[vlc-devel] [PATCH] New mpg123 audio converter
Ludovic Fauvet
etix at videolan.org
Mon Sep 2 16:42:58 CEST 2013
As of now, mpg123 is licensed under the LGPL 2.1. In terms of performances it
should perform better than the existing libmad module because of various
assembly optimizations.
---
configure.ac | 6 +
modules/audio_filter/Modules.am | 1 +
.../audio_filter/converter/mpgatofloat32_mpg123.c | 239 +++++++++++++++++++++
3 files changed, 246 insertions(+)
create mode 100644 modules/audio_filter/converter/mpgatofloat32_mpg123.c
diff --git a/configure.ac b/configure.ac
index 0f6ea2a..dd9dc6e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2264,6 +2264,12 @@ then
fi
fi
+dnl mpg123 plugin
+dnl
+dnl
+PKG_ENABLE_MODULES_VLC([MPG123], [mpgatofloat32_mpg123], [libmpg123], [libmpg123 decoder support], [auto])
+
+
AC_ARG_ENABLE(merge-ffmpeg,
[ --enable-merge-ffmpeg merge FFmpeg-based plugins (default disabled)],, [
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
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;
+
+ int i_reject_count;
+ size_t i_size;
+ 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" );
+ 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 ||
+ ( 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 );
+}
+
--
1.8.4
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