[vlc-devel] [PATCH] New mpg123 audio converter
Rémi Denis-Courmont
remi at remlab.net
Mon Sep 2 18:29:47 CEST 2013
Le lundi 2 septembre 2013 16:42:58 Ludovic Fauvet a écrit :
> diff --git a/modules/audio_filter/Modules.am
> b/modules/audio_filter/Modules.am index d3454e9..d730baf 100644
> --- a/modules/audio_filter/Modules.am
> +++ b/modules/audio_filter/Modules.am
> @@ -51,6 +51,7 @@ SOURCES_a52tofloat32 = converter/a52tofloat32.c
> SOURCES_dtstospdif = converter/dtstospdif.c
> SOURCES_dtstofloat32 = converter/dtstofloat32.c
> SOURCES_mpgatofixed32 = converter/mpgatofixed32.c
> +SOURCES_mpgatofloat32_mpg123 = converter/mpgatofloat32_mpg123.c
Can you please use a less awful plugin name?
> libaudio_format_plugin_la_SOURCES = converter/format.c
> libaudio_format_plugin_la_CFLAGS = $(AM_CFLAGS)
> libaudio_format_plugin_la_LIBADD = $(AM_LIBADD) $(LIBM)
> diff --git a/modules/audio_filter/converter/mpgatofloat32_mpg123.c
> b/modules/audio_filter/converter/mpgatofloat32_mpg123.c new file mode
> 100644
> index 0000000..9588e5b
> --- /dev/null
> +++ b/modules/audio_filter/converter/mpgatofloat32_mpg123.c
> @@ -0,0 +1,239 @@
> +/**************************************************************************
> *** + * mpgatofloat32_mpg123.c: MPEG-1 & 2 audio layer I, II, III + MPEG 2.5
> + * decoder, using MPG123
> +
> ***************************************************************************
> ** + * Copyright (C) 2001-2013 VLC authors and VideoLAN
> + *
> + * Authors: Christophe Massiot <massiot at via.ecp.fr>
> + * Jean-Paul Saman <jpsaman _at_ videolan _dot_ org>
> + * William Hahne <will07c5 at gmail.com>
> + * Ludovic Fauvet <etix at videolan.org>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU Lesser General Public License as published by
> + * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser 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
> +
> ***************************************************************************
> **/ +
> +#include <mpg123.h>
> +
> +#ifdef HAVE_CONFIG_H
> +# include "config.h"
> +#endif
> +#include <assert.h>
> +
> +#include <vlc_common.h>
> +#include <vlc_plugin.h>
> +#include <vlc_aout.h>
> +#include <vlc_block.h>
> +#include <vlc_filter.h>
> +
> +/**************************************************************************
> *** + * Local prototypes
> +
> ***************************************************************************
> **/ +static int OpenFilter ( vlc_object_t * );
> +static void CloseFilter( vlc_object_t * );
> +static block_t *Convert( filter_t *, block_t * );
> +
> +/**************************************************************************
> *** + * Local structures
> +
> ***************************************************************************
> **/ +struct filter_sys_t
> +{
> + mpg123_handle * p_handle;
> + unsigned char * p_buffer;
Why that?
> +
> + int i_reject_count;
> + size_t i_size;
Ditto.
> + off_t i_offset;
> +};
> +
> +/**************************************************************************
> *** + * Module descriptor
> +
> ***************************************************************************
> **/ +vlc_module_begin ()
> + set_category( CAT_INPUT )
> + set_subcategory( SUBCAT_INPUT_ACODEC )
> + set_description( N_("MPEG audio decoder using mpg123") )
> + set_capability( "audio converter", 123 )
> + set_callbacks( OpenFilter, CloseFilter )
> +vlc_module_end ()
> +
> +/**************************************************************************
> *** + * DoWork: decode an MPEG audio frame.
> +
> ***************************************************************************
> **/ +static void DoWork( filter_t * p_filter,
> + block_t * p_in_buf, block_t * p_out_buf )
> +{
> + filter_sys_t *p_sys = p_filter->p_sys;
> +
> + p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
> + p_out_buf->i_buffer = p_in_buf->i_nb_samples * sizeof(float) *
> + aout_FormatNbChannels( &p_filter->fmt_out.audio
> ); +
> +
> + /* Ignore the last 8 bytes due to a hack for libmad */
> + /* FIXME: This hack should be removed somehow --etix */
> + if ( p_in_buf->i_buffer < 8 )
> + return;
> + int i_err = mpg123_feed( p_sys->p_handle, p_in_buf->p_buffer,
> + p_in_buf->i_buffer - 8 );
> +
> + /* Do the actual decoding now */
> + if ( i_err != MPG123_OK || mpg123_decode_frame( p_sys->p_handle,
> + &p_sys->i_offset, &p_sys->p_buffer, &p_sys->i_size ) != MPG123_OK
> ) + {
> + msg_Warn( p_filter, "mpg123 error: %s",
> + mpg123_strerror( p_sys->p_handle ) );
> + p_sys->i_reject_count = 3;
> + }
> + else if( p_in_buf->i_flags & BLOCK_FLAG_DISCONTINUITY )
> + {
> + p_sys->i_reject_count = 3;
> + }
> +
> + if( p_sys->i_reject_count > 0 )
> + {
> + memset( p_out_buf->p_buffer, 0, p_out_buf->i_buffer );
> + p_sys->i_reject_count--;
> + return;
> + }
> +
> + assert( p_out_buf->i_size >= p_sys->i_size );
> + memcpy( p_out_buf->p_buffer, p_sys->p_buffer, p_sys->i_size );
> +}
> +
> +static block_t *Convert( filter_t *p_filter, block_t *p_block )
> +{
> + if( !p_block || !p_block->i_nb_samples )
> + {
> + if( p_block )
> + block_Release( p_block );
> + return NULL;
> + }
> +
> + size_t i_out_size = p_block->i_nb_samples *
> + p_filter->fmt_out.audio.i_bitspersample *
> + p_filter->fmt_out.audio.i_channels / 8;
> +
> + block_t *p_out = block_Alloc( i_out_size );
> + if( unlikely( !p_out ) )
> + {
> + msg_Warn( p_filter, "can't get output buffer" );
Why?
> + block_Release( p_block );
> + return NULL;
> + }
> +
> + p_out->i_nb_samples = p_block->i_nb_samples;
> + p_out->i_dts = p_block->i_dts;
> + p_out->i_pts = p_block->i_pts;
> + p_out->i_length = p_block->i_length;
> +
> + DoWork( p_filter, p_block, p_out );
> +
> + block_Release( p_block );
> +
> + return p_out;
> +}
> +
> +/**************************************************************************
> *** + * OpenFilter:
> +
> ***************************************************************************
> **/ +static int OpenFilter( vlc_object_t *p_this )
> +{
> + filter_t *p_filter = (filter_t *)p_this;
> + filter_sys_t *p_sys;
> +
> + if( p_filter->fmt_in.i_codec != VLC_CODEC_MPGA &&
> + p_filter->fmt_in.i_codec != VLC_FOURCC('m','p','g','3') )
> + return VLC_EGENERIC;
> +
> + if( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio,
> &p_filter->fmt_out.audio ) ) + return VLC_EGENERIC;
> +
> + if( p_filter->fmt_out.audio.i_format != VLC_CODEC_FL32 )
> + return VLC_EGENERIC;
> +
> + /* Allocate the memory needed to store the module's structure */
> + p_sys = p_filter->p_sys = malloc( sizeof(filter_sys_t) );
> + if( p_sys == NULL )
> + return VLC_EGENERIC;
> +
> + /* Initialize libmpg123 */
> + if( mpg123_init() != MPG123_OK ||
Not reentrant.
> + ( p_sys->p_handle = mpg123_new( NULL, NULL ) ) == NULL )
> + {
> + goto error;
> + }
> +
> + /* Open a new bitstream */
> + if( mpg123_open_feed( p_sys->p_handle ) != MPG123_OK )
> + {
> + msg_Err( p_this, "mpg123 error: can't open feed" );
> + mpg123_delete( p_sys->p_handle );
> + goto error;
> + }
> +
> + /* Disable resync stream after error */
> + mpg123_param( p_sys->p_handle, MPG123_ADD_FLAGS, MPG123_NO_RESYNC, 0 );
> +
> + /* Setup output format */
> + mpg123_format_none( p_sys->p_handle );
> +
> + if( MPG123_OK != mpg123_format( p_sys->p_handle,
> + p_filter->fmt_in.audio.i_rate,
> + MPG123_MONO | MPG123_STEREO,
> + MPG123_ENC_FLOAT_32 ) )
> + {
> + msg_Err( p_this, "mpg123 error: %s",
> + mpg123_strerror( p_sys->p_handle ) );
> + mpg123_close( p_sys->p_handle );
> + mpg123_delete( p_sys->p_handle );
> + goto error;
> + }
> +
> + p_sys->i_reject_count = 0;
> + p_filter->pf_audio_filter = Convert;
> + p_filter->fmt_out.audio.i_format = p_filter->fmt_out.i_codec;
> + p_filter->fmt_out.audio.i_bitspersample =
> + aout_BitsPerSample( p_filter->fmt_out.i_codec );
> +
> + msg_Dbg( p_this, "%4.4s->%4.4s, bits per sample: %i",
> + (char *)&p_filter->fmt_in.i_codec,
> + (char *)&p_filter->fmt_out.i_codec,
> + p_filter->fmt_in.audio.i_bitspersample );
> +
> + return VLC_SUCCESS;
> +error:
> + mpg123_exit();
> + free( p_sys );
> + return VLC_EGENERIC;
> +}
> +
> +/**************************************************************************
> *** + * CloseFilter : deallocate data structures
> +
> ***************************************************************************
> **/ +static void CloseFilter( vlc_object_t *p_this )
> +{
> + filter_t *p_filter = (filter_t *)p_this;
> + filter_sys_t *p_sys = p_filter->p_sys;
> +
> + mpg123_close( p_sys->p_handle );
> + mpg123_delete( p_sys->p_handle );
> + mpg123_exit();
> + free( p_sys );
> +}
> +
--
Rémi Denis-Courmont
http://www.remlab.net/
More information about the vlc-devel
mailing list