Add support for serving HLS playlists.

[cubemap] / stream.h

diff --git a/stream.h b/stream.h
index 17df7f35dade3fc17b577e481031af24ffe2eb8c..77e9d8a8f0510fe06ebcb5a11b0440d4456b79b0 100644 (file)
--- a/stream.h
+++ b/stream.h
@@ -9,18 +9,34 @@
 #include <sys/types.h>
 #include <sys/uio.h>
 #include <deque>
+#include <memory>
 #include <mutex>
 #include <string>
 #include <vector>
 
+#include "metacube2.h"
+
 class StreamProto;
 struct Client;
 
+// metacube2_pts_packet except the type and byteswapping.
+struct RationalPTS {
+       int64_t pts = 0;
+       uint64_t timebase_num = 0, timebase_den = 0;  // 0/0 for unknown PTS.
+};
+
 struct Stream {
        // Must be in sync with StreamConfig::Encoding.
        enum Encoding { STREAM_ENCODING_RAW = 0, STREAM_ENCODING_METACUBE };
 
-       Stream(const std::string &stream_id, size_t backlog_size, size_t prebuffering_bytes, Encoding encoding, Encoding src_encoding);
+       Stream(const std::string &url,
+              size_t backlog_size,
+              size_t prebuffering_bytes,
+              Encoding encoding,
+              Encoding src_encoding,
+              unsigned hls_frag_duration,
+              size_t hls_backlog_margin,
+              const std::string &allow_origin);
        ~Stream();
 
        // Serialization/deserialization.
@@ -50,6 +66,9 @@ struct Stream {
        // What encoding we expect the incoming data to be in (usually Metacube).
        Encoding src_encoding;
 
+       // Contents of CORS header (Access-Control-Allow-Origin), if any.
+       std::string allow_origin;
+
        // The stream data itself, stored in a circular buffer.
        //
        // We store our data in a file, so that we can send the data to the
@@ -78,7 +97,42 @@ struct Stream {
        // A list of points in the stream that is suitable to start new clients at
        // (after having sent the header). Empty if no such point exists yet.
        std::deque<size_t> suitable_starting_points;
-       
+
+       // A list of HLS fragment boundaries currently in the backlog; the first fragment
+       // is between point 0 and 1, the second is between 1 and 2, and so on.
+       // This roughly mirrors suitable_starting_points, but we generally make much
+       // larger fragments (we try to get as close as possible without exceeding
+       // <hls_frag_duration> seconds by too much).
+       //
+       // We keep this list even if we don't have HLS, given that we have pts data
+       // from the input stream.
+       //
+       // NOTE: The last fragment is an in-progress fragment, which can still be
+       // extended and thus should not be output. So the last fragment output is
+       // from points N-3..N-2.
+       struct FragmentStart {
+               size_t byte_position;
+               double pts;
+       };
+       std::deque<FragmentStart> fragments;
+       size_t first_fragment_index = 0, discontinuity_counter = 0;
+
+       // HLS target duration, in seconds.
+       unsigned hls_frag_duration = 6;
+
+       // Don't advertise new HLS fragments beginning before this point after the
+       // start of the backlog, so that we're reasonably sure that we can actually
+       // serve them even if the client can't completely keep up.
+       size_t hls_backlog_margin = 0;
+
+       // HLS playlists for this stream, in the form of a HTTP response, with
+       // headers and all. These are created on-demand, re-used by clients as
+       // needed, and cleared when they are no longer valid (e.g., when new fragments
+       // are added).
+       std::shared_ptr<const std::string> hls_playlist_http10;
+       std::shared_ptr<const std::string> hls_playlist_http11_close;
+       std::shared_ptr<const std::string> hls_playlist_http11_persistent;
+
        // Clients that are in SENDING_DATA, but that we don't listen on,
        // because we currently don't have any data for them.
        // See put_client_to_sleep() and wake_up_all_clients().
@@ -96,6 +150,7 @@ struct Stream {
        struct DataElement {
                iovec data;
                uint16_t metacube_flags;
+               RationalPTS pts;
        };
        std::vector<DataElement> queued_data;
 
@@ -106,12 +161,17 @@ struct Stream {
 
        // Add more data to <queued_data>, adding Metacube headers if needed.
        // Does not take ownership of <data>.
-       void add_data_deferred(const char *data, size_t bytes, uint16_t metacube_flags);
+       void add_data_deferred(const char *data, size_t bytes, uint16_t metacube_flags, const RationalPTS &pts);
 
        // Add queued data to the stream, if any.
        // You should hold the owning Server's <mutex>.
        void process_queued_data();
 
+       // Generate a HLS playlist based on the current state, including HTTP headers.
+       std::shared_ptr<const std::string> generate_hls_playlist(bool http_11, bool close_after_response);
+
+       void clear_hls_playlist_cache();
+
 private:
        Stream(const Stream& other);
 
@@ -125,6 +185,11 @@ private:
        // in the backlog.
        // You should hold the owning Server's <mutex>.
        void remove_obsolete_starting_points();
+
+       // Extend the in-progress fragment to the given position, or finish it and start
+       // a new one if that would make it too long. Returns true if a new fragment
+       // was created (ie., the HLS playlists need to be regenerated).
+       bool add_fragment_boundary(size_t byte_position, const RationalPTS &pts);
 };
 
 #endif  // !defined(_STREAM_H)