#include <assert.h>
#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <math.h>
#include <netinet/in.h>
+#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <unistd.h>
+#include <sys/types.h>
+#include <algorithm>
#include <string>
+#include <queue>
#include <vector>
#include "log.h"
-#include "metacube.h"
+#include "metacube2.h"
#include "state.pb.h"
#include "stream.h"
#include "util.h"
using namespace std;
-Stream::Stream(const string &stream_id, size_t backlog_size, Encoding encoding)
- : stream_id(stream_id),
+Stream::Stream(const string &url,
+ size_t backlog_size,
+ uint64_t prebuffering_bytes,
+ Encoding encoding,
+ Encoding src_encoding,
+ unsigned hls_frag_duration,
+ size_t hls_backlog_margin,
+ const std::string &allow_origin)
+ : url(url),
encoding(encoding),
+ src_encoding(src_encoding),
+ allow_origin(allow_origin),
data_fd(make_tempfile("")),
- backlog_size(backlog_size),
- bytes_received(0),
- mark_pool(NULL)
+ backlog_size(backlog_size),
+ prebuffering_bytes(prebuffering_bytes),
+ hls_frag_duration(hls_frag_duration),
+ hls_backlog_margin(hls_backlog_margin)
{
if (data_fd == -1) {
exit(1);
}
Stream::Stream(const StreamProto &serialized, int data_fd)
- : stream_id(serialized.stream_id()),
+ : url(serialized.url()),
+ unavailable(serialized.unavailable()),
http_header(serialized.http_header()),
stream_header(serialized.stream_header()),
encoding(Stream::STREAM_ENCODING_RAW), // Will be changed later.
data_fd(data_fd),
backlog_size(serialized.backlog_size()),
bytes_received(serialized.bytes_received()),
- mark_pool(NULL)
+ first_fragment_index(serialized.first_fragment_index()),
+ discontinuity_counter(serialized.discontinuity_counter())
{
if (data_fd == -1) {
exit(1);
}
- // Split old-style headers into HTTP and video headers.
- if (!serialized.header().empty()) {
- string header = serialized.header();
- size_t split = header.find("\r\n\r\n");
- if (split == string::npos) {
- http_header = header;
- stream_header = "";
- } else {
- http_header = header.substr(0, split + 2); // Split off the second \r\n.
- stream_header = header.substr(split, string::npos);
+ for (ssize_t point : serialized.suitable_starting_point()) {
+ if (point == -1) {
+ // Can happen when upgrading from before 1.1.3,
+ // where this was an optional field with -1 signifying
+ // "no such point".
+ continue;
}
+ suitable_starting_points.push_back(point);
+ }
+
+ for (const FragmentStartProto &fragment : serialized.fragment()) {
+ fragments.push_back(FragmentStart { size_t(fragment.byte_position()), fragment.pts(), fragment.begins_header() });
}
}
StreamProto Stream::serialize()
{
StreamProto serialized;
+ serialized.set_unavailable(unavailable);
serialized.set_http_header(http_header);
serialized.set_stream_header(stream_header);
serialized.add_data_fds(data_fd);
serialized.set_backlog_size(backlog_size);
serialized.set_bytes_received(bytes_received);
- serialized.set_stream_id(stream_id);
+ for (size_t point : suitable_starting_points) {
+ serialized.add_suitable_starting_point(point);
+ }
+ for (const FragmentStart &fragment : fragments) {
+ FragmentStartProto *proto = serialized.add_fragment();
+ proto->set_byte_position(fragment.byte_position);
+ proto->set_pts(fragment.pts);
+ proto->set_begins_header(fragment.begins_header);
+ }
+ serialized.set_first_fragment_index(first_fragment_index);
+ serialized.set_discontinuity_counter(discontinuity_counter);
+
+ serialized.set_url(url);
data_fd = -1;
return serialized;
}
// Now cheat a bit by rewinding, and adding all the old data back.
bytes_received -= existing_data.size();
- add_data(existing_data.data(), existing_data.size());
+ DataElement data_element;
+ data_element.data.iov_base = const_cast<char *>(existing_data.data());
+ data_element.data.iov_len = existing_data.size();
+ data_element.metacube_flags = 0; // Ignored by add_data_raw().
+
+ vector<DataElement> data_elements;
+ data_elements.push_back(data_element);
+ add_data_raw(data_elements);
+ remove_obsolete_starting_points();
+}
+
+void Stream::set_header(const std::string &new_http_header, const std::string &new_stream_header)
+{
+ unavailable = false;
+ http_header = new_http_header;
+ if (new_stream_header == stream_header) {
+ return;
+ }
+
+ // We cannot start at any of the older starting points anymore,
+ // since they'd get the wrong header for the stream (not to mention
+ // that a changed header probably means the stream restarted,
+ // which means any client starting on the old one would probably
+ // stop playing properly at the change point). Next block
+ // should be a suitable starting point (if not, something is
+ // pretty strange), so it will fill up again soon enough.
+ suitable_starting_points.clear();
+
+ // HLS, on the other hand, can deal with discontinuities and multiple
+ // headers. At least in theory (client support varies wildly).
+ if (!fragments.empty()) {
+ // Commit the old header to the backlog, so that we can serve it
+ // for all the old fragments for as long as they exist.
+ if (!stream_header.empty()) {
+ // End the current fragment and make a new one for the header.
+ fragments.push_back(Stream::FragmentStart { bytes_received, 0.0, true });
+ process_queued_data();
+ Stream::DataElement elem;
+ elem.data.iov_base = (char *)stream_header.data();
+ elem.data.iov_len = stream_header.size();
+ add_data_raw({ elem });
+ remove_obsolete_starting_points();
+
+ // The discontinuity counter will be increased when
+ // this header goes out of the backlog.
+ }
+ clear_hls_playlist_cache();
+ }
+ stream_header = new_stream_header;
}
void Stream::put_client_to_sleep(Client *client)
sleeping_clients.push_back(client);
}
-void Stream::add_data(const char *data, ssize_t bytes)
+// Return a new set of iovecs that contains only the first <bytes_wanted> bytes of <data>.
+vector<iovec> collect_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
+{
+ vector<iovec> ret;
+ size_t max_iovecs = min<size_t>(data.size(), IOV_MAX);
+ for (size_t i = 0; i < max_iovecs && bytes_wanted > 0; ++i) {
+ if (data[i].data.iov_len <= bytes_wanted) {
+ // Consume the entire iovec.
+ ret.push_back(data[i].data);
+ bytes_wanted -= data[i].data.iov_len;
+ } else {
+ // Take only parts of this iovec.
+ iovec iov;
+ iov.iov_base = data[i].data.iov_base;
+ iov.iov_len = bytes_wanted;
+ ret.push_back(iov);
+ bytes_wanted = 0;
+ }
+ }
+ return ret;
+}
+
+// Return a new set of iovecs that contains all of <data> except the first <bytes_wanted> bytes.
+vector<Stream::DataElement> remove_iovecs(const vector<Stream::DataElement> &data, size_t bytes_wanted)
{
- if (encoding == Stream::STREAM_ENCODING_RAW) {
- add_data_raw(data, bytes);
- } else if (encoding == STREAM_ENCODING_METACUBE) {
- metacube_block_header hdr;
- memcpy(hdr.sync, METACUBE_SYNC, sizeof(hdr.sync));
+ vector<Stream::DataElement> ret;
+ size_t i;
+ for (i = 0; i < data.size() && bytes_wanted > 0; ++i) {
+ if (data[i].data.iov_len <= bytes_wanted) {
+ // Consume the entire iovec.
+ bytes_wanted -= data[i].data.iov_len;
+ } else {
+ // Take only parts of this iovec.
+ Stream::DataElement data_element;
+ data_element.data.iov_base = reinterpret_cast<char *>(data[i].data.iov_base) + bytes_wanted;
+ data_element.data.iov_len = data[i].data.iov_len - bytes_wanted;
+ data_element.metacube_flags = METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START;
+ data_element.pts = RationalPTS();
+ ret.push_back(data_element);
+ bytes_wanted = 0;
+ }
+ }
+
+ // Add the rest of the iovecs unchanged.
+ ret.insert(ret.end(), data.begin() + i, data.end());
+ return ret;
+}
+
+void Stream::add_data_raw(const vector<DataElement> &orig_data)
+{
+ vector<DataElement> data = orig_data;
+ while (!data.empty()) {
+ size_t pos = bytes_received % backlog_size;
+
+ // Collect as many iovecs as we can before we hit the point
+ // where the circular buffer wraps around.
+ vector<iovec> to_write = collect_iovecs(data, backlog_size - pos);
+ ssize_t ret;
+ do {
+ ret = pwritev(data_fd, to_write.data(), to_write.size(), pos);
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret == -1) {
+ log_perror("pwritev");
+ // Dazed and confused, but trying to continue...
+ return;
+ }
+ bytes_received += ret;
+
+ // Remove the data that was actually written from the set of iovecs.
+ data = remove_iovecs(data, ret);
+ }
+}
+
+void Stream::remove_obsolete_starting_points()
+{
+ // We could do a binary search here (std::lower_bound), but it seems
+ // overkill for removing what's probably only a few points.
+ while (!suitable_starting_points.empty() &&
+ bytes_received - suitable_starting_points[0] > backlog_size) {
+ suitable_starting_points.pop_front();
+ }
+ assert(backlog_size >= hls_backlog_margin);
+ while (!fragments.empty() &&
+ bytes_received - fragments[0].byte_position > (backlog_size - hls_backlog_margin)) {
+ if (fragments[0].begins_header) {
+ ++discontinuity_counter;
+ } else {
+ ++first_fragment_index;
+ }
+ fragments.pop_front();
+ clear_hls_playlist_cache();
+ }
+}
+
+void Stream::add_data_deferred(const char *data, size_t bytes, uint16_t metacube_flags, const RationalPTS &pts)
+{
+ // For regular output, we don't want to send the client twice
+ // (it's already sent out together with the HTTP header).
+ // However, for Metacube output, we need to send it so that
+ // the Cubemap instance in the other end has a chance to update it.
+ // It may come twice in its stream, but Cubemap doesn't care.
+ if (encoding == Stream::STREAM_ENCODING_RAW &&
+ (metacube_flags & METACUBE_FLAGS_HEADER) != 0) {
+ return;
+ }
+
+ lock_guard<mutex> lock(queued_data_mutex);
+
+ DataElement data_element;
+ data_element.metacube_flags = metacube_flags;
+ data_element.pts = pts;
+
+ if (encoding == Stream::STREAM_ENCODING_METACUBE) {
+ // Construct a PTS metadata block. (We'll avoid sending it out
+ // if we don't have a valid PTS.)
+ metacube2_pts_packet pts_packet;
+ pts_packet.type = htobe64(METACUBE_METADATA_TYPE_NEXT_BLOCK_PTS);
+ pts_packet.pts = htobe64(pts.pts);
+ pts_packet.timebase_num = htobe64(pts.timebase_num);
+ pts_packet.timebase_den = htobe64(pts.timebase_den);
+
+ metacube2_block_header pts_hdr;
+ memcpy(pts_hdr.sync, METACUBE2_SYNC, sizeof(pts_hdr.sync));
+ pts_hdr.size = htonl(sizeof(pts_packet));
+ pts_hdr.flags = htons(METACUBE_FLAGS_METADATA);
+ pts_hdr.csum = htons(metacube2_compute_crc(&pts_hdr));
+
+ // Add a Metacube block header before the data.
+ metacube2_block_header hdr;
+ memcpy(hdr.sync, METACUBE2_SYNC, sizeof(hdr.sync));
hdr.size = htonl(bytes);
- hdr.flags = htonl(0);
+ hdr.flags = htons(metacube_flags);
+ hdr.csum = htons(metacube2_compute_crc(&hdr));
+
+ data_element.data.iov_len = bytes + sizeof(hdr);
+ if (pts.timebase_num != 0) {
+ data_element.data.iov_len += sizeof(pts_hdr) + sizeof(pts_packet);
+ }
+ data_element.data.iov_base = new char[data_element.data.iov_len];
+
+ char *ptr = reinterpret_cast<char *>(data_element.data.iov_base);
+ if (pts.timebase_num != 0) {
+ memcpy(ptr, &pts_hdr, sizeof(pts_hdr));
+ ptr += sizeof(pts_hdr);
+ memcpy(ptr, &pts_packet, sizeof(pts_packet));
+ ptr += sizeof(pts_packet);
+ }
+
+ memcpy(ptr, &hdr, sizeof(hdr));
+ ptr += sizeof(hdr);
+ memcpy(ptr, data, bytes);
+
+ queued_data.push_back(data_element);
+ } else if (encoding == Stream::STREAM_ENCODING_RAW) {
+ // Just add the data itself.
+ data_element.data.iov_base = new char[bytes];
+ memcpy(data_element.data.iov_base, data, bytes);
+ data_element.data.iov_len = bytes;
- char *block = new char[bytes + sizeof(hdr)];
- memcpy(block, &hdr, sizeof(hdr));
- memcpy(block + sizeof(hdr), data, bytes);
- add_data_raw(block, bytes + sizeof(hdr));
- delete[] block;
+ queued_data.push_back(data_element);
} else {
assert(false);
}
}
-void Stream::add_data_raw(const char *data, ssize_t bytes)
+void Stream::process_queued_data()
{
- size_t pos = bytes_received % backlog_size;
- bytes_received += bytes;
+ vector<DataElement> queued_data_copy;
- if (pos + bytes > backlog_size) {
- ssize_t to_copy = backlog_size - pos;
- while (to_copy > 0) {
- int ret = pwrite(data_fd, data, to_copy, pos);
- if (ret == -1 && errno == EINTR) {
- continue;
+ // Hold the lock for as short as possible, since add_data_raw() can possibly
+ // write to disk, which might disturb the input thread.
+ {
+ lock_guard<mutex> lock(queued_data_mutex);
+ if (queued_data.empty()) {
+ return;
+ }
+
+ swap(queued_data, queued_data_copy);
+ }
+
+ // Add suitable starting points for the stream, if the queued data
+ // contains such starting points. Note that we drop starting points
+ // if they're less than 10 kB apart, so that we don't get a huge
+ // amount of them for e.g. each and every MPEG-TS 188-byte cell.
+ // The 10 kB value is somewhat arbitrary, but at least it should make
+ // the RAM cost of saving the position ~0.1% (or less) of the actual
+ // data, and 10 kB is a very fine granularity in most streams.
+ static const int minimum_start_point_distance = 10240;
+ size_t byte_position = bytes_received;
+ bool need_hls_clear = false;
+ for (const DataElement &elem : queued_data_copy) {
+ if ((elem.metacube_flags & METACUBE_FLAGS_NOT_SUITABLE_FOR_STREAM_START) == 0) {
+ size_t num_points = suitable_starting_points.size();
+ if (num_points >= 2 &&
+ suitable_starting_points[num_points - 1] - suitable_starting_points[num_points - 2] < minimum_start_point_distance) {
+ // p[n-1] - p[n-2] < 10 kB, so drop p[n-1].
+ suitable_starting_points.pop_back();
}
- if (ret == -1) {
- log_perror("pwrite");
- // Dazed and confused, but trying to continue...
- break;
+ suitable_starting_points.push_back(byte_position);
+
+ if (elem.pts.timebase_num != 0) {
+ need_hls_clear |= add_fragment_boundary(byte_position, elem.pts);
}
- pos += ret;
- data += ret;
- to_copy -= ret;
- bytes -= ret;
}
- pos = 0;
+ byte_position += elem.data.iov_len;
+ }
+ if (need_hls_clear) {
+ clear_hls_playlist_cache();
}
- while (bytes > 0) {
- int ret = pwrite(data_fd, data, bytes, pos);
- if (ret == -1 && errno == EINTR) {
- continue;
- }
- if (ret == -1) {
- log_perror("pwrite");
- // Dazed and confused, but trying to continue...
- break;
- }
- pos += ret;
- data += ret;
- bytes -= ret;
+ add_data_raw(queued_data_copy);
+ remove_obsolete_starting_points();
+ for (const DataElement &elem : queued_data_copy) {
+ char *data = reinterpret_cast<char *>(elem.data.iov_base);
+ delete[] data;
}
-}
-void Stream::wake_up_all_clients()
-{
+ // We have more data, so wake up all clients.
if (to_process.empty()) {
swap(sleeping_clients, to_process);
} else {
sleeping_clients.clear();
}
}
+
+bool Stream::add_fragment_boundary(size_t byte_position, const RationalPTS &pts)
+{
+ double pts_double = double(pts.pts) * pts.timebase_den / pts.timebase_num;
+
+ if (fragments.size() <= 1 ||
+ fragments[fragments.size() - 1].begins_header ||
+ fragments[fragments.size() - 2].begins_header) {
+ // Just starting up, so try to establish the first in-progress fragment.
+ fragments.push_back(FragmentStart{ byte_position, pts_double, false });
+ return false;
+ }
+
+ // Keep extending the in-progress fragment as long as we do not
+ // exceed the target duration by more than half a second
+ // (RFC 8216 4.3.3.1) and we get closer to the target by doing so.
+ // Note that in particular, this means we'll always extend
+ // as long as we don't exceed the target duration.
+ double current_duration = pts_double - fragments[fragments.size() - 1].pts;
+ double candidate_duration = pts_double - fragments[fragments.size() - 2].pts;
+ if (lrintf(candidate_duration) <= hls_frag_duration &&
+ fabs(candidate_duration - hls_frag_duration) < fabs(current_duration - hls_frag_duration)) {
+ fragments.back() = FragmentStart{ byte_position, pts_double, false };
+ return false;
+ } else {
+ // Extending the in-progress fragment would make it too long,
+ // so finalize it and start a new in-progress fragment.
+ fragments.push_back(FragmentStart{ byte_position, pts_double, false });
+ return true;
+ }
+}
+
+void Stream::clear_hls_playlist_cache()
+{
+ hls_playlist_http10.reset();
+ hls_playlist_http11_close.reset();
+ hls_playlist_http11_persistent.reset();
+}
+
+shared_ptr<const string> Stream::generate_hls_playlist(bool http_11, bool close_after_response)
+{
+ char buf[256];
+ snprintf(buf, sizeof(buf),
+ "#EXTM3U\r\n"
+ "#EXT-X-VERSION:7\r\n"
+ "#EXT-X-TARGETDURATION:%u\r\n"
+ "#EXT-X-MEDIA-SEQUENCE:%" PRIu64 "\r\n"
+ "#EXT-X-DISCONTINUITY-SEQUENCE:%" PRIu64 "\r\n",
+ hls_frag_duration,
+ first_fragment_index,
+ discontinuity_counter);
+
+ string playlist = buf;
+
+ if (fragments.size() >= 3) {
+ bool printed_header_for_this_group = false;
+ bool printed_first_header = false;
+ for (size_t i = 0; i < fragments.size() - 2; ++i) {
+ char buf[256];
+
+ if (fragments[i].begins_header) {
+ // End of this group. (We've already printed the header
+ // as part of the previous group.)
+ printed_header_for_this_group = false;
+ continue;
+ }
+ if (!printed_header_for_this_group) {
+ // Look forward until we find the header for this group (if any).
+ for (size_t j = i + 1; j < fragments.size() - 1; ++j) {
+ if (fragments[j].begins_header) {
+ if (printed_first_header) {
+ playlist += "#EXT-X-DISCONTINUITY\r\n";
+ }
+ snprintf(buf, sizeof(buf),
+ "#EXT-X-MAP:URI=\"%s?frag=%" PRIu64 "-%" PRIu64 "\"\r\n",
+ url.c_str(), fragments[j].byte_position,
+ fragments[j + 1].byte_position);
+ playlist += buf;
+ printed_first_header = true;
+ printed_header_for_this_group = true;
+ break;
+ }
+ }
+
+ if (!printed_header_for_this_group && !stream_header.empty()) {
+ if (printed_first_header) {
+ playlist += "#EXT-X-DISCONTINUITY\r\n";
+ }
+ snprintf(buf, sizeof(buf), "#EXT-X-MAP:URI=\"%s?frag=header\"\r\n", url.c_str());
+ playlist += buf;
+ }
+
+ // Even if we didn't find anything, we don't want to search again for each fragment.
+ printed_first_header = true;
+ printed_header_for_this_group = true;
+ }
+
+ if (fragments[i + 1].begins_header) {
+ // Since we only have start pts for each block and not duration,
+ // we have no idea how long this fragment is; the encoder restarted
+ // before it got to output the next pts. However, it's likely
+ // to be very short, so instead of trying to guess, we just skip it.
+ continue;
+ }
+
+ snprintf(buf, sizeof(buf), "#EXTINF:%f,\r\n%s?frag=%" PRIu64 "-%" PRIu64 "\r\n",
+ fragments[i + 1].pts - fragments[i].pts,
+ url.c_str(),
+ fragments[i].byte_position,
+ fragments[i + 1].byte_position);
+ playlist += buf;
+ }
+ }
+
+ string response;
+ if (http_11) {
+ response = "HTTP/1.1 200 OK\r\n";
+ if (close_after_response) {
+ response.append("Connection: close\r\n");
+ }
+ } else {
+ assert(close_after_response);
+ response = "HTTP/1.0 200 OK\r\n";
+ }
+ snprintf(buf, sizeof(buf), "Content-Length: %zu\r\n", playlist.size());
+ response.append(buf);
+ response.append("Content-Type: application/x-mpegURL\r\n");
+ if (!allow_origin.empty()) {
+ response.append("Access-Control-Allow-Origin: ");
+ response.append(allow_origin);
+ response.append("\r\n");
+ }
+ response.append("\r\n");
+ response.append(move(playlist));
+
+ return shared_ptr<const string>(new string(move(response)));
+}
projects / cubemap / blobdiff