means the PES
204 while( GetBits( &p_spdif->bit_stream, 8 ) != 0x0b );
205 p_spdif->i_real_pts = p_spdif->i_pts;
207 b_sync = ( ShowBits( &p_spdif->bit_stream, 8 ) == 0x77 );
209 RemoveBits( &p_spdif->bit_stream, 8 );
211 /* Read data from bitstream */
212 GetChunk( &p_spdif->bit_stream, p_spdif->p_ac3 + 2,
213 p_spdif->ac3_info.i_frame_size - 2 );
216 /* If b_error is set, the ac3 spdif thread enters the error loop */
217 if( p_spdif->p_fifo->b_error )
219 DecoderError( p_spdif->p_fifo );
222 /* End of the ac3 decoder thread */
223 EndThread( p_spdif );
228 /****************************************************************************
229 * InitThread: initialize thread data and create output fifo
230 ****************************************************************************/
231 static int InitThread( ac3_spdif_thread_t * p_spdif )
233 boolean_t b_sync = 0;
235 /* Temporary buffer to store ac3 frames to be transformed */
236 p_spdif->p_ac3 = malloc( SPDIF_FRAME_SIZE );
238 if( p_spdif->p_ac3 == NULL )
240 free( p_spdif->p_ac3 );
245 * Initialize the thread properties
247 p_spdif->p_fifo = p_spdif->p_config->p_decoder_fifo;
249 p_spdif->p_config->pf_init_bit_stream(
250 &p_spdif->bit_stream,
251 p_spdif->p_config->p_decoder_fifo,
252 BitstreamCallback, (void*)p_spdif );
254 /* Creating the audio output fifo */
255 p_spdif->p_aout_fifo = aout_CreateFifo( AOUT_ADEC_SPDIF_FIFO, 1, 48000, 0,
256 SPDIF_FRAME_SIZE, NULL );
258 if( p_spdif->p_aout_fifo == NULL )
263 intf_WarnMsg( 3, "spdif: aout fifo #%d created",
264 p_spdif->p_aout_fifo->i_fifo );
267 p_spdif->p_ac3[0] = 0x0b;
268 p_spdif->p_ac3[1] = 0x77;
273 while( GetBits( &p_spdif->bit_stream, 8 ) != 0x0b );
274 p_spdif->i_real_pts = p_spdif->i_pts;
276 b_sync = ( ShowBits( &p_spdif->bit_stream, 8 ) == 0x77 );
278 RemoveBits( &p_spdif->bit_stream, 8 );
280 /* Check stream properties */
281 if( ac3_iec958_parse_syncinfo( p_spdif ) < 0 )
283 intf_ErrMsg( "spdif error: stream not valid");
285 aout_DestroyFifo( p_spdif->p_aout_fifo );
289 /* Check that we can handle the rate
290 * FIXME: we should check that we have the same rate for all fifos
291 * but all rates should be supported by the decoder (32, 44.1, 48) */
292 if( p_spdif->ac3_info.i_sample_rate != 48000 )
294 intf_ErrMsg( "spdif error: Only 48000 Hz streams supported");
296 aout_DestroyFifo( p_spdif->p_aout_fifo );
299 p_spdif->p_aout_fifo->l_rate = p_spdif->ac3_info.i_sample_rate;
301 GetChunk( &p_spdif->bit_stream, p_spdif->p_ac3 + sizeof(sync_frame_t),
302 p_spdif->ac3_info.i_frame_size - sizeof(sync_frame_t) );
307 /*****************************************************************************
308 * EndThread : ac3 spdif thread destruction
309 *****************************************************************************/
310 static void EndThread( ac3_spdif_thread_t * p_spdif )
312 intf_DbgMsg( "spdif debug: destroying thread %p", p_spdif );
314 /* If the audio output fifo was created, we destroy it */
315 if( p_spdif->p_aout_fifo != NULL )
317 aout_DestroyFifo( p_spdif->p_aout_fifo );
319 /* Make sure the output thread leaves the NextFrame() function */
320 vlc_mutex_lock( &(p_spdif->p_aout_fifo->data_lock ) );
321 vlc_cond_signal( &(p_spdif->p_aout_fifo->data_wait ) );
322 vlc_mutex_unlock( &(p_spdif->p_aout_fifo->data_lock ) );
326 /* Destroy descriptor */
327 free( p_spdif->p_ac3 );
330 intf_DbgMsg ("spdif debug: thread %p destroyed", p_spdif );
333 /*****************************************************************************
334 * BitstreamCallback: Import parameters from the new data/PES packet
335 *****************************************************************************
336 * This function is called by input's NextDataPacket.
337 *****************************************************************************/
338 static void BitstreamCallback ( bit_stream_t * p_bit_stream,
341 ac3_spdif_thread_t * p_spdif;
345 p_spdif = (ac3_spdif_thread_t *)p_bit_stream->p_callback_arg;
347 p_bit_stream->p_byte += 3;
350 DECODER_FIFO_START( *p_bit_stream->p_decoder_fifo )->i_pts;
351 DECODER_FIFO_START( *p_bit_stream->p_decoder_fifo )->i_pts = 0;