/*****************************************************************************
* vorbis.c: vorbis decoder/encoder/packetizer module making use of libvorbis.
*****************************************************************************
- * Copyright (C) 1999-2001 VideoLAN
- * $Id: vorbis.c,v 1.22 2003/11/16 21:07:30 gbazin Exp $
+ * Copyright (C) 2001-2003 VideoLAN
+ * $Id$
*
- * Authors: Gildas Bazin <gbazin@netcourrier.com>
+ * Authors: Gildas Bazin <gbazin@videolan.org>
*
* 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
/*****************************************************************************
* Preamble
*****************************************************************************/
-#include <stdlib.h> /* malloc(), free() */
-#include <string.h> /* memcpy(), memset() */
-
#include <vlc/vlc.h>
#include <vlc/decoder.h>
#include <vlc/input.h>
+#include <vlc/sout.h>
#include <ogg/ogg.h>
};
-static int pi_channels_maps[6] =
+static int pi_channels_maps[7] =
{
0,
- AOUT_CHAN_CENTER, AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
+ AOUT_CHAN_CENTER,
+ AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
AOUT_CHAN_CENTER | AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARLEFT
| AOUT_CHAN_REARRIGHT,
AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
- | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
+ | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT,
+ AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
+ | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE
};
/****************************************************************************
static void CloseDecoder ( vlc_object_t * );
static void *DecodeBlock ( decoder_t *, block_t ** );
+static int ProcessHeaders( decoder_t * );
static void *ProcessPacket ( decoder_t *, ogg_packet *, block_t ** );
static aout_buffer_t *DecodePacket ( decoder_t *, ogg_packet * );
#ifndef MODULE_NAME_IS_tremor
static int OpenEncoder ( vlc_object_t * );
static void CloseEncoder ( vlc_object_t * );
-static block_t *Headers ( encoder_t * );
static block_t *Encode ( encoder_t *, aout_buffer_t * );
#endif
/*****************************************************************************
* Module descriptor
*****************************************************************************/
+#define ENC_QUALITY_TEXT N_("Encoding quality")
+#define ENC_QUALITY_LONGTEXT N_( \
+ "Allows you to specify a quality between 1 (low) and 10 (high), instead " \
+ "of specifying a particular bitrate. This will produce a VBR stream." )
+#define ENC_MAXBR_TEXT N_("Maximum encoding bitrate")
+#define ENC_MAXBR_LONGTEXT N_( \
+ "Allows you to specify a maximum bitrate in kbps. " \
+ "Useful for streaming applications." )
+#define ENC_MINBR_TEXT N_("Minimum encoding bitrate")
+#define ENC_MINBR_LONGTEXT N_( \
+ "Allows you to specify a minimum bitrate in kbps. " \
+ "Useful for encoding for a fixed-size channel." )
+#define ENC_CBR_TEXT N_("CBR encoding")
+#define ENC_CBR_LONGTEXT N_( \
+ "Allows you to force a constant bitrate encoding (CBR)." )
+
vlc_module_begin();
set_description( _("Vorbis audio decoder") );
#else
set_capability( "decoder", 100 );
#endif
+ set_category( CAT_INPUT );
+ set_subcategory( SUBCAT_INPUT_ACODEC );
set_callbacks( OpenDecoder, CloseDecoder );
add_submodule();
set_callbacks( OpenPacketizer, CloseDecoder );
#ifndef MODULE_NAME_IS_tremor
+# define ENC_CFG_PREFIX "sout-vorbis-"
add_submodule();
set_description( _("Vorbis audio encoder") );
set_capability( "encoder", 100 );
set_callbacks( OpenEncoder, CloseEncoder );
+
+ add_integer( ENC_CFG_PREFIX "quality", 3, NULL, ENC_QUALITY_TEXT,
+ ENC_QUALITY_LONGTEXT, VLC_FALSE );
+ add_integer( ENC_CFG_PREFIX "max-bitrate", 0, NULL, ENC_MAXBR_TEXT,
+ ENC_MAXBR_LONGTEXT, VLC_FALSE );
+ add_integer( ENC_CFG_PREFIX "min-bitrate", 0, NULL, ENC_MINBR_TEXT,
+ ENC_MINBR_LONGTEXT, VLC_FALSE );
+ add_bool( ENC_CFG_PREFIX "cbr", 0, NULL, ENC_CBR_TEXT,
+ ENC_CBR_LONGTEXT, VLC_FALSE );
#endif
vlc_module_end();
+#ifndef MODULE_NAME_IS_tremor
+static const char *ppsz_enc_options[] = {
+ "quality", "max-bitrate", "min-bitrate", "cbr", NULL
+};
+#endif
+
/*****************************************************************************
* OpenDecoder: probe the decoder and return score
*****************************************************************************/
oggpacket.e_o_s = 0;
oggpacket.packetno = 0;
- if( p_sys->i_headers == 0 )
+ /* Check for headers */
+ if( p_sys->i_headers == 0 && p_dec->fmt_in.i_extra )
{
- /* Take care of the initial Vorbis header */
+ /* Headers already available as extra data */
+ p_sys->i_headers = 3;
+ }
+ else if( oggpacket.bytes && p_sys->i_headers < 3 )
+ {
+ /* Backup headers as extra data */
+ uint8_t *p_extra;
+
+ p_dec->fmt_in.p_extra =
+ realloc( p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra +
+ oggpacket.bytes + 2 );
+ p_extra = p_dec->fmt_in.p_extra + p_dec->fmt_in.i_extra;
+ *(p_extra++) = oggpacket.bytes >> 8;
+ *(p_extra++) = oggpacket.bytes & 0xFF;
+
+ memcpy( p_extra, oggpacket.packet, oggpacket.bytes );
+ p_dec->fmt_in.i_extra += oggpacket.bytes + 2;
+
+ block_Release( *pp_block );
+ p_sys->i_headers++;
+ return NULL;
+ }
- oggpacket.b_o_s = 1; /* yes this actually is a b_o_s packet :) */
- if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc,
- &oggpacket ) < 0 )
+ if( p_sys->i_headers == 3 )
+ {
+ if( ProcessHeaders( p_dec ) != VLC_SUCCESS )
{
- msg_Err( p_dec, "This bitstream does not contain Vorbis "
- "audio data");
+ p_sys->i_headers = 0;
+ p_dec->fmt_in.i_extra = 0;
block_Release( *pp_block );
return NULL;
}
- p_sys->i_headers++;
+ else p_sys->i_headers++;
+ }
- /* Setup the format */
- p_dec->fmt_out.audio.i_rate = p_sys->vi.rate;
- p_dec->fmt_out.audio.i_channels = p_sys->vi.channels;
- p_dec->fmt_out.audio.i_bitrate = p_sys->vi.bitrate_nominal;
- p_dec->fmt_out.audio.i_physical_channels =
- p_dec->fmt_out.audio.i_original_channels =
- pi_channels_maps[p_sys->vi.channels];
+ return ProcessPacket( p_dec, &oggpacket, pp_block );
+}
- aout_DateInit( &p_sys->end_date, p_sys->vi.rate );
+/*****************************************************************************
+ * ProcessHeaders: process Vorbis headers.
+ *****************************************************************************/
+static int ProcessHeaders( decoder_t *p_dec )
+{
+ decoder_sys_t *p_sys = p_dec->p_sys;
+ ogg_packet oggpacket;
+ uint8_t *p_extra;
+ int i_extra;
- msg_Dbg( p_dec, "channels:%d samplerate:%ld bitrate:%ld",
- p_sys->vi.channels, p_sys->vi.rate,
- p_sys->vi.bitrate_nominal );
+ if( !p_dec->fmt_in.i_extra ) return VLC_EGENERIC;
- return ProcessPacket( p_dec, &oggpacket, pp_block );
+ oggpacket.granulepos = -1;
+ oggpacket.b_o_s = 1; /* yes this actually is a b_o_s packet :) */
+ oggpacket.e_o_s = 0;
+ oggpacket.packetno = 0;
+ p_extra = p_dec->fmt_in.p_extra;
+ i_extra = p_dec->fmt_in.i_extra;
+
+ /* Take care of the initial Vorbis header */
+ oggpacket.bytes = *(p_extra++) << 8;
+ oggpacket.bytes |= (*(p_extra++) & 0xFF);
+ oggpacket.packet = p_extra;
+ p_extra += oggpacket.bytes;
+ i_extra -= (oggpacket.bytes + 2);
+ if( i_extra < 0 )
+ {
+ msg_Err( p_dec, "header data corrupted");
+ return VLC_EGENERIC;
}
- if( p_sys->i_headers == 1 )
+ if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket ) < 0 )
{
- /* The next packet in order is the comments header */
- if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket )
- < 0 )
- {
- msg_Err( p_dec, "2nd Vorbis header is corrupted" );
- block_Release( *pp_block );
- return NULL;
- }
- p_sys->i_headers++;
-
- ParseVorbisComments( p_dec );
+ msg_Err( p_dec, "this bitstream does not contain Vorbis audio data");
+ return VLC_EGENERIC;
+ }
+
+ /* Setup the format */
+ p_dec->fmt_out.audio.i_rate = p_sys->vi.rate;
+ p_dec->fmt_out.audio.i_channels = p_sys->vi.channels;
+ p_dec->fmt_out.audio.i_physical_channels =
+ p_dec->fmt_out.audio.i_original_channels =
+ pi_channels_maps[p_sys->vi.channels];
+ p_dec->fmt_out.i_bitrate = p_sys->vi.bitrate_nominal;
+
+ aout_DateInit( &p_sys->end_date, p_sys->vi.rate );
+ aout_DateSet( &p_sys->end_date, 0 );
+
+ msg_Dbg( p_dec, "channels:%d samplerate:%ld bitrate:%ld",
+ p_sys->vi.channels, p_sys->vi.rate, p_sys->vi.bitrate_nominal );
- return ProcessPacket( p_dec, &oggpacket, pp_block );
+ /* The next packet in order is the comments header */
+ oggpacket.b_o_s = 0;
+ oggpacket.bytes = *(p_extra++) << 8;
+ oggpacket.bytes |= (*(p_extra++) & 0xFF);
+ oggpacket.packet = p_extra;
+ p_extra += oggpacket.bytes;
+ i_extra -= (oggpacket.bytes + 2);
+ if( i_extra < 0 )
+ {
+ msg_Err( p_dec, "header data corrupted");
+ return VLC_EGENERIC;
}
- if( p_sys->i_headers == 2 )
+ if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket ) < 0 )
{
- /* The next packet in order is the codebooks header
- We need to watch out that this packet is not missing as a
- missing or corrupted header is fatal. */
- if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket )
- < 0 )
- {
- msg_Err( p_dec, "3rd Vorbis header is corrupted" );
- block_Release( *pp_block );
- return NULL;
- }
- p_sys->i_headers++;
-
- if( !p_sys->b_packetizer )
- {
- /* Initialize the Vorbis packet->PCM decoder */
- vorbis_synthesis_init( &p_sys->vd, &p_sys->vi );
- vorbis_block_init( &p_sys->vd, &p_sys->vb );
- }
+ msg_Err( p_dec, "2nd Vorbis header is corrupted" );
+ return VLC_EGENERIC;
+ }
+ ParseVorbisComments( p_dec );
+
+ /* The next packet in order is the codebooks header
+ * We need to watch out that this packet is not missing as a
+ * missing or corrupted header is fatal. */
+ oggpacket.bytes = *(p_extra++) << 8;
+ oggpacket.bytes |= (*(p_extra++) & 0xFF);
+ oggpacket.packet = p_extra;
+ i_extra -= (oggpacket.bytes + 2);
+ if( i_extra < 0 )
+ {
+ msg_Err( p_dec, "header data corrupted");
+ return VLC_EGENERIC;
+ }
- return ProcessPacket( p_dec, &oggpacket, pp_block );
+ if( vorbis_synthesis_headerin( &p_sys->vi, &p_sys->vc, &oggpacket ) < 0 )
+ {
+ msg_Err( p_dec, "3rd Vorbis header is corrupted" );
+ return VLC_EGENERIC;
}
- return ProcessPacket( p_dec, &oggpacket, pp_block );
+ if( !p_sys->b_packetizer )
+ {
+ /* Initialize the Vorbis packet->PCM decoder */
+ vorbis_synthesis_init( &p_sys->vd, &p_sys->vi );
+ vorbis_block_init( &p_sys->vd, &p_sys->vb );
+ }
+ else
+ {
+ p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
+ p_dec->fmt_out.p_extra =
+ realloc( p_dec->fmt_out.p_extra, p_dec->fmt_out.i_extra );
+ memcpy( p_dec->fmt_out.p_extra,
+ p_dec->fmt_in.p_extra, p_dec->fmt_out.i_extra );
+ }
+
+ return VLC_SUCCESS;
}
/*****************************************************************************
else
p_aout_buffer = NULL;
- if( p_block )
- {
- block_Release( p_block );
- }
+ if( p_block ) block_Release( p_block );
return p_aout_buffer;
}
}
static void ParseVorbisComments( decoder_t *p_dec )
{
input_thread_t *p_input = (input_thread_t *)p_dec->p_parent;
- input_info_category_t *p_cat =
- input_InfoCategory( p_input, _("Vorbis Comment") );
- int i = 0;
char *psz_name, *psz_value, *psz_comment;
- while ( i < p_dec->p_sys->vc.comments )
+ int i = 0;
+
+ if( p_input->i_object_type != VLC_OBJECT_INPUT ) return;
+
+ while( i < p_dec->p_sys->vc.comments )
{
psz_comment = strdup( p_dec->p_sys->vc.user_comments[i] );
if( !psz_comment )
{
- msg_Warn( p_dec, "Out of memory" );
+ msg_Warn( p_dec, "out of memory" );
break;
}
psz_name = psz_comment;
{
*psz_value = '\0';
psz_value++;
- input_AddInfo( p_cat, psz_name, psz_value );
+ input_Control( p_input, INPUT_ADD_INFO, _("Vorbis comment"),
+ psz_name, psz_value );
+ /* HACK, we should use meta */
+ if( strstr( psz_name, "artist" ) )
+ {
+ input_Control( p_input, INPUT_ADD_INFO, _("Meta-information"),
+ _("Artist"), psz_value );
+ }
+ else if( strstr( psz_name, "title" ) )
+ {
+ p_input->input.p_item->psz_name = strdup( psz_value );
+ }
}
+ /* FIXME */
+ var_SetInteger( p_input, "item-change", p_input->input.p_item->i_id );
free( psz_comment );
i++;
}
/*****************************************************************************
* Interleave: helper function to interleave channels
*****************************************************************************/
+static void Interleave(
#ifdef MODULE_NAME_IS_tremor
-static void Interleave( int32_t *p_out, const int32_t **pp_in,
+ int32_t *p_out, const int32_t **pp_in,
#else
-static void Interleave( float *p_out, const float **pp_in,
+ float *p_out, const float **pp_in,
#endif
int i_nb_channels, int i_samples )
{
#if defined(HAVE_VORBIS_VORBISENC_H) && !defined(MODULE_NAME_IS_tremor)
/*****************************************************************************
- * encoder_sys_t : theora encoder descriptor
+ * encoder_sys_t : vorbis encoder descriptor
*****************************************************************************/
struct encoder_sys_t
{
- /*
- * Input properties
- */
- int i_headers;
-
/*
* Vorbis properties
*/
{
encoder_t *p_enc = (encoder_t *)p_this;
encoder_sys_t *p_sys;
+ int i_quality, i_min_bitrate, i_max_bitrate, i;
+ ogg_packet header[3];
+ vlc_value_t val;
+ uint8_t *p_extra;
- if( p_enc->fmt_out.i_codec != VLC_FOURCC('v','o','r','b') )
+ if( p_enc->fmt_out.i_codec != VLC_FOURCC('v','o','r','b') &&
+ !p_enc->b_force )
{
return VLC_EGENERIC;
}
}
p_enc->p_sys = p_sys;
- p_enc->pf_header = Headers;
p_enc->pf_encode_audio = Encode;
p_enc->fmt_in.i_codec = VLC_FOURCC('f','l','3','2');
+ p_enc->fmt_out.i_codec = VLC_FOURCC('v','o','r','b');
+
+ sout_CfgParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );
+
+ var_Get( p_enc, ENC_CFG_PREFIX "quality", &val );
+ i_quality = val.i_int;
+ if( i_quality > 10 ) i_quality = 10;
+ if( i_quality < 0 ) i_quality = 0;
+ var_Get( p_enc, ENC_CFG_PREFIX "cbr", &val );
+ if( val.b_bool ) i_quality = 0;
+ var_Get( p_enc, ENC_CFG_PREFIX "max-bitrate", &val );
+ i_max_bitrate = val.i_int;
+ var_Get( p_enc, ENC_CFG_PREFIX "min-bitrate", &val );
+ i_min_bitrate = val.i_int;
/* Initialize vorbis encoder */
vorbis_info_init( &p_sys->vi );
- if( vorbis_encode_setup_managed( &p_sys->vi,
- p_enc->fmt_in.audio.i_channels, p_enc->fmt_in.audio.i_rate,
- -1, p_enc->fmt_out.i_bitrate, -1 ) ||
- vorbis_encode_ctl( &p_sys->vi, OV_ECTL_RATEMANAGE_AVG, NULL ) ||
- vorbis_encode_setup_init( &p_sys->vi ) ){}
+ if( i_quality > 0 )
+ {
+ /* VBR mode */
+ if( vorbis_encode_setup_vbr( &p_sys->vi,
+ p_enc->fmt_in.audio.i_channels, p_enc->fmt_in.audio.i_rate,
+ i_quality * 0.1 ) )
+ {
+ vorbis_info_clear( &p_sys->vi );
+ free( p_enc->p_sys );
+ msg_Err( p_enc, "VBR mode initialisation failed" );
+ return VLC_EGENERIC;
+ }
+
+ /* Do we have optional hard quality restrictions? */
+ if( i_max_bitrate > 0 || i_min_bitrate > 0 )
+ {
+ struct ovectl_ratemanage_arg ai;
+ vorbis_encode_ctl( &p_sys->vi, OV_ECTL_RATEMANAGE_GET, &ai );
+
+ ai.bitrate_hard_min = i_min_bitrate;
+ ai.bitrate_hard_max = i_max_bitrate;
+ ai.management_active = 1;
- /* add a comment */
+ vorbis_encode_ctl( &p_sys->vi, OV_ECTL_RATEMANAGE_SET, &ai );
+
+ }
+ else
+ {
+ /* Turn off management entirely */
+ vorbis_encode_ctl( &p_sys->vi, OV_ECTL_RATEMANAGE_SET, NULL );
+ }
+ }
+ else
+ {
+ if( vorbis_encode_setup_managed( &p_sys->vi,
+ p_enc->fmt_in.audio.i_channels, p_enc->fmt_in.audio.i_rate,
+ i_min_bitrate > 0 ? i_min_bitrate * 1000: -1,
+ p_enc->fmt_out.i_bitrate,
+ i_max_bitrate > 0 ? i_max_bitrate * 1000: -1 ) )
+ {
+ vorbis_info_clear( &p_sys->vi );
+ msg_Err( p_enc, "CBR mode initialisation failed" );
+ free( p_enc->p_sys );
+ return VLC_EGENERIC;
+ }
+ }
+
+ vorbis_encode_setup_init( &p_sys->vi );
+
+ /* Add a comment */
vorbis_comment_init( &p_sys->vc);
vorbis_comment_add_tag( &p_sys->vc, "ENCODER", "VLC media player");
- /* set up the analysis state and auxiliary encoding storage */
+ /* Set up the analysis state and auxiliary encoding storage */
vorbis_analysis_init( &p_sys->vd, &p_sys->vi );
vorbis_block_init( &p_sys->vd, &p_sys->vb );
+ /* Create and store headers */
+ vorbis_analysis_headerout( &p_sys->vd, &p_sys->vc,
+ &header[0], &header[1], &header[2]);
+ p_enc->fmt_out.i_extra = 3 * 2 + header[0].bytes +
+ header[1].bytes + header[2].bytes;
+ p_extra = p_enc->fmt_out.p_extra = malloc( p_enc->fmt_out.i_extra );
+ for( i = 0; i < 3; i++ )
+ {
+ *(p_extra++) = header[i].bytes >> 8;
+ *(p_extra++) = header[i].bytes & 0xFF;
+ memcpy( p_extra, header[i].packet, header[i].bytes );
+ p_extra += header[i].bytes;
+ }
+
p_sys->i_channels = p_enc->fmt_in.audio.i_channels;
p_sys->i_last_block_size = 0;
p_sys->i_samples_delay = 0;
- p_sys->i_headers = 0;
p_sys->i_pts = 0;
return VLC_SUCCESS;
}
-/****************************************************************************
- * Encode: the whole thing
- ****************************************************************************
- * This function spits out ogg packets.
- ****************************************************************************/
-static block_t *Headers( encoder_t *p_enc )
-{
- encoder_sys_t *p_sys = p_enc->p_sys;
- block_t *p_block, *p_chain = NULL;
-
- /* Create theora headers */
- if( !p_sys->i_headers )
- {
- ogg_packet header[3];
- int i;
-
- vorbis_analysis_headerout( &p_sys->vd, &p_sys->vc,
- &header[0], &header[1], &header[2]);
- for( i = 0; i < 3; i++ )
- {
- p_block = block_New( p_enc, header[i].bytes );
- memcpy( p_block->p_buffer, header[i].packet, header[i].bytes );
-
- p_block->i_dts = p_block->i_pts = p_block->i_length = 0;
-
- block_ChainAppend( &p_chain, p_block );
- }
- p_sys->i_headers = 3;
- }
-
- return p_chain;
-}
-
/****************************************************************************
* Encode: the whole thing
****************************************************************************
ogg_packet oggpacket;
block_t *p_block, *p_chain = NULL;
float **buffer;
- int i, j;
+ int i;
+ unsigned int j;
p_sys->i_pts = p_aout_buf->start_date -
(mtime_t)1000000 * (mtime_t)p_sys->i_samples_delay /
buffer = vorbis_analysis_buffer( &p_sys->vd, p_aout_buf->i_nb_samples );
-#if 0
- if( id->ff_dec_c->channels != id->ff_enc_c->channels )
- {
- int i, j;
-
- /* dumb downmixing */
- for( i = 0; i < id->ff_enc_c->frame_size; i++ )
- {
- for( j = 0 ; j < id->f_dst.i_channels; j++ )
- {
- p_buffer[i*id->f_dst.i_channels+j] =
- p_buffer[i*id->f_src.i_channels+j];
- }
- }
- }
-#endif
-
/* convert samples to float and uninterleave */
for( i = 0; i < p_sys->i_channels; i++ )
{
for( j = 0 ; j < p_aout_buf->i_nb_samples ; j++ )
{
- buffer[i][j]= ((float)( ((int16_t *)p_aout_buf->p_buffer )
- [j * p_sys->i_channels + i ] )) / 32768.f;
+ buffer[i][j]= ((float *)p_aout_buf->p_buffer)
+ [j * p_sys->i_channels + i ];
}
}
}
/*****************************************************************************
- * CloseEncoder: theora encoder destruction
+ * CloseEncoder: vorbis encoder destruction
*****************************************************************************/
static void CloseEncoder( vlc_object_t *p_this )
{