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vlc/modules/packetizer/dirac.c

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/*****************************************************************************
* dirac.c
*****************************************************************************
* Copyright (C) 2008 the VideoLAN team
* $Id$
*
* Authors: David Flynn <davidf@rd.bbc.co.uk>
*
* 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
* (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 General Public License for more details.
*
* You should have received a copy of the GNU 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.
*****************************************************************************/
/* Dirac packetizer, formed of three parts:
* 1) Bitstream synchroniser (dirac_DoSync)
* - Given an arbitrary sequence of bytes, extract whole Dirac Data Units
* - Maps timestamps in supplied block_t's to the extracted Data Unit
* A time stamp applies to the next Data Unit to commence at, or after
* the first byte of the block_t with the timestamp.
* 2) Encapsulation Unit generation (dirac_BuildEncapsulationUnit)
* - Takes multiple well formed Dirac Data Units and forms them into a
* single encapsulation unit, suitable for muxing.
* - Sorts out any time stamps so that they only apply to pictures.
* 3) Timestamp generator (dirac_TimeGenPush)
* - Many streams will not be correctly timestamped, ie, DTS&PTS for
* every encapsulation unit. Timestamp generator syncs to avaliable
* timestamps and produces DTS&PTS for each encapsulation unit.
* - For 'Occasional' missing PTS|DTS:
* Missing timestamp is generated using interpolation from last
* known good values.
* - for All PTS missing:
* It is assumed that DTS values are fake, and are actually
* in the sequence of the PTS values at the output of a decoder.
* Fill in PTS by copying from DTS (accounting for reordering,
* by simulating reorder buffer); adjust DTS to provide correct
* value. This is how demuxers like AVI work.
* - for All DTS missing:
* (Ie, PTS is present), reorder buffer is simulated to determine
* PTS for each encapsulation unit.
* - NB, doesn't handle all pts missing with real dts. (no way to
* distinguish from the fake dts case.)
*
* DIRAC_NON_DATED is used to show a block should not have a time stamp
* associated (ie, don't interpolate a counter). At the output, these
* blocks get dated with the last used timestamp (or are merged with
* another encapsulation unit).
*/
/*****************************************************************************
* Preamble
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <assert.h>
#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_codec.h>
#include <vlc_block.h>
#include <vlc_bits.h>
#include <vlc_block_helper.h>
#define SANITIZE_PREV_PARSE_OFFSET 1
/*****************************************************************************
* Module descriptor
*****************************************************************************/
static int Open ( vlc_object_t * );
static void Close( vlc_object_t * );
vlc_module_begin()
set_category( CAT_SOUT )
set_subcategory( SUBCAT_SOUT_PACKETIZER )
set_description( N_("Dirac packetizer") )
set_capability( "packetizer", 50 )
set_callbacks( Open, Close )
vlc_module_end()
/*****************************************************************************
* Local prototypes
*****************************************************************************/
struct decoder_sys_t
{
/* sync state */
block_bytestream_t bytestream;
int i_state;
size_t i_offset;
uint32_t u_last_npo;
/* recovered timestamp from bytesteram for use
* by synchroniser: should only get reset by the
* synchronizer upon a discontinuity sentinel */
mtime_t i_sync_pts;
mtime_t i_sync_dts;
/* build encapsulation unit state */
block_t *p_eu; /*< Current encapsulation unit being built */
block_t **pp_eu_last;
uint32_t u_eu_last_npo; /* last next_parse_offset at input to encapsulation */
mtime_t i_eu_pts;
mtime_t i_eu_dts;
/* timestamp generator state */
date_t dts; /*< timegen decode clock, increments at picture rate */
bool b_dts; /*< timegen decode clock valid */
bool b_pts; /*< timegen presentation time valid */
mtime_t i_pts; /*< timegen presentation time of picture u_pts_picnum */
uint32_t u_pts_picnum; /*< picture number of timegen presentation time */
mtime_t i_pts_offset; /*< maximum time between pts and dts */
/* p_outqueue is the list of encapsulation units that have been
* fed to the timegenerator. the timegenerator stamps them in
* the order it solves the time. the main packetizer loop removes
* completed encapsulation units from the front */
block_t *p_outqueue;
block_t **pp_outqueue_last;
/* p_out_dts points to an element in p_outqueue. It is used for VLC's
* fake pts hidden in DTS hack, as used by AVI */
block_t *p_out_dts;
uint32_t u_tg_last_picnum; /*< most recent picturenumber output from RoB */
bool b_tg_last_picnum; /*< u_tg_last_picnum valid */
struct dirac_reorder_buffer {
int u_size_max;
int u_size;
struct dirac_reorder_entry {
struct dirac_reorder_entry *p_next;
block_t *p_eu;
uint32_t u_picnum;
} p_entries[32], *p_head, *p_empty;
} reorder_buf; /*< reorder buffer, used by timegenerator */
/* packetizer state */
mtime_t i_pts_last_out; /*< last output [from packetizer] pts */
mtime_t i_dts_last_out; /*< last output [from packetizer] dts */
struct seq_hdr_t {
uint32_t u_width;
uint32_t u_height;
uint32_t u_fps_num;
uint32_t u_fps_den;
enum picture_coding_mode_t {
DIRAC_FRAME_CODING=0,
DIRAC_FIELD_CODING=1,
} u_picture_coding_mode;
} seq_hdr; /*< sequence header */
bool b_seen_seq_hdr; /* sequence header valid */
bool b_seen_eos; /* last data unit to be handled was an EOS */
};
typedef struct {
uint32_t u_next_offset;
uint32_t u_prev_offset;
int i_parse_code;
} parse_info_t;
typedef struct {
block_free_t pf_blk_release;
/*> next_parse_offset of the final data unit in associated block_t */
uint32_t u_last_next_offset;
/*> picture number is invalid if block has flags DIRAC_NON_DATED */
uint32_t u_picture_number;
} dirac_block_encap_t;
enum {
NOT_SYNCED=0,
TRY_SYNC,
SYNCED,
SYNCED_INCOMPLETEDU,
};
enum {
DIRAC_NON_DATED = (1 << BLOCK_FLAG_PRIVATE_SHIFT),
DIRAC_DISCARD = (2 << BLOCK_FLAG_PRIVATE_SHIFT),
};
enum {
DIRAC_DU_IN_EU,
DIRAC_DU_ENDS_EU,
};
/***
* Block encapsulation functions.
* Things are greately simplified by associating some metadata
* with a block as it passes through the packetizer (saves having
* to determine it again)
*
* unfortunately p_block doesn't have a p_priv, so some fakage
* needs to happen:
* - Create a dummy block that has some extra storage, set up
* members to be identical to the actual block
* - Store private data there and pointer to orig block
* - modify block pointer to point to fake block
*
* NB, the add/new functions must not be used to blocks
* that are referenced in lists, etc., [in this code, this is ok]
* NB, don't call add on the same block multiple times (will leak)
*
* davidf has a patch that reverts this to use a p_priv in block_t.
*/
typedef struct {
block_t fake;
block_t *p_orig;
void *p_priv;
} fake_block_t;
static dirac_block_encap_t *dirac_RemoveBlockEncap( block_t *p_block )
{
fake_block_t *p_fake = (fake_block_t *)p_block;
dirac_block_encap_t *p_dbe = p_fake->p_priv;
if( !p_dbe ) return NULL;
p_fake->p_priv = NULL;
p_dbe->pf_blk_release = NULL;
return p_dbe;
}
static void dirac_ReleaseBlockAndEncap( block_t *p_block )
{
fake_block_t *p_fake = (fake_block_t *)p_block;
free( dirac_RemoveBlockEncap( p_block ) );
p_fake->p_orig->pf_release( p_fake->p_orig );
free( p_fake );
}
static void dirac_AddBlockEncap( block_t **pp_block, dirac_block_encap_t *p_dbe )
{
fake_block_t *p_fake = calloc( 1, sizeof( *p_fake ) );
assert( p_fake ); /* must not fail, fixby: adding a p_priv to block_t */
p_fake->p_orig = *pp_block;
memcpy( &p_fake->fake, *pp_block, sizeof( block_t ) );
*pp_block = &p_fake->fake;
p_fake->p_priv = p_dbe;
p_dbe->pf_blk_release = p_fake->p_orig->pf_release;
p_fake->fake.pf_release = dirac_ReleaseBlockAndEncap;
}
static dirac_block_encap_t *dirac_NewBlockEncap( block_t **pp_block )
{
dirac_block_encap_t *p_dbe = calloc( 1, sizeof( *p_dbe ) );
if( p_dbe ) dirac_AddBlockEncap( pp_block, p_dbe );
return p_dbe;
}
static dirac_block_encap_t *dirac_GetBlockEncap( block_t *p_block )
{
return (dirac_block_encap_t*) ((fake_block_t *)p_block)->p_priv;
}
/***
* General utility funcions
*/
/**
* given a chain of block_t, allocate and return an array containing
* pointers to all the blocks. (Acts as a replacement for the old p_prev
* member of block_t) */
static int block_ChainToArray( block_t *p_block, block_t ***ppp_array)
{
if( !ppp_array )
return 0;
int i_num_blocks;
block_ChainProperties( p_block, &i_num_blocks, NULL, NULL );
*ppp_array = calloc( i_num_blocks, sizeof( block_t* ) );
if( !*ppp_array ) return 0;
for( int i = 0; i < i_num_blocks; i++ )
{
(*ppp_array)[i] = p_block;
p_block = p_block->p_next;
}
return i_num_blocks;
}
/**
* Destructively find and recover the earliest timestamp from start of
* bytestream, upto i_length.
*/
static void dirac_RecoverTimestamps ( decoder_t *p_dec, size_t i_length )
{
decoder_sys_t *p_sys = p_dec->p_sys;
block_t *p_block = p_sys->bytestream.p_block;
/* Find the block with first non-flushed data */
size_t i_offset = p_sys->bytestream.i_offset;
for(; p_block != NULL; p_block = p_block->p_next )
{
if( i_offset < p_block->i_buffer )
break;
i_offset -= p_block->i_buffer;
}
i_offset += i_length;
for(; p_block != NULL; p_block = p_block->p_next )
{
if( p_sys->i_sync_pts <= VLC_TS_INVALID && p_sys->i_sync_dts <= VLC_TS_INVALID )
{
/* oldest timestamp wins */
p_sys->i_sync_pts = p_block->i_pts;
p_sys->i_sync_dts = p_block->i_dts;
}
/* clear timestamps -- more than one data unit can come from a block */
p_block->i_flags = 0;
p_block->i_pts = p_block->i_dts = VLC_TS_INVALID;
if( i_offset < p_block->i_buffer )
break;
i_offset -= p_block->i_buffer;
}
}
/* backdate the list [p_block .. p_block->p_next where p_next == p_last] */
static void dirac_BackdateDTS( block_t *p_block, block_t *p_last, date_t *p_dts )
{
/* Transverse p_last backwards. (no p_prev anymore) */
block_t **pp_array = NULL;
int n = block_ChainToArray( p_block, &pp_array );
while( n ) if( pp_array[--n] == p_last ) break;
/* want to start at p_last->p_prev */
while( n-- )
{
if( pp_array[n]->i_flags & DIRAC_NON_DATED )
continue;
if( pp_array[n]->i_dts <= VLC_TS_INVALID )
pp_array[n]->i_dts = date_Decrement( p_dts, 1 );
}
free( pp_array );
}
/* backdate the list [p_block .. p_block->p_next where p_next == p_last] */
static void dirac_BackdatePTS( block_t *p_block, block_t *p_last, date_t *p_pts, uint32_t u_pts_picnum )
{
/* Transverse p_last backwards. (no p_prev anymore) */
block_t **pp_array = NULL;
int n = block_ChainToArray( p_block, &pp_array );
while( n ) if( pp_array[--n] == p_last ) break;
/* want to start at p_last->p_prev */
while( n-- )
{
if( pp_array[n]->i_flags & DIRAC_NON_DATED )
continue;
if( pp_array[n]->i_dts > VLC_TS_INVALID )
continue;
dirac_block_encap_t *dbe = dirac_GetBlockEncap( pp_array[n] );
int32_t u_pic_num = dbe ? dbe->u_picture_number : 0;
int32_t i_dist = u_pic_num - u_pts_picnum;
date_t pts = *p_pts;
if( i_dist >= 0 )
pp_array[n]->i_pts = date_Increment( &pts, i_dist );
else
pp_array[n]->i_pts = date_Decrement( &pts, -i_dist );
}
free( pp_array );
}
/***
* Dirac spec defined relations
*/
static bool dirac_isEOS( uint8_t u_parse_code ) { return 0x10 == u_parse_code; }
static bool dirac_isSeqHdr( uint8_t u_parse_code ) { return 0 == u_parse_code; }
static bool dirac_isPicture( uint8_t u_parse_code ) { return 0x08 & u_parse_code; }
static int dirac_numRefs( uint8_t u_parse_code ) { return 0x3 & u_parse_code; }
static inline bool dirac_PictureNbeforeM( uint32_t u_n, uint32_t u_m )
{
/* specified as: u_n occurs before u_m if:
* (u_m - u_n) mod (1<<32) < D */
return (uint32_t)(u_m - u_n) < (1u<<31);
}
/***
* Reorder buffer model
*/
static void dirac_ReorderInit( struct dirac_reorder_buffer *p_rb )
{
memset( p_rb, 0, sizeof(*p_rb) );
p_rb->u_size_max = 2;
p_rb->p_empty = p_rb->p_entries;
p_rb->p_entries[31].p_next = NULL;
for( int i = 0; i < 31; i++ )
p_rb->p_entries[i].p_next = &p_rb->p_entries[i+1];
}
/* simulate the dirac picture reorder buffer */
static block_t *dirac_Reorder( decoder_t *p_dec, block_t *p_block_in, uint32_t u_picnum )
{
decoder_sys_t *p_sys = p_dec->p_sys;
if( !p_sys->reorder_buf.u_size_max )
/* reorder buffer disabled */
return p_block_in;
/* Modeling the reorder buffer:
* 1. If the reorder buffer is not full, insert picture for reordering.
* No picture is output by the system this picture period
* 2. If the reorder buffer is full:
* a. The picture decoded this period (u_picnum) bypasses the reorder
* buffer if it has a lower picture number than any entry in the
* reorder buffer. This picture is output by the system.
* b. Otherwise, the lowest picture number in the reorder buffer is
* removed from the buffer and output by the system. The current
* decoded picture (u_picnum) is inserted into the reorder buffer
*/
block_t *p_block = NULL;
/* Determine if the picture needs to be inserted */
if( p_sys->reorder_buf.u_size == p_sys->reorder_buf.u_size_max )
{
/* (2) reorder buffer is full */
if( !p_sys->reorder_buf.u_size_max ||
dirac_PictureNbeforeM( u_picnum, p_sys->reorder_buf.p_head->u_picnum ) )
{
/* (2a) current picture is first in order */
return p_block_in;
}
/* (2b) extract the youngest picture in the buffer */
p_block = p_sys->reorder_buf.p_head->p_eu;
struct dirac_reorder_entry *p_tmp = p_sys->reorder_buf.p_head;
p_sys->reorder_buf.p_head = p_tmp->p_next;
p_tmp->p_next = p_sys->reorder_buf.p_empty;
p_sys->reorder_buf.p_empty = p_tmp;
p_sys->reorder_buf.u_size--;
}
/* (1) and (2b) both require u_picnum to be inserted */
struct dirac_reorder_entry *p_current = p_sys->reorder_buf.p_empty;
p_sys->reorder_buf.p_empty = p_current->p_next;
p_sys->reorder_buf.u_size++;
/* insertion sort to keep p_head always sorted, earliest first */
struct dirac_reorder_entry **pp_at = &p_sys->reorder_buf.p_head;
for( ; *pp_at; pp_at = &(*pp_at)->p_next )
if( dirac_PictureNbeforeM( u_picnum, (*pp_at)->u_picnum ) )
break;
p_current->u_picnum = u_picnum;
p_current->p_eu = p_block_in;
p_current->p_next = *pp_at;
*pp_at = p_current;
return p_block;
}
/***
* bytestream parsing and unmarshalling functions
*/
static bool dirac_UnpackParseInfo( parse_info_t *p_pi, block_bytestream_t *p_bs,
size_t u_offset )
{
uint8_t p_d[13];
if( VLC_SUCCESS != block_PeekOffsetBytes( p_bs, u_offset, p_d, 13 ) )
return false;
if( p_d[0] != 'B' || p_d[1] != 'B' || p_d[2] != 'C' || p_d[3] != 'D' )
return false;
p_pi->i_parse_code = p_d[4];
p_pi->u_next_offset = p_d[5] << 24 | p_d[6] << 16 | p_d[7] << 8 | p_d[8];
p_pi->u_prev_offset = p_d[9] << 24 | p_d[10] << 16 | p_d[11] << 8 | p_d[12];
return true;
}
static uint32_t dirac_uint( bs_t *p_bs )
{
uint32_t u_count = 0, u_value = 0;
while( !bs_eof( p_bs ) && !bs_read( p_bs, 1 ) )
{
u_count++;
u_value <<= 1;
u_value |= bs_read( p_bs, 1 );
}
return (1 << u_count) - 1 + u_value;
}
static int dirac_bool( bs_t *p_bs )
{
return bs_read( p_bs, 1 );
}
/* read in useful bits from sequence header */
static bool dirac_UnpackSeqHdr( struct seq_hdr_t *p_sh, block_t *p_block )
{
bs_t bs;
bs_init( &bs, p_block->p_buffer, p_block->i_buffer );
bs_skip( &bs, 13*8 ); /* parse_info_header */
dirac_uint( &bs ); /* major_version */
dirac_uint( &bs ); /* minor_version */
dirac_uint( &bs ); /* profile */
dirac_uint( &bs ); /* level */
uint32_t u_video_format = dirac_uint( &bs ); /* index */
if( u_video_format > 20 )
{
/* dont know how to parse this header */
return false;
}
static const struct {
uint32_t u_w, u_h;
} dirac_size_tbl[] = {
{640,480}, {176,120}, {176,144}, {352,240}, {352,288}, {704,480},
{704,576}, {720,480}, {720,576}, {1280,720}, {1280,720}, {1920,1080},
{1920,1080}, {1920,1080}, {1920,1080}, {2048,1080}, {4096,2160},
{3840,2160}, {3840,2160}, {7680,4320}, {7680,4320},
};
p_sh->u_width = dirac_size_tbl[u_video_format].u_w;
p_sh->u_height = dirac_size_tbl[u_video_format].u_h;
if( dirac_bool( &bs ) )
{
p_sh->u_width = dirac_uint( &bs ); /* frame_width */
p_sh->u_height = dirac_uint( &bs ); /* frame_height */
}
if( dirac_bool( &bs ) )
{
dirac_uint( &bs ); /* chroma_format */
}
if( dirac_bool( &bs ) )
{
dirac_uint( &bs ); /* scan_format */
}
static const struct {
uint32_t u_n /* numerator */, u_d /* denominator */;
} dirac_frate_tbl[] = { /* table 10.3 */
{1, 1}, /* this value is not used */
{24000,1001}, {24,1}, {25,1}, {30000,1001}, {30,1},
{50,1}, {60000,1001}, {60,1}, {15000,1001}, {25,2},
};
const unsigned dirac_frate_tbl_size =
sizeof( dirac_frate_tbl ) / sizeof( *dirac_frate_tbl );
static const uint32_t dirac_vidfmt_frate[] = { /* table C.1 */
1, 9, 10, 9, 10, 9, 10, 4, 3, 7, 6, 4, 3, 7, 6, 2, 2, 7, 6, 7, 6,
};
p_sh->u_fps_num = dirac_frate_tbl[dirac_vidfmt_frate[u_video_format]].u_n;
p_sh->u_fps_den = dirac_frate_tbl[dirac_vidfmt_frate[u_video_format]].u_d;
if( dirac_bool( &bs ) )
{
uint32_t frame_rate_index = dirac_uint( &bs );
p_sh->u_fps_num = dirac_frate_tbl[frame_rate_index].u_n;
p_sh->u_fps_den = dirac_frate_tbl[frame_rate_index].u_d;
if( frame_rate_index >= dirac_frate_tbl_size )
{
/* invalid header */
return false;
}
if( frame_rate_index == 0 )
{
p_sh->u_fps_num = dirac_uint( &bs ); /* frame_rate_numerator */
p_sh->u_fps_den = dirac_uint( &bs ); /* frame_rate_denominator */
}
}
/* must have a valid framerate */
if( !p_sh->u_fps_num || !p_sh->u_fps_den )
return false;
if( dirac_bool( &bs ) )
{
uint32_t par_index = dirac_uint( &bs );
if( !par_index )
{
dirac_uint( &bs ); /* par_num */
dirac_uint( &bs ); /* par_den */
}
}
if( dirac_bool( &bs ) )
{
dirac_uint( &bs ); /* clean_width */
dirac_uint( &bs ); /* clean_height */
dirac_uint( &bs ); /* clean_left_offset */
dirac_uint( &bs ); /* clean_top_offset */
}
if( dirac_bool( &bs ) )
{
uint32_t signal_range_index = dirac_uint( &bs );
if( !signal_range_index )
{
dirac_uint( &bs ); /* luma_offset */
dirac_uint( &bs ); /* luma_excursion */
dirac_uint( &bs ); /* chroma_offset */
dirac_uint( &bs ); /* chroma_excursion */
}
}
if( dirac_bool( &bs ) )
{
uint32_t colour_spec_index = dirac_uint( &bs );
if( !colour_spec_index )
{
if( dirac_bool( &bs ) )
{
dirac_uint( &bs ); /* colour_primaries_index */
}
if( dirac_bool( &bs ) )
{
dirac_uint( &bs ); /* colour_matrix_index */
}
if( dirac_bool( &bs ) )
{
dirac_uint( &bs ); /* transfer_function_index */
}
}
}
p_sh->u_picture_coding_mode = dirac_uint( &bs );
return true;
}
/***
* Data Unit marshalling functions
*/
static block_t *dirac_EmitEOS( decoder_t *p_dec, uint32_t i_prev_parse_offset )
{
const uint8_t p_eos[] = { 'B','B','C','D',0x10,0,0,0,13,0,0,0,0 };
block_t *p_block = block_New( p_dec, 13 );
if( !p_block )
return NULL;
memcpy( p_block->p_buffer, p_eos, 13 );
SetDWBE( p_block->p_buffer + 9, i_prev_parse_offset );
p_block->i_flags = DIRAC_NON_DATED;
return p_block;
(void) p_dec;
}
/***
* Bytestream synchronizer
* maps [Bytes] -> DataUnit
*/
static block_t *dirac_DoSync( decoder_t *p_dec )
{
decoder_sys_t *p_sys = p_dec->p_sys;
parse_info_t pu;
static const uint8_t p_parsecode[4] = {'B','B','C','D'};
do {
switch( p_sys->i_state )
{
case NOT_SYNCED:
{
if( VLC_SUCCESS !=
block_FindStartcodeFromOffset( &p_sys->bytestream, &p_sys->i_offset, p_parsecode, 4 ) )
{
/* p_sys->i_offset will have been set to:
* end of bytestream - amount of prefix found
* can resume search from this point when more data arrives */
return NULL;
}
/* candidate parse_code_prefix has been found at p_sys->i_offset */
if( VLC_SUCCESS != block_PeekOffsetBytes( &p_sys->bytestream, p_sys->i_offset + 12, NULL, 0 ) )
{
/* insufficient data has been accumulated to fully extract
* a parse_info header. exit for now in the hope of more
* data later to retry at exactly the same point */
return NULL;
}
p_sys->i_state = TRY_SYNC;
break; /* candidate found, try to sync */
}
case SYNCED: /* -> TRY_SYNC | NOT_SYNCED */
/* sanity: can only reach this after having extracted a DU,
* which causes data to be consumed and local i_offset to be reset */
assert( p_sys->i_offset == 0 );
if( VLC_SUCCESS != block_PeekOffsetBytes( &p_sys->bytestream, 12, NULL, 0 ) )
{
/* insufficient data has been accumulated to fully extract
* a parse_info header, retry later */
return NULL;
}
if( !dirac_UnpackParseInfo( &pu, &p_sys->bytestream, 0 )
|| !pu.u_next_offset || (p_sys->u_last_npo != pu.u_prev_offset) )
{
/* !a: not a valid parse info.
* !pu.u_next_offset: don't know the length of the data unit
* search for the next one that points back
* to this one to determine length.
* (p_sys->u_last_npo != pu.u_prev_offset): some desync
*/
p_sys->i_state = NOT_SYNCED;
break;
}
if( pu.u_next_offset > 1024*1024 )
{
/* sanity check for erronious hugs next_parse_offsets
* (eg, 2^32-1) that would cause a very long wait
* and large space consumption: fall back to try sync */
p_sys->i_state = TRY_SYNC;
break;
}
/* check that the start of the next data unit is avaliable */
if( VLC_SUCCESS !=
block_PeekOffsetBytes( &p_sys->bytestream, pu.u_next_offset + 12, NULL, 0 ) )
{
return NULL; /* retry later */
}
/* attempt to syncronise backwards from pu.u_next_offset */
p_sys->i_offset = pu.u_next_offset;
/* fall through */
case TRY_SYNC: /* -> SYNCED | NOT_SYNCED */
{
if( !p_sys->i_offset )
goto sync_fail; /* if a is at start of bytestream, b can't be in buffer */
parse_info_t pu_a;
bool a = dirac_UnpackParseInfo( &pu_a, &p_sys->bytestream, p_sys->i_offset );
if( !a || (pu_a.u_prev_offset > p_sys->i_offset) )
goto sync_fail; /* b lies beyond start of bytestream: can't sync */
if( !pu_a.u_prev_offset )
{
if( p_sys->i_state == TRY_SYNC )
{
goto sync_fail; /* can't find different pu_b from pu_a */
}
/* state == SYNCED: already know where pu_b is.
* pu_a has probably been inserted by something that doesn't
* know what the last next_parse_offset was */
pu_a.u_prev_offset = pu.u_next_offset;
}
parse_info_t *pu_b = &pu;
bool b = dirac_UnpackParseInfo( pu_b, &p_sys->bytestream, p_sys->i_offset - pu_a.u_prev_offset );
if( !b || (pu_b->u_next_offset && pu_a.u_prev_offset != pu_b->u_next_offset) )
{
/* if pu_b->u_next_offset = 0, have to assume we've synced, ie,
* just rely on finding a valid pu_b from pu_a. */
goto sync_fail;
}
p_sys->u_last_npo = pu_b->u_next_offset;
if( !pu_b->u_next_offset ) pu_b->u_next_offset = pu_a.u_prev_offset;
/* offset was pointing at pu_a, rewind to point at pu_b */
p_sys->i_offset -= pu_a.u_prev_offset;
p_sys->i_state = SYNCED;
break;
}
sync_fail:
if( p_sys->i_state == SYNCED ) p_sys->i_offset = 0;
p_sys->i_offset++;
p_sys->i_state = NOT_SYNCED;
break; /* find somewhere else to try again */
default:;
}
} while( SYNCED != p_sys->i_state );
/*
* synced, attempt to extract a data unit
*/
/* recover any timestamps from the data that is about to be flushed */
dirac_RecoverTimestamps( p_dec, p_sys->i_offset );
/* flush everything upto the start of the DU */
block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
block_BytestreamFlush( &p_sys->bytestream );
p_sys->i_offset = 0;
/* setup the data unit buffer */
block_t *p_block = block_New( p_dec, pu.u_next_offset );
if( !p_block )
return NULL;
p_block->i_pts = p_sys->i_sync_pts;
p_block->i_dts = p_sys->i_sync_dts;
p_sys->i_sync_pts = p_sys->i_sync_dts = VLC_TS_INVALID;
/* recover any new timestamps from the data that is about to be consumed */
dirac_RecoverTimestamps( p_dec, p_sys->i_offset );
block_GetBytes( &p_sys->bytestream, p_block->p_buffer, p_block->i_buffer );
/* save parse offset in private area for later use */
dirac_block_encap_t *p_dbe = dirac_NewBlockEncap( &p_block );
if( p_dbe ) p_dbe->u_last_next_offset = pu.u_next_offset;
return p_block;
}
/***
* Packet (Data Unit) inspection, learns parameters from sequence
* headers, sets up flags, drops unwanted data units, sets
* encapsulation unit termination policy
*/
static int dirac_InspectDataUnit( decoder_t *p_dec, block_t **pp_block, block_t *p_eu )
{
decoder_sys_t *p_sys = p_dec->p_sys;
block_t *p_block = *pp_block;
uint8_t u_parse_code = p_block->p_buffer[4];
if( dirac_isEOS( u_parse_code ) )
{
if( p_sys->b_seen_eos )
{
/* remove duplicate EOS packets */
block_Release( p_block );
*pp_block = NULL;
return DIRAC_DU_IN_EU;
}
/* p_block is an EOS packet */
p_eu->i_flags |= BLOCK_FLAG_END_OF_SEQUENCE;
/* for the moment, let this end an encapsulation unit */
/* seeing an eos packet requires a flush of the packetizer
* this is detected by the caller of this function */
p_sys->b_seen_seq_hdr = false;
p_sys->b_seen_eos = true;
return DIRAC_DU_ENDS_EU;
#if 0
/* let anything down streem know too */
/*
Actually, this is a bad idea:
- It sets the discontinuity for every dirac EOS packet
which doesnt imply a time discontinuity.
- When the syncronizer detects a real discontinuity, it
should copy the flags through.
p_eu->i_flags |= BLOCK_FLAG_DISCONTINUITY;
*/
#endif
}
p_sys->b_seen_eos = false;
if( dirac_isPicture( u_parse_code ) )
{
/* timestamps apply to pictures only */
p_eu->i_dts = p_sys->i_eu_dts;
p_eu->i_pts = p_sys->i_eu_pts;
p_sys->i_eu_dts = p_sys->i_eu_pts = VLC_TS_INVALID;
if( !p_sys->b_seen_seq_hdr )
{
/* can't timestamp in this case, discard later
* so that the timestamps aren't lost */
p_eu->i_flags |= DIRAC_DISCARD;
}
/* p_block is a picture -- it ends the 'encapsulation unit' */
if( dirac_numRefs( u_parse_code ) )
{
/* if this picture is not an I frame, ensure that the
* random access point flags are not set */
p_eu->i_flags &= ~BLOCK_FLAG_TYPE_I;
}
dirac_block_encap_t *p_dbe = dirac_GetBlockEncap( p_block );
if( p_dbe && p_block->i_buffer > 13+4 )
{
/* record the picture number to save the time gen functions
* from having to inspect the data for it */
p_dbe->u_picture_number = GetDWBE( p_block->p_buffer + 13 );
}
return DIRAC_DU_ENDS_EU;
}
if( dirac_isSeqHdr( u_parse_code ) )
{
if( !dirac_UnpackSeqHdr( &p_sys->seq_hdr, p_block ) )
{
/* couldn't parse the sequence header, just ignore it */
return DIRAC_DU_IN_EU;
}
p_sys->b_seen_seq_hdr = true;
/* a sequence header followed by an I frame is a random
* access point; assume that this is the case */
p_eu->i_flags |= BLOCK_FLAG_TYPE_I;
es_format_t *p_es = &p_dec->fmt_out;
p_es->video.i_width = p_sys->seq_hdr.u_width;
p_es->video.i_height = p_sys->seq_hdr.u_height;
vlc_ureduce( &p_es->video.i_frame_rate, &p_es->video.i_frame_rate_base
, p_sys->seq_hdr.u_fps_num, p_sys->seq_hdr.u_fps_den, 0 );
/* when field coding, dts needs to be incremented in terms of field periods */
unsigned u_pics_per_sec = p_sys->seq_hdr.u_fps_num;
if( p_sys->seq_hdr.u_picture_coding_mode == DIRAC_FIELD_CODING )
{
u_pics_per_sec *= 2;
}
date_Change( &p_sys->dts, u_pics_per_sec, p_sys->seq_hdr.u_fps_den );
/* TODO: set p_sys->reorder_buf.u_size_max */
p_sys->i_pts_offset = p_sys->reorder_buf.u_size_max
* 1000000
* p_es->video.i_frame_rate_base / p_es->video.i_frame_rate + 1;
/* stash a copy of the seqhdr
* - required for ogg muxing
* - useful for error checking
* - it isn't allowed to change until an eos */
free( p_es->p_extra );
p_es->p_extra = calloc( 1, p_block->i_buffer + 13 );
if( !p_es->p_extra )
{
p_es->i_extra = 0;
return DIRAC_DU_IN_EU;
}
p_es->i_extra = p_block->i_buffer;
memcpy( p_es->p_extra, p_block->p_buffer, p_block->i_buffer );
/* append EOS as per Ogg guidelines */
p_block = dirac_EmitEOS( p_dec, p_block->i_buffer );
if( p_block )
{
memcpy( (uint8_t*)p_es->p_extra + p_es->i_extra, p_block->p_buffer, 13 );
p_es->i_extra += 13;
}
return DIRAC_DU_IN_EU;
}
/* doesn't end an encapsulation unit */
return DIRAC_DU_IN_EU;
}
/***
* Encapsulation (packetization) suitable for all muxing standards
* maps [DataUnit] -> EncapsulationUnit
*/
static block_t *dirac_BuildEncapsulationUnit( decoder_t *p_dec, block_t *p_block )
{
decoder_sys_t *p_sys = p_dec->p_sys;
assert(p_block->i_buffer >= 13 && 0x42424344 == GetDWBE( p_block->p_buffer ));
if( p_sys->i_eu_pts <= VLC_TS_INVALID && p_sys->i_eu_dts <= VLC_TS_INVALID )
{
/* earliest block with pts/dts gets to set the pts/dts for the dated
* encapsulation unit as a whole */
/* NB, the 'earliest block' criteria is aribtary */
if( p_block->i_pts > VLC_TS_INVALID || p_block->i_dts > VLC_TS_INVALID )
{
p_sys->i_eu_pts = p_block->i_pts;
p_sys->i_eu_dts = p_block->i_dts;
}
}
/* inpectdataunit also updates flags for the EU.
* - if this is the first block in the EU, then it hasn't been added
* to the chain yet (so, p_block will become the front of the chain
* - otherwise, use the flags of the chain (first block) */
block_t *p_eu = p_sys->p_eu ? p_sys->p_eu : p_block;
int i_block = dirac_InspectDataUnit( p_dec, &p_block, p_eu);
if( !p_block )
{
/* block has been discarded during inspection */
/* becareful, don't discard anything that is dated,
* as this needs to go into the timegen loop. set
* the DIRAC_DISCARD block flag, and it'll be dropped
* at output time */
return NULL;
}
block_ChainLastAppend( &p_sys->pp_eu_last, p_block );
dirac_block_encap_t *p_dbe = dirac_GetBlockEncap( p_block );
#ifdef SANITIZE_PREV_PARSE_OFFSET
/* fixup prev_parse_offset to point to the last data unit
* to arrive */
if( p_dbe )
{
SetDWBE( p_block->p_buffer + 9, p_sys->u_eu_last_npo );
p_sys->u_eu_last_npo = p_dbe->u_last_next_offset;
}
#endif
if( i_block != DIRAC_DU_ENDS_EU )
{
/* encapsulation unit not ended */
return NULL;
}
/* gather up encapsulation unit, reassociating the final
* private state with the gathered block */
block_t *p_eu_last = (block_t*) p_sys->pp_eu_last - offsetof( block_t, p_next );
p_dbe = dirac_RemoveBlockEncap( p_eu_last );
uint8_t u_parse_code = p_block->p_buffer[4];
/* gather up the encapsulation unit */
p_block = block_ChainGather( p_sys->p_eu );
assert( p_block ); /* block_ChainGather doesn't define when it frees chain */
p_block->i_flags |= DIRAC_NON_DATED;
if( p_dbe )
{
dirac_AddBlockEncap( &p_block, p_dbe );
if( dirac_isPicture( u_parse_code ) ) p_block->i_flags &= ~DIRAC_NON_DATED;
}
p_sys->p_eu = NULL;
p_sys->pp_eu_last = &p_sys->p_eu;
return p_block;
}
/**
* dirac_TimeGenPush:
* @p_dec: vlc object
* @p_block_in: whole encapsulation unit to generate timestamps for
*
* Returns:
* 0: everything ok
* 1: EOS occured, please flush and reset
* 2: picture number discontinuity, please flush and reset
*/
static int dirac_TimeGenPush( decoder_t *p_dec, block_t *p_block_in )
{
decoder_sys_t *p_sys = p_dec->p_sys;
dirac_block_encap_t *p_dbe;
if( p_block_in->i_flags & BLOCK_FLAG_END_OF_SEQUENCE )
{
/* NB, this test occurs after the timegen push, so as to
* push the block into the output queue */
return 1;
}
if( p_block_in->i_flags & DIRAC_NON_DATED )
{
/* no picture found, which means p_block_in is a non-dated EU,
* do not try and put a date on it */
return 0;
}
p_dbe = dirac_GetBlockEncap( p_block_in );
uint32_t u_picnum = p_dbe ? p_dbe->u_picture_number : 0;
/*
* Simple DTS regeneration:
* - DTS values linearly increase in stream order.
* - Every time a DTS occurs at the input, sync to it
* - If this is the first DTS seen, backdate all the previous ones that are undated
* - If a DTS is missing, guess that it increases by one picture period
* - If never seen DTS, don't do anything
*/
/*
* Simple PTS regeneration
* - PTS values do not linearly increase in stream order.
* - Every time a PTS occurs at the input, sync to it and record picture number
* - If a PTS is missing, guess that it differs by the product of picture
* period and difference between picture number of sync point and current picture
* - If this is the first PTS seen, backdate all previous ones that are undated
* - If never seen PTS, don't do anything
*/
/*
* Stage 1, sync to input timestamps, backdate timestamps for old
* EUs that are in the outqueue with missing dates
*/
if( p_block_in->i_dts > VLC_TS_INVALID )
do {
/* if timestamps exist, sync to them */
if( p_sys->b_dts )
break;
/* first dts seen, backdate any packets in outqueue */
p_sys->b_dts = true;
date_t dts = p_sys->dts;
dirac_BackdateDTS( p_sys->p_outqueue, p_block_in, &dts );
} while( 0 );
if( p_block_in->i_pts > VLC_TS_INVALID )
do {
/* if timestamps exist, sync to them */
p_sys->u_pts_picnum = u_picnum;
p_sys->i_pts = p_block_in->i_pts;
if( p_sys->b_pts )
break;
/* first pts seen, backdate any packets in outqueue */
p_sys->b_pts = true;
date_t pts = p_sys->dts;
date_Set( &pts, p_sys->i_pts );
dirac_BackdatePTS( p_sys->p_outqueue, p_block_in, &pts, p_sys->u_pts_picnum );
} while( 0 );
/*
* Stage 2, don't attempt to forwards interpolate timestamps for
* blocks if the picture rates aren't known
*/
if( !p_sys->b_seen_seq_hdr )
{
return 0;
}
/*
* Stage 3, for block_in, interpolate any missing timestamps
*/
if( p_sys->b_dts && p_block_in->i_dts <= VLC_TS_INVALID )
{
/* dts has previously been seen, but not this time, interpolate */
p_block_in->i_dts = date_Increment( &p_sys->dts, 1 );
}
if( p_sys->b_pts && p_block_in->i_pts <= VLC_TS_INVALID )
{
/* pts has previously been seen, but not this time, interpolate */
date_t pts = p_sys->dts;
date_Set( &pts, p_sys->i_pts );
int32_t i_dist = u_picnum - p_sys->u_pts_picnum;
if( i_dist >= 0 )
p_block_in->i_pts = date_Increment( &pts, i_dist );
else
p_block_in->i_pts = date_Decrement( &pts, -i_dist );
}
/* If pts and dts have been seen, there is no need to simulate operation
* of the decoder reorder buffer */
/* If neither have been seen, there is little point in simulating */
if( p_sys->b_dts == p_sys->b_pts )
return 0;
if( !p_sys->p_out_dts )
p_sys->p_out_dts = p_sys->p_outqueue;
/* model the reorder buffer */
block_t *p_block = dirac_Reorder( p_dec, p_block_in, u_picnum );
if( !p_block )
return 0;
/* A future ehancement is to stop modeling the reorder buffer as soon as
* the first packet is output -- interpolate the past and freewheel for
* the future */
p_dbe = dirac_GetBlockEncap( p_block );
u_picnum = p_dbe ? p_dbe->u_picture_number : 0;
if( p_sys->b_tg_last_picnum )
{
if( dirac_PictureNbeforeM( u_picnum, p_sys->u_tg_last_picnum ) )
{
msg_Warn( p_dec, "stream jumped? %d < %d: resetting"
, u_picnum, p_sys->u_tg_last_picnum );
/* pictures only emerge from the reorder buffer in sequence
* if a stream suddenly jumped backwards without a signaling
* a discontinuity, some pictures will get stuck in the RoB.
* flush the RoB. */
/* this could be a bit less indiscriminate */
p_dbe = dirac_GetBlockEncap( p_sys->p_outqueue );
uint32_t u_prev_parse_offset = p_dbe ? p_dbe->u_last_next_offset : 0;
block_ChainRelease( p_sys->p_outqueue );
p_sys->p_outqueue = dirac_EmitEOS( p_dec, u_prev_parse_offset );
if( p_sys->p_outqueue )
p_sys->p_outqueue->i_flags = BLOCK_FLAG_DISCONTINUITY | DIRAC_NON_DATED;
/* return 2, so as not to reset the b_dts flags -- needed if
* using the rawdirac demuxer with broken stream */
return 2;
}
}
p_sys->b_tg_last_picnum = true;
p_sys->u_tg_last_picnum = u_picnum;
if( !p_sys->b_pts )
{
/* some demuxers (eg, AVI) will provide a series of fake dts values,
* which are actually inorder pts values (ie, what should be seen at
* the output of a decoder. A main reason for simulating the reorder
* buffer is to turn the inorder fakedts into an out-of-order pts */
p_block->i_pts = p_sys->p_out_dts->i_dts;
p_sys->p_out_dts->i_dts = VLC_TS_INVALID;
}
/* If pts was copied from dts, the dts needs to be corrected to account for reordering*/
/* If dts has never been seen, the same needs to happen */
p_sys->p_out_dts->i_dts = p_block->i_pts - p_sys->i_pts_offset;
/* move dts pointer */
if( p_sys->p_out_dts )
p_sys->p_out_dts = p_sys->p_out_dts->p_next;
return 0;
}
/*****************************************************************************
* Packetize: form dated encapsulation units from anything
*****************************************************************************/
static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
{
decoder_sys_t *p_sys = p_dec->p_sys;
block_t *p_block = NULL;
int i_flushing = 0;
if( pp_block && *pp_block )
{
p_block = *pp_block;
*pp_block = NULL;
if( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY )
{
/* pre-emptively insert an EOS at a discontinuity, protects
* any decoders from any sudden changes */
block_Release( p_block );
p_block = dirac_EmitEOS( p_dec, 0 );
if( p_block )
{
p_block->p_next = dirac_EmitEOS( p_dec, 13 );
/* need two EOS to ensure it gets detected by syncro
* duplicates get discarded in forming encapsulation unit */
}
}
else if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
{
/* silently discard corruption sentinels,
* synchronizer will then discard affected data units.
* do not produce an EOS data unit as this is very
* disruptive to the stream (and may make a larger error). */
block_Release( p_block );
p_block = NULL;
}
if( p_block )
block_BytestreamPush( &p_sys->bytestream, p_block );
}
/* form as many encapsulation units as possible, give up
* when the syncronizer runs out of input data */
while( ( p_block = dirac_DoSync( p_dec ) ) )
{
p_block = dirac_BuildEncapsulationUnit( p_dec, p_block );
if( !p_block )
continue;
/* add to tail of output queue (ie, not reordered) */
block_ChainLastAppend( &p_sys->pp_outqueue_last, p_block );
/* insert encapsulation unit into timestamp generator
* which then calculates some timestamps if required */
i_flushing = dirac_TimeGenPush( p_dec, p_block );
if( i_flushing )
break;
}
block_t *p_output = NULL;
block_t **pp_output = &p_output;
/* extract all the dated packets from the head of the output queue */
/* explicitly nondated packets repeat the previous timestamps to
* stop vlc discarding them */
while( (p_block = p_sys->p_outqueue) )
{
if( p_block->i_flags & DIRAC_DISCARD )
{
p_sys->p_outqueue = p_block->p_next;
p_block->p_next = NULL;
block_Release( p_block );
continue;
}
if( i_flushing || p_block->i_flags & DIRAC_NON_DATED )
{
p_block->i_dts = p_sys->i_dts_last_out;
p_block->i_pts = p_sys->i_pts_last_out;
}
else if( p_block->i_pts <= VLC_TS_INVALID ) break;
else if( p_block->i_dts <= VLC_TS_INVALID ) break;
p_sys->i_dts_last_out = p_block->i_dts;
p_sys->i_pts_last_out = p_block->i_pts;
p_sys->p_outqueue = p_block->p_next;
p_block->p_next = NULL;
/* clear any flags we set */
p_block->i_flags &= ~BLOCK_FLAG_PRIVATE_MASK;
block_ChainLastAppend( &pp_output, p_block );
mtime_t i_delay = p_block->i_pts - p_block->i_dts;
if( i_delay < 0 )
msg_Err( p_dec, "pts - dts is negative(%"PRId64"): incorrect RoB size", i_delay );
}
if( i_flushing )
{
p_sys->i_eu_dts = p_sys->i_eu_pts = VLC_TS_INVALID;
/* reset timegen state (except synchronizer) */
p_sys->b_seen_seq_hdr = false;
if( i_flushing < 2 )
{
/* this state isn't safe to loose if there was
* an unsignalled discontinuity */
p_sys->b_pts = p_sys->b_dts = false;
}
p_sys->b_tg_last_picnum = false;
dirac_ReorderInit( &p_sys->reorder_buf );
assert( p_sys->p_outqueue == NULL );
p_sys->p_out_dts = NULL;
}
/* perform sanity check:
* if there were a block at the front of outqueue that never
* satisfied the extraction criteria, but all blocks after did,
* the output queue would grow bounded by the stream length.
* If there are 10 data units in the output queue, assume this
* has happened and purge all blocks that fail extraction criteria */
int i_count;
block_ChainProperties( p_sys->p_outqueue, &i_count, NULL, NULL );
if( i_count > 9 )
{
p_block = p_sys->p_outqueue;
while( p_block )
{
block_t *p_block_next = p_block->p_next;
if( p_block->i_pts > VLC_TS_INVALID && p_block->i_dts > VLC_TS_INVALID )
break;
block_Release( p_block );
p_sys->p_outqueue = p_block = p_block_next;
}
}
if( !p_sys->p_outqueue )
{
p_sys->pp_outqueue_last = &p_sys->p_outqueue;
}
return p_output;
}
/*****************************************************************************
* Open: probe the packetizer and return score
*****************************************************************************/
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_DIRAC )
return VLC_EGENERIC;
p_dec->pf_packetize = Packetize;
/* Create the output format */
es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
p_dec->p_sys = p_sys = calloc( 1, sizeof( decoder_sys_t ) );
if( !p_sys )
return VLC_ENOMEM;
p_sys->i_eu_pts = p_sys->i_eu_dts = VLC_TS_INVALID;
p_sys->i_sync_pts = p_sys->i_sync_dts = VLC_TS_INVALID;
p_sys->i_dts_last_out = p_sys->i_pts_last_out = VLC_TS_INVALID;
p_sys->i_state = NOT_SYNCED;
block_BytestreamInit( &p_sys->bytestream );
p_sys->pp_outqueue_last = &p_sys->p_outqueue;
p_sys->pp_eu_last = &p_sys->p_eu;
date_Init( &p_sys->dts, 1, 1 );
dirac_ReorderInit( &p_sys->reorder_buf );
if( p_dec->fmt_in.i_extra > 0 )
{
/* handle hacky systems like ogg that dump some headers
* in p_extra. and packetizers that expect it to be filled
* in before real startup */
block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
if( !p_init )
{
/* memory might be avaliable soon. it isn't the end of
* the world that fmt_in.i_extra isn't handled */
return VLC_SUCCESS;
}
memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra );
/* in theory p_extra should contain just a seqhdr&EOS. if just a
* seqhdr, ensure it is extracted by appending an EOS with
* prev_offset = seqhdr length, ie i_extra. If all were actually
* ok, this won't do anything bad */
if( ( p_init->p_next = dirac_EmitEOS( p_dec, p_dec->fmt_in.i_extra ) ) )
{
/* to ensure that one of these two EOS dataunits gets extracted,
* send a second one */
p_init->p_next->p_next = dirac_EmitEOS( p_dec, 13 );
}
block_t *p_block;
while( ( p_block = Packetize( p_dec, &p_init ) ) )
block_Release( p_block );
}
return VLC_SUCCESS;
}
/*****************************************************************************
* Close:
*****************************************************************************/
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 );
if( p_sys->p_outqueue )
block_ChainRelease( p_sys->p_outqueue );
if( p_sys->p_eu )
block_ChainRelease( p_sys->p_eu );
free( p_sys );
}