* ALL: Introduce a buffering scheme to smooth packet output (see README).

git-svn-id: svn://svn.videolan.org/dvblast/trunk@146 55d3f8b6-4a41-4d2d-a900-313d1436a5b8

README

@@ -26,7 +26,8 @@ Current features
  - Lightweight program designed for extreme memory and CPU conditions
  - Only one dependancy: libdvbpsi
  - CAM menus (MMI) support via an external application
- - The configuration file describing outputs can be reloaded without losing a single packet
+ - The configuration file describing outputs can be reloaded without losing
+   a single packet
  - Support for the new S2API of linux-dvb
  - IPv6 network support
  - UDP rather than RTP output for IPTV STBs which don't support RTP
@@ -55,6 +56,11 @@ information.
 Alternative inputs
 ==================
 
+DVBlast may handle several DVB adapters in the same machine with the -a switch:
+-a 3 will use /dev/dvb/adapter3.  Additionally, selecting between frontends on
+a single card is supported with the -n switch.  This is useful for hybrid 
+DVB/S + DVB/T cards.
+
 If you own a Computer Modules DVB-ASI input card, you can have DVBlast
 filter and demultiplex the inputs. You just need to specify the slot number
 with -A.
@@ -140,6 +146,48 @@ from the command-line :
 dvblast -c /tmp/dvblast.conf
 
 
+Buffering
+=========
+
+DVB cards usually output packets in big chunks. This can be problematic
+with low bitrate multiplexes. By default, DVBlast bufferizes 200 ms
+and tries to smooth the output. It may be desired to change this value
+with the -L option. The appropriate value should be :
+  chunk_size / multiplex_bitrate
+
+The chunk size for saa7146-based cards is 512000 bits ; for cx23885-based
+cards is 192512 bits. The multiplex_bitrate depends on the symbol rate and
+many other factors such as the modulation.
+
+The current default value allows for multiplex_rates as low as 2.56 Mbi/s.
+Smaller multiplexes are rare but exist, so in that case you may want to
+increase the buffer size. A typical DVB multiplex is 30 or 40 Mbi/s, so
+the default introduces a superfluous latency ; the buffer can be lowered
+to 50 ms if latency is an issue.
+
+DVBlast also has another parameter called "max retention time" (-E).
+This controls how TS packets are grouped together in IP datagrams : the
+difference between the theorical output times of the first and the last
+TS packets cannot exceed the maximal retention time.
+
+IP datagrams are normally output at the output time of the earliest TS
+packet ; it implies that the next TS packets are sent too soon and must
+be buffered at the receiver level. ISO/IEC 13818-1 makes no provision for
+this, since IP wasn't in mind when designing TS, so in theory we risk a
+buffer overflow.
+
+However normal IP receivers feature a jitter buffer which can absorb the
+overflow ; DVB recommends a 50 ms buffer. DVBlast's default maximal
+retention time is just below, at 40 ms, which should be fine in most
+situations.
+
+If some anal set-top-box complains about buffer overflows or clock issues,
+you may try to lower the value ; the drawback is that on low bitrate
+streams it will introduce padding. People with low bitrate streams and
+nice receivers with big buffers can raise this value to avoid superfluous
+padding and lower the total bitrate.
+
+
 Monitoring
 ==========
 
@@ -163,11 +211,6 @@ dvblast_mmi.sh -r /tmp/dvblast.sock
 Advanced features
 =================
 
-DVBlast may handle several DVB adapters in the same machine with the -a switch:
--a 3 will use /dev/dvb/adapter3.  Additionally, selecting between frontends on
-a single card is supported with the -n switch.  This is useful for hybrid 
-DVB/S + DVB/T cards.
-
 For better latency, run DVBlast in real-time priority: -i 1 (requires root
 privileges).
 
@@ -183,3 +226,4 @@ unused ones, can be output. With -e, dvblast also streams EIT and SDT packets
 for the related services.
 
 Other options are self-understandable, and are listed in dvblast -h.
+

TODO

 - Test and enhance the API for DVB-C, H, and ATSC support
 - Win32 support
 - Improve build system (autostuff)
-- Rework the EN 50 221 machinery to avoid blocking TPDU_Recv and Send
+- bitstream support

asi.c

@@ -167,82 +167,86 @@ void asi_Open( void )
 /*****************************************************************************
  * asi_Read : read packets from the device
  *****************************************************************************/
-block_t *asi_Read( void )
+block_t *asi_Read( mtime_t i_poll_timeout )
 {
-    int i, i_len;
-    struct iovec p_iov[i_bufsize / TS_SIZE];
-    block_t *p_ts, **pp_current = &p_ts;
+    struct pollfd pfd;
+    int i_ret;
 
-    for ( ; ; )
-    {
-        struct pollfd pfd;
+    pfd.fd = i_handle;
+    pfd.events = POLLIN | POLLPRI;
 
-        pfd.fd = i_handle;
-        pfd.events = POLLIN | POLLPRI;
+    i_ret = poll( &pfd, 1, (i_poll_timeout + 999) / 1000 );
 
-        if ( poll(&pfd, 1, -1) < 0 )
-        {
+    i_wallclock = mdate();
+
+    if ( i_ret < 0 )
+    {
+        if( errno != EINTR )
             msg_Err( NULL, "couldn't poll from device " ASI_DEVICE " (%s)",
                      i_asi_adapter, strerror(errno) );
-            continue;
-        }
+        return NULL;
+    }
 
-        if ( (pfd.revents & POLLPRI) )
+    if ( (pfd.revents & POLLPRI) )
+    {
+        unsigned int i_val;
+
+        if ( ioctl(i_handle, ASI_IOC_RXGETEVENTS, &i_val) < 0 )
+            msg_Err( NULL, "couldn't RXGETEVENTS (%s)", strerror(errno) );
+        else
         {
-            unsigned int i_val;
-
-            if ( ioctl(i_handle, ASI_IOC_RXGETEVENTS, &i_val) < 0 )
-                msg_Err( NULL, "couldn't RXGETEVENTS (%s)", strerror(errno) );
-            else
-            {
-                if ( i_val & ASI_EVENT_RX_BUFFER )
-                    msg_Warn( NULL, "driver receive buffer queue overrun" );
-                if ( i_val & ASI_EVENT_RX_FIFO )
-                    msg_Warn( NULL, "onboard receive FIFO overrun" );
-                if ( i_val & ASI_EVENT_RX_CARRIER )
-                    msg_Warn( NULL, "carrier status change" );
-                if ( i_val & ASI_EVENT_RX_LOS )
-                    msg_Warn( NULL, "loss of packet synchronization" );
-                if ( i_val & ASI_EVENT_RX_AOS )
-                    msg_Warn( NULL, "acquisition of packet synchronization" );
-                if ( i_val & ASI_EVENT_RX_DATA )
-                    msg_Warn( NULL, "receive data status change" );
-            }
+            if ( i_val & ASI_EVENT_RX_BUFFER )
+                msg_Warn( NULL, "driver receive buffer queue overrun" );
+            if ( i_val & ASI_EVENT_RX_FIFO )
+                msg_Warn( NULL, "onboard receive FIFO overrun" );
+            if ( i_val & ASI_EVENT_RX_CARRIER )
+                msg_Warn( NULL, "carrier status change" );
+            if ( i_val & ASI_EVENT_RX_LOS )
+                msg_Warn( NULL, "loss of packet synchronization" );
+            if ( i_val & ASI_EVENT_RX_AOS )
+                msg_Warn( NULL, "acquisition of packet synchronization" );
+            if ( i_val & ASI_EVENT_RX_DATA )
+                msg_Warn( NULL, "receive data status change" );
         }
-
-        if ( (pfd.revents & POLLIN) )
-            break;
     }
 
-    for ( i = 0; i < i_bufsize / TS_SIZE; i++ )
+    if ( (pfd.revents & POLLIN) )
     {
-        *pp_current = block_New();
-        p_iov[i].iov_base = (*pp_current)->p_ts;
-        p_iov[i].iov_len = TS_SIZE;
-        pp_current = &(*pp_current)->p_next;
-    }
+        struct iovec p_iov[i_bufsize / TS_SIZE];
+        block_t *p_ts, **pp_current = &p_ts;
+        int i, i_len;
 
-    if ( (i_len = readv(i_handle, p_iov, i_bufsize / TS_SIZE)) < 0 )
-    {
-        msg_Err( NULL, "couldn't read from device " ASI_DEVICE " (%s)",
-                 i_asi_adapter, strerror(errno) );
-        i_len = 0;
-    }
-    i_len /= TS_SIZE;
+        for ( i = 0; i < i_bufsize / TS_SIZE; i++ )
+        {
+            *pp_current = block_New();
+            p_iov[i].iov_base = (*pp_current)->p_ts;
+            p_iov[i].iov_len = TS_SIZE;
+            pp_current = &(*pp_current)->p_next;
+        }
 
-    pp_current = &p_ts;
-    while ( i_len && *pp_current )
-    {
-        pp_current = &(*pp_current)->p_next;
-        i_len--;
-    }
+        if ( (i_len = readv(i_handle, p_iov, i_bufsize / TS_SIZE)) < 0 )
+        {
+            msg_Err( NULL, "couldn't read from device " ASI_DEVICE " (%s)",
+                     i_asi_adapter, strerror(errno) );
+            i_len = 0;
+        }
+        i_len /= TS_SIZE;
+
+        pp_current = &p_ts;
+        while ( i_len && *pp_current )
+        {
+            pp_current = &(*pp_current)->p_next;
+            i_len--;
+        }
 
-    if ( *pp_current )
-        msg_Dbg( NULL, "partial buffer received" );
-    block_DeleteChain( *pp_current );
-    *pp_current = NULL;
+        if ( *pp_current )
+            msg_Dbg( NULL, "partial buffer received" );
+        block_DeleteChain( *pp_current );
+        *pp_current = NULL;
 
-    return p_ts;
+        return p_ts;
+    }
+    return NULL;
 }
 
 /*****************************************************************************
@@ -251,7 +255,7 @@ block_t *asi_Read( void )
 int asi_SetFilter( uint16_t i_pid )
 {
 #ifdef USE_HARDWARE_FILTERING
-    p_pid_filter[ i_pid / 8 ] |= (0x01 << (i_pid % 8)); 
+    p_pid_filter[ i_pid / 8 ] |= (0x01 << (i_pid % 8));
     if ( ioctl( i_handle, ASI_IOC_RXSETPF, p_pid_filter ) < 0 )
         msg_Warn( NULL, "couldn't add filter on PID %u", i_pid );
 

demux.c

 /*****************************************************************************
  * demux.c
  *****************************************************************************
- * Copyright (C) 2004, 2008-2009 VideoLAN
+ * Copyright (C) 2004, 2008-2010 VideoLAN
  * $Id$
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
@@ -76,6 +76,7 @@ static dvbpsi_handle p_sdt_dvbpsi_handle;
 static dvbpsi_handle p_eit_dvbpsi_handle;
 static dvbpsi_pat_t *p_current_pat = NULL;
 static dvbpsi_sdt_t *p_current_sdt = NULL;
+static mtime_t i_last_dts = -1;
 static int i_demux_fd;
 static int i_nb_errors = 0;
 static mtime_t i_last_error = 0;
@@ -84,6 +85,7 @@ static mtime_t i_last_error = 0;
  * Local prototypes
  *****************************************************************************/
 static void demux_Handle( block_t *p_ts );
+static void SetDTS( block_t *p_list );
 static void SetPID( uint16_t i_pid );
 static void UnsetPID( uint16_t i_pid );
 static void StartPID( output_t *p_output, uint16_t i_pid );
@@ -98,9 +100,9 @@ static void GetPIDS( uint16_t **ppi_wanted_pids, int *pi_nb_wanted_pids,
 static int SIDIsSelected( uint16_t i_sid );
 int PIDWouldBeSelected( dvbpsi_pmt_es_t *p_es );
 static int PMTNeedsDescrambling( dvbpsi_pmt_t *p_pmt );
-static void SendPAT( void );
-static void SendSDT( void );
-static void SendPMT( sid_t *p_sid );
+static void SendPAT( mtime_t i_dts );
+static void SendSDT( mtime_t i_dts );
+static void SendPMT( sid_t *p_sid, mtime_t i_dts );
 static void NewPAT( output_t *p_output );
 static void NewSDT( output_t *p_output );
 static void NewPMT( output_t *p_output );
@@ -148,9 +150,9 @@ void demux_Open( void )
 /*****************************************************************************
  * demux_Run
  *****************************************************************************/
-void demux_Run( void )
+void demux_Run( block_t *p_ts )
 {
-    block_t *p_ts = pf_Read();
+    SetDTS( p_ts );
 
     while ( p_ts != NULL )
     {
@@ -207,7 +209,7 @@ static void demux_Handle( block_t *p_ts )
         {
             dvbpsi_PushPacket( p_pat_dvbpsi_handle, p_ts->p_ts );
             if ( block_UnitStart( p_ts ) )
-                SendPAT();
+                SendPAT( p_ts->i_dts );
         }
         else if ( b_enable_epg && i_pid == EIT_PID )
         {
@@ -217,11 +219,11 @@ static void demux_Handle( block_t *p_ts )
         {
             dvbpsi_PushPacket( p_sdt_dvbpsi_handle, p_ts->p_ts );
             if ( block_UnitStart( p_ts ) )
-            {   
+            {
                 uint8_t *p_payload = block_GetPayload( p_ts );
 
                 if ( p_payload && *(p_payload + *p_payload + 1) == 0x42 )
-                    SendSDT();
+                    SendSDT( p_ts->i_dts );
             }
 
         }
@@ -242,7 +244,7 @@ static void demux_Handle( block_t *p_ts )
                     dvbpsi_PushPacket( pp_sids[i]->p_dvbpsi_handle,
                                        p_ts->p_ts );
                     if ( block_UnitStart( p_ts ) )
-                        SendPMT( pp_sids[i] );
+                        SendPMT( pp_sids[i], p_ts->i_dts );
                 }
             }
         }
@@ -265,7 +267,7 @@ static void demux_Handle( block_t *p_ts )
                     if ( pp_outputs[j]->i_sid == i_sid )
                     {
                         pp_outputs[j]->i_ref_timestamp = i_timestamp;
-                        pp_outputs[j]->i_ref_wallclock = 0;
+                        pp_outputs[j]->i_ref_wallclock = p_ts->i_dts;
                     }
                 }
             }
@@ -430,7 +432,7 @@ void demux_Change( output_t *p_output, uint16_t i_sid,
         {
             if ( pp_sids[i]->i_sid == i_sid )
             {
-                if ( pp_sids[i]->p_current_pmt != NULL 
+                if ( pp_sids[i]->p_current_pmt != NULL
                       && PMTNeedsDescrambling( pp_sids[i]->p_current_pmt ) )
                     en50221_UpdatePMT( pp_sids[i]->p_current_pmt );
                 break;
@@ -454,6 +456,40 @@ void demux_Change( output_t *p_output, uint16_t i_sid,
         NewPMT( p_output );
 }
 
+/*****************************************************************************
+ * SetDTS
+ *****************************************************************************/
+static void SetDTS( block_t *p_list )
+{
+    int i_nb_ts = 0, i;
+    mtime_t i_duration;
+    block_t *p_ts = p_list;
+
+    while ( p_ts != NULL )
+    {
+        i_nb_ts++;
+        p_ts = p_ts->p_next;
+    }
+
+    /* We suppose the stream is CBR, at least between two consecutive read().
+     * This is especially true in budget mode */
+    if ( i_last_dts == -1 )
+        i_duration = 0;
+    else
+        i_duration = i_wallclock - i_last_dts;
+
+    p_ts = p_list;
+    i = i_nb_ts - 1;
+    while ( p_ts != NULL )
+    {
+        p_ts->i_dts = i_wallclock - i_duration * i / i_nb_ts;
+        i--;
+        p_ts = p_ts->p_next;
+    }
+
+    i_last_dts = i_wallclock;
+}
+
 /*****************************************************************************
  * SetPID/UnsetPID
  *****************************************************************************/
@@ -630,7 +666,8 @@ static void GetPIDS( uint16_t **ppi_wanted_pids, int *pi_nb_wanted_pids,
  * WritePSISection
  *****************************************************************************/
 static block_t *WritePSISection( dvbpsi_psi_section_t *p_section,
-                                 uint16_t i_pid, uint8_t *pi_cc )
+                                 uint16_t i_pid, uint8_t *pi_cc,
+                                 mtime_t i_dts )
 {
     block_t *p_block, **pp_last = &p_block;
     uint32_t i_length;
@@ -678,6 +715,8 @@ static block_t *WritePSISection( dvbpsi_psi_section_t *p_section,
         for( i = 4 + b_first + i_copy; i < 188; i++ )
             p_ts->p_ts[i] = 0xff;
 
+        p_ts->i_dts = i_dts;
+
         b_first = 0;
         i_length -= i_copy;
         p_data += i_copy;
@@ -690,7 +729,7 @@ static block_t *WritePSISection( dvbpsi_psi_section_t *p_section,
 /*****************************************************************************
  * SendPAT
  *****************************************************************************/
-static void SendPAT( void )
+static void SendPAT( mtime_t i_dts )
 {
     int i;
 
@@ -720,7 +759,7 @@ static void SendPAT( void )
             block_t *p_block;
 
             p_block = WritePSISection( pp_outputs[i]->p_pat_section, PAT_PID,
-                                       &pp_outputs[i]->i_pat_cc );
+                                       &pp_outputs[i]->i_pat_cc, i_dts );
             while ( p_block != NULL )
             {
                 block_t *p_next = p_block->p_next;
@@ -735,7 +774,7 @@ static void SendPAT( void )
 /*****************************************************************************
  * SendSDT
  *****************************************************************************/
-static void SendSDT( void )
+static void SendSDT( mtime_t i_dts )
 {
     int i;
 
@@ -746,7 +785,7 @@ static void SendSDT( void )
             block_t *p_block;
 
             p_block = WritePSISection( pp_outputs[i]->p_sdt_section, SDT_PID,
-                                       &pp_outputs[i]->i_sdt_cc );
+                                       &pp_outputs[i]->i_sdt_cc, i_dts );
             while ( p_block != NULL )
             {
                 block_t *p_next = p_block->p_next;
@@ -761,7 +800,7 @@ static void SendSDT( void )
 /*****************************************************************************
  * SendPMT
  *****************************************************************************/
-static void SendPMT( sid_t *p_sid )
+static void SendPMT( sid_t *p_sid, mtime_t i_dts )
 {
     int i;
 
@@ -775,7 +814,7 @@ static void SendPMT( sid_t *p_sid )
 
                 p_block = WritePSISection( pp_outputs[i]->p_pmt_section,
                                            p_sid->i_pmt_pid,
-                                           &pp_outputs[i]->i_pmt_cc );
+                                           &pp_outputs[i]->i_pmt_cc, i_dts );
                 while ( p_block != NULL )
                 {
                     block_t *p_next = p_block->p_next;
@@ -812,7 +851,7 @@ static void SendEIT( dvbpsi_psi_section_t *p_section, uint16_t i_sid,
 
             p_block = WritePSISection( p_section,
                                        EIT_PID,
-                                       &pp_outputs[i]->i_eit_cc );
+                                       &pp_outputs[i]->i_eit_cc, i_wallclock );
             while ( p_block != NULL )
             {
                 block_t *p_next = p_block->p_next;

dvb.c

 /*****************************************************************************
  * dvb.c: linux-dvb input for DVBlast
  *****************************************************************************
- * Copyright (C) 2008-2009 VideoLAN
+ * Copyright (C) 2008-2010 VideoLAN
  * $Id$
  *
  * Authors: Christophe Massiot <massiot@via.ecp.fr>
@@ -119,11 +119,10 @@ void dvb_Reset( void )
 /*****************************************************************************
  * dvb_Read
  *****************************************************************************/
-block_t *dvb_Read( void )
+block_t *dvb_Read( mtime_t i_poll_timeout )
 {
     struct pollfd ufds[4];
     int i_ret, i_nb_fd = 2;
-    mtime_t i_wallclock;
     block_t *p_blocks = NULL;
 
     memset( ufds, 0, sizeof(ufds) );
@@ -144,7 +143,9 @@ block_t *dvb_Read( void )
         i_nb_fd++;
     }
 
-    i_ret = poll( ufds, i_nb_fd, 100 );
+    i_ret = poll( ufds, i_nb_fd, (i_poll_timeout + 999) / 1000 );
+
+    i_wallclock = mdate();
 
     if ( i_ret < 0 )
     {
@@ -156,7 +157,6 @@ block_t *dvb_Read( void )
     if ( ufds[0].revents )
         p_blocks = DVRRead();
 
-    i_wallclock = mdate();
     if ( i_ca_handle && i_ca_type == CA_CI_LINK )
     {
         if ( ufds[i_nb_fd - 1].revents )
@@ -353,7 +353,7 @@ static void FrontendPoll( void )
             else
             {
                 msg_Dbg( NULL, "frontend has lost lock" );
-                i_frontend_timeout = mdate() + FRONTEND_LOCK_TIMEOUT;
+                i_frontend_timeout = i_wallclock + FRONTEND_LOCK_TIMEOUT;
             }
 
             IF_UP( FE_REINIT )
@@ -802,7 +802,7 @@ static void FrontendSet( bool b_init )
     }
 
     i_last_status = 0;
-    i_frontend_timeout = mdate() + FRONTEND_LOCK_TIMEOUT;
+    i_frontend_timeout = i_wallclock + FRONTEND_LOCK_TIMEOUT;
 }
 
 #else /* !S2API */
@@ -896,7 +896,7 @@ static void FrontendSet( bool b_init )
     }
 
     i_last_status = 0;
-    i_frontend_timeout = mdate() + FRONTEND_LOCK_TIMEOUT;
+    i_frontend_timeout = i_wallclock + FRONTEND_LOCK_TIMEOUT;
 }
 
 #endif /* S2API */

dvblast.c

@@ -41,6 +41,7 @@
 /*****************************************************************************
  * Local declarations
  *****************************************************************************/
+mtime_t i_wallclock = 0;
 output_t **pp_outputs = NULL;
 int i_nb_outputs = 0;
 output_t output_dup = { 0 };
@@ -65,6 +66,8 @@ int b_slow_cam = 0;
 int b_output_udp = 0;
 int b_enable_epg = 0;
 int b_unique_tsid = 0;
+mtime_t i_output_latency = DEFAULT_OUTPUT_LATENCY;
+mtime_t i_max_retention = DEFAULT_MAX_RETENTION;
 volatile int b_hup_received = 0;
 int i_verbose = DEFAULT_VERBOSITY;
 int i_syslog = 0;
@@ -74,7 +77,7 @@ int b_src_rawudp = 0;
 int i_asi_adapter = 0;
 
 void (*pf_Open)( void ) = NULL;
-block_t * (*pf_Read)( void ) = NULL;
+block_t * (*pf_Read)( mtime_t i_poll_timeout ) = NULL;
 int (*pf_SetFilter)( uint16_t i_pid ) = NULL;
 void (*pf_UnsetFilter)( int i_fd, uint16_t i_pid ) = NULL;
 
@@ -315,7 +318,7 @@ static void DisplayVersion()
  *****************************************************************************/
 void usage()
 {
-    msg_Raw( NULL, "Usage: dvblast [-q] [-c <config file>] [-r <remote socket>] [-t <ttl>] [-o <SSRC IP>] [-i <RT priority>] [-a <adapter>] [-n <frontend number>] [-S <diseqc>] [-f <frequency>|-D <src mcast>:<port>|-A <ASI adapter>] [-F <fec inner>] [-R <rolloff>] [-s <symbol rate>] [-v <0|13|18>] [-p] [-b <bandwidth>] [-m <modulation] [-u] [-W] [-U] [-d <dest IP:port>] [-e] [-T]" );
+    msg_Raw( NULL, "Usage: dvblast [-q] [-c <config file>] [-r <remote socket>] [-t <ttl>] [-o <SSRC IP>] [-i <RT priority>] [-a <adapter>] [-n <frontend number>] [-S <diseqc>] [-f <frequency>|-D <src mcast>:<port>|-A <ASI adapter>] [-F <fec inner>] [-R <rolloff>] [-s <symbol rate>] [-v <0|13|18>] [-p] [-b <bandwidth>] [-m <modulation] [-u] [-W] [-U] [-L <latency>] [-E <retention>] [-d <dest IP:port>] [-e] [-T]" );
 
     msg_Raw( NULL, "Input:" );
     msg_Raw( NULL, "  -a --adapter <adapter>" );
@@ -343,6 +346,8 @@ void usage()
 
     msg_Raw( NULL, "Output:" );
     msg_Raw( NULL, "  -c --config-file <config file>" );
+    msg_Raw( NULL, "  -L --latency          maximum latency allowed between input and output (default: 100 ms)" );
+    msg_Raw( NULL, "  -E --retention        maximum retention allowed between input and output (default: 40 ms)" );
     msg_Raw( NULL, "  -d --duplicate        duplicate all received packets to a given destination" );
     msg_Raw( NULL, "  -o --rtp-output <SSRC IP>" );
     msg_Raw( NULL, "  -t --ttl <ttl>        TTL of the output stream" );
@@ -360,6 +365,7 @@ void usage()
 
 int main( int i_argc, char **pp_argv )
 {
+    mtime_t i_poll_timeout = MAX_POLL_TIMEOUT;
     struct sched_param param;
     int i_error;
     int c;
@@ -393,6 +399,8 @@ int main( int i_argc, char **pp_argv )
         { "slow-cam",        no_argument,       NULL, 'W' },
         { "udp",             no_argument,       NULL, 'U' },
         { "unique-ts-id",    no_argument,       NULL, 'T' },
+        { "latency",         required_argument, NULL, 'L' },
+        { "retention",       required_argument, NULL, 'E' },
         { "duplicate",       required_argument, NULL, 'd' },
         { "rtp-input",       required_argument, NULL, 'D' },
         { "asi-adapter",     required_argument, NULL, 'A' },
@@ -401,9 +409,9 @@ int main( int i_argc, char **pp_argv )
         { "help",            no_argument,       NULL, 'h' },
         { "version",         no_argument,       NULL, 'V' },
         { 0, 0, 0, 0}
-    }; 
+    };
 
-    while ( ( c = getopt_long(i_argc, pp_argv, "q::c:r:t:o:i:a:n:f:F:R:s:S:v:pb:m:uWUTd:D:A:lehV", long_options, NULL)) != -1 )
+    while ( ( c = getopt_long(i_argc, pp_argv, "q::c:r:t:o:i:a:n:f:F:R:s:S:v:pb:m:uWUTL:E:d:D:A:lehV", long_options, NULL)) != -1 )
     {
         switch ( c )
         {
@@ -522,6 +530,14 @@ int main( int i_argc, char **pp_argv )
             b_output_udp = 1;
             break;
 
+        case 'L':
+            i_output_latency = strtoll( optarg, NULL, 0 ) * 1000;
+            break;
+
+        case 'E':
+            i_max_retention = strtoll( optarg, NULL, 0 ) * 1000;
+            break;
+
         case 'd':
         {
             char *psz_token, *psz_displayname;
@@ -720,6 +736,8 @@ int main( int i_argc, char **pp_argv )
 
     for ( ; ; )
     {
+        block_t *p_ts;
+
         if ( b_hup_received )
         {
             b_hup_received = 0;
@@ -727,7 +745,12 @@ int main( int i_argc, char **pp_argv )
             ReadConfiguration( psz_conf_file );
         }
 
-        demux_Run();
+        p_ts = pf_Read( i_poll_timeout );
+        if ( p_ts != NULL )
+            demux_Run( p_ts );
+        i_poll_timeout = output_Send();
+        if ( i_poll_timeout == -1 || i_poll_timeout > MAX_POLL_TIMEOUT )
+            i_poll_timeout = MAX_POLL_TIMEOUT;
     }
 
     if ( b_enable_syslog )

dvblast.h

@@ -39,6 +39,9 @@
 #define WATCHDOG_WAIT 10000000LL
 #define MAX_ERRORS 1000
 #define DEFAULT_VERBOSITY 3
+#define MAX_POLL_TIMEOUT 100000 /* 100 ms */
+#define DEFAULT_OUTPUT_LATENCY 200000 /* 200 ms */
+#define DEFAULT_MAX_RETENTION 40000 /* 40 ms */
 
 /*****************************************************************************
  * Output configuration flags (for output_t -> i_config) - bit values
@@ -61,9 +64,12 @@ typedef struct block_t
 {
     uint8_t p_ts[TS_SIZE];
     int i_refcount;
+    mtime_t i_dts;
     struct block_t *p_next;
 } block_t;
 
+typedef struct packet_t packet_t;
+
 typedef struct output_t
 {
     /* address information, protocol agnostic */
@@ -75,8 +81,7 @@ typedef struct output_t
 
     /* output */
     int i_handle;
-    block_t *pp_blocks[NB_BLOCKS];
-    int i_depth;
+    packet_t *p_packets, *p_last_packet;
     uint16_t i_cc;
     mtime_t i_ref_timestamp;
     mtime_t i_ref_wallclock;
@@ -124,6 +129,9 @@ extern int b_slow_cam;
 extern int b_output_udp;
 extern int b_enable_epg;
 extern int b_unique_tsid;
+extern mtime_t i_output_latency;
+extern mtime_t i_max_retention;
+extern mtime_t i_wallclock;
 extern volatile int b_hup_received;
 extern int i_comm_fd;
 extern uint16_t i_src_port;
@@ -132,7 +140,7 @@ extern int b_src_rawudp;
 extern int i_asi_adapter;
 
 extern void (*pf_Open)( void );
-extern block_t * (*pf_Read)( void );
+extern block_t * (*pf_Read)( mtime_t i_poll_timeout );
 extern int (*pf_SetFilter)( uint16_t i_pid );
 extern void (*pf_UnsetFilter)( int i_fd, uint16_t i_pid );
 
@@ -158,32 +166,35 @@ void hexDump( uint8_t *p_data, uint32_t i_len );
 
 void dvb_Open( void );
 void dvb_Reset( void );
-block_t * dvb_Read( void );
+block_t * dvb_Read( mtime_t i_poll_timeout );
 int dvb_SetFilter( uint16_t i_pid );
 void dvb_UnsetFilter( int i_fd, uint16_t i_pid );
 uint8_t dvb_FrontendStatus( uint8_t *p_answer, ssize_t *pi_size );
 
 void udp_Open( void );
-block_t * udp_Read( void );
+block_t * udp_Read( mtime_t i_poll_timeout );
 int udp_SetFilter( uint16_t i_pid );
 void udp_UnsetFilter( int i_fd, uint16_t i_pid );
 
 void asi_Open( void );
-block_t * asi_Read( void );
+block_t * asi_Read( mtime_t i_poll_timeout );
 int asi_SetFilter( uint16_t i_pid );
 void asi_UnsetFilter( int i_fd, uint16_t i_pid );
 
 void demux_Open( void );
-void demux_Run( void );
+void demux_Run( block_t *p_ts );
 void demux_Change( output_t *p_output, uint16_t i_sid,
                    uint16_t *pi_pids, int i_nb_pids );
 void demux_ResendCAPMTs( void );
 int PIDIsSelected( uint16_t i_pid );
 
-output_t *output_Create( uint8_t i_config, const char *psz_displayname, void *p_init_data );
-int output_Init( output_t *p_output, uint8_t i_config, const char *psz_displayname, void *p_init_data );
+output_t *output_Create( uint8_t i_config, const char *psz_displayname,
+                         void *p_init_data );
+int output_Init( output_t *p_output, uint8_t i_config,
+                 const char *psz_displayname, void *p_init_data );
 void output_Close( output_t *p_output );
 void output_Put( output_t *p_output, block_t *p_block );
+mtime_t output_Send( void );
 
 void comm_Open( void );
 void comm_Read( void );
@@ -302,4 +313,3 @@ static inline uint8_t *block_GetPayload( block_t *p_block )
         return &p_block->p_ts[4];
     return &p_block->p_ts[ 5 + p_block->p_ts[4] ];
 }
-

en50221.c

@@ -1492,7 +1492,7 @@ static void DateTimeSend( access_t * p_access, int i_session_id )
 
         APDUSend( p_access, i_session_id, AOT_DATE_TIME, p_response, 7 );
 
-        p_date->i_last = mdate();
+        p_date->i_last = i_wallclock;
     }
 }
 
@@ -1540,7 +1540,7 @@ static void DateTimeManage( access_t * p_access, int i_session_id )
         (date_time_t *)p_sessions[i_session_id - 1].p_sys;
 
     if ( p_date->i_interval
-          && mdate() > p_date->i_last + (mtime_t)p_date->i_interval * 1000000 )
+          && i_wallclock > p_date->i_last + (mtime_t)p_date->i_interval * 1000000 )
     {
         DateTimeSend( p_access, i_session_id );
     }
@@ -2188,7 +2188,7 @@ void en50221_Poll( void )
         {
             if ( !p_slot->i_init_timeout )
                 InitSlot( NULL, i_slot );
-            else if ( p_slot->i_init_timeout < mdate() )
+            else if ( p_slot->i_init_timeout < i_wallclock )
             {
                 msg_Dbg( NULL, "en50221_Poll: resetting slot %d", i_slot );
                 ResetSlot( i_slot );

udp.c

@@ -96,52 +96,76 @@ void udp_Open( void )
 /*****************************************************************************
  * udp_Read
  *****************************************************************************/
-block_t *udp_Read( void )
+block_t *udp_Read( mtime_t i_poll_timeout )
 {
-    int i = 0, i_len;
-    struct iovec p_iov[NB_BLOCKS + !b_src_rawudp];
-    block_t *p_ts, **pp_current = &p_ts;
-    uint8_t p_rtp_hdr[RTP_SIZE];
+    struct pollfd pfd;
+    int i_ret;
 
-    if ( !b_src_rawudp )
-    {
-        /* FIXME : this is wrong if RTP header > 12 bytes */
-        p_iov[i].iov_base = p_rtp_hdr;
-        p_iov[i].iov_len = RTP_SIZE;
-        i++;
-    }
+    pfd.fd = i_handle;
+    pfd.events = POLLIN;
 
-    for ( ; i < NB_BLOCKS + !b_src_rawudp; i++ )
-    {
-        *pp_current = block_New();
-        p_iov[i].iov_base = (*pp_current)->p_ts;
-        p_iov[i].iov_len = TS_SIZE;
-        pp_current = &(*pp_current)->p_next;
-    }
+    i_ret = poll( &pfd, 1, (i_poll_timeout + 999) / 1000 );
+
+    i_wallclock = mdate();
 
-    if ( (i_len = readv( i_handle, p_iov, NB_BLOCKS + !b_src_rawudp )) < 0 )
+    if ( i_ret < 0 )
     {
-        msg_Err( NULL, "couldn't read from network (%s)",
-                 strerror(errno) );
-        i_len = 0;
+        if( errno != EINTR )
+            msg_Err( NULL, "couldn't poll from socket (%s)",
+                     strerror(errno) );
+        return NULL;
     }
-    if ( !b_src_rawudp )
-        i_len -= RTP_SIZE;
-    i_len /= TS_SIZE;
 
-    pp_current = &p_ts;
-    while ( i_len && *pp_current )
+    if ( pfd.revents )
     {
-        pp_current = &(*pp_current)->p_next;
-        i_len--;
-    }
+        struct iovec p_iov[NB_BLOCKS + !b_src_rawudp];
+        block_t *p_ts, **pp_current = &p_ts;
+        int i = 0, i_len;
+        uint8_t p_rtp_hdr[RTP_SIZE];
+
+        if ( !b_src_rawudp )
+        {
+            /* FIXME : this is wrong if RTP header > 12 bytes */
+            p_iov[i].iov_base = p_rtp_hdr;
+            p_iov[i].iov_len = RTP_SIZE;
+            i++;
+        }
+
+        for ( ; i < NB_BLOCKS + !b_src_rawudp; i++ )
+        {
+            *pp_current = block_New();
+            p_iov[i].iov_base = (*pp_current)->p_ts;
+            p_iov[i].iov_len = TS_SIZE;
+            pp_current = &(*pp_current)->p_next;
+        }
+
+        if ( (i_len = readv( i_handle, p_iov, NB_BLOCKS + !b_src_rawudp )) < 0 )
+        {
+            msg_Err( NULL, "couldn't read from network (%s)",
+                     strerror(errno) );
+            i_len = 0;
+        }
+        if ( !b_src_rawudp )
+            i_len -= RTP_SIZE;
+        i_len /= TS_SIZE;
 
-    if ( *pp_current )
-        msg_Dbg( NULL, "partial buffer received" );
-    block_DeleteChain( *pp_current );
-    *pp_current = NULL;
+        pp_current = &p_ts;
+        while ( i_len && *pp_current )
+        {
+            pp_current = &(*pp_current)->p_next;
+            i_len--;
+        }
+
+        i_wallclock = mdate();
 
-    return p_ts;
+        if ( *pp_current )
+            msg_Dbg( NULL, "partial buffer received" );
+        block_DeleteChain( *pp_current );
+        *pp_current = NULL;
+
+        return p_ts;
+    }
+    return NULL;
 }
 
 /* From now on these are just stubs */