Reset audio resampler when FFmpeg inputs restart due to errors.

Not relevant for Kaeru, but will be relevant when Nageru gets FFmpeg
audio inputs soon.

diff --git a/ffmpeg_capture.cpp b/ffmpeg_capture.cpp
index 8fdb6a58adf38a8a14c771b6b6853c6cea610103..9ae35042d1ce998701e34b9072ca26b2700d047f 100644 (file)
--- a/ffmpeg_capture.cpp
+++ b/ffmpeg_capture.cpp
@@ -211,6 +211,8 @@ FFmpegCapture::FFmpegCapture(const string &filename, unsigned width, unsigned he
        // Not really used for anything.
        description = "Video: " + filename;
 
+       last_frame = steady_clock::now();
+
        avformat_network_init();  // In case someone wants this.
 }
 
@@ -338,6 +340,7 @@ void FFmpegCapture::send_disconnected_frame()
                frame_callback(-1, AVRational{1, TIMEBASE}, -1, AVRational{1, TIMEBASE}, timecode++,
                        video_frame, /*video_offset=*/0, video_format,
                        FrameAllocator::Frame(), /*audio_offset=*/0, AudioFormat());
+               last_frame_was_connected = false;
        }
 }
 
@@ -423,6 +426,7 @@ bool FFmpegCapture::play_video(const string &pathname)
        internal_rewind();
 
        // Main loop.
+       bool first_frame = true;
        while (!producer_thread_should_quit.should_quit()) {
                if (process_queued_commands(format_ctx.get(), pathname, last_modified, /*rewound=*/nullptr)) {
                        return true;
@@ -471,6 +475,14 @@ bool FFmpegCapture::play_video(const string &pathname)
                                pts_origin = frame->pts;        
                        }
                        next_frame_start = compute_frame_start(frame->pts, pts_origin, video_timebase, start, rate);
+                       if (first_frame && last_frame_was_connected) {
+                               // If reconnect took more than one second, this is probably a live feed,
+                               // and we should reset the resampler. (Or the rate is really, really low,
+                               // in which case a reset on the first frame is fine anyway.)
+                               if (duration<double>(next_frame_start - last_frame).count() >= 1.0) {
+                                       last_frame_was_connected = false;
+                               }
+                       }
                        video_frame->received_timestamp = next_frame_start;
                        audio_frame->received_timestamp = next_frame_start;
                        bool finished_wakeup = producer_thread_should_quit.sleep_until(next_frame_start);
@@ -478,9 +490,19 @@ bool FFmpegCapture::play_video(const string &pathname)
                                if (audio_frame->len > 0) {
                                        assert(audio_pts != -1);
                                }
+                               if (!last_frame_was_connected) {
+                                       // We're recovering from an error (or really slow load, see above).
+                                       // Make sure to get the audio resampler reset. (This is a hack;
+                                       // ideally, the frame callback should just accept a way to signal
+                                       // audio discontinuity.)
+                                       timecode += MAX_FPS * 2 + 1;
+                               }
                                frame_callback(frame->pts, video_timebase, audio_pts, audio_timebase, timecode++,
                                        video_frame.get_and_release(), 0, video_format,
                                        audio_frame.get_and_release(), 0, audio_format);
+                               first_frame = false;
+                               last_frame = steady_clock::now();
+                               last_frame_was_connected = true;
                                break;
                        } else {
                                if (producer_thread_should_quit.should_quit()) break;

diff --git a/ffmpeg_capture.h b/ffmpeg_capture.h
index 705d25ffe5a47461e297401e81e7c6ccd6b69eaf..0fbc3e895ddaa6726fa976378f3d8a526009ab06 100644 (file)
--- a/ffmpeg_capture.h
+++ b/ffmpeg_capture.h
@@ -225,6 +225,7 @@ private:
        int card_index = -1;
        double rate = 1.0;
        std::atomic<bool> should_interrupt{false};
+       bool last_frame_was_connected = true;
 
        bool has_dequeue_callbacks = false;
        std::function<void()> dequeue_init_callback = nullptr;
@@ -246,7 +247,7 @@ private:
        std::thread producer_thread;
 
        int64_t pts_origin, last_pts;
-       std::chrono::steady_clock::time_point start, next_frame_start;
+       std::chrono::steady_clock::time_point start, next_frame_start, last_frame;
 
        std::mutex queue_mu;
        struct QueuedCommand {