[vlc-devel] [PATCH 4/4] chromecast: add an experimental sout module that connects to a ChromeCast device and streams using the HTTP access output

Adrien Maglo magsoft at videolan.org
Thu Aug 28 09:08:35 CEST 2014


Signed-off-by: Jean-Baptiste Kempf <jb at videolan.org>
---
 configure.ac                           |   3 +-
 modules/stream_out/Modules.am          |  15 +
 modules/stream_out/chromecast/cast.cpp | 892 +++++++++++++++++++++++++++++++++
 3 files changed, 909 insertions(+), 1 deletion(-)
 create mode 100644 modules/stream_out/chromecast/cast.cpp

diff --git a/configure.ac b/configure.ac
index a71055e..7389849 100644
--- a/configure.ac
+++ b/configure.ac
@@ -78,6 +78,7 @@ AM_PROG_AS
 AC_ARG_VAR([DESKTOP_FILE_VALIDATE], [Validator for desktop entry files])
 AC_CHECK_PROGS(DESKTOP_FILE_VALIDATE, [${DESKTOP_FILE_VALIDATE} desktop-file-validate], :)
 AC_CHECK_PROGS(YASM, yasm)
+AC_CHECK_PROGS(PROTOC, protoc)
 
 dnl Check for compiler properties
 AC_C_CONST
@@ -637,7 +638,7 @@ AC_CHECK_FUNCS([if_nameindex if_nametoindex])
 VLC_RESTORE_FLAGS
 
 AS_IF([test -n "$SOCKET_LIBS"], [
-  VLC_ADD_LIBS([access_rtmp access_output_shout sap stream_out_standard stream_out_rtp stream_out_raop vod_rtsp oldrc netsync ts remoteosd audiobargraph_a],[${SOCKET_LIBS}])
+  VLC_ADD_LIBS([access_rtmp access_output_shout sap stream_out_standard stream_out_rtp stream_out_raop stream_out_chromecast vod_rtsp oldrc netsync ts remoteosd audiobargraph_a],[${SOCKET_LIBS}])
 ])
 AC_SUBST(SOCKET_LIBS)
 
diff --git a/modules/stream_out/Modules.am b/modules/stream_out/Modules.am
index d307c34..bed5889 100644
--- a/modules/stream_out/Modules.am
+++ b/modules/stream_out/Modules.am
@@ -69,3 +69,18 @@ BUILT_SOURCES += dummy.cpp
 
 dummy.cpp:
 	touch dummy.cpp
+
+# Chromecast plugin
+SUFFIXES += .proto .pb.cc
+BUILT_SOURCES += chromecast/cast_channel.pb.cc
+
+.proto.pb.cc:
+	$(PROTOC) --cpp_out=. -I$(srcdir) $<
+
+libstream_out_chromecast_plugin_la_SOURCES = chromecast/cast_channel.proto chromecast/cast.cpp
+nodist_libstream_out_chromecast_plugin_la_SOURCES = chromecast/cast_channel.pb.cc
+libstream_out_chromecast_plugin_la_CPPFLAGS = $(AM_CPPFLAGS)
+libstream_out_chromecast_plugin_la_CXXFLAGS = $(AM_CFLAGS) -I/home/jb/VideoLAN/dev/vlc/build/modules/stream_out/chromecast
+libstream_out_chromecast_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(stream_outdir)'
+libstream_out_chromecast_plugin_la_LIBADD = -lprotobuf-lite -ljsoncpp $(LIBS_stream_out_chromecast)
+stream_out_LTLIBRARIES += libstream_out_chromecast_plugin.la
diff --git a/modules/stream_out/chromecast/cast.cpp b/modules/stream_out/chromecast/cast.cpp
new file mode 100644
index 0000000..1bce71d
--- /dev/null
+++ b/modules/stream_out/chromecast/cast.cpp
@@ -0,0 +1,892 @@
+/*****************************************************************************
+ * cast.cpp: Chromecast module for vlc
+ *****************************************************************************
+ * Copyright © 2014 VideoLAN
+ *
+ * Authors: Jean-Baptiste Kempf <jb at videolan.org>
+ *          Adrien Maglo <magsoft at videolan.org>
+ *
+ * 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
+
+#ifdef HAVE_POLL
+# include <poll.h>
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_sout.h>
+#include <vlc_tls.h>
+#include <vlc_url.h>
+#include <vlc_threads.h>
+#include <vlc_atomic.h>
+
+#include <errno.h>
+
+#include <iostream>
+#include <sstream>
+#include <queue>
+
+#include <google/protobuf/io/zero_copy_stream_impl.h>
+#include <google/protobuf/io/coded_stream.h>
+#include "cast_channel.pb.h"
+
+#include <json/json.h>
+
+using namespace google::protobuf::io;
+using namespace std;
+using namespace castchannel;
+
+// Status
+enum
+{
+    CHROMECAST_DISCONNECTED,
+    CHROMECAST_TLS_CONNECTED,
+    CHROMECAST_AUTHENTICATED,
+    CHROMECAST_APP_STARTED,
+    CHROMECAST_CONNECTION_DEAD,
+};
+
+#define PACKET_MAX_LEN 10 * 1024
+#define PACKET_HEADER_LEN 4
+
+struct sout_stream_sys_t
+{
+    sout_stream_sys_t()
+        : i_received(0), i_status(CHROMECAST_DISCONNECTED),
+          b_threadStarted(false), b_pingSent(false),
+          p_out(NULL)
+    {
+        atomic_init(&ab_error, false);
+    }
+
+    string serverIP;
+
+    int i_sock_fd;
+    vlc_tls_creds_t *p_creds;
+    vlc_tls_t *p_tls;
+
+    vlc_thread_t chromecastThread;
+
+    unsigned i_received;
+    char p_packet[PACKET_MAX_LEN];
+    unsigned i_requestId;
+    string appTransportId;
+
+    queue<CastMessage> messagesToSend;
+
+    int i_status;
+    bool b_threadStarted;
+    bool b_pingSent;
+    atomic_bool ab_error;
+    vlc_mutex_t loadCommandMutex;
+    vlc_cond_t loadCommandCond;
+
+    sout_stream_t *p_out;
+};
+
+// Media player Chromecast app id
+#define APP_ID "CC1AD845" // Default media player
+//#define APP_ID "698A9477"
+#define CHROMECAST_CONTROL_PORT 8009 // Chromecast control port
+
+#define SOUT_CFG_PREFIX "sout-chromecast-"
+
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int Open(vlc_object_t *);
+static void Close(vlc_object_t *);
+static void clean(sout_stream_sys_t *p_sys);
+static int connectChromecast(sout_stream_t *p_stream, char *psz_ipChromecast);
+static void disconnectChromecast(sout_stream_t *p_stream);
+static int sendMessages(sout_stream_t *p_stream);
+
+static void msgAuth(sout_stream_t *p_stream);
+static void msgPing(sout_stream_t *p_stream);
+static void msgPong(sout_stream_t *p_stream);
+static void msgConnect(sout_stream_t *p_stream, string destinationId);
+static void msgClose(sout_stream_t *p_stream, string destinationId);
+static void msgLaunch(sout_stream_t *p_stream);
+static void msgLoad(sout_stream_t *p_stream);
+
+static void *chromecastThread(void *data);
+
+static string JsonToString(Json::Value data);
+static Json::Value StringToJson(string str);
+
+static const char *const ppsz_sout_options[] = {
+    "receiver-ip", "sender-ip", "mux", "mime", NULL
+};
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+
+#define RECEIVER_IP_TEXT N_("Chromecast IP address")
+#define RECEIVER_IP_LONGTEXT N_("This sets the ip adress of the Chromecast receiver.")
+#define SENDER_IP_TEXT N_("Sender IP address")
+#define SENDER_IP_LONGTEXT N_("This sets the ip address that the Chromecast" \
+                              "will use to connect to HTTP stream.")
+#define MUX_TEXT N_("Muxer")
+#define MUX_LONGTEXT N_("This sets the muxer used to stream to the Chromecast.")
+#define MIME_TEXT N_("Mime type")
+#define MIME_LONGTEXT N_("This sets the media mine type sent to the Chromecast.")
+
+vlc_module_begin ()
+
+    set_shortname(N_("Chromecast"))
+    set_description(N_("Chromecast stream output"))
+    set_capability("sout stream", 0)
+    add_shortcut("chromecast")
+    set_category(CAT_SOUT)
+    set_subcategory(SUBCAT_SOUT_STREAM)
+    set_callbacks(Open, Close)
+
+    add_string(SOUT_CFG_PREFIX "receiver-ip", "", RECEIVER_IP_TEXT, RECEIVER_IP_LONGTEXT, false)
+    add_string(SOUT_CFG_PREFIX "sender-ip", "", SENDER_IP_TEXT, SENDER_IP_LONGTEXT, false)
+    add_string(SOUT_CFG_PREFIX "mux", "avformat{mux=mp4}", MUX_TEXT, MUX_LONGTEXT, false)
+    add_string(SOUT_CFG_PREFIX "mime", "video/mp4", MIME_TEXT, MIME_LONGTEXT, false)
+
+vlc_module_end ()
+
+
+/*****************************************************************************
+ * Sout callbacks
+ *****************************************************************************/
+static sout_stream_id_sys_t *Add(sout_stream_t *p_stream, es_format_t *p_fmt)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+    return p_sys->p_out->pf_add(p_sys->p_out, p_fmt);
+}
+
+
+static int Del(sout_stream_t *p_stream, sout_stream_id_sys_t *id)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+    return p_sys->p_out->pf_del(p_sys->p_out, id);
+}
+
+
+static int Send(sout_stream_t *p_stream, sout_stream_id_sys_t *id,
+                block_t *p_buffer)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+    if (atomic_load(&p_sys->ab_error))
+        return VLC_EGENERIC;
+
+    return p_sys->p_out->pf_send(p_sys->p_out, id, p_buffer);
+}
+
+
+/*****************************************************************************
+ * Open: connect to the Chromecast and initialize the sout
+ *****************************************************************************/
+static int Open(vlc_object_t *p_this)
+{
+    sout_stream_t *p_stream = (sout_stream_t*)p_this;
+    sout_stream_sys_t *p_sys;
+    p_sys = new(nothrow) sout_stream_sys_t();
+    if (p_sys == NULL)
+        return VLC_ENOMEM;
+    p_stream->p_sys = p_sys;
+
+    config_ChainParse(p_stream, SOUT_CFG_PREFIX, ppsz_sout_options, p_stream->p_cfg);
+
+    char *psz_ipLocal = var_GetNonEmptyString(p_stream, SOUT_CFG_PREFIX "sender-ip");
+    if (psz_ipLocal == NULL)
+    {
+        msg_Err(p_stream, "No sender IP provided");
+        clean(p_sys);
+        return VLC_EGENERIC;
+    }
+    p_sys->serverIP = psz_ipLocal;
+    free(psz_ipLocal);
+
+    char *psz_ipChromecast = var_GetNonEmptyString(p_stream, SOUT_CFG_PREFIX "receiver-ip");
+    if (psz_ipChromecast == NULL)
+    {
+        msg_Err(p_stream, "No Chromecast receiver IP provided");
+        clean(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    p_sys->i_sock_fd = connectChromecast(p_stream, psz_ipChromecast);
+    free(psz_ipChromecast);
+    if (p_sys->i_sock_fd < 0)
+    {
+        msg_Err(p_stream, "Could not connect the Chromecast");
+        clean(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    char *psz_mux = var_GetNonEmptyString(p_stream, SOUT_CFG_PREFIX "mux");
+    char *psz_chain = NULL;
+    int i_bytes = asprintf(&psz_chain, "http{dst=:8009/stream,mux=%s}", psz_mux);
+    free(psz_mux);
+    if (i_bytes < 0)
+    {
+        clean(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    p_sys->p_out = sout_StreamChainNew(p_stream->p_sout, psz_chain, NULL, NULL);
+    free(psz_chain);
+    if (p_sys->p_out == NULL)
+    {
+        clean(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    vlc_mutex_init(&p_sys->loadCommandMutex);
+    vlc_cond_init(&p_sys->loadCommandCond);
+
+    // Start the Chromecast event thread.
+    if (vlc_clone(&p_sys->chromecastThread, chromecastThread, p_stream,
+                  VLC_THREAD_PRIORITY_LOW))
+    {
+        msg_Err(p_stream, "Could not start the Chromecast talking thread");
+        clean(p_sys);
+        return VLC_EGENERIC;
+    }
+
+    p_sys->b_threadStarted = true;
+
+    /* Ugly part:
+     * We want to be sure that the Chromecast receives the first data packet sent by
+     * the HTTP server. */
+
+    // Lock the sout thread until we have sent the media loading command to the Chromecast.
+    vlc_mutex_lock(&p_sys->loadCommandMutex);
+    const mtime_t deadline = mdate() + 6000 * 1000;
+    int i_ret = vlc_cond_timedwait(&p_sys->loadCommandCond, &p_sys->loadCommandMutex, deadline);
+    if (i_ret == ETIMEDOUT)
+    {
+        msg_Err(p_stream, "Timeout reached before sending the media loading command");
+        vlc_mutex_unlock(&p_sys->loadCommandMutex);
+        clean(p_sys);
+        return VLC_EGENERIC;
+    }
+    vlc_mutex_unlock(&p_sys->loadCommandMutex);
+
+    /* Even uglier: sleep more to let to the Chromecast initiate the connection
+     * to the http server. */
+    msleep(2000 * 1000);
+
+    // Set the sout callbacks.
+    p_stream->pf_add    = Add;
+    p_stream->pf_del    = Del;
+    p_stream->pf_send   = Send;
+
+    return VLC_SUCCESS;
+}
+
+
+/*****************************************************************************
+ * Close: destroy interface
+ *****************************************************************************/
+static void Close(vlc_object_t *p_this)
+{
+    sout_stream_t *p_stream = (sout_stream_t *)p_this;
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    if (p_sys->b_threadStarted)
+    {
+        vlc_cancel(p_sys->chromecastThread);
+        vlc_join(p_sys->chromecastThread, NULL);
+    }
+
+    // Generate the close messages.
+    if (p_sys->i_status == CHROMECAST_APP_STARTED)
+    {
+        msgClose(p_stream, p_sys->appTransportId);
+        p_sys->i_status = CHROMECAST_AUTHENTICATED;
+    }
+
+    if (p_sys->i_status == CHROMECAST_AUTHENTICATED)
+    {
+        msgClose(p_stream, "receiver-0");
+        p_sys->i_status = CHROMECAST_TLS_CONNECTED;
+    }
+
+    // Send the just added close messages.
+    sendMessages(p_stream);
+
+    if (p_sys->i_status == CHROMECAST_TLS_CONNECTED)
+    {
+        disconnectChromecast(p_stream);
+        p_sys->i_status = CHROMECAST_DISCONNECTED;
+    }
+
+    clean(p_sys);
+}
+
+
+/**
+ * @brief Clean and release the variables in a sout_stream_sys_t structure
+ */
+static void clean(sout_stream_sys_t *p_sys)
+{
+    if (p_sys->p_out)
+    {
+        vlc_mutex_destroy(&p_sys->loadCommandMutex);
+        vlc_cond_destroy(&p_sys->loadCommandCond);
+        sout_StreamChainDelete(p_sys->p_out, p_sys->p_out);
+    }
+
+    delete p_sys;
+}
+
+
+/**
+ * @brief Connect to the Chromecast
+ * @param p_stream the sout_stream_t structure
+ * @return the opened socket file descriptor or -1 on error
+ */
+static int connectChromecast(sout_stream_t *p_stream, char *psz_ipChromecast)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+    int fd = net_ConnectTCP(p_stream, psz_ipChromecast, CHROMECAST_CONTROL_PORT);
+    if (fd < 0)
+        return -1;
+
+    p_sys->p_creds = vlc_tls_ClientCreate(VLC_OBJECT(p_stream));
+    if (p_sys->p_creds == NULL)
+        return -1;
+
+    p_sys->p_tls = vlc_tls_ClientSessionCreate(p_sys->p_creds, fd, psz_ipChromecast,
+                                               "tcps", NULL, NULL);
+
+    if (p_sys->p_tls == NULL)
+    {
+        vlc_tls_Delete(p_sys->p_creds);
+        return -1;
+    }
+
+    p_sys->i_status = CHROMECAST_TLS_CONNECTED;
+    return fd;
+}
+
+
+/**
+ * @brief Disconnect from the Chromecast
+ */
+static void disconnectChromecast(sout_stream_t *p_stream)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    vlc_tls_SessionDelete(p_sys->p_tls);
+    vlc_tls_Delete(p_sys->p_creds);
+}
+
+
+/**
+ * @brief Send a message to the Chromecast
+ * @param p_stream the sout_stream_t structure
+ * @param msg the CastMessage to send
+ * @return the number of bytes sent or -1 on error
+ */
+static int sendMessage(sout_stream_t *p_stream, CastMessage &msg)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    uint32_t i_size = msg.ByteSize();
+    uint32_t i_sizeNetwork = hton32(i_size);
+
+    char p_data[PACKET_HEADER_LEN + i_size];
+    memcpy(p_data, (char *)&i_sizeNetwork, PACKET_HEADER_LEN);
+    msg.SerializeWithCachedSizesToArray((uint8_t *)(p_data + PACKET_HEADER_LEN));
+
+    return tls_Send(p_sys->p_tls, p_data, sizeof(p_data));
+}
+
+
+/**
+ * @brief Send all the messages in the pending queue to the Chromecast
+ * @param p_stream the sout_stream_t structure
+ * @param msg the CastMessage to send
+ * @return the number of bytes sent or -1 on error
+ */
+static int sendMessages(sout_stream_t *p_stream)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    int i_ret = 0;
+    while (!p_sys->messagesToSend.empty())
+    {
+        unsigned i_retSend = sendMessage(p_stream, p_sys->messagesToSend.front());
+        if (i_retSend <= 0)
+            return i_retSend;
+
+        p_sys->messagesToSend.pop();
+        i_ret += i_retSend;
+    }
+
+    return i_ret;
+}
+
+
+/**
+ * @brief Receive a data packet from the Chromecast
+ * @param p_stream the sout_stream_t structure
+ * @param b_msgReceived returns true if a message has been entirely received else false
+ * @param i_payloadSize returns the payload size of the message received
+ * @return the number of bytes received of -1 on error
+ */
+static int recvPacket(sout_stream_t *p_stream, bool &b_msgReceived,
+                      uint32_t &i_payloadSize)
+{
+    // Use here only C linkage and POD types as this function is a cancelation point.
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+    struct pollfd ufd[1];
+    ufd[0].fd = p_sys->i_sock_fd;
+    ufd[0].events = POLLIN;
+
+    mtime_t deadline = mdate();
+    deadline += 6 * 1000 * 1000; // 6 seconds
+
+    mtime_t now = mdate();
+    if (now > deadline)
+        now = deadline;
+
+    /* The Chromecast normally sends a PING command every 5 seconds or so.
+     * If we do not receive one after 6 seconds, we send a PING.
+     * If after this PING, we do not receive a PONG, then we consider the
+     * connection as dead. */
+    if (poll(ufd, 1, (deadline - now) / 1000) == 0)
+    {
+        if (p_sys->b_pingSent)
+        {
+            msg_Err(p_stream, "No PONG answer received from the Chromecast");
+            return 0; // Connection died
+        }
+        msg_Warn(p_stream, "No PING received from the Chromecast, sending a PING");
+        msgPing(p_stream);
+        p_sys->b_pingSent = true;
+        return -1;
+    }
+
+    p_sys->b_pingSent = false;
+    char *p_data = p_sys->p_packet;
+    int i_ret;
+
+    /* Packet structure:
+     * +------------------------------------+------------------------------+
+     * | Payload size (uint32_t big endian) |         Payload data         |
+     * +------------------------------------+------------------------------+ */
+    if (p_sys->i_received < PACKET_HEADER_LEN)
+    {
+        // We receive the header.
+        i_ret = tls_Recv(p_sys->p_tls, p_data, PACKET_HEADER_LEN - p_sys->i_received);
+        if (i_ret <= 0)
+            return i_ret;
+        p_sys->i_received += i_ret;
+    }
+    else
+    {
+        // We receive the payload.
+
+        // Get the size of the payload
+        memcpy(&i_payloadSize, p_data, PACKET_HEADER_LEN);
+        i_payloadSize = hton32(i_payloadSize);
+        const uint32_t i_maxPayloadSize = PACKET_MAX_LEN - PACKET_HEADER_LEN;
+
+        if (i_payloadSize > i_maxPayloadSize)
+        {
+            // Error case: the packet sent by the Chromecast is too long: we drop it.
+            msg_Err(p_stream, "Packet too long: droping its data");
+
+            uint32_t i_size = i_payloadSize - (p_sys->i_received - PACKET_HEADER_LEN);
+            if (i_size > i_maxPayloadSize)
+                i_size = i_maxPayloadSize;
+
+            i_ret = tls_Recv(p_sys->p_tls, p_data + PACKET_HEADER_LEN, i_size);
+            if (i_ret <= 0)
+                return i_ret;
+            p_sys->i_received += i_ret;
+
+            if (p_sys->i_received < i_payloadSize + PACKET_HEADER_LEN)
+                return i_ret;
+
+            p_sys->i_received = 0;
+            return -1;
+        }
+
+        // Normal case
+        i_ret = tls_Recv(p_sys->p_tls, p_data + p_sys->i_received,
+                         i_payloadSize - (p_sys->i_received - PACKET_HEADER_LEN));
+        if (i_ret <= 0)
+            return i_ret;
+        p_sys->i_received += i_ret;
+
+        if (p_sys->i_received < i_payloadSize + PACKET_HEADER_LEN)
+            return i_ret;
+
+        assert(p_sys->i_received == i_payloadSize + PACKET_HEADER_LEN);
+        p_sys->i_received = 0;
+        b_msgReceived = true;
+        return i_ret;
+    }
+
+    return i_ret;
+}
+
+
+/**
+ * @brief Process a message received from the Chromecast
+ * @param p_stream the sout_stream_t structure
+ * @param msg the CastMessage to process
+ * @return 0 if the message has been successfuly processed else -1
+ */
+static int processMessage(sout_stream_t *p_stream, CastMessage &msg)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+    string namespace_ = msg.namespace_();
+
+    if (namespace_ == "urn:x-cast:com.google.cast.tp.deviceauth")
+    {
+        DeviceAuthMessage authMessage;
+        authMessage.ParseFromString(msg.payload_binary());
+
+        if (authMessage.has_error())
+        {
+            msg_Err(p_stream, "Authentification error: %d", authMessage.error().error_type());
+            return -1;
+        }
+
+        if (!authMessage.has_response()) {
+            msg_Err(p_stream, "Authentification message has no response field");
+            return -1;
+        }
+
+        p_sys->i_status = CHROMECAST_AUTHENTICATED;
+        msgConnect(p_stream, "receiver-0");
+        msgLaunch(p_stream);
+    }
+    else if (namespace_ == "urn:x-cast:com.google.cast.tp.heartbeat")
+    {
+        Json::Value data = StringToJson(msg.payload_utf8());
+        string type = data.get("type", "none").asString();
+
+        if (type == "PING")
+        {
+            msg_Dbg(p_stream, "PING received from the Chromecast");
+            msgPong(p_stream);
+        }
+        else if (type == "PONG")
+        {
+            msg_Dbg(p_stream, "PONG received from the Chromecast");
+        }
+        else
+        {
+            msg_Err(p_stream, "Heartbeat command not supported");
+            return -1;
+        }
+    }
+    else if (namespace_ == "urn:x-cast:com.google.cast.receiver")
+    {
+        Json::Value data = StringToJson(msg.payload_utf8());
+        string type = data.get("type", "none").asString();
+
+        if (type == "RECEIVER_STATUS")
+        {
+            Json::Value status = data["status"];
+            Json::Value applications = status["applications"];
+            for (unsigned i = 0; i < applications.size(); ++i)
+            {
+                string appId = applications[i]["appId"].asString();
+                if (appId == APP_ID)
+                    p_sys->appTransportId = applications[i]["transportId"].asString();
+            }
+            if (p_sys->appTransportId != ""
+                && p_sys->i_status == CHROMECAST_AUTHENTICATED)
+            {
+                p_sys->i_status = CHROMECAST_APP_STARTED;
+                msgConnect(p_stream, p_sys->appTransportId);
+                msgLoad(p_stream);
+            }
+        }
+        else
+        {
+            msg_Err(p_stream, "Receiver command not supported: %s",
+                    msg.payload_utf8().c_str());
+            return -1;
+        }
+    }
+    else if (namespace_ == "urn:x-cast:com.google.cast.media")
+    {
+        Json::Value data = StringToJson(msg.payload_utf8());
+        string type = data.get("type", "none").asString();
+
+        if (type == "MEDIA_STATUS")
+        {
+            Json::Value status = data["status"];
+            msg_Dbg(p_stream, "Player state: %s",
+                    status[0u]["playerState"].asString().c_str());
+        }
+        else if (type == "LOAD_FAILED")
+        {
+            msg_Err(p_stream, "Media load failed");
+            atomic_store(&p_sys->ab_error, true);
+        }
+        else
+        {
+            msg_Err(p_stream, "Media command not supported: %s",
+                    msg.payload_utf8().c_str());
+            return -1;
+        }
+    }
+    else
+    {
+        msg_Err(p_stream, "Unknown namespace: %s", msg.namespace_().c_str());
+        return -1;
+    }
+
+    return 0;
+}
+
+
+/**
+ * @brief Build a CastMessage to send to the Chromecast
+ * @param namespace_ the message namespace
+ * @param payloadType the payload type (CastMessage_PayloadType_STRING or
+ * CastMessage_PayloadType_BINARY
+ * @param payload the payload
+ * @param destinationId the destination idenifier
+ * @return the generated CastMessage
+ */
+static CastMessage buildMessage(string namespace_,
+                                castchannel::CastMessage_PayloadType payloadType,
+                                string payload, string destinationId = "receiver-0")
+{
+    CastMessage msg;
+
+    msg.set_protocol_version(CastMessage_ProtocolVersion_CASTV2_1_0);
+    msg.set_namespace_(namespace_);
+    msg.set_payload_type(payloadType);
+    msg.set_source_id("sender-vlc");
+    msg.set_destination_id(destinationId);
+    if (payloadType == CastMessage_PayloadType_STRING)
+        msg.set_payload_utf8(payload);
+    else // CastMessage_PayloadType_BINARY
+        msg.set_payload_binary(payload);
+
+    return msg;
+}
+
+
+/*****************************************************************************
+ * String-JSON conversion
+ *****************************************************************************/
+static string JsonToString(Json::Value data)
+{
+    Json::FastWriter writer;
+    return writer.write(data);
+}
+
+
+static Json::Value StringToJson(string str)
+{
+    Json::Reader reader;
+    Json::Value data;
+    reader.parse(str, data);
+    return data;
+}
+
+
+/*****************************************************************************
+ * Message preparation
+ *****************************************************************************/
+static void msgAuth(sout_stream_t *p_stream)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    DeviceAuthMessage authMessage;
+    authMessage.mutable_challenge();
+    std::string authMessageString;
+    authMessage.SerializeToString(&authMessageString);
+
+    CastMessage msg = buildMessage("urn:x-cast:com.google.cast.tp.deviceauth",
+        CastMessage_PayloadType_BINARY, authMessageString);
+
+    p_sys->messagesToSend.push(msg);
+}
+
+
+static void msgPing(sout_stream_t *p_stream)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    Json::Value data;
+    data["type"] = "PING";
+
+    CastMessage msg = buildMessage("urn:x-cast:com.google.cast.tp.heartbeat",
+        CastMessage_PayloadType_STRING, JsonToString(data));
+
+    p_sys->messagesToSend.push(msg);
+}
+
+
+static void msgPong(sout_stream_t *p_stream)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    Json::Value data;
+    data["type"] = "PONG";
+
+    CastMessage msg = buildMessage("urn:x-cast:com.google.cast.tp.heartbeat",
+        CastMessage_PayloadType_STRING, JsonToString(data));
+
+    p_sys->messagesToSend.push(msg);
+}
+
+
+static void msgConnect(sout_stream_t *p_stream, string destinationId)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    Json::Value data;
+    data["type"] = "CONNECT";
+
+    CastMessage msg = buildMessage("urn:x-cast:com.google.cast.tp.connection",
+        CastMessage_PayloadType_STRING, JsonToString(data), destinationId);
+
+    p_sys->messagesToSend.push(msg);
+}
+
+
+static void msgClose(sout_stream_t *p_stream, string destinationId)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    Json::Value data;
+    data["type"] = "CLOSE";
+
+    CastMessage msg = buildMessage("urn:x-cast:com.google.cast.tp.connection",
+        CastMessage_PayloadType_STRING, JsonToString(data), destinationId);
+
+    p_sys->messagesToSend.push(msg);
+}
+
+
+static void msgLaunch(sout_stream_t *p_stream)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    Json::Value data;
+    data["type"] = "LAUNCH";
+    data["appId"] = APP_ID;
+    data["requestId"] = p_stream->p_sys->i_requestId++;
+
+    CastMessage msg = buildMessage("urn:x-cast:com.google.cast.receiver",
+        CastMessage_PayloadType_STRING, JsonToString(data));
+
+    p_sys->messagesToSend.push(msg);
+}
+
+
+static void msgLoad(sout_stream_t *p_stream)
+{
+    sout_stream_sys_t *p_sys = p_stream->p_sys;
+
+    char *psz_mime = var_GetNonEmptyString(p_stream, SOUT_CFG_PREFIX "mime");
+
+    Json::Value data;
+    data["type"] = "LOAD";
+    Json::Value media;
+    media["contentId"] = "http://" + p_sys->serverIP + ":8009/stream";
+    media["streamType"] = "LIVE";
+    media["contentType"] = psz_mime;
+    data["media"] = media;
+    data["requestId"] = p_sys->i_requestId++;
+
+    free(psz_mime);
+
+    CastMessage msg = buildMessage("urn:x-cast:com.google.cast.media",
+        CastMessage_PayloadType_STRING, JsonToString(data),
+        p_sys->appTransportId);
+
+    p_sys->messagesToSend.push(msg);
+
+    // Unlock the sout tread.
+    vlc_mutex_lock(&p_sys->loadCommandMutex);
+    vlc_cond_signal(&p_sys->loadCommandCond);
+    vlc_mutex_unlock(&p_sys->loadCommandMutex);
+}
+
+
+/*****************************************************************************
+ * Chromecast thread
+ *****************************************************************************/
+static void* chromecastThread(void* p_data)
+{
+    sout_stream_t* p_stream = (sout_stream_t*)p_data;
+    sout_stream_sys_t* p_sys = p_stream->p_sys;
+
+    int canc = vlc_savecancel();
+    // Not cancellation-safe part.
+    msgAuth(p_stream);
+    sendMessages(p_stream);
+    vlc_restorecancel(canc);
+
+    while (1)
+    {
+        bool b_msgReceived = false;
+        uint32_t i_payloadSize = 0;
+        int i_ret = recvPacket(p_stream, b_msgReceived, i_payloadSize);
+
+        canc = vlc_savecancel();
+        // Not cancellation-safe part.
+
+        if ((i_ret < 0 && errno != EAGAIN) || i_ret == 0)
+        {
+            msg_Err(p_stream, "The connection to the Chromecast died.");
+            p_sys->i_status = CHROMECAST_CONNECTION_DEAD;
+            atomic_store(&p_sys->ab_error, true);
+            break;
+        }
+
+        if (b_msgReceived)
+        {
+            CastMessage msg;
+            msg.ParseFromArray(p_sys->p_packet + PACKET_HEADER_LEN, i_payloadSize);
+            processMessage(p_stream, msg);
+            // Send the answer messages if there is any.
+            if (!p_sys->messagesToSend.empty())
+            {
+                i_ret = sendMessages(p_stream);
+                if ((i_ret < 0 && errno != EAGAIN) || i_ret == 0)
+                {
+                    msg_Err(p_stream, "The connection to the Chromecast died.");
+                    p_sys->i_status = CHROMECAST_CONNECTION_DEAD;
+                    atomic_store(&p_sys->ab_error, true);
+                    break;
+                }
+            }
+        }
+        vlc_restorecancel(canc);
+    }
+
+    return NULL;
+}
-- 
1.9.1




More information about the vlc-devel mailing list