Add an option --http-coarse-timebase for streaming to MP4.

diff --git a/flags.cpp b/flags.cpp
index 0fe2236e44b51801808eee8228d7652e7798d6e8..0c01e23799812a3a4f0060ac33d5bb98cbf12b55 100644 (file)
--- a/flags.cpp
+++ b/flags.cpp
@@ -17,6 +17,8 @@ void usage()
        fprintf(stderr, "                                    ($DISPLAY spec or /dev/dri/render* path)\n");
        fprintf(stderr, "      --http-uncompressed-video   send uncompressed NV12 video to HTTP clients\n");
        fprintf(stderr, "      --http-mux=NAME             mux to use for HTTP streams (default " DEFAULT_STREAM_MUX_NAME ")\n");
+       fprintf(stderr, "      --http-coarse-timebase      use less timebase for HTTP (recommended for muxers\n");
+       fprintf(stderr, "                                  that handle large pts poorly, like e.g. MP4)\n");
        fprintf(stderr, "      --flat-audio                start with most audio processing turned off\n");
        fprintf(stderr, "      --no-flush-pbos             do not explicitly signal texture data uploads\n");
        fprintf(stderr, "                                    (will give display corruption, but makes it\n");
@@ -32,6 +34,7 @@ void parse_flags(int argc, char * const argv[])
                { "va-display", required_argument, 0, 1000 },
                { "http-uncompressed-video", no_argument, 0, 1001 },
                { "http-mux", required_argument, 0, 1004 },
+               { "http-coarse-timebase", no_argument, 0, 1005 },
                { "flat-audio", no_argument, 0, 1002 },
                { "no-flush-pbos", no_argument, 0, 1003 },
                { 0, 0, 0, 0 }
@@ -59,6 +62,9 @@ void parse_flags(int argc, char * const argv[])
                case 1004:
                        global_flags.stream_mux_name = optarg;
                        break;
+               case 1005:
+                       global_flags.stream_coarse_timebase = true;
+                       break;
                case 1002:
                        global_flags.flat_audio = true;
                        break;

diff --git a/flags.h b/flags.h
index 308e3103bfd6be6c068406f166971bc24cc17994..b2dedb6c05a1ca689b1d5b588b994142da552f20 100644 (file)
--- a/flags.h
+++ b/flags.h
@@ -13,6 +13,7 @@ struct Flags {
        bool flat_audio = false;
        bool flush_pbos = true;
        std::string stream_mux_name = DEFAULT_STREAM_MUX_NAME;
+       bool stream_coarse_timebase = false;
 };
 extern Flags global_flags;
 

diff --git a/httpd.cpp b/httpd.cpp
index f6664b3df900879fe89a6f14c7c72160e7293ed2..d860a58311a7ac467d5ccfef7d01b2bd4126434c 100644 (file)
--- a/httpd.cpp
+++ b/httpd.cpp
@@ -70,7 +70,7 @@ void HTTPD::open_output_file(const string &filename)
                exit(1);
        }
 
-       file_mux.reset(new Mux(avctx, width, height, Mux::CODEC_H264));
+       file_mux.reset(new Mux(avctx, width, height, Mux::CODEC_H264, TIMEBASE));
 }
 
 void HTTPD::close_output_file()
@@ -94,7 +94,9 @@ int HTTPD::answer_to_connection(MHD_Connection *connection,
 {
        AVOutputFormat *oformat = av_guess_format(global_flags.stream_mux_name.c_str(), nullptr, nullptr);
        assert(oformat != nullptr);
-       HTTPD::Stream *stream = new HTTPD::Stream(oformat, width, height);
+
+       int time_base = global_flags.stream_coarse_timebase ? COARSE_TIMEBASE : TIMEBASE;
+       HTTPD::Stream *stream = new HTTPD::Stream(oformat, width, height, time_base);
        {
                unique_lock<mutex> lock(streams_mutex);
                streams.insert(stream);
@@ -138,7 +140,7 @@ void HTTPD::request_completed(struct MHD_Connection *connection, void **con_cls,
        }
 }
 
-HTTPD::Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec)
+HTTPD::Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, int time_base)
        : avctx(avctx)
 {
        AVCodec *codec_video = avcodec_find_encoder((video_codec == CODEC_H264) ? AV_CODEC_ID_H264 : AV_CODEC_ID_RAWVIDEO);
@@ -147,7 +149,7 @@ HTTPD::Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec
                fprintf(stderr, "avformat_new_stream() failed\n");
                exit(1);
        }
-       avstream_video->time_base = AVRational{1, TIMEBASE};
+       avstream_video->time_base = AVRational{1, time_base};
        avstream_video->codec->codec_type = AVMEDIA_TYPE_VIDEO;
        if (video_codec == CODEC_H264) {
                avstream_video->codec->codec_id = AV_CODEC_ID_H264;
@@ -158,7 +160,7 @@ HTTPD::Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec
        }
        avstream_video->codec->width = width;
        avstream_video->codec->height = height;
-       avstream_video->codec->time_base = AVRational{1, TIMEBASE};
+       avstream_video->codec->time_base = AVRational{1, time_base};
        avstream_video->codec->ticks_per_frame = 1;  // or 2?
 
        // Colorspace details. Closely correspond to settings in EffectChain_finalize,
@@ -181,13 +183,13 @@ HTTPD::Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec
                fprintf(stderr, "avformat_new_stream() failed\n");
                exit(1);
        }
-       avstream_audio->time_base = AVRational{1, TIMEBASE};
+       avstream_audio->time_base = AVRational{1, time_base};
        avstream_audio->codec->bit_rate = AUDIO_OUTPUT_BIT_RATE;
        avstream_audio->codec->sample_rate = OUTPUT_FREQUENCY;
        avstream_audio->codec->sample_fmt = AUDIO_OUTPUT_SAMPLE_FMT;
        avstream_audio->codec->channels = 2;
        avstream_audio->codec->channel_layout = AV_CH_LAYOUT_STEREO;
-       avstream_audio->codec->time_base = AVRational{1, TIMEBASE};
+       avstream_audio->codec->time_base = AVRational{1, time_base};
        if (avctx->oformat->flags & AVFMT_GLOBALHEADER) {
                avstream_audio->codec->flags = AV_CODEC_FLAG_GLOBAL_HEADER;
        }
@@ -239,7 +241,7 @@ void HTTPD::Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts)
        av_packet_unref(&pkt_copy);
 }
 
-HTTPD::Stream::Stream(AVOutputFormat *oformat, int width, int height)
+HTTPD::Stream::Stream(AVOutputFormat *oformat, int width, int height, int time_base)
 {
        AVFormatContext *avctx = avformat_alloc_context();
        avctx->oformat = oformat;
@@ -255,7 +257,7 @@ HTTPD::Stream::Stream(AVOutputFormat *oformat, int width, int height)
 
        avctx->flags = AVFMT_FLAG_CUSTOM_IO;
 
-       mux.reset(new Mux(avctx, width, height, video_codec));
+       mux.reset(new Mux(avctx, width, height, video_codec, time_base));
 }
 
 ssize_t HTTPD::Stream::reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max)

diff --git a/httpd.h b/httpd.h
index 695c7082cd36436b8bbf345f48fd53681f924a33..e6f12d99698feae9d5cec1bd0d4c55d4fdbf2a02 100644 (file)
--- a/httpd.h
+++ b/httpd.h
@@ -67,7 +67,7 @@ private:
                        CODEC_NV12,  // Uncompressed 4:2:0.
                };
 
-               Mux(AVFormatContext *avctx, int width, int height, Codec video_codec);  // Takes ownership of avctx.
+               Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, int time_base);  // Takes ownership of avctx.
                ~Mux();
                void add_packet(const AVPacket &pkt, int64_t pts, int64_t dts);
 
@@ -79,7 +79,7 @@ private:
 
        class Stream {
        public:
-               Stream(AVOutputFormat *oformat, int width, int height);
+               Stream(AVOutputFormat *oformat, int width, int height, int time_base);
 
                static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
                ssize_t reader_callback(uint64_t pos, char *buf, size_t max);

diff --git a/timebase.h b/timebase.h
index be2362b2ef7d376222564ccb81d09fa557aea6b5..3d335fd3ca9ccec07a4eb628559f178d1079f33a 100644 (file)
--- a/timebase.h
+++ b/timebase.h
@@ -14,4 +14,11 @@
 // going to 44100000; probably a bit excessive.
 #define TIMEBASE 60000
 
+// Some muxes, like MP4 (or at least avformat's implementation of it),
+// are not too fond of values above 2^31. At timebase 60000, that's only
+// about ten hours or so, so we define a coarser timebase that doesn't
+// get 59.94 precisely (so there will be a marginal amount of pts jitter),
+// but can do at least 50 and 60 precisely, and months of streaming.
+#define COARSE_TIMEBASE 300
+
 #endif  // !defined(_TIMEBASE_H)