/src/vlc/modules/packetizer/dts.c

Source (jump to first uncovered line)
/*****************************************************************************
 * dts.c: parse DTS audio sync info and packetize the stream
 *****************************************************************************
 * Copyright (C) 2001-2016 VLC authors and VideoLAN
 *
 * Authors: Gildas Bazin <gbazin@videolan.org>
 *          Thomas Guillem <thomas@gllm.fr>
 *
 * 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
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdbit.h>

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_codec.h>
#include <vlc_block_helper.h>
#include <vlc_modules.h>

#include "dts_header.h"

#include "packetizer_helper.h"

static int  Open( vlc_object_t * );
static void Close( vlc_object_t * );

vlc_module_begin ()
    set_subcategory( SUBCAT_SOUT_PACKETIZER )
    set_description( N_("DTS audio packetizer") )
    set_capability( "audio packetizer", 10 )
    set_callbacks( Open, Close )
vlc_module_end ()

typedef struct
{
    /*
     * Input properties
     */
    int i_state;

    block_bytestream_t bytestream;
    size_t i_next_offset;

    /*
     * Common properties
     */
    date_t  end_date;
    bool    b_date_set;

    vlc_tick_t i_pts;
    bool    b_discontinuity;

    vlc_dts_header_t first, second;
    size_t  i_input_size;
} decoder_sys_t;

enum
{
    STATE_SYNC_SUBSTREAM_EXTENSIONS = STATE_CUSTOM_FIRST,
    STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS,
};

static void PacketizeFlush( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    p_sys->b_discontinuity = true;
    date_Set( &p_sys->end_date, VLC_TICK_INVALID );
    p_sys->i_state = STATE_NOSYNC;
    block_BytestreamEmpty( &p_sys->bytestream );
}

static block_t *GetOutBuffer( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    if( !p_sys->b_date_set
     || p_dec->fmt_out.audio.i_rate != p_sys->first.i_rate )
    {
        msg_Dbg( p_dec, "DTS samplerate:%d bitrate:%d",
                 p_sys->first.i_rate, p_sys->first.i_bitrate );

        date_Init( &p_sys->end_date, p_sys->first.i_rate, 1 );
        date_Set( &p_sys->end_date, p_sys->i_pts );
        p_sys->b_date_set = true;
    }

    p_dec->fmt_out.audio.i_rate     = p_sys->first.i_rate;
    if( p_dec->fmt_out.audio.i_bytes_per_frame < p_sys->first.i_frame_size )
        p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->first.i_frame_size;
    p_dec->fmt_out.audio.i_frame_length = p_sys->first.i_frame_length;

    p_dec->fmt_out.audio.i_chan_mode = p_sys->first.i_chan_mode;
    p_dec->fmt_out.audio.i_physical_channels = p_sys->first.i_physical_channels;
    p_dec->fmt_out.audio.i_channels =
        stdc_count_ones( p_dec->fmt_out.audio.i_physical_channels );

    p_dec->fmt_out.i_bitrate = p_sys->first.i_bitrate;

    block_t *p_block = block_Alloc( p_sys->i_input_size );
    if( p_block == NULL )
        return NULL;

    p_block->i_nb_samples = p_sys->first.i_frame_length;
    p_block->i_pts = p_block->i_dts = date_Get( &p_sys->end_date );
    p_block->i_length =
        date_Increment( &p_sys->end_date, p_block->i_nb_samples ) - p_block->i_pts;
    return p_block;
}

static block_t *PacketizeBlock( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    uint8_t p_header[VLC_DTS_HEADER_SIZE];
    block_t *p_out_buffer;

    block_t *p_block = pp_block ? *pp_block : NULL;

    if( p_block )
    {
        if ( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) ) {
            /* First always drain complete blocks before discontinuity */
            block_t *p_drain = PacketizeBlock( p_dec, NULL );
            if(p_drain)
                return p_drain;

            PacketizeFlush( p_dec );

            if ( p_block->i_flags & BLOCK_FLAG_CORRUPTED ) {
                block_Release( p_block );
                return NULL;
            }
        }

        if ( p_block->i_pts == VLC_TICK_INVALID &&
             date_Get( &p_sys->end_date ) == VLC_TICK_INVALID ) {
            /* We've just started the stream, wait for the first PTS. */
            block_Release( p_block );
            return NULL;
        }

        block_BytestreamPush( &p_sys->bytestream, p_block );
    }

    while( 1 )
    {
        switch( p_sys->i_state )
        {
        case STATE_NOSYNC:
            while( block_PeekBytes( &p_sys->bytestream, p_header, 6 )
                   == VLC_SUCCESS )
            {
                if( vlc_dts_header_IsSync( p_header, 6 ) )
                {
                    p_sys->i_state = STATE_SYNC;
                    break;
                }
                block_SkipByte( &p_sys->bytestream );
            }
            if( p_sys->i_state != STATE_SYNC )
            {
                block_BytestreamFlush( &p_sys->bytestream );

                /* Need more data */
                return NULL;
            }
            /* fallthrough */

        case STATE_SYNC:
            /* New frame, set the Presentation Time Stamp */
            p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
            if( p_sys->i_pts != VLC_TICK_INVALID &&
                p_sys->i_pts != date_Get( &p_sys->end_date ) )
            {
                date_Set( &p_sys->end_date, p_sys->i_pts );
            }
            p_sys->i_state = STATE_HEADER;
            /* fallthrough */

        case STATE_HEADER:
            /* Get DTS frame header (VLC_DTS_HEADER_SIZE bytes) */
            if( block_PeekBytes( &p_sys->bytestream, p_header,
                                 VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
            {
                /* Need more data */
                return NULL;
            }

            /* Check if frame is valid and get frame info */
            if( vlc_dts_header_Parse( &p_sys->first, p_header,
                                      VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS
             || p_sys->first.i_frame_size == 0 )
            {
                msg_Dbg( p_dec, "emulated sync word" );
                block_SkipByte( &p_sys->bytestream );
                p_sys->i_state = STATE_NOSYNC;
                break;
            }

            if( p_sys->first.syncword == DTS_SYNC_SUBSTREAM )
                p_sys->i_state = STATE_SYNC_SUBSTREAM_EXTENSIONS;
            else
                p_sys->i_state = STATE_NEXT_SYNC;
            p_sys->i_input_size = p_sys->i_next_offset = p_sys->first.i_frame_size;
            break;

        case STATE_SYNC_SUBSTREAM_EXTENSIONS:
            /* Peek into the substream extension (sync + header size < frame_size) */
            if( block_PeekOffsetBytes( &p_sys->bytestream,
                                       p_sys->first.i_substream_header_size,
                                       p_header,
                                       VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
            {
                /* Need more data */
                return NULL;
            }

            vlc_dts_header_t xssheader;
            if( vlc_dts_header_Parse( &xssheader, p_header,
                                      VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
            {
                msg_Dbg( p_dec, "emulated substream sync word, can't find extension" );
                block_SkipByte( &p_sys->bytestream );
                p_sys->i_state = STATE_NOSYNC;
                break;
            }

            if( xssheader.syncword == DTS_SYNC_SUBSTREAM_LBR )
            {
                /*
                 * LBR exists as independent SUBSTREAM. It is seen valid
                 * only when SUBSTREAM[LBR]..SUBTREAM.
                 * CORE...SUBSTREAM is regular extension.
                 * SUBSTREAM...CORE is sync issue.
                 */
                p_dec->fmt_out.i_profile = PROFILE_DTS_EXPRESS;
                p_sys->first.i_rate = xssheader.i_rate;
                p_sys->first.i_frame_length = xssheader.i_frame_length;
                p_sys->i_state = STATE_NEXT_SYNC;
                break;
            }

            msg_Warn( p_dec, "substream without the paired core stream, skip it" );
            p_sys->i_state = STATE_NOSYNC;
            p_dec->fmt_out.i_profile = PROFILE_DTS;
            if( block_SkipBytes( &p_sys->bytestream,
                                 p_sys->first.i_frame_size ) != VLC_SUCCESS )
                return NULL;
            break;

        case STATE_NEXT_SYNC:
            /* Check if next expected frame contains the sync word */
            while( p_sys->i_state == STATE_NEXT_SYNC )
            {
                if( block_PeekOffsetBytes( &p_sys->bytestream,
                                           p_sys->i_next_offset, p_header,
                                           VLC_DTS_HEADER_SIZE )
                                           != VLC_SUCCESS )
                {
                    if( p_block == NULL ) /* drain */
                    {
                        p_sys->i_state = STATE_GET_DATA;
                        break;
                    }
                    /* Need more data */
                    return NULL;
                }

                if( p_header[0] == 0 )
                {
                    /* DTS wav files, audio CD's and some mkvs use stuffing */
                    p_sys->i_next_offset++;
                    continue;
                }

                if( !vlc_dts_header_IsSync( p_header, VLC_DTS_HEADER_SIZE ) )
                {
                    /* Even frame size is likely incorrect FSIZE #18166 */
                    if( (p_sys->first.i_frame_size % 2) && p_sys->i_next_offset > 0 &&
                        block_PeekOffsetBytes( &p_sys->bytestream,
                                               p_sys->i_next_offset - 1, p_header,
                                               VLC_DTS_HEADER_SIZE ) == 0 &&
                         vlc_dts_header_IsSync( p_header, VLC_DTS_HEADER_SIZE ) )
                    {
                        p_sys->i_input_size = p_sys->i_next_offset = p_sys->first.i_frame_size - 1;
                        /* reenter */
                        break;
                    }
                    msg_Dbg( p_dec, "emulated sync word "
                             "(no sync on following frame)" );
                    p_sys->i_state = STATE_NOSYNC;
                    block_SkipByte( &p_sys->bytestream );
                    break;
                }

                /* Check if a DTS substream packet is located just after
                 * the core packet */
                if( p_sys->i_next_offset == p_sys->first.i_frame_size &&
                    vlc_dts_header_Parse( &p_sys->second,
                                          p_header, VLC_DTS_HEADER_SIZE ) == VLC_SUCCESS &&
                    p_sys->second.syncword == DTS_SYNC_SUBSTREAM )
                {
                    p_sys->i_state = STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS;
                }
                else
                {
                    p_dec->fmt_out.i_profile = PROFILE_DTS;
                    p_sys->i_state = STATE_GET_DATA;
                }
            }
            break;

        case STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS:
            assert(p_sys->second.syncword == DTS_SYNC_SUBSTREAM);
            if( p_sys->first.syncword == DTS_SYNC_SUBSTREAM )
            {
                /* First substream must have been LBR */
                p_dec->fmt_out.i_profile = PROFILE_DTS_EXPRESS;
            }
            else /* Otherwise that's core + extensions, we need to output both */
            {
                p_dec->fmt_out.i_profile = PROFILE_DTS_HD;
                p_sys->i_input_size += p_sys->second.i_frame_size;
            }
            p_sys->i_state = STATE_GET_DATA;
            break;

        case STATE_GET_DATA:
            /* Make sure we have enough data. */
            if( block_WaitBytes( &p_sys->bytestream,
                                 p_sys->i_input_size ) != VLC_SUCCESS )
            {
                /* Need more data */
                return NULL;
            }
            p_sys->i_state = STATE_SEND_DATA;
            /* fallthrough */

        case STATE_SEND_DATA:
            if( !(p_out_buffer = GetOutBuffer( p_dec )) )
            {
                return NULL;
            }

            /* Copy the whole frame into the buffer. When we reach this point
             * we already know we have enough data available. */
            block_GetBytes( &p_sys->bytestream, p_out_buffer->p_buffer,
                            p_out_buffer->i_buffer );

            /* Make sure we don't reuse the same pts twice */
            if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
                p_sys->i_pts = p_sys->bytestream.p_block->i_pts = VLC_TICK_INVALID;

            if( p_sys->b_discontinuity )
            {
                p_sys->b_discontinuity = false;
                p_out_buffer->i_flags |= BLOCK_FLAG_DISCONTINUITY;
            }

            /* So p_block doesn't get re-added several times */
            if( pp_block )
                *pp_block = block_BytestreamPop( &p_sys->bytestream );

            p_sys->i_state = STATE_NOSYNC;

            return p_out_buffer;
        }
    }
}

static void Close( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys = p_dec->p_sys;

    block_BytestreamRelease( &p_sys->bytestream );

    free( p_sys );
}

static int Open( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;

    if( p_dec->fmt_in->i_codec != VLC_CODEC_DTS )
        return VLC_EGENERIC;

    /* Allocate the memory needed to store the decoder's structure */
    if( ( p_dec->p_sys = p_sys = malloc(sizeof(decoder_sys_t)) ) == NULL )
        return VLC_ENOMEM;

    /* Misc init */
    p_sys->i_state = STATE_NOSYNC;
    date_Set( &p_sys->end_date, VLC_TICK_INVALID );
    p_sys->i_pts = VLC_TICK_INVALID;
    p_sys->b_date_set = false;
    p_sys->b_discontinuity = false;
    memset(&p_sys->first, 0, sizeof(vlc_dts_header_t));
    memset(&p_sys->second, 0, sizeof(vlc_dts_header_t));
    block_BytestreamInit( &p_sys->bytestream );

    /* Set output properties (passthrough only) */
    p_dec->fmt_out.i_codec = p_dec->fmt_in->i_codec;
    p_dec->fmt_out.audio = p_dec->fmt_in->audio;

    /* Set callback */
    p_dec->pf_packetize = PacketizeBlock;
    p_dec->pf_flush     = PacketizeFlush;
    p_dec->pf_get_cc    = NULL;
    return VLC_SUCCESS;
}

Coverage Report

Created: 2025-07-23 06:11

Line	Count	Source (jump to first uncovered line)
1		/*****************************************************************************
2		* dts.c: parse DTS audio sync info and packetize the stream
3		*****************************************************************************
4		* Copyright (C) 2001-2016 VLC authors and VideoLAN
5		*
6		* Authors: Gildas Bazin <gbazin@videolan.org>
7		* Thomas Guillem <thomas@gllm.fr>
8		*
9		* This program is free software; you can redistribute it and/or modify it
10		* under the terms of the GNU Lesser General Public License as published by
11		* the Free Software Foundation; either version 2.1 of the License, or
12		* (at your option) any later version.
13		*
14		* This program is distributed in the hope that it will be useful,
15		* but WITHOUT ANY WARRANTY; without even the implied warranty of
16		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17		* GNU Lesser General Public License for more details.
18		*
19		* You should have received a copy of the GNU Lesser General Public License
20		* along with this program; if not, write to the Free Software Foundation,
21		* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22		*****************************************************************************/
23
24		/*****************************************************************************
25		* Preamble
26		*****************************************************************************/
27		#ifdef HAVE_CONFIG_H
28		# include "config.h"
29		#endif
30
31		#include <stdbit.h>
32
33		#include <vlc_common.h>
34		#include <vlc_plugin.h>
35		#include <vlc_codec.h>
36		#include <vlc_block_helper.h>
37		#include <vlc_modules.h>
38
39		#include "dts_header.h"
40
41		#include "packetizer_helper.h"
42
43		static int Open( vlc_object_t * );
44		static void Close( vlc_object_t * );
45
46	4	vlc_module_begin ()
47	2	set_subcategory( SUBCAT_SOUT_PACKETIZER )
48	2	set_description( N_("DTS audio packetizer") )
49	2	set_capability( "audio packetizer", 10 )
50	4	set_callbacks( Open, Close )
51	2	vlc_module_end ()
52
53		typedef struct
54		{
55		/*
56		* Input properties
57		*/
58		int i_state;
59
60		block_bytestream_t bytestream;
61		size_t i_next_offset;
62
63		/*
64		* Common properties
65		*/
66		date_t end_date;
67		bool b_date_set;
68
69		vlc_tick_t i_pts;
70		bool b_discontinuity;
71
72		vlc_dts_header_t first, second;
73		size_t i_input_size;
74		} decoder_sys_t;
75
76		enum
77		{
78		STATE_SYNC_SUBSTREAM_EXTENSIONS = STATE_CUSTOM_FIRST,
79		STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS,
80		};
81
82		static void PacketizeFlush( decoder_t *p_dec )
83	0	{
84	0	decoder_sys_t *p_sys = p_dec->p_sys;
85
86	0	p_sys->b_discontinuity = true;
87	0	date_Set( &p_sys->end_date, VLC_TICK_INVALID );
88	0	p_sys->i_state = STATE_NOSYNC;
89	0	block_BytestreamEmpty( &p_sys->bytestream );
90	0	}
91
92		static block_t GetOutBuffer( decoder_t p_dec )
93	0	{
94	0	decoder_sys_t *p_sys = p_dec->p_sys;
95
96	0	if( !p_sys->b_date_set
97	0	\|\| p_dec->fmt_out.audio.i_rate != p_sys->first.i_rate )
98	0	{
99	0	msg_Dbg( p_dec, "DTS samplerate:%d bitrate:%d",
100	0	p_sys->first.i_rate, p_sys->first.i_bitrate );
101
102	0	date_Init( &p_sys->end_date, p_sys->first.i_rate, 1 );
103	0	date_Set( &p_sys->end_date, p_sys->i_pts );
104	0	p_sys->b_date_set = true;
105	0	}
106
107	0	p_dec->fmt_out.audio.i_rate = p_sys->first.i_rate;
108	0	if( p_dec->fmt_out.audio.i_bytes_per_frame < p_sys->first.i_frame_size )
109	0	p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->first.i_frame_size;
110	0	p_dec->fmt_out.audio.i_frame_length = p_sys->first.i_frame_length;
111
112	0	p_dec->fmt_out.audio.i_chan_mode = p_sys->first.i_chan_mode;
113	0	p_dec->fmt_out.audio.i_physical_channels = p_sys->first.i_physical_channels;
114	0	p_dec->fmt_out.audio.i_channels =
115	0	stdc_count_ones( p_dec->fmt_out.audio.i_physical_channels );
116
117	0	p_dec->fmt_out.i_bitrate = p_sys->first.i_bitrate;
118
119	0	block_t *p_block = block_Alloc( p_sys->i_input_size );
120	0	if( p_block == NULL )
121	0	return NULL;
122
123	0	p_block->i_nb_samples = p_sys->first.i_frame_length;
124	0	p_block->i_pts = p_block->i_dts = date_Get( &p_sys->end_date );
125	0	p_block->i_length =
126	0	date_Increment( &p_sys->end_date, p_block->i_nb_samples ) - p_block->i_pts;
127	0	return p_block;
128	0	}
129
130		static block_t PacketizeBlock( decoder_t p_dec, block_t **pp_block )
131	0	{
132	0	decoder_sys_t *p_sys = p_dec->p_sys;
133	0	uint8_t p_header[VLC_DTS_HEADER_SIZE];
134	0	block_t *p_out_buffer;
135
136	0	block_t p_block = pp_block ? pp_block : NULL;
137
138	0	if( p_block )
139	0	{
140	0	if ( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY\|BLOCK_FLAG_CORRUPTED) ) {
141		/* First always drain complete blocks before discontinuity */
142	0	block_t *p_drain = PacketizeBlock( p_dec, NULL );
143	0	if(p_drain)
144	0	return p_drain;
145
146	0	PacketizeFlush( p_dec );
147
148	0	if ( p_block->i_flags & BLOCK_FLAG_CORRUPTED ) {
149	0	block_Release( p_block );
150	0	return NULL;
151	0	}
152	0	}
153
154	0	if ( p_block->i_pts == VLC_TICK_INVALID &&
155	0	date_Get( &p_sys->end_date ) == VLC_TICK_INVALID ) {
156		/* We've just started the stream, wait for the first PTS. */
157	0	block_Release( p_block );
158	0	return NULL;
159	0	}
160
161	0	block_BytestreamPush( &p_sys->bytestream, p_block );
162	0	}
163
164	0	while( 1 )
165	0	{
166	0	switch( p_sys->i_state )
167	0	{
168	0	case STATE_NOSYNC:
169	0	while( block_PeekBytes( &p_sys->bytestream, p_header, 6 )
170	0	== VLC_SUCCESS )
171	0	{
172	0	if( vlc_dts_header_IsSync( p_header, 6 ) )
173	0	{
174	0	p_sys->i_state = STATE_SYNC;
175	0	break;
176	0	}
177	0	block_SkipByte( &p_sys->bytestream );
178	0	}
179	0	if( p_sys->i_state != STATE_SYNC )
180	0	{
181	0	block_BytestreamFlush( &p_sys->bytestream );
182
183		/* Need more data */
184	0	return NULL;
185	0	}
186		/* fallthrough */
187
188	0	case STATE_SYNC:
189		/* New frame, set the Presentation Time Stamp */
190	0	p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
191	0	if( p_sys->i_pts != VLC_TICK_INVALID &&
192	0	p_sys->i_pts != date_Get( &p_sys->end_date ) )
193	0	{
194	0	date_Set( &p_sys->end_date, p_sys->i_pts );
195	0	}
196	0	p_sys->i_state = STATE_HEADER;
197		/* fallthrough */
198
199	0	case STATE_HEADER:
200		/* Get DTS frame header (VLC_DTS_HEADER_SIZE bytes) */
201	0	if( block_PeekBytes( &p_sys->bytestream, p_header,
202	0	VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
203	0	{
204		/* Need more data */
205	0	return NULL;
206	0	}
207
208		/* Check if frame is valid and get frame info */
209	0	if( vlc_dts_header_Parse( &p_sys->first, p_header,
210	0	VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS
211	0	\|\| p_sys->first.i_frame_size == 0 )
212	0	{
213	0	msg_Dbg( p_dec, "emulated sync word" );
214	0	block_SkipByte( &p_sys->bytestream );
215	0	p_sys->i_state = STATE_NOSYNC;
216	0	break;
217	0	}
218
219	0	if( p_sys->first.syncword == DTS_SYNC_SUBSTREAM )
220	0	p_sys->i_state = STATE_SYNC_SUBSTREAM_EXTENSIONS;
221	0	else
222	0	p_sys->i_state = STATE_NEXT_SYNC;
223	0	p_sys->i_input_size = p_sys->i_next_offset = p_sys->first.i_frame_size;
224	0	break;
225
226	0	case STATE_SYNC_SUBSTREAM_EXTENSIONS:
227		/* Peek into the substream extension (sync + header size < frame_size) */
228	0	if( block_PeekOffsetBytes( &p_sys->bytestream,
229	0	p_sys->first.i_substream_header_size,
230	0	p_header,
231	0	VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
232	0	{
233		/* Need more data */
234	0	return NULL;
235	0	}
236
237	0	vlc_dts_header_t xssheader;
238	0	if( vlc_dts_header_Parse( &xssheader, p_header,
239	0	VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
240	0	{
241	0	msg_Dbg( p_dec, "emulated substream sync word, can't find extension" );
242	0	block_SkipByte( &p_sys->bytestream );
243	0	p_sys->i_state = STATE_NOSYNC;
244	0	break;
245	0	}
246
247	0	if( xssheader.syncword == DTS_SYNC_SUBSTREAM_LBR )
248	0	{
249		/*
250		* LBR exists as independent SUBSTREAM. It is seen valid
251		* only when SUBSTREAM[LBR]..SUBTREAM.
252		* CORE...SUBSTREAM is regular extension.
253		* SUBSTREAM...CORE is sync issue.
254		*/
255	0	p_dec->fmt_out.i_profile = PROFILE_DTS_EXPRESS;
256	0	p_sys->first.i_rate = xssheader.i_rate;
257	0	p_sys->first.i_frame_length = xssheader.i_frame_length;
258	0	p_sys->i_state = STATE_NEXT_SYNC;
259	0	break;
260	0	}
261
262	0	msg_Warn( p_dec, "substream without the paired core stream, skip it" );
263	0	p_sys->i_state = STATE_NOSYNC;
264	0	p_dec->fmt_out.i_profile = PROFILE_DTS;
265	0	if( block_SkipBytes( &p_sys->bytestream,
266	0	p_sys->first.i_frame_size ) != VLC_SUCCESS )
267	0	return NULL;
268	0	break;
269
270	0	case STATE_NEXT_SYNC:
271		/* Check if next expected frame contains the sync word */
272	0	while( p_sys->i_state == STATE_NEXT_SYNC )
273	0	{
274	0	if( block_PeekOffsetBytes( &p_sys->bytestream,
275	0	p_sys->i_next_offset, p_header,
276	0	VLC_DTS_HEADER_SIZE )
277	0	!= VLC_SUCCESS )
278	0	{
279	0	if( p_block == NULL ) /* drain */
280	0	{
281	0	p_sys->i_state = STATE_GET_DATA;
282	0	break;
283	0	}
284		/* Need more data */
285	0	return NULL;
286	0	}
287
288	0	if( p_header[0] == 0 )
289	0	{
290		/* DTS wav files, audio CD's and some mkvs use stuffing */
291	0	p_sys->i_next_offset++;
292	0	continue;
293	0	}
294
295	0	if( !vlc_dts_header_IsSync( p_header, VLC_DTS_HEADER_SIZE ) )
296	0	{
297		/* Even frame size is likely incorrect FSIZE #18166 */
298	0	if( (p_sys->first.i_frame_size % 2) && p_sys->i_next_offset > 0 &&
299	0	block_PeekOffsetBytes( &p_sys->bytestream,
300	0	p_sys->i_next_offset - 1, p_header,
301	0	VLC_DTS_HEADER_SIZE ) == 0 &&
302	0	vlc_dts_header_IsSync( p_header, VLC_DTS_HEADER_SIZE ) )
303	0	{
304	0	p_sys->i_input_size = p_sys->i_next_offset = p_sys->first.i_frame_size - 1;
305		/* reenter */
306	0	break;
307	0	}
308	0	msg_Dbg( p_dec, "emulated sync word "
309	0	"(no sync on following frame)" );
310	0	p_sys->i_state = STATE_NOSYNC;
311	0	block_SkipByte( &p_sys->bytestream );
312	0	break;
313	0	}
314
315		/* Check if a DTS substream packet is located just after
316		* the core packet */
317	0	if( p_sys->i_next_offset == p_sys->first.i_frame_size &&
318	0	vlc_dts_header_Parse( &p_sys->second,
319	0	p_header, VLC_DTS_HEADER_SIZE ) == VLC_SUCCESS &&
320	0	p_sys->second.syncword == DTS_SYNC_SUBSTREAM )
321	0	{
322	0	p_sys->i_state = STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS;
323	0	}
324	0	else
325	0	{
326	0	p_dec->fmt_out.i_profile = PROFILE_DTS;
327	0	p_sys->i_state = STATE_GET_DATA;
328	0	}
329	0	}
330	0	break;
331
332	0	case STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS:
333	0	assert(p_sys->second.syncword == DTS_SYNC_SUBSTREAM);
334	0	if( p_sys->first.syncword == DTS_SYNC_SUBSTREAM )
335	0	{
336		/* First substream must have been LBR */
337	0	p_dec->fmt_out.i_profile = PROFILE_DTS_EXPRESS;
338	0	}
339	0	else /* Otherwise that's core + extensions, we need to output both */
340	0	{
341	0	p_dec->fmt_out.i_profile = PROFILE_DTS_HD;
342	0	p_sys->i_input_size += p_sys->second.i_frame_size;
343	0	}
344	0	p_sys->i_state = STATE_GET_DATA;
345	0	break;
346
347	0	case STATE_GET_DATA:
348		/* Make sure we have enough data. */
349	0	if( block_WaitBytes( &p_sys->bytestream,
350	0	p_sys->i_input_size ) != VLC_SUCCESS )
351	0	{
352		/* Need more data */
353	0	return NULL;
354	0	}
355	0	p_sys->i_state = STATE_SEND_DATA;
356		/* fallthrough */
357
358	0	case STATE_SEND_DATA:
359	0	if( !(p_out_buffer = GetOutBuffer( p_dec )) )
360	0	{
361	0	return NULL;
362	0	}
363
364		/* Copy the whole frame into the buffer. When we reach this point
365		* we already know we have enough data available. */
366	0	block_GetBytes( &p_sys->bytestream, p_out_buffer->p_buffer,
367	0	p_out_buffer->i_buffer );
368
369		/* Make sure we don't reuse the same pts twice */
370	0	if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
371	0	p_sys->i_pts = p_sys->bytestream.p_block->i_pts = VLC_TICK_INVALID;
372
373	0	if( p_sys->b_discontinuity )
374	0	{
375	0	p_sys->b_discontinuity = false;
376	0	p_out_buffer->i_flags \|= BLOCK_FLAG_DISCONTINUITY;
377	0	}
378
379		/* So p_block doesn't get re-added several times */
380	0	if( pp_block )
381	0	*pp_block = block_BytestreamPop( &p_sys->bytestream );
382
383	0	p_sys->i_state = STATE_NOSYNC;
384
385	0	return p_out_buffer;
386	0	}
387	0	}
388	0	}
389
390		static void Close( vlc_object_t *p_this )
391	0	{
392	0	decoder_t p_dec = (decoder_t)p_this;
393	0	decoder_sys_t *p_sys = p_dec->p_sys;
394
395	0	block_BytestreamRelease( &p_sys->bytestream );
396
397	0	free( p_sys );
398	0	}
399
400		static int Open( vlc_object_t *p_this )
401	0	{
402	0	decoder_t p_dec = (decoder_t)p_this;
403	0	decoder_sys_t *p_sys;
404
405	0	if( p_dec->fmt_in->i_codec != VLC_CODEC_DTS )
406	0	return VLC_EGENERIC;
407
408		/* Allocate the memory needed to store the decoder's structure */
409	0	if( ( p_dec->p_sys = p_sys = malloc(sizeof(decoder_sys_t)) ) == NULL )
410	0	return VLC_ENOMEM;
411
412		/* Misc init */
413	0	p_sys->i_state = STATE_NOSYNC;
414	0	date_Set( &p_sys->end_date, VLC_TICK_INVALID );
415	0	p_sys->i_pts = VLC_TICK_INVALID;
416	0	p_sys->b_date_set = false;
417	0	p_sys->b_discontinuity = false;
418	0	memset(&p_sys->first, 0, sizeof(vlc_dts_header_t));
419	0	memset(&p_sys->second, 0, sizeof(vlc_dts_header_t));
420	0	block_BytestreamInit( &p_sys->bytestream );
421
422		/* Set output properties (passthrough only) */
423	0	p_dec->fmt_out.i_codec = p_dec->fmt_in->i_codec;
424	0	p_dec->fmt_out.audio = p_dec->fmt_in->audio;
425
426		/* Set callback */
427	0	p_dec->pf_packetize = PacketizeBlock;
428	0	p_dec->pf_flush = PacketizeFlush;
429	0	p_dec->pf_get_cc = NULL;
430	0	return VLC_SUCCESS;
431	0	}