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704 lines
20 KiB
704 lines
20 KiB
/*****************************************************************************
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* flac.c: flac packetizer module.
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*****************************************************************************
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* Copyright (C) 1999-2001 the VideoLAN team
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* $Id$
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*
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* Authors: Gildas Bazin <gbazin@videolan.org>
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* Sigmund Augdal Helberg <dnumgis@videolan.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
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*****************************************************************************/
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/*****************************************************************************
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* Preamble
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*****************************************************************************/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <vlc_common.h>
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#include <vlc_plugin.h>
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#include <vlc_codec.h>
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#include <vlc_block_helper.h>
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#include <vlc_bits.h>
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/*****************************************************************************
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* Module descriptor
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*****************************************************************************/
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static int Open ( vlc_object_t * );
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static void Close( vlc_object_t * );
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vlc_module_begin()
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set_category( CAT_SOUT )
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set_subcategory( SUBCAT_SOUT_PACKETIZER )
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set_description( N_("Flac audio packetizer") )
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set_capability( "packetizer", 50 )
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set_callbacks( Open, Close )
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vlc_module_end()
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/*****************************************************************************
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* decoder_sys_t : FLAC decoder descriptor
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*****************************************************************************/
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#define MAX_FLAC_HEADER_SIZE 16
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struct decoder_sys_t
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{
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/*
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* Input properties
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*/
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int i_state;
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block_bytestream_t bytestream;
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/*
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* FLAC properties
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*/
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struct
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{
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unsigned min_blocksize, max_blocksize;
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unsigned min_framesize, max_framesize;
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unsigned sample_rate;
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unsigned channels;
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unsigned bits_per_sample;
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} stream_info;
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bool b_stream_info;
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/*
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* Common properties
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*/
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date_t end_date;
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mtime_t i_pts;
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int i_frame_length;
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size_t i_frame_size;
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unsigned int i_rate, i_channels, i_bits_per_sample;
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};
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enum
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{
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STATE_NOSYNC,
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STATE_SYNC,
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STATE_HEADER,
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STATE_NEXT_SYNC,
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STATE_GET_DATA,
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STATE_SEND_DATA
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};
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/*****************************************************************************
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* Local prototypes
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*****************************************************************************/
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static block_t *Packetize( decoder_t *, block_t ** );
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static int SyncInfo( decoder_t *, uint8_t *, unsigned int *,
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unsigned int *, unsigned int * );
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static uint64_t read_utf8( const uint8_t *p_buf, int *pi_read );
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static uint8_t flac_crc8( const uint8_t *data, unsigned len );
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static int Open( vlc_object_t *p_this )
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{
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decoder_t *p_dec = (decoder_t*)p_this;
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decoder_sys_t *p_sys;
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if( p_dec->fmt_in.i_codec != VLC_CODEC_FLAC )
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return VLC_EGENERIC;
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/* */
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p_dec->p_sys = p_sys = malloc(sizeof(*p_sys));
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if( !p_sys )
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return VLC_ENOMEM;
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date_Set( &p_sys->end_date, 0 );
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p_sys->i_state = STATE_NOSYNC;
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p_sys->b_stream_info = false;
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p_sys->i_pts = VLC_TS_INVALID;
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p_sys->bytestream = block_BytestreamInit();
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/* */
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es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
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p_dec->fmt_out.i_cat = AUDIO_ES;
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p_dec->fmt_out.i_codec = VLC_CODEC_FLAC;
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/* */
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p_dec->pf_decode_audio = NULL;
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p_dec->pf_packetize = Packetize;
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return VLC_SUCCESS;
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}
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static void Close( vlc_object_t *p_this )
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{
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decoder_t *p_dec = (decoder_t *)p_this;
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decoder_sys_t *p_sys = p_dec->p_sys;
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block_BytestreamRelease( &p_sys->bytestream );
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free( p_sys );
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}
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/*****************************************************************************
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* ProcessHeader: process Flac header.
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*****************************************************************************/
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static void ProcessHeader( decoder_t *p_dec )
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{
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decoder_sys_t *p_sys = p_dec->p_sys;
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bs_t bs;
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if( p_dec->fmt_in.i_extra < 8 + 14 )
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return;
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bs_init( &bs, (uint8_t*)p_dec->fmt_in.p_extra + 8, p_dec->fmt_in.i_extra - 8 );
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p_sys->stream_info.min_blocksize = bs_read( &bs, 16 );
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p_sys->stream_info.max_blocksize = bs_read( &bs, 16 );
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p_sys->stream_info.min_framesize = bs_read( &bs, 24 );
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p_sys->stream_info.max_framesize = bs_read( &bs, 24 );
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p_sys->stream_info.sample_rate = bs_read( &bs, 20 );
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p_sys->stream_info.channels = bs_read( &bs, 3 ) + 1;
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p_sys->stream_info.bits_per_sample = bs_read( &bs, 5 ) + 1;
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p_sys->b_stream_info = true;
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p_dec->fmt_out.i_extra = p_dec->fmt_in.i_extra;
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p_dec->fmt_out.p_extra = xrealloc( p_dec->fmt_out.p_extra,
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p_dec->fmt_out.i_extra );
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memcpy( p_dec->fmt_out.p_extra,
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p_dec->fmt_in.p_extra, p_dec->fmt_out.i_extra );
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}
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/* */
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static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
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{
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decoder_sys_t *p_sys = p_dec->p_sys;
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uint8_t p_header[MAX_FLAC_HEADER_SIZE];
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block_t *p_sout_block;
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if( !pp_block || !*pp_block ) return NULL;
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if( (*pp_block)->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
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{
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if( (*pp_block)->i_flags&BLOCK_FLAG_CORRUPTED )
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{
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p_sys->i_state = STATE_NOSYNC;
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block_BytestreamEmpty( &p_sys->bytestream );
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}
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date_Set( &p_sys->end_date, 0 );
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block_Release( *pp_block );
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return NULL;
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}
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if( !p_sys->b_stream_info )
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ProcessHeader( p_dec );
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if( p_sys->stream_info.channels > 8 )
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{
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msg_Err( p_dec, "This stream uses too many audio channels" );
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return NULL;
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}
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if( !date_Get( &p_sys->end_date ) && (*pp_block)->i_pts <= VLC_TS_INVALID )
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{
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/* We've just started the stream, wait for the first PTS. */
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block_Release( *pp_block );
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return NULL;
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}
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else if( !date_Get( &p_sys->end_date ) )
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{
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/* The first PTS is as good as anything else. */
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p_sys->i_rate = p_dec->fmt_out.audio.i_rate;
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date_Init( &p_sys->end_date, p_sys->i_rate, 1 );
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date_Set( &p_sys->end_date, (*pp_block)->i_pts );
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}
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block_BytestreamPush( &p_sys->bytestream, *pp_block );
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while( 1 )
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{
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switch( p_sys->i_state )
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{
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case STATE_NOSYNC:
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while( block_PeekBytes( &p_sys->bytestream, p_header, 2 )
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== VLC_SUCCESS )
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{
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if( p_header[0] == 0xFF && (p_header[1] & 0xFE) == 0xF8 )
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{
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p_sys->i_state = STATE_SYNC;
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break;
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}
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block_SkipByte( &p_sys->bytestream );
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}
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if( p_sys->i_state != STATE_SYNC )
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{
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block_BytestreamFlush( &p_sys->bytestream );
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/* Need more data */
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return NULL;
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}
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case STATE_SYNC:
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/* New frame, set the Presentation Time Stamp */
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p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
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if( p_sys->i_pts > VLC_TS_INVALID &&
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p_sys->i_pts != date_Get( &p_sys->end_date ) )
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{
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date_Set( &p_sys->end_date, p_sys->i_pts );
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}
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p_sys->i_state = STATE_HEADER;
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case STATE_HEADER:
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/* Get FLAC frame header (MAX_FLAC_HEADER_SIZE bytes) */
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if( block_PeekBytes( &p_sys->bytestream, p_header,
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MAX_FLAC_HEADER_SIZE ) != VLC_SUCCESS )
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{
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/* Need more data */
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return NULL;
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}
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/* Check if frame is valid and get frame info */
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p_sys->i_frame_length = SyncInfo( p_dec, p_header,
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&p_sys->i_channels,
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&p_sys->i_rate,
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&p_sys->i_bits_per_sample );
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if( !p_sys->i_frame_length )
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{
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msg_Dbg( p_dec, "emulated sync word" );
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block_SkipByte( &p_sys->bytestream );
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p_sys->i_state = STATE_NOSYNC;
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break;
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}
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if( p_sys->i_rate != p_dec->fmt_out.audio.i_rate )
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{
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p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
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const mtime_t i_end_date = date_Get( &p_sys->end_date );
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date_Init( &p_sys->end_date, p_sys->i_rate, 1 );
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date_Set( &p_sys->end_date, i_end_date );
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}
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p_sys->i_state = STATE_NEXT_SYNC;
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p_sys->i_frame_size = p_sys->b_stream_info && p_sys->stream_info.min_framesize > 0 ?
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p_sys->stream_info.min_framesize : 1;
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case STATE_NEXT_SYNC:
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/* TODO: If pp_block == NULL, flush the buffer without checking the
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* next sync word */
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/* Check if next expected frame contains the sync word */
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while( block_PeekOffsetBytes( &p_sys->bytestream,
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p_sys->i_frame_size, p_header,
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MAX_FLAC_HEADER_SIZE )
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== VLC_SUCCESS )
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{
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if( p_header[0] == 0xFF && (p_header[1] & 0xFE) == 0xF8 )
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{
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/* Check if frame is valid and get frame info */
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int i_frame_length =
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SyncInfo( p_dec, p_header,
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&p_sys->i_channels,
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&p_sys->i_rate,
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&p_sys->i_bits_per_sample );
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if( i_frame_length )
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{
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p_sys->i_state = STATE_SEND_DATA;
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break;
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}
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}
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p_sys->i_frame_size++;
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}
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if( p_sys->i_state != STATE_SEND_DATA )
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{
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if( p_sys->b_stream_info && p_sys->stream_info.max_framesize > 0 &&
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p_sys->i_frame_size > p_sys->stream_info.max_framesize )
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{
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block_SkipByte( &p_sys->bytestream );
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p_sys->i_state = STATE_NOSYNC;
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return NULL;
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}
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/* Need more data */
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return NULL;
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}
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case STATE_SEND_DATA:
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p_sout_block = block_New( p_dec, p_sys->i_frame_size );
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/* Copy the whole frame into the buffer. When we reach this point
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* we already know we have enough data available. */
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block_GetBytes( &p_sys->bytestream, p_sout_block->p_buffer,
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p_sys->i_frame_size );
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/* Make sure we don't reuse the same pts twice */
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if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
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p_sys->i_pts = p_sys->bytestream.p_block->i_pts = VLC_TS_INVALID;
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/* So p_block doesn't get re-added several times */
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*pp_block = block_BytestreamPop( &p_sys->bytestream );
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p_sys->i_state = STATE_NOSYNC;
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/* Date management */
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p_sout_block->i_pts =
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p_sout_block->i_dts = date_Get( &p_sys->end_date );
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date_Increment( &p_sys->end_date, p_sys->i_frame_length );
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p_sout_block->i_length =
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date_Get( &p_sys->end_date ) - p_sout_block->i_pts;
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return p_sout_block;
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}
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}
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return NULL;
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}
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/*****************************************************************************
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* SyncInfo: parse FLAC sync info
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*****************************************************************************/
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static int SyncInfo( decoder_t *p_dec, uint8_t *p_buf,
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unsigned int * pi_channels,
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unsigned int * pi_sample_rate,
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unsigned int * pi_bits_per_sample )
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{
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decoder_sys_t *p_sys = p_dec->p_sys;
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int i_header, i_temp, i_read;
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unsigned i_blocksize = 0;
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int i_blocksize_hint = 0, i_sample_rate_hint = 0;
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/* Check syncword */
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if( p_buf[0] != 0xFF || (p_buf[1] & 0xFE) != 0xF8 ) return 0;
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/* Check there is no emulated sync code in the rest of the header */
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if( p_buf[2] == 0xff || p_buf[3] == 0xFF ) return 0;
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/* Find blocksize (framelength) */
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switch( i_temp = p_buf[2] >> 4 )
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{
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case 0:
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if( p_sys->b_stream_info &&
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p_sys->stream_info.min_blocksize == p_sys->stream_info.max_blocksize )
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i_blocksize = p_sys->stream_info.min_blocksize;
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else return 0; /* We can't do anything with this */
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break;
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case 1:
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i_blocksize = 192;
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break;
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case 2:
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case 3:
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case 4:
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case 5:
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i_blocksize = 576 << (i_temp - 2);
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break;
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case 6:
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case 7:
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i_blocksize_hint = i_temp;
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break;
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case 8:
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case 9:
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case 10:
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case 11:
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case 12:
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case 13:
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case 14:
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case 15:
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i_blocksize = 256 << (i_temp - 8);
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break;
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}
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if( p_sys->b_stream_info &&
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( i_blocksize < p_sys->stream_info.min_blocksize ||
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i_blocksize > p_sys->stream_info.max_blocksize ) )
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return 0;
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/* Find samplerate */
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switch( i_temp = p_buf[2] & 0x0f )
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{
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case 0:
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if( p_sys->b_stream_info )
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*pi_sample_rate = p_sys->stream_info.sample_rate;
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else return 0; /* We can't do anything with this */
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break;
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case 1:
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*pi_sample_rate = 88200;
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break;
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case 2:
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*pi_sample_rate = 176400;
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break;
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case 3:
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*pi_sample_rate = 192000;
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break;
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case 4:
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*pi_sample_rate = 8000;
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break;
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case 5:
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*pi_sample_rate = 16000;
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break;
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case 6:
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*pi_sample_rate = 22050;
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break;
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case 7:
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*pi_sample_rate = 24000;
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break;
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case 8:
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*pi_sample_rate = 32000;
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break;
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case 9:
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*pi_sample_rate = 44100;
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break;
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case 10:
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*pi_sample_rate = 48000;
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break;
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case 11:
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*pi_sample_rate = 96000;
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break;
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case 12:
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case 13:
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case 14:
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i_sample_rate_hint = i_temp;
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break;
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case 15:
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return 0;
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}
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/* Find channels */
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i_temp = (unsigned)(p_buf[3] >> 4);
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if( i_temp & 8 )
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{
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if( ( i_temp & 7 ) >= 3 )
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return 0;
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*pi_channels = 2;
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}
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else
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{
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*pi_channels = i_temp + 1;
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}
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/* Find bits per sample */
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switch( i_temp = (unsigned)(p_buf[3] & 0x0e) >> 1 )
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{
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case 0:
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if( p_sys->b_stream_info )
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*pi_bits_per_sample = p_sys->stream_info.bits_per_sample;
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else
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return 0;
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break;
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case 1:
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*pi_bits_per_sample = 8;
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break;
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case 2:
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*pi_bits_per_sample = 12;
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break;
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case 4:
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|
*pi_bits_per_sample = 16;
|
|
break;
|
|
|
|
case 5:
|
|
*pi_bits_per_sample = 20;
|
|
break;
|
|
|
|
case 6:
|
|
*pi_bits_per_sample = 24;
|
|
break;
|
|
|
|
case 3:
|
|
case 7:
|
|
return 0;
|
|
break;
|
|
}
|
|
|
|
/* Zero padding bit */
|
|
if( p_buf[3] & 0x01 ) return 0;
|
|
|
|
/* End of fixed size header */
|
|
i_header = 4;
|
|
|
|
/* Check Sample/Frame number */
|
|
if( read_utf8( &p_buf[i_header++], &i_read ) == INT64_C(0xffffffffffffffff) )
|
|
return 0;
|
|
|
|
i_header += i_read;
|
|
|
|
/* Read blocksize */
|
|
if( i_blocksize_hint )
|
|
{
|
|
int i_val1 = p_buf[i_header++];
|
|
if( i_blocksize_hint == 7 )
|
|
{
|
|
int i_val2 = p_buf[i_header++];
|
|
i_val1 = (i_val1 << 8) | i_val2;
|
|
}
|
|
i_blocksize = i_val1 + 1;
|
|
}
|
|
|
|
/* Read sample rate */
|
|
if( i_sample_rate_hint )
|
|
{
|
|
int i_val1 = p_buf[i_header++];
|
|
if( i_sample_rate_hint != 12 )
|
|
{
|
|
int i_val2 = p_buf[i_header++];
|
|
i_val1 = (i_val1 << 8) | i_val2;
|
|
}
|
|
if( i_sample_rate_hint == 12 ) *pi_sample_rate = i_val1 * 1000;
|
|
else if( i_sample_rate_hint == 13 ) *pi_sample_rate = i_val1;
|
|
else *pi_sample_rate = i_val1 * 10;
|
|
}
|
|
|
|
/* Check the CRC-8 byte */
|
|
if( flac_crc8( p_buf, i_header ) != p_buf[i_header] )
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* Sanity check using stream info header when possible */
|
|
if( p_sys->b_stream_info )
|
|
{
|
|
if( i_blocksize < p_sys->stream_info.min_blocksize ||
|
|
i_blocksize > p_sys->stream_info.max_blocksize )
|
|
return 0;
|
|
if( *pi_bits_per_sample != p_sys->stream_info.bits_per_sample )
|
|
return 0;
|
|
if( *pi_sample_rate != p_sys->stream_info.sample_rate )
|
|
return 0;
|
|
}
|
|
return i_blocksize;
|
|
}
|
|
|
|
/* Will return 0xffffffffffffffff for an invalid utf-8 sequence */
|
|
static uint64_t read_utf8( const uint8_t *p_buf, int *pi_read )
|
|
{
|
|
uint64_t i_result = 0;
|
|
unsigned i, j;
|
|
|
|
if( !(p_buf[0] & 0x80) ) /* 0xxxxxxx */
|
|
{
|
|
i_result = p_buf[0];
|
|
i = 0;
|
|
}
|
|
else if( p_buf[0] & 0xC0 && !(p_buf[0] & 0x20) ) /* 110xxxxx */
|
|
{
|
|
i_result = p_buf[0] & 0x1F;
|
|
i = 1;
|
|
}
|
|
else if( p_buf[0] & 0xE0 && !(p_buf[0] & 0x10) ) /* 1110xxxx */
|
|
{
|
|
i_result = p_buf[0] & 0x0F;
|
|
i = 2;
|
|
}
|
|
else if( p_buf[0] & 0xF0 && !(p_buf[0] & 0x08) ) /* 11110xxx */
|
|
{
|
|
i_result = p_buf[0] & 0x07;
|
|
i = 3;
|
|
}
|
|
else if( p_buf[0] & 0xF8 && !(p_buf[0] & 0x04) ) /* 111110xx */
|
|
{
|
|
i_result = p_buf[0] & 0x03;
|
|
i = 4;
|
|
}
|
|
else if( p_buf[0] & 0xFC && !(p_buf[0] & 0x02) ) /* 1111110x */
|
|
{
|
|
i_result = p_buf[0] & 0x01;
|
|
i = 5;
|
|
}
|
|
else if( p_buf[0] & 0xFE && !(p_buf[0] & 0x01) ) /* 11111110 */
|
|
{
|
|
i_result = 0;
|
|
i = 6;
|
|
}
|
|
else {
|
|
return INT64_C(0xffffffffffffffff);
|
|
}
|
|
|
|
for( j = 1; j <= i; j++ )
|
|
{
|
|
if( !(p_buf[j] & 0x80) || (p_buf[j] & 0x40) ) /* 10xxxxxx */
|
|
{
|
|
return INT64_C(0xffffffffffffffff);
|
|
}
|
|
i_result <<= 6;
|
|
i_result |= (p_buf[j] & 0x3F);
|
|
}
|
|
|
|
*pi_read = i;
|
|
return i_result;
|
|
}
|
|
|
|
/* CRC-8, poly = x^8 + x^2 + x^1 + x^0, init = 0 */
|
|
static const uint8_t flac_crc8_table[256] = {
|
|
0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15,
|
|
0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D,
|
|
0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
|
|
0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D,
|
|
0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5,
|
|
0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
|
|
0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85,
|
|
0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD,
|
|
0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
|
|
0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA,
|
|
0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2,
|
|
0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
|
|
0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32,
|
|
0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A,
|
|
0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
|
|
0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A,
|
|
0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C,
|
|
0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
|
|
0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC,
|
|
0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4,
|
|
0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
|
|
0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44,
|
|
0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C,
|
|
0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
|
|
0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B,
|
|
0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63,
|
|
0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
|
|
0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13,
|
|
0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB,
|
|
0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
|
|
0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB,
|
|
0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3
|
|
};
|
|
|
|
static uint8_t flac_crc8( const uint8_t *data, unsigned len )
|
|
{
|
|
uint8_t crc = 0;
|
|
|
|
while(len--)
|
|
crc = flac_crc8_table[crc ^ *data++];
|
|
|
|
return crc;
|
|
}
|
|
|
|
|