mpv/libmpdemux/demux_rtp.cpp

527 lines
17 KiB
C++

////////// Routines (with C-linkage) that interface between "MPlayer"
////////// and the "LIVE.COM Streaming Media" libraries:
extern "C" {
#include "demux_rtp.h"
#include "stheader.h"
}
#include "demux_rtp_internal.h"
#include "BasicUsageEnvironment.hh"
#include "liveMedia.hh"
#include "GroupsockHelper.hh"
#include <unistd.h>
extern "C" stream_t* stream_open_sdp(int fd, off_t fileSize,
int* file_format) {
*file_format = DEMUXER_TYPE_RTP;
stream_t* newStream = NULL;
do {
char* sdpDescription = (char*)malloc(fileSize+1);
if (sdpDescription == NULL) break;
ssize_t numBytesRead = read(fd, sdpDescription, fileSize);
if (numBytesRead != fileSize) break;
sdpDescription[fileSize] = '\0'; // to be safe
newStream = (stream_t*)calloc(sizeof (stream_t), 1);
if (newStream == NULL) break;
// Store the SDP description in the 'priv' field, for later use:
newStream->priv = sdpDescription;
} while (0);
return newStream;
}
extern "C" int _rtsp_streaming_seek(int /*fd*/, off_t /*pos*/,
streaming_ctrl_t* /*streaming_ctrl*/) {
return -1; // For now, we don't handle RTSP stream seeking
}
extern "C" int rtsp_streaming_start(stream_t* stream) {
stream->streaming_ctrl->streaming_seek = _rtsp_streaming_seek;
return 0;
}
// A data structure representing input data for each stream:
class ReadBufferQueue {
public:
ReadBufferQueue(MediaSubsession* subsession, demuxer_t* demuxer,
char const* tag);
virtual ~ReadBufferQueue();
FramedSource* readSource() const { return fReadSource; }
RTPSource* rtpSource() const { return fRTPSource; }
demuxer_t* ourDemuxer() const { return fOurDemuxer; }
char const* tag() const { return fTag; }
char blockingFlag; // used to implement synchronous reads
// For A/V synchronization:
Boolean prevPacketWasSynchronized;
float prevPacketPTS;
ReadBufferQueue** otherQueue;
// The 'queue' actually consists of just a single "demux_packet_t"
// (because the underlying OS does the actual queueing/buffering):
demux_packet_t* dp;
// However, we sometimes inspect buffers before delivering them.
// For this, we maintain a queue of pending buffers:
void savePendingBuffer(demux_packet_t* dp);
demux_packet_t* getPendingBuffer();
private:
demux_packet_t* pendingDPHead;
demux_packet_t* pendingDPTail;
FramedSource* fReadSource;
RTPSource* fRTPSource;
demuxer_t* fOurDemuxer;
char const* fTag; // used for debugging
};
// A structure of RTP-specific state, kept so that we can cleanly
// reclaim it:
typedef struct RTPState {
char const* sdpDescription;
RTSPClient* rtspClient;
MediaSession* mediaSession;
ReadBufferQueue* audioBufferQueue;
ReadBufferQueue* videoBufferQueue;
unsigned flags;
struct timeval firstSyncTime;
};
int rtspStreamOverTCP = 0;
extern "C" void demux_open_rtp(demuxer_t* demuxer) {
do {
TaskScheduler* scheduler = BasicTaskScheduler::createNew();
if (scheduler == NULL) break;
UsageEnvironment* env = BasicUsageEnvironment::createNew(*scheduler);
if (env == NULL) break;
RTSPClient* rtspClient = NULL;
if (demuxer == NULL || demuxer->stream == NULL) break; // shouldn't happen
demuxer->stream->eof = 0; // just in case
// Look at the stream's 'priv' field to see if we were initiated
// via a SDP description:
char* sdpDescription = (char*)(demuxer->stream->priv);
if (sdpDescription == NULL) {
// We weren't given a SDP description directly, so assume that
// we were given a RTSP URL:
char const* url = demuxer->stream->streaming_ctrl->url->url;
extern int verbose;
rtspClient = RTSPClient::createNew(*env, verbose, "MPlayer");
if (rtspClient == NULL) {
fprintf(stderr, "Failed to create RTSP client: %s\n",
env->getResultMsg());
break;
}
sdpDescription = rtspClient->describeURL(url);
if (sdpDescription == NULL) {
fprintf(stderr, "Failed to get a SDP description from URL \"%s\": %s\n",
url, env->getResultMsg());
break;
}
}
// Now that we have a SDP description, create a MediaSession from it:
MediaSession* mediaSession = MediaSession::createNew(*env, sdpDescription);
if (mediaSession == NULL) break;
// Create a 'RTPState' structure containing the state that we just created,
// and store it in the demuxer's 'priv' field, for future reference:
RTPState* rtpState = new RTPState;
rtpState->sdpDescription = sdpDescription;
rtpState->rtspClient = rtspClient;
rtpState->mediaSession = mediaSession;
rtpState->audioBufferQueue = rtpState->videoBufferQueue = NULL;
rtpState->flags = 0;
rtpState->firstSyncTime.tv_sec = rtpState->firstSyncTime.tv_usec = 0;
demuxer->priv = rtpState;
// Create RTP receivers (sources) for each subsession:
MediaSubsessionIterator iter(*mediaSession);
MediaSubsession* subsession;
unsigned desiredReceiveBufferSize;
while ((subsession = iter.next()) != NULL) {
// Ignore any subsession that's not audio or video:
if (strcmp(subsession->mediumName(), "audio") == 0) {
desiredReceiveBufferSize = 100000;
} else if (strcmp(subsession->mediumName(), "video") == 0) {
desiredReceiveBufferSize = 2000000;
} else {
continue;
}
if (!subsession->initiate()) {
fprintf(stderr, "Failed to initiate \"%s/%s\" RTP subsession: %s\n", subsession->mediumName(), subsession->codecName(), env->getResultMsg());
} else {
fprintf(stderr, "Initiated \"%s/%s\" RTP subsession\n", subsession->mediumName(), subsession->codecName());
// Set the OS's socket receive buffer sufficiently large to avoid
// incoming packets getting dropped between successive reads from this
// subsession's demuxer. Depending on the bitrate(s) that you expect,
// you may wish to tweak the "desiredReceiveBufferSize" values above.
int rtpSocketNum = subsession->rtpSource()->RTPgs()->socketNum();
int receiveBufferSize
= increaseReceiveBufferTo(*env, rtpSocketNum,
desiredReceiveBufferSize);
if (verbose > 0) {
fprintf(stderr, "Increased %s socket receive buffer to %d bytes \n",
subsession->mediumName(), receiveBufferSize);
}
if (rtspClient != NULL) {
// Issue a RTSP "SETUP" command on the chosen subsession:
if (!rtspClient->setupMediaSubsession(*subsession, False,
rtspStreamOverTCP)) break;
}
}
}
if (rtspClient != NULL) {
// Issue a RTSP aggregate "PLAY" command on the whole session:
if (!rtspClient->playMediaSession(*mediaSession)) break;
}
// Now that the session is ready to be read, do additional
// MPlayer codec-specific initialization on each subsession:
iter.reset();
while ((subsession = iter.next()) != NULL) {
if (subsession->readSource() == NULL) continue; // not reading this
unsigned flags = 0;
if (strcmp(subsession->mediumName(), "audio") == 0) {
rtpState->audioBufferQueue
= new ReadBufferQueue(subsession, demuxer, "audio");
rtpState->audioBufferQueue->otherQueue = &(rtpState->videoBufferQueue);
rtpCodecInitialize_audio(demuxer, subsession, flags);
} else if (strcmp(subsession->mediumName(), "video") == 0) {
rtpState->videoBufferQueue
= new ReadBufferQueue(subsession, demuxer, "video");
rtpState->videoBufferQueue->otherQueue = &(rtpState->audioBufferQueue);
rtpCodecInitialize_video(demuxer, subsession, flags);
}
rtpState->flags |= flags;
}
} while (0);
}
extern "C" int demux_is_mpeg_rtp_stream(demuxer_t* demuxer) {
// Get the RTP state that was stored in the demuxer's 'priv' field:
RTPState* rtpState = (RTPState*)(demuxer->priv);
return (rtpState->flags&RTPSTATE_IS_MPEG12_VIDEO) != 0;
}
static demux_packet_t* getBuffer(demuxer_t* demuxer, demux_stream_t* ds,
Boolean mustGetNewData,
float& ptsBehind); // forward
extern "C" int demux_rtp_fill_buffer(demuxer_t* demuxer, demux_stream_t* ds) {
// Get a filled-in "demux_packet" from the RTP source, and deliver it.
// Note that this is called as a synchronous read operation, so it needs
// to block in the (hopefully infrequent) case where no packet is
// immediately available.
while (1) {
float ptsBehind;
demux_packet_t* dp = getBuffer(demuxer, ds, False, ptsBehind); // blocking
if (dp == NULL) return 0;
if (demuxer->stream->eof) return 0; // source stream has closed down
// Before using this packet, check to make sure that its presentation
// time is not far behind the other stream (if any). If it is,
// then we discard this packet, and get another instead. (The rest of
// MPlayer doesn't always do a good job of synchronizing when the
// audio and video streams get this far apart.)
// (We don't do this when streaming over TCP, because then the audio and
// video streams are interleaved.)
const float ptsBehindThreshold = 1.0; // seconds
if (ptsBehind < ptsBehindThreshold || rtspStreamOverTCP) { // packet's OK
ds_add_packet(ds, dp);
break;
}
#ifdef DEBUG_PRINT_DISCARDED_PACKETS
RTPState* rtpState = (RTPState*)(demuxer->priv);
ReadBufferQueue* bufferQueue = ds == demuxer->video ? rtpState->videoBufferQueue : rtpState->audioBufferQueue;
fprintf(stderr, "Discarding %s packet (%fs behind)\n", bufferQueue->tag(), ptsBehind);
#endif
free_demux_packet(dp); // give back this packet, and get another one
}
return 1;
}
Boolean awaitRTPPacket(demuxer_t* demuxer, demux_stream_t* ds,
unsigned char*& packetData, unsigned& packetDataLen,
float& pts) {
// Similar to "demux_rtp_fill_buffer()", except that the "demux_packet"
// is not delivered to the "demux_stream".
float ptsBehind;
demux_packet_t* dp = getBuffer(demuxer, ds, True, ptsBehind); // blocking
if (dp == NULL) return False;
packetData = dp->buffer;
packetDataLen = dp->len;
pts = dp->pts;
return True;
}
Boolean insertRTPData(demuxer_t* demuxer, demux_stream_t* ds,
unsigned char* data, unsigned dataLen) {
// Begin by finding the buffer queue that we want to add data to.
// (Get this from the RTP state, which we stored in
// the demuxer's 'priv' field)
RTPState* rtpState = (RTPState*)(demuxer->priv);
ReadBufferQueue* bufferQueue = NULL;
if (ds == demuxer->video) {
bufferQueue = rtpState->videoBufferQueue;
} else if (ds == demuxer->audio) {
bufferQueue = rtpState->audioBufferQueue;
} else {
fprintf(stderr, "(demux_rtp)insertRTPData: internal error: unknown stream\n");
return False;
}
if (data == NULL || dataLen == 0) return False;
demux_packet_t* dp = new_demux_packet(dataLen);
if (dp == NULL) return False;
// Copy our data into the buffer, and save it:
memmove(dp->buffer, data, dataLen);
dp->len = dataLen;
dp->pts = 0;
bufferQueue->savePendingBuffer(dp);
}
static void teardownRTSPSession(RTPState* rtpState); // forward
extern "C" void demux_close_rtp(demuxer_t* demuxer) {
// Reclaim all RTP-related state:
// Get the RTP state that was stored in the demuxer's 'priv' field:
RTPState* rtpState = (RTPState*)(demuxer->priv);
if (rtpState == NULL) return;
teardownRTSPSession(rtpState);
UsageEnvironment* env = NULL;
TaskScheduler* scheduler = NULL;
if (rtpState->mediaSession != NULL) {
env = &(rtpState->mediaSession->envir());
scheduler = &(env->taskScheduler());
}
Medium::close(rtpState->mediaSession);
Medium::close(rtpState->rtspClient);
delete rtpState->audioBufferQueue;
delete rtpState->videoBufferQueue;
delete rtpState->sdpDescription;
delete rtpState;
delete env; delete scheduler;
}
////////// Extra routines that help implement the above interface functions:
#define MAX_RTP_FRAME_SIZE 50000
// >= the largest conceivable frame composed from one or more RTP packets
static void afterReading(void* clientData, unsigned frameSize,
struct timeval presentationTime) {
if (frameSize >= MAX_RTP_FRAME_SIZE) {
fprintf(stderr, "Saw an input frame too large (>=%d). Increase MAX_RTP_FRAME_SIZE in \"demux_rtp.cpp\".\n",
MAX_RTP_FRAME_SIZE);
}
ReadBufferQueue* bufferQueue = (ReadBufferQueue*)clientData;
demuxer_t* demuxer = bufferQueue->ourDemuxer();
RTPState* rtpState = (RTPState*)(demuxer->priv);
if (frameSize > 0) demuxer->stream->eof = 0;
demux_packet_t* dp = bufferQueue->dp;
dp->len = frameSize;
// Set the packet's presentation time stamp, depending on whether or
// not our RTP source's timestamps have been synchronized yet:
Boolean hasBeenSynchronized
= bufferQueue->rtpSource()->hasBeenSynchronizedUsingRTCP();
if (hasBeenSynchronized) {
if (verbose > 0 && !bufferQueue->prevPacketWasSynchronized) {
fprintf(stderr, "%s stream has been synchronized using RTCP \n",
bufferQueue->tag());
}
struct timeval* fst = &(rtpState->firstSyncTime); // abbrev
if (fst->tv_sec == 0 && fst->tv_usec == 0) {
*fst = presentationTime;
}
// For the "pts" field, use the time differential from the first
// synchronized time, rather than absolute time, in order to avoid
// round-off errors when converting to a float:
dp->pts = presentationTime.tv_sec - fst->tv_sec
+ (presentationTime.tv_usec - fst->tv_usec)/1000000.0;
bufferQueue->prevPacketPTS = dp->pts;
} else {
if (verbose > 0 && bufferQueue->prevPacketWasSynchronized) {
fprintf(stderr, "%s stream is no longer RTCP-synchronized \n",
bufferQueue->tag());
}
// use the previous packet's "pts" once again:
dp->pts = bufferQueue->prevPacketPTS;
}
bufferQueue->prevPacketWasSynchronized = hasBeenSynchronized;
dp->pos = demuxer->filepos;
demuxer->filepos += frameSize;
// Signal any pending 'doEventLoop()' call on this queue:
bufferQueue->blockingFlag = ~0;
}
static void onSourceClosure(void* clientData) {
ReadBufferQueue* bufferQueue = (ReadBufferQueue*)clientData;
demuxer_t* demuxer = bufferQueue->ourDemuxer();
demuxer->stream->eof = 1;
// Signal any pending 'doEventLoop()' call on this queue:
bufferQueue->blockingFlag = ~0;
}
static demux_packet_t* getBuffer(demuxer_t* demuxer, demux_stream_t* ds,
Boolean mustGetNewData,
float& ptsBehind) {
// Begin by finding the buffer queue that we want to read from:
// (Get this from the RTP state, which we stored in
// the demuxer's 'priv' field)
RTPState* rtpState = (RTPState*)(demuxer->priv);
ReadBufferQueue* bufferQueue = NULL;
if (ds == demuxer->video) {
bufferQueue = rtpState->videoBufferQueue;
} else if (ds == demuxer->audio) {
bufferQueue = rtpState->audioBufferQueue;
} else {
fprintf(stderr, "(demux_rtp)getBuffer: internal error: unknown stream\n");
return NULL;
}
if (bufferQueue == NULL || bufferQueue->readSource() == NULL) {
fprintf(stderr, "(demux_rtp)getBuffer failed: no appropriate RTP subsession has been set up\n");
return NULL;
}
demux_packet_t* dp;
if (!mustGetNewData) {
// Check whether we have a previously-saved buffer that we can use:
dp = bufferQueue->getPendingBuffer();
if (dp != NULL) return dp;
}
// Allocate a new packet buffer, and arrange to read into it:
dp = new_demux_packet(MAX_RTP_FRAME_SIZE);
bufferQueue->dp = dp;
if (dp == NULL) return NULL;
// Schedule the read operation:
bufferQueue->blockingFlag = 0;
bufferQueue->readSource()->getNextFrame(dp->buffer, MAX_RTP_FRAME_SIZE,
afterReading, bufferQueue,
onSourceClosure, bufferQueue);
// Block ourselves until data becomes available:
TaskScheduler& scheduler
= bufferQueue->readSource()->envir().taskScheduler();
scheduler.doEventLoop(&bufferQueue->blockingFlag);
// Set the "ptsBehind" result parameter:
if (bufferQueue->prevPacketPTS != 0.0 && *(bufferQueue->otherQueue) != NULL
&& (*(bufferQueue->otherQueue))->prevPacketPTS != 0.0) {
ptsBehind = (*(bufferQueue->otherQueue))->prevPacketPTS
- bufferQueue->prevPacketPTS;
} else {
ptsBehind = 0.0;
}
if (mustGetNewData) {
// Save this buffer for future reads:
bufferQueue->savePendingBuffer(dp);
}
return dp;
}
static void teardownRTSPSession(RTPState* rtpState) {
RTSPClient* rtspClient = rtpState->rtspClient;
MediaSession* mediaSession = rtpState->mediaSession;
if (rtspClient == NULL || mediaSession == NULL) return;
MediaSubsessionIterator iter(*mediaSession);
MediaSubsession* subsession;
while ((subsession = iter.next()) != NULL) {
rtspClient->teardownMediaSubsession(*subsession);
}
}
////////// "ReadBuffer" and "ReadBufferQueue" implementation:
ReadBufferQueue::ReadBufferQueue(MediaSubsession* subsession,
demuxer_t* demuxer, char const* tag)
: prevPacketWasSynchronized(False), prevPacketPTS(0.0), otherQueue(NULL),
dp(NULL), pendingDPHead(NULL), pendingDPTail(NULL),
fReadSource(subsession == NULL ? NULL : subsession->readSource()),
fRTPSource(subsession == NULL ? NULL : subsession->rtpSource()),
fOurDemuxer(demuxer), fTag(strdup(tag)) {
}
ReadBufferQueue::~ReadBufferQueue() {
delete fTag;
// Free any pending buffers (that never got delivered):
demux_packet_t* dp = pendingDPHead;
while (dp != NULL) {
demux_packet_t* dpNext = dp->next;
dp->next = NULL;
free_demux_packet(dp);
dp = dpNext;
}
}
void ReadBufferQueue::savePendingBuffer(demux_packet_t* dp) {
// Keep this buffer around, until MPlayer asks for it later:
if (pendingDPTail == NULL) {
pendingDPHead = pendingDPTail = dp;
} else {
pendingDPTail->next = dp;
pendingDPTail = dp;
}
dp->next = NULL;
}
demux_packet_t* ReadBufferQueue::getPendingBuffer() {
demux_packet_t* dp = pendingDPHead;
if (dp != NULL) {
pendingDPHead = dp->next;
if (pendingDPHead == NULL) pendingDPTail = NULL;
dp->next = NULL;
}
return dp;
}