[vlc-devel] [PATCH v6 2/3] access_out:srt: introduce SRT ouput module

Justin Kim justin.kim at collabora.com
Thu Sep 14 11:43:39 CEST 2017


The access_output_srt module is a SRT client to send a stream.

Signed-off-by: Justin Kim <justin.kim at collabora.com>
---
 configure.ac                      |   2 +-
 modules/MODULES_LIST              |   1 +
 modules/access_output/Makefile.am |   8 +
 modules/access_output/srt.c       | 328 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 338 insertions(+), 1 deletion(-)
 create mode 100644 modules/access_output/srt.c

diff --git a/configure.ac b/configure.ac
index 0014629c92..9ad582dd8a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3884,7 +3884,7 @@ AM_CONDITIONAL([HAVE_LIRC], [test "${have_lirc}" = "yes"])
 dnl
 dnl  SRT plugin
 dnl
-PKG_ENABLE_MODULES_VLC([SRT], [access_srt], [srt >= 1.2.0], [SRT input plugin], [auto])
+PKG_ENABLE_MODULES_VLC([SRT], [access_srt access_output_srt], [srt >= 1.2.0], [SRT input/output plugin], [auto])
 
 EXTEND_HELP_STRING([Visualisations and Video filter plugins:])
 dnl
diff --git a/modules/MODULES_LIST b/modules/MODULES_LIST
index 0e117115a7..5fb499eda2 100644
--- a/modules/MODULES_LIST
+++ b/modules/MODULES_LIST
@@ -14,6 +14,7 @@ $Id$
  * access_output_http: HTTP Network access module
  * access_output_livehttp: Live HTTP stream output
  * access_output_shout: Shoutcast access output
+ * access_output_srt: SRT (Secure Reliable Transport) access_output module
  * access_output_udp: UDP Network access_output module
  * access_qtsound: Quicktime Audio Capture
  * access_realrtsp: Real RTSP access
diff --git a/modules/access_output/Makefile.am b/modules/access_output/Makefile.am
index 7c9311646c..bc954ee03b 100644
--- a/modules/access_output/Makefile.am
+++ b/modules/access_output/Makefile.am
@@ -26,3 +26,11 @@ libaccess_output_shout_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(access_outdir
 libaccess_output_shout_plugin_la_LIBADD = $(SHOUT_LIBS) $(SOCKET_LIBS)
 access_out_LTLIBRARIES += $(LTLIBaccess_output_shout)
 EXTRA_LTLIBRARIES += libaccess_output_shout_plugin.la
+
+### SRT ###
+libaccess_output_srt_plugin_la_SOURCES = access_output/srt.c
+libaccess_output_srt_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) $(SRT_CPPFLAGS)
+libaccess_output_srt_plugin_la_LIBADD = $(SRT_LIBS) $(LIBPTHREAD)
+libaccess_output_srt_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(access_outdir)'
+access_out_LTLIBRARIES += $(LTLIBaccess_output_srt)
+EXTRA_LTLIBRARIES += libaccess_output_srt_plugin.la
diff --git a/modules/access_output/srt.c b/modules/access_output/srt.c
new file mode 100644
index 0000000000..cbf431169a
--- /dev/null
+++ b/modules/access_output/srt.c
@@ -0,0 +1,328 @@
+/*****************************************************************************
+ * srt.c: SRT (Secure Reliable Transport) output module
+ *****************************************************************************
+ * Copyright (C) 2017, Collabora Ltd.
+ *
+ * Authors: Justin Kim <justin.kim at collabora.com>
+ *
+ * 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.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <errno.h>
+#include <sys/eventfd.h>
+#include <sys/epoll.h>
+
+#include <vlc_common.h>
+#include <vlc_interrupt.h>
+#include <vlc_plugin.h>
+#include <vlc_sout.h>
+#include <vlc_block.h>
+#include <vlc_network.h>
+
+#include <srt/srt.h>
+
+/* libsrt defines default packet size as 1316 internally
+ * so srt module takes same value. */
+#define SRT_DEFAULT_CHUNK_SIZE 1316
+/* libsrt tutorial uses 9000 as a default binding port */
+#define SRT_DEFAULT_PORT 9000
+/* The default timeout is -1 (infinite) */
+#define SRT_DEFAULT_POLL_TIMEOUT 100
+
+struct sout_access_out_sys_t
+{
+    SRTSOCKET     sock;
+    int           i_poll_id;
+    int           i_poll_timeout;
+    size_t        i_chunk_size;
+    int           i_event_fd;
+
+    vlc_mutex_t   lock;
+};
+
+static void srt_wait_interrupted(void *p_data)
+{
+    sout_access_out_t *p_access = p_data;
+    sout_access_out_sys_t *p_sys = p_access->p_sys;
+    vlc_mutex_lock( &p_sys->lock );
+    msg_Dbg( p_access, "Waking up srt_epoll_wait");
+    if ( write( p_sys->i_event_fd, &( bool ) { true }, sizeof( bool ) ) < 0 )
+    {
+        msg_Err( p_access, "Failed to send data to event fd");
+    }
+    vlc_mutex_unlock( &p_sys->lock );
+}
+
+
+
+static ssize_t Write( sout_access_out_t *p_access, block_t *p_buffer )
+{
+    sout_access_out_sys_t *p_sys = p_access->p_sys;
+    int i_len = 0;
+
+    vlc_interrupt_register( srt_wait_interrupted, p_access);
+    vlc_mutex_lock( &p_sys->lock );
+
+    while( p_buffer )
+    {
+        block_t *p_next;
+
+        i_len += p_buffer->i_buffer;
+
+        while( p_buffer->i_buffer )
+        {
+            size_t i_write = __MIN( p_buffer->i_buffer, p_sys->i_chunk_size );
+            SRTSOCKET ready[2];
+
+            struct epoll_event event[1] = { 0 };
+retry:
+            if ( srt_epoll_wait( p_sys->i_poll_id,
+                0, 0, ready, &(int){ 2 }, p_sys->i_poll_timeout,
+                &(int) { p_sys->i_event_fd }, &(int) { 1 }, 0, 0 ) == -1 )
+            {
+                /* Assuming that timeout error is normal when SRT socket is connected. */
+                if ( srt_getlasterror( NULL ) == SRT_ETIMEOUT && srt_getsockstate( p_sys->sock ) == SRTS_CONNECTED )
+                {
+                    srt_clearlasterror();
+                    goto retry;
+                }
+                
+                i_len = VLC_EGENERIC;
+                goto out;
+            }
+
+            if ( event[0].events & EPOLLIN )
+            {
+                bool cancel = 0;
+                int ret = read( event[0].data.fd, &cancel, sizeof( bool ) );
+                if ( ret < 0 )
+                {
+                    goto retry;
+                }
+
+                if ( cancel )
+                {
+                    msg_Dbg( p_access, "Cancelled running" );
+                    i_len = 0;
+                    goto out;
+                }
+            }
+
+            if ( srt_sendmsg2( p_sys->sock, (char *)p_buffer->p_buffer, i_write, 0 ) == SRT_ERROR )
+                msg_Warn( p_access, "send error: %s", srt_getlasterror_str() );
+
+            p_buffer->p_buffer += i_write;
+            p_buffer->i_buffer -= i_write;
+        }
+
+        p_next = p_buffer->p_next;
+        block_Release( p_buffer );
+        p_buffer = p_next;
+    }
+
+out:
+    vlc_mutex_unlock( &p_sys->lock );
+    vlc_interrupt_unregister();
+    if ( i_len <= 0 ) block_ChainRelease( p_buffer );
+    return i_len;
+}
+
+static int Control( sout_access_out_t *p_access, int i_query, va_list args )
+{
+    sout_access_out_sys_t *p_sys = p_access->p_sys;
+    int i_ret = VLC_SUCCESS;
+
+    vlc_mutex_lock( &p_sys->lock );
+
+    switch( i_query )
+    {
+        case ACCESS_OUT_CONTROLS_PACE:
+            *va_arg( args, bool * ) = false;
+            break;
+
+        default:
+            i_ret = VLC_EGENERIC;
+            break;
+    }
+
+    vlc_mutex_unlock( &p_sys->lock );
+
+    return i_ret;
+}
+
+static int Open( vlc_object_t *p_this )
+{
+    sout_access_out_t       *p_access = (sout_access_out_t*)p_this;
+    sout_access_out_sys_t   *p_sys = NULL;
+
+    char                    *psz_dst_addr = NULL;
+    int                      i_dst_port;
+    int                      stat;
+
+    struct addrinfo hints = {
+        .ai_socktype = SOCK_DGRAM,
+    }, *res = NULL;
+ 
+    if (var_Create ( p_access, "dst-port", VLC_VAR_INTEGER )
+     || var_Create ( p_access, "src-port", VLC_VAR_INTEGER )
+     || var_Create ( p_access, "dst-addr", VLC_VAR_STRING )
+     || var_Create ( p_access, "src-addr", VLC_VAR_STRING ) )
+    {
+         msg_Err( p_access, "Valid network information is required." );
+        return VLC_ENOMEM;
+    }
+
+    if( !( p_sys = malloc ( sizeof( *p_sys ) ) ) )
+        return VLC_ENOMEM;
+
+    p_sys->i_chunk_size = var_InheritInteger( p_access, "chunk-size" );
+    p_sys->i_poll_timeout = var_InheritInteger( p_access, "poll-timeout" );
+    p_sys->i_poll_id = -1;
+    p_sys->i_event_fd = -1;
+
+    vlc_mutex_init( &p_sys->lock );
+
+    p_access->p_sys = p_sys;
+
+
+    i_dst_port = SRT_DEFAULT_PORT;
+    char *psz_parser = psz_dst_addr = strdup( p_access->psz_path );
+    if( !psz_dst_addr )
+    {
+        free( p_sys );
+        return VLC_ENOMEM;
+    }
+
+    if (psz_parser[0] == '[')
+        psz_parser = strchr (psz_parser, ']');
+
+    psz_parser = strchr (psz_parser ? psz_parser : psz_dst_addr, ':');
+    if (psz_parser != NULL)
+    {
+        *psz_parser++ = '\0';
+        i_dst_port = atoi (psz_parser);
+    }
+
+    msg_Dbg( p_access, "Setting SRT socket (dest addresss: %s, port: %d).",
+             psz_dst_addr, i_dst_port );
+
+    stat = vlc_getaddrinfo( psz_dst_addr, i_dst_port, &hints, &res );
+    if ( stat )
+    {
+        msg_Err( p_access, "Cannot resolve [%s]:%d (reason: %s)",
+                 psz_dst_addr,
+                 i_dst_port,
+                 gai_strerror( stat ) );
+            
+        goto failed;
+    }
+
+    p_sys->sock = srt_socket( res->ai_family, SOCK_DGRAM, 0 );
+    if ( p_sys->sock == SRT_ERROR )
+    {
+        msg_Err( p_access, "Failed to open socket." );
+        goto failed;
+    }
+
+    /* Make SRT non-blocking */
+    srt_setsockopt( p_sys->sock, 0, SRTO_SNDSYN, &(bool) { false }, sizeof( bool ) );
+    p_sys->i_poll_id = srt_epoll_create();
+    if ( p_sys->i_poll_id == -1 )
+    {
+        msg_Err( p_access, "Failed to create poll id for SRT socket (reason: %s)",
+                 srt_getlasterror_str() );
+
+        goto failed;
+    }
+
+    srt_epoll_add_usock( p_sys->i_poll_id, p_sys->sock, &(int) { SRT_EPOLL_OUT });
+    srt_setsockopt( p_sys->sock, 0, SRTO_SENDER, &(int) { 1 }, sizeof(int) );
+
+    p_sys->i_event_fd = eventfd( 0, EFD_NONBLOCK );
+    srt_epoll_add_ssock( p_sys->i_poll_id, p_sys->i_event_fd, &(int) { EPOLLIN } );
+
+    stat = srt_connect( p_sys->sock, res->ai_addr, sizeof (struct sockaddr));
+    if ( stat == SRT_ERROR )
+    {
+        msg_Err( p_access, "Failed to connect to server (reason: %s)",
+                 srt_getlasterror_str() );
+        goto failed;
+    } 
+
+    p_access->pf_write = Write;
+    p_access->pf_control = Control;
+
+    free( psz_dst_addr );
+    freeaddrinfo( res );
+
+    return VLC_SUCCESS;
+
+failed:
+    if ( psz_dst_addr != NULL)
+        free( psz_dst_addr );
+
+    if ( res != NULL )
+        freeaddrinfo( res );
+
+    if ( p_sys != NULL )
+    {
+        if ( p_sys->i_poll_id != -1 ) srt_epoll_release( p_sys->i_poll_id );
+        if ( p_sys->sock != -1 ) srt_close( p_sys->sock );
+        if ( p_sys->i_event_fd != -1 ) close( p_sys->i_event_fd );
+
+        free( p_sys );
+    }
+
+    return VLC_EGENERIC;
+}
+
+static void Close( vlc_object_t * p_this )
+{
+    sout_access_out_t     *p_access = (sout_access_out_t*)p_this;
+    sout_access_out_sys_t *p_sys = p_access->p_sys;
+
+    srt_epoll_release( p_sys->i_poll_id );
+    srt_close( p_sys->sock );
+
+    if ( p_sys->i_event_fd != -1 )
+    {
+        close( p_sys->i_event_fd );
+        p_sys->i_event_fd = -1;
+    }
+
+    vlc_mutex_destroy( &p_sys->lock );
+
+    free( p_sys );
+}
+
+/* Module descriptor */
+vlc_module_begin()
+    set_shortname( N_("SRT") )
+    set_description( N_("SRT stream output") )
+    set_category( CAT_SOUT )
+    set_subcategory( SUBCAT_SOUT_ACO )
+
+    add_integer( "chunk-size", SRT_DEFAULT_CHUNK_SIZE, N_("SRT chunk size (bytes)"), NULL, true )
+    add_integer( "poll-timeout", SRT_DEFAULT_POLL_TIMEOUT, N_("Return poll wait after timeout miliseconds (-1 = infinite)"), NULL, true )
+
+    set_capability( "sout access", 0 )
+    add_shortcut( "srt" )
+
+    set_callbacks( Open, Close )
+vlc_module_end ()
-- 
2.14.1



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