X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=stream.cpp;h=3ee1a434d2e6fe6c3cc73fcc84d89d860efd0f05;hp=f5abbfd0f3e07795a0502c3d562ec56a01d3a5f4;hb=7ec54788f88dde7b083ba6cfd30732b32295b54a;hpb=a0fe013448d188b324c00383cfd91695d9d3d076 diff --git a/stream.cpp b/stream.cpp index f5abbfd..3ee1a43 100644 --- a/stream.cpp +++ b/stream.cpp @@ -1,6 +1,8 @@ #include #include +#include #include +#include #include #include #include @@ -13,28 +15,33 @@ #include "log.h" #include "metacube2.h" -#include "mutexlock.h" #include "state.pb.h" #include "stream.h" #include "util.h" using namespace std; -Stream::Stream(const string &url, size_t backlog_size, size_t prebuffering_bytes, Encoding encoding, Encoding src_encoding) +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), + backlog_size(backlog_size), prebuffering_bytes(prebuffering_bytes), - bytes_received(0), - pacing_rate(~0U) + hls_frag_duration(hls_frag_duration), + hls_backlog_margin(hls_backlog_margin) { if (data_fd == -1) { exit(1); } - - pthread_mutex_init(&queued_data_mutex, nullptr); } Stream::~Stream() @@ -46,14 +53,15 @@ Stream::~Stream() Stream::Stream(const StreamProto &serialized, int data_fd) : 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()), - prebuffering_bytes(serialized.prebuffering_bytes()), bytes_received(serialized.bytes_received()), - pacing_rate(~0U) + first_fragment_index(serialized.first_fragment_index()), + discontinuity_counter(serialized.discontinuity_counter()) { if (data_fd == -1) { exit(1); @@ -69,21 +77,32 @@ Stream::Stream(const StreamProto &serialized, int data_fd) suitable_starting_points.push_back(point); } - pthread_mutex_init(&queued_data_mutex, nullptr); + 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_prebuffering_bytes(prebuffering_bytes); serialized.set_bytes_received(bytes_received); 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; @@ -135,6 +154,46 @@ void Stream::set_backlog_size(size_t new_size) 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); @@ -177,6 +236,7 @@ vector remove_iovecs(const vector &dat data_element.data.iov_base = reinterpret_cast(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; } @@ -221,9 +281,20 @@ void Stream::remove_obsolete_starting_points() 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) +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). @@ -235,12 +306,27 @@ void Stream::add_data_deferred(const char *data, size_t bytes, uint16_t metacube return; } - MutexLock lock(&queued_data_mutex); + lock_guard 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)); @@ -248,11 +334,23 @@ void Stream::add_data_deferred(const char *data, size_t bytes, uint16_t metacube hdr.flags = htons(metacube_flags); hdr.csum = htons(metacube2_compute_crc(&hdr)); - data_element.data.iov_base = new char[bytes + sizeof(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(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(data_element.data.iov_base, &hdr, sizeof(hdr)); - memcpy(reinterpret_cast(data_element.data.iov_base) + sizeof(hdr), data, bytes); + 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) { @@ -274,7 +372,7 @@ void Stream::process_queued_data() // Hold the lock for as short as possible, since add_data_raw() can possibly // write to disk, which might disturb the input thread. { - MutexLock lock(&queued_data_mutex); + lock_guard lock(queued_data_mutex); if (queued_data.empty()) { return; } @@ -291,6 +389,7 @@ void Stream::process_queued_data() // 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(); @@ -300,9 +399,16 @@ void Stream::process_queued_data() suitable_starting_points.pop_back(); } suitable_starting_points.push_back(byte_position); + + if (elem.pts.timebase_num != 0) { + need_hls_clear |= add_fragment_boundary(byte_position, elem.pts); + } } byte_position += elem.data.iov_len; } + if (need_hls_clear) { + clear_hls_playlist_cache(); + } add_data_raw(queued_data_copy); remove_obsolete_starting_points(); @@ -319,3 +425,140 @@ void Stream::process_queued_data() 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 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(new string(move(response))); +}