git.sesse.net Git - nageru/blob - httpd.h

   1 #ifndef _HTTPD_H
   2 #define _HTTPD_H
   3
   4 // A class dealing with stream output, both to HTTP (thus the class name)
   5 // and to local output files. Since we generally have very few outputs
   6 // (end clients are not meant to connect directly to our stream; it should be
   7 // transcoded by something else and then sent to a reflector), we don't need to
   8 // care a lot about performance. Thus, we solve this by the simplest possible
   9 // way, namely having one ffmpeg mux per output.
  10
  11 #include <microhttpd.h>
  12 #include <stddef.h>
  13 #include <stdint.h>
  14 #include <sys/types.h>
  15 #include <condition_variable>
  16 #include <deque>
  17 #include <memory>
  18 #include <mutex>
  19 #include <set>
  20 #include <string>
  21
  22 struct MHD_Connection;
  23
  24 extern "C" {
  25 #include <libavcodec/avcodec.h>
  26 #include <libavformat/avformat.h>
  27 #include <libavformat/avio.h>
  28 }
  29
  30 class HTTPD {
  31 public:
  32         enum PacketDestination {
  33                 DESTINATION_FILE_ONLY,
  34                 DESTINATION_HTTP_ONLY,
  35                 DESTINATION_FILE_AND_HTTP
  36         };
  37
  38         HTTPD(int width, int height);
  39         void start(int port);
  40         void add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, PacketDestination destination);
  41
  42         // You can only have one going at the same time.
  43         void open_output_file(const std::string &filename);
  44         void close_output_file();
  45
  46 private:
  47         static int answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  48                                               const char *url, const char *method,
  49                                               const char *version, const char *upload_data,
  50                                               size_t *upload_data_size, void **con_cls);
  51
  52         int answer_to_connection(MHD_Connection *connection,
  53                                  const char *url, const char *method,
  54                                  const char *version, const char *upload_data,
  55                                  size_t *upload_data_size, void **con_cls);
  56
  57         static void free_stream(void *cls);
  58
  59         static void request_completed_thunk(void *cls, struct MHD_Connection *connection, void **con_cls, enum MHD_RequestTerminationCode toe);
  60
  61         void request_completed(struct MHD_Connection *connection, void **con_cls, enum MHD_RequestTerminationCode toe);
  62
  63         class Mux {
  64         public:
  65                 enum Codec {
  66                         CODEC_H264,
  67                         CODEC_NV12,  // Uncompressed 4:2:0.
  68                 };
  69
  70                 Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, int time_base);  // Takes ownership of avctx.
  71                 ~Mux();
  72                 void add_packet(const AVPacket &pkt, int64_t pts, int64_t dts);
  73
  74         private:
  75                 bool seen_keyframe = false;
  76                 AVFormatContext *avctx;
  77                 AVStream *avstream_video, *avstream_audio;
  78         };
  79
  80         class Stream {
  81         public:
  82                 Stream(AVOutputFormat *oformat, int width, int height, int time_base);
  83
  84                 static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
  85                 ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
  86
  87                 void add_packet(const AVPacket &pkt, int64_t pts, int64_t dts);
  88
  89         private:
  90                 static int write_packet_thunk(void *opaque, uint8_t *buf, int buf_size);
  91                 int write_packet(uint8_t *buf, int buf_size);
  92
  93                 std::mutex buffer_mutex;
  94                 std::condition_variable has_buffered_data;
  95                 std::deque<std::string> buffered_data;  // Protected by <mutex>.
  96                 size_t used_of_buffered_data = 0;  // How many bytes of the first element of <buffered_data> that is already used. Protected by <mutex>.
  97
  98                 std::unique_ptr<Mux> mux;  // Must come last to be destroyed before buffered_data, since the destructor can write bytes.
  99         };
 100
 101         std::mutex streams_mutex;
 102         std::set<Stream *> streams;  // Not owned.
 103
 104         int width, height;
 105         std::unique_ptr<Mux> file_mux;  // To local disk.
 106 };
 107
 108 #endif  // !defined(_HTTPD_H)