]> git.sesse.net Git - nageru/blobdiff - video_stream.cpp
Allow symlinked frame files. Useful for testing.
[nageru] / video_stream.cpp
index e89839a6314f963f410f577dc7607f135499a579..d425ed190b6fa3187a6f3311c3c980d7ff48c031 100644 (file)
@@ -7,6 +7,7 @@ extern "C" {
 
 #include "chroma_subsampler.h"
 #include "context.h"
+#include "flags.h"
 #include "flow.h"
 #include "httpd.h"
 #include "jpeg_frame_view.h"
@@ -21,32 +22,10 @@ extern "C" {
 #include <unistd.h>
 
 using namespace std;
+using namespace std::chrono;
 
 extern HTTPD *global_httpd;
 
-namespace {
-
-string read_file(const string &filename)
-{
-       FILE *fp = fopen(filename.c_str(), "rb");
-       if (fp == nullptr) {
-               perror(filename.c_str());
-               return "";
-       }
-
-       fseek(fp, 0, SEEK_END);
-       long len = ftell(fp);
-       rewind(fp);
-
-       string ret;
-       ret.resize(len);
-       fread(&ret[0], len, 1, fp);
-       fclose(fp);
-       return ret;
-}
-
-}  // namespace
-
 struct VectorDestinationManager {
        jpeg_destination_mgr pub;
        std::vector<uint8_t> dest;
@@ -155,12 +134,12 @@ VideoStream::VideoStream()
        GLuint fade_y_output_tex[num_interpolate_slots], fade_cbcr_output_tex[num_interpolate_slots];
        GLuint cb_tex[num_interpolate_slots], cr_tex[num_interpolate_slots];
 
-       glCreateTextures(GL_TEXTURE_2D_ARRAY, 10, input_tex);
-       glCreateTextures(GL_TEXTURE_2D_ARRAY, 10, gray_tex);
-       glCreateTextures(GL_TEXTURE_2D, 10, fade_y_output_tex);
-       glCreateTextures(GL_TEXTURE_2D, 10, fade_cbcr_output_tex);
-       glCreateTextures(GL_TEXTURE_2D, 10, cb_tex);
-       glCreateTextures(GL_TEXTURE_2D, 10, cr_tex);
+       glCreateTextures(GL_TEXTURE_2D_ARRAY, num_interpolate_slots, input_tex);
+       glCreateTextures(GL_TEXTURE_2D_ARRAY, num_interpolate_slots, gray_tex);
+       glCreateTextures(GL_TEXTURE_2D, num_interpolate_slots, fade_y_output_tex);
+       glCreateTextures(GL_TEXTURE_2D, num_interpolate_slots, fade_cbcr_output_tex);
+       glCreateTextures(GL_TEXTURE_2D, num_interpolate_slots, cb_tex);
+       glCreateTextures(GL_TEXTURE_2D, num_interpolate_slots, cr_tex);
        check_error();
 
        constexpr size_t width = 1280, height = 720;  // FIXME: adjustable width, height
@@ -179,52 +158,66 @@ VideoStream::VideoStream()
                glTextureStorage2D(cr_tex[i], 1, GL_R8, width / 2, height);
                check_error();
 
-               InterpolatedFrameResources resource;
-               resource.input_tex = input_tex[i];
-               resource.gray_tex = gray_tex[i];
-               resource.fade_y_output_tex = fade_y_output_tex[i];
-               resource.fade_cbcr_output_tex = fade_cbcr_output_tex[i];
-               resource.cb_tex = cb_tex[i];
-               resource.cr_tex = cr_tex[i];
-               glCreateFramebuffers(2, resource.input_fbos);
+               unique_ptr<InterpolatedFrameResources> resource(new InterpolatedFrameResources);
+               resource->owner = this;
+               resource->input_tex = input_tex[i];
+               resource->gray_tex = gray_tex[i];
+               resource->fade_y_output_tex = fade_y_output_tex[i];
+               resource->fade_cbcr_output_tex = fade_cbcr_output_tex[i];
+               resource->cb_tex = cb_tex[i];
+               resource->cr_tex = cr_tex[i];
+               glCreateFramebuffers(2, resource->input_fbos);
                check_error();
-               glCreateFramebuffers(1, &resource.fade_fbo);
+               glCreateFramebuffers(1, &resource->fade_fbo);
                check_error();
 
-               glNamedFramebufferTextureLayer(resource.input_fbos[0], GL_COLOR_ATTACHMENT0, input_tex[i], 0, 0);
+               glNamedFramebufferTextureLayer(resource->input_fbos[0], GL_COLOR_ATTACHMENT0, input_tex[i], 0, 0);
                check_error();
-               glNamedFramebufferTextureLayer(resource.input_fbos[0], GL_COLOR_ATTACHMENT1, gray_tex[i], 0, 0);
+               glNamedFramebufferTextureLayer(resource->input_fbos[0], GL_COLOR_ATTACHMENT1, gray_tex[i], 0, 0);
                check_error();
-               glNamedFramebufferTextureLayer(resource.input_fbos[1], GL_COLOR_ATTACHMENT0, input_tex[i], 0, 1);
+               glNamedFramebufferTextureLayer(resource->input_fbos[1], GL_COLOR_ATTACHMENT0, input_tex[i], 0, 1);
                check_error();
-               glNamedFramebufferTextureLayer(resource.input_fbos[1], GL_COLOR_ATTACHMENT1, gray_tex[i], 0, 1);
+               glNamedFramebufferTextureLayer(resource->input_fbos[1], GL_COLOR_ATTACHMENT1, gray_tex[i], 0, 1);
                check_error();
-               glNamedFramebufferTexture(resource.fade_fbo, GL_COLOR_ATTACHMENT0, fade_y_output_tex[i], 0);
+               glNamedFramebufferTexture(resource->fade_fbo, GL_COLOR_ATTACHMENT0, fade_y_output_tex[i], 0);
                check_error();
-               glNamedFramebufferTexture(resource.fade_fbo, GL_COLOR_ATTACHMENT1, fade_cbcr_output_tex[i], 0);
+               glNamedFramebufferTexture(resource->fade_fbo, GL_COLOR_ATTACHMENT1, fade_cbcr_output_tex[i], 0);
                check_error();
 
                GLuint bufs[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 };
-               glNamedFramebufferDrawBuffers(resource.input_fbos[0], 2, bufs);
+               glNamedFramebufferDrawBuffers(resource->input_fbos[0], 2, bufs);
                check_error();
-               glNamedFramebufferDrawBuffers(resource.input_fbos[1], 2, bufs);
+               glNamedFramebufferDrawBuffers(resource->input_fbos[1], 2, bufs);
                check_error();
-               glNamedFramebufferDrawBuffers(resource.fade_fbo, 2, bufs);
+               glNamedFramebufferDrawBuffers(resource->fade_fbo, 2, bufs);
                check_error();
 
-               glCreateBuffers(1, &resource.pbo);
+               glCreateBuffers(1, &resource->pbo);
                check_error();
-               glNamedBufferStorage(resource.pbo, width * height * 4, nullptr, GL_MAP_READ_BIT | GL_MAP_PERSISTENT_BIT);
+               glNamedBufferStorage(resource->pbo, width * height * 4, nullptr, GL_MAP_READ_BIT | GL_MAP_PERSISTENT_BIT);
                check_error();
-               resource.pbo_contents = glMapNamedBufferRange(resource.pbo, 0, width * height * 4, GL_MAP_READ_BIT | GL_MAP_PERSISTENT_BIT);
-               interpolate_resources.push_back(resource);
+               resource->pbo_contents = glMapNamedBufferRange(resource->pbo, 0, width * height * 4, GL_MAP_READ_BIT | GL_MAP_PERSISTENT_BIT);
+               interpolate_resources.push_back(move(resource));
        }
 
        check_error();
 
-       compute_flow.reset(new DISComputeFlow(width, height, operating_point2));
-       interpolate.reset(new Interpolate(operating_point2, /*split_ycbcr_output=*/true));
-       interpolate_no_split.reset(new Interpolate(operating_point2, /*split_ycbcr_output=*/false));
+       OperatingPoint op;
+       if (global_flags.interpolation_quality == 1) {
+               op = operating_point1;
+       } else if (global_flags.interpolation_quality == 2) {
+               op = operating_point2;
+       } else if (global_flags.interpolation_quality == 3) {
+               op = operating_point3;
+       } else if (global_flags.interpolation_quality == 4) {
+               op = operating_point4;
+       } else {
+               assert(false);
+       }
+
+       compute_flow.reset(new DISComputeFlow(width, height, op));
+       interpolate.reset(new Interpolate(op, /*split_ycbcr_output=*/true));
+       interpolate_no_split.reset(new Interpolate(op, /*split_ycbcr_output=*/false));
        chroma_subsampler.reset(new ChromaSubsampler);
        check_error();
 
@@ -267,78 +260,107 @@ void VideoStream::stop()
        encode_thread.join();
 }
 
-void VideoStream::schedule_original_frame(int64_t output_pts, unsigned stream_idx, int64_t input_pts)
+void VideoStream::clear_queue()
+{
+       deque<QueuedFrame> q;
+
+       {
+               unique_lock<mutex> lock(queue_lock);
+               q = move(frame_queue);
+       }
+
+       // These are not RAII-ed, unfortunately, so we'll need to clean them ourselves.
+       // Note that release_texture() is thread-safe.
+       for (const QueuedFrame &qf : q) {
+               if (qf.type == QueuedFrame::INTERPOLATED ||
+                   qf.type == QueuedFrame::FADED_INTERPOLATED) {
+                       compute_flow->release_texture(qf.flow_tex);
+               }
+               if (qf.type == QueuedFrame::INTERPOLATED) {
+                       interpolate->release_texture(qf.output_tex);
+                       interpolate->release_texture(qf.cbcr_tex);
+               }
+       }
+
+       // Destroy q outside the mutex, as that would be a double-lock.
+}
+
+void VideoStream::schedule_original_frame(steady_clock::time_point local_pts,
+                                          int64_t output_pts, function<void()> &&display_func,
+                                          QueueSpotHolder &&queue_spot_holder,
+                                          FrameOnDisk frame)
 {
-       fprintf(stderr, "output_pts=%ld  original      input_pts=%ld\n", output_pts, input_pts);
+       fprintf(stderr, "output_pts=%ld  original      input_pts=%ld\n", output_pts, frame.pts);
+
+       // Preload the file from disk, so that the encoder thread does not get stalled.
+       // TODO: Consider sending it through the queue instead.
+       (void)frame_reader.read_frame(frame);
 
        QueuedFrame qf;
+       qf.local_pts = local_pts;
        qf.type = QueuedFrame::ORIGINAL;
        qf.output_pts = output_pts;
-       qf.stream_idx = stream_idx;
-       qf.input_first_pts = input_pts;
+       qf.frame1 = frame;
+       qf.display_func = move(display_func);
+       qf.queue_spot_holder = move(queue_spot_holder);
 
        unique_lock<mutex> lock(queue_lock);
-       frame_queue.push_back(qf);
-       queue_nonempty.notify_all();
+       frame_queue.push_back(move(qf));
+       queue_changed.notify_all();
 }
 
-void VideoStream::schedule_faded_frame(int64_t output_pts, unsigned stream_idx, int64_t input_pts, int secondary_stream_idx, int64_t secondary_input_pts, float fade_alpha)
+void VideoStream::schedule_faded_frame(steady_clock::time_point local_pts, int64_t output_pts,
+                                       function<void()> &&display_func,
+                                       QueueSpotHolder &&queue_spot_holder,
+                                       FrameOnDisk frame1_spec, FrameOnDisk frame2_spec,
+                                       float fade_alpha)
 {
-       fprintf(stderr, "output_pts=%ld  faded         input_pts=%ld,%ld  fade_alpha=%.2f\n", output_pts, input_pts, secondary_input_pts, fade_alpha);
+       fprintf(stderr, "output_pts=%ld  faded         input_pts=%ld,%ld  fade_alpha=%.2f\n", output_pts, frame1_spec.pts, frame2_spec.pts, fade_alpha);
 
        // Get the temporary OpenGL resources we need for doing the fade.
        // (We share these with interpolated frames, which is slightly
        // overkill, but there's no need to waste resources on keeping
        // separate pools around.)
-       InterpolatedFrameResources resources;
+       BorrowedInterpolatedFrameResources resources;
        {
                unique_lock<mutex> lock(queue_lock);
                if (interpolate_resources.empty()) {
                        fprintf(stderr, "WARNING: Too many interpolated frames already in transit; dropping one.\n");
                        return;
                }
-               resources = interpolate_resources.front();
+               resources = BorrowedInterpolatedFrameResources(interpolate_resources.front().release());
                interpolate_resources.pop_front();
        }
 
        bool did_decode;
 
-       JPEGID jpeg_id1;
-       jpeg_id1.stream_idx = stream_idx;
-       jpeg_id1.pts = input_pts;
-       jpeg_id1.interpolated = false;
-       shared_ptr<Frame> frame1 = decode_jpeg_with_cache(jpeg_id1, DECODE_IF_NOT_IN_CACHE, &did_decode);
+       shared_ptr<Frame> frame1 = decode_jpeg_with_cache(frame1_spec, DECODE_IF_NOT_IN_CACHE, &frame_reader, &did_decode);
+       shared_ptr<Frame> frame2 = decode_jpeg_with_cache(frame2_spec, DECODE_IF_NOT_IN_CACHE, &frame_reader, &did_decode);
 
-       JPEGID jpeg_id2;
-       jpeg_id2.stream_idx = secondary_stream_idx;
-       jpeg_id2.pts = secondary_input_pts;
-       jpeg_id2.interpolated = false;
-       shared_ptr<Frame> frame2 = decode_jpeg_with_cache(jpeg_id2, DECODE_IF_NOT_IN_CACHE, &did_decode);
-
-       ycbcr_semiplanar_converter->prepare_chain_for_fade(frame1, frame2, fade_alpha)->render_to_fbo(resources.fade_fbo, 1280, 720);
+       ycbcr_semiplanar_converter->prepare_chain_for_fade(frame1, frame2, fade_alpha)->render_to_fbo(resources->fade_fbo, 1280, 720);
 
        QueuedFrame qf;
+       qf.local_pts = local_pts;
        qf.type = QueuedFrame::FADED;
        qf.output_pts = output_pts;
-       qf.stream_idx = stream_idx;
-       qf.resources = resources;
-       qf.input_first_pts = input_pts;
+       qf.frame1 = frame1_spec;
+       qf.display_func = move(display_func);
+       qf.queue_spot_holder = move(queue_spot_holder);
 
-       qf.secondary_stream_idx = secondary_stream_idx;
-       qf.secondary_input_pts = secondary_input_pts;
+       qf.secondary_frame = frame2_spec;
 
        // Subsample and split Cb/Cr.
-       chroma_subsampler->subsample_chroma(resources.fade_cbcr_output_tex, 1280, 720, resources.cb_tex, resources.cr_tex);
+       chroma_subsampler->subsample_chroma(resources->fade_cbcr_output_tex, 1280, 720, resources->cb_tex, resources->cr_tex);
 
        // Read it down (asynchronously) to the CPU.
        glPixelStorei(GL_PACK_ROW_LENGTH, 0);
-       glBindBuffer(GL_PIXEL_PACK_BUFFER, resources.pbo);
+       glBindBuffer(GL_PIXEL_PACK_BUFFER, resources->pbo);
        check_error();
-       glGetTextureImage(resources.fade_y_output_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 4, BUFFER_OFFSET(0));
+       glGetTextureImage(resources->fade_y_output_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 4, BUFFER_OFFSET(0));
        check_error();
-       glGetTextureImage(resources.cb_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3, BUFFER_OFFSET(1280 * 720));
+       glGetTextureImage(resources->cb_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3, BUFFER_OFFSET(1280 * 720));
        check_error();
-       glGetTextureImage(resources.cr_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3 - 640 * 720, BUFFER_OFFSET(1280 * 720 + 640 * 720));
+       glGetTextureImage(resources->cr_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3 - 640 * 720, BUFFER_OFFSET(1280 * 720 + 640 * 720));
        check_error();
        glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
 
@@ -347,93 +369,86 @@ void VideoStream::schedule_faded_frame(int64_t output_pts, unsigned stream_idx,
        check_error();
        qf.fence = RefCountedGLsync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
        check_error();
+       qf.resources = move(resources);
+       qf.local_pts = local_pts;
 
        unique_lock<mutex> lock(queue_lock);
-       frame_queue.push_back(qf);
-       queue_nonempty.notify_all();
+       frame_queue.push_back(move(qf));
+       queue_changed.notify_all();
 }
 
-void VideoStream::schedule_interpolated_frame(int64_t output_pts, unsigned stream_idx, int64_t input_first_pts, int64_t input_second_pts, float alpha, int secondary_stream_idx, int64_t secondary_input_pts, float fade_alpha)
+void VideoStream::schedule_interpolated_frame(steady_clock::time_point local_pts,
+                                              int64_t output_pts, function<void(shared_ptr<Frame>)> &&display_func,
+                                              QueueSpotHolder &&queue_spot_holder,
+                                              FrameOnDisk frame1, FrameOnDisk frame2,
+                                              float alpha, FrameOnDisk secondary_frame, float fade_alpha)
 {
-       if (secondary_stream_idx != -1) {
-               fprintf(stderr, "output_pts=%ld  interpolated  input_pts1=%ld input_pts2=%ld alpha=%.3f  secondary_pts=%ld  fade_alpha=%.2f\n", output_pts, input_first_pts, input_second_pts, alpha, secondary_input_pts, fade_alpha);
+       if (secondary_frame.pts != -1) {
+               fprintf(stderr, "output_pts=%ld  interpolated  input_pts1=%ld input_pts2=%ld alpha=%.3f  secondary_pts=%ld  fade_alpha=%.2f\n", output_pts, frame1.pts, frame2.pts, alpha, secondary_frame.pts, fade_alpha);
        } else {
-               fprintf(stderr, "output_pts=%ld  interpolated  input_pts1=%ld input_pts2=%ld alpha=%.3f\n", output_pts, input_first_pts, input_second_pts, alpha);
-       }
-
-       JPEGID id;
-       if (secondary_stream_idx == -1) {
-               id = JPEGID{ stream_idx, output_pts, /*interpolated=*/true };
-       } else {
-               id = create_jpegid_for_interpolated_fade(stream_idx, output_pts, secondary_stream_idx, secondary_input_pts);
+               fprintf(stderr, "output_pts=%ld  interpolated  input_pts1=%ld input_pts2=%ld alpha=%.3f\n", output_pts, frame1.pts, frame2.pts, alpha);
        }
 
        // Get the temporary OpenGL resources we need for doing the interpolation.
-       InterpolatedFrameResources resources;
+       BorrowedInterpolatedFrameResources resources;
        {
                unique_lock<mutex> lock(queue_lock);
                if (interpolate_resources.empty()) {
                        fprintf(stderr, "WARNING: Too many interpolated frames already in transit; dropping one.\n");
-                       JPEGFrameView::insert_interpolated_frame(id, nullptr);
                        return;
                }
-               resources = interpolate_resources.front();
+               resources = BorrowedInterpolatedFrameResources(interpolate_resources.front().release());
                interpolate_resources.pop_front();
        }
 
        QueuedFrame qf;
-       qf.type = (secondary_stream_idx == -1) ? QueuedFrame::INTERPOLATED : QueuedFrame::FADED_INTERPOLATED;
+       qf.type = (secondary_frame.pts == -1) ? QueuedFrame::INTERPOLATED : QueuedFrame::FADED_INTERPOLATED;
        qf.output_pts = output_pts;
-       qf.stream_idx = stream_idx;
-       qf.resources = resources;
-       qf.id = id;
+       qf.display_decoded_func = move(display_func);
+       qf.queue_spot_holder = move(queue_spot_holder);
+       qf.local_pts = local_pts;
 
        check_error();
 
        // Convert frame0 and frame1 to OpenGL textures.
        for (size_t frame_no = 0; frame_no < 2; ++frame_no) {
-               JPEGID jpeg_id;
-               jpeg_id.stream_idx = stream_idx;
-               jpeg_id.pts = frame_no == 1 ? input_second_pts : input_first_pts;
-               jpeg_id.interpolated = false;
+               FrameOnDisk frame_spec = frame_no == 1 ? frame2 : frame1;
                bool did_decode;
-               shared_ptr<Frame> frame = decode_jpeg_with_cache(jpeg_id, DECODE_IF_NOT_IN_CACHE, &did_decode);
-               ycbcr_converter->prepare_chain_for_conversion(frame)->render_to_fbo(resources.input_fbos[frame_no], 1280, 720);
+               shared_ptr<Frame> frame = decode_jpeg_with_cache(frame_spec, DECODE_IF_NOT_IN_CACHE, &frame_reader, &did_decode);
+               ycbcr_converter->prepare_chain_for_conversion(frame)->render_to_fbo(resources->input_fbos[frame_no], 1280, 720);
        }
 
-       glGenerateTextureMipmap(resources.input_tex);
+       glGenerateTextureMipmap(resources->input_tex);
        check_error();
-       glGenerateTextureMipmap(resources.gray_tex);
+       glGenerateTextureMipmap(resources->gray_tex);
        check_error();
 
        // Compute the interpolated frame.
-       qf.flow_tex = compute_flow->exec(resources.gray_tex, DISComputeFlow::FORWARD_AND_BACKWARD, DISComputeFlow::DO_NOT_RESIZE_FLOW);
+       qf.flow_tex = compute_flow->exec(resources->gray_tex, DISComputeFlow::FORWARD_AND_BACKWARD, DISComputeFlow::DO_NOT_RESIZE_FLOW);
        check_error();
 
-       if (secondary_stream_idx != -1) {
+       if (secondary_frame.pts != -1) {
                // Fade. First kick off the interpolation.
-               tie(qf.output_tex, ignore) = interpolate_no_split->exec(resources.input_tex, resources.gray_tex, qf.flow_tex, 1280, 720, alpha);
+               tie(qf.output_tex, ignore) = interpolate_no_split->exec(resources->input_tex, resources->gray_tex, qf.flow_tex, 1280, 720, alpha);
                check_error();
 
                // Now decode the image we are fading against.
-               JPEGID jpeg_id;
-               jpeg_id.stream_idx = secondary_stream_idx;
-               jpeg_id.pts = secondary_input_pts;
-               jpeg_id.interpolated = false;
                bool did_decode;
-               shared_ptr<Frame> frame2 = decode_jpeg_with_cache(jpeg_id, DECODE_IF_NOT_IN_CACHE, &did_decode);
+               shared_ptr<Frame> frame2 = decode_jpeg_with_cache(secondary_frame, DECODE_IF_NOT_IN_CACHE, &frame_reader, &did_decode);
 
                // Then fade against it, putting it into the fade Y' and CbCr textures.
-               ycbcr_semiplanar_converter->prepare_chain_for_fade_from_texture(qf.output_tex, frame2, fade_alpha)->render_to_fbo(resources.fade_fbo, 1280, 720);
+               ycbcr_semiplanar_converter->prepare_chain_for_fade_from_texture(qf.output_tex, frame2, fade_alpha)->render_to_fbo(resources->fade_fbo, 1280, 720);
 
                // Subsample and split Cb/Cr.
-               chroma_subsampler->subsample_chroma(resources.fade_cbcr_output_tex, 1280, 720, resources.cb_tex, resources.cr_tex);
+               chroma_subsampler->subsample_chroma(resources->fade_cbcr_output_tex, 1280, 720, resources->cb_tex, resources->cr_tex);
+
+               interpolate_no_split->release_texture(qf.output_tex);
        } else {
-               tie(qf.output_tex, qf.cbcr_tex) = interpolate->exec(resources.input_tex, resources.gray_tex, qf.flow_tex, 1280, 720, alpha);
+               tie(qf.output_tex, qf.cbcr_tex) = interpolate->exec(resources->input_tex, resources->gray_tex, qf.flow_tex, 1280, 720, alpha);
                check_error();
 
                // Subsample and split Cb/Cr.
-               chroma_subsampler->subsample_chroma(qf.cbcr_tex, 1280, 720, resources.cb_tex, resources.cr_tex);
+               chroma_subsampler->subsample_chroma(qf.cbcr_tex, 1280, 720, resources->cb_tex, resources->cr_tex);
        }
 
        // We could have released qf.flow_tex here, but to make sure we don't cause a stall
@@ -442,17 +457,17 @@ void VideoStream::schedule_interpolated_frame(int64_t output_pts, unsigned strea
 
        // Read it down (asynchronously) to the CPU.
        glPixelStorei(GL_PACK_ROW_LENGTH, 0);
-       glBindBuffer(GL_PIXEL_PACK_BUFFER, resources.pbo);
+       glBindBuffer(GL_PIXEL_PACK_BUFFER, resources->pbo);
        check_error();
-       if (secondary_stream_idx != -1) {
-               glGetTextureImage(resources.fade_y_output_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 4, BUFFER_OFFSET(0));
+       if (secondary_frame.pts != -1) {
+               glGetTextureImage(resources->fade_y_output_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 4, BUFFER_OFFSET(0));
        } else {
                glGetTextureImage(qf.output_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 4, BUFFER_OFFSET(0));
        }
        check_error();
-       glGetTextureImage(resources.cb_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3, BUFFER_OFFSET(1280 * 720));
+       glGetTextureImage(resources->cb_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3, BUFFER_OFFSET(1280 * 720));
        check_error();
-       glGetTextureImage(resources.cr_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3 - 640 * 720, BUFFER_OFFSET(1280 * 720 + 640 * 720));
+       glGetTextureImage(resources->cr_tex, 0, GL_RED, GL_UNSIGNED_BYTE, 1280 * 720 * 3 - 640 * 720, BUFFER_OFFSET(1280 * 720 + 640 * 720));
        check_error();
        glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
 
@@ -461,20 +476,26 @@ void VideoStream::schedule_interpolated_frame(int64_t output_pts, unsigned strea
        check_error();
        qf.fence = RefCountedGLsync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
        check_error();
+       qf.resources = move(resources);
 
        unique_lock<mutex> lock(queue_lock);
-       frame_queue.push_back(qf);
-       queue_nonempty.notify_all();
+       frame_queue.push_back(move(qf));
+       queue_changed.notify_all();
 }
 
-void VideoStream::schedule_refresh_frame(int64_t output_pts)
+void VideoStream::schedule_refresh_frame(steady_clock::time_point local_pts,
+                                         int64_t output_pts, function<void()> &&display_func,
+                                         QueueSpotHolder &&queue_spot_holder)
 {
-       AVPacket pkt;
-       av_init_packet(&pkt);
-       pkt.stream_index = 0;
-       pkt.data = (uint8_t *)last_frame.data();
-       pkt.size = last_frame.size();
-       stream_mux->add_packet(pkt, output_pts, output_pts);
+       QueuedFrame qf;
+       qf.type = QueuedFrame::REFRESH;
+       qf.output_pts = output_pts;
+       qf.display_func = move(display_func);
+       qf.queue_spot_holder = move(queue_spot_holder);
+
+       unique_lock<mutex> lock(queue_lock);
+       frame_queue.push_back(move(qf));
+       queue_changed.notify_all();
 }
 
 namespace {
@@ -523,16 +544,29 @@ void VideoStream::encode_thread_func()
                QueuedFrame qf;
                {
                        unique_lock<mutex> lock(queue_lock);
-                       queue_nonempty.wait(lock, [this]{
+
+                       // Wait until we have a frame to play.
+                       queue_changed.wait(lock, [this]{
                                return !frame_queue.empty();
                        });
-                       qf = frame_queue.front();
+                       steady_clock::time_point frame_start = frame_queue.front().local_pts;
+
+                       // Now sleep until the frame is supposed to start (the usual case),
+                       // _or_ clear_queue() happened.
+                       bool aborted = queue_changed.wait_until(lock, frame_start, [this, frame_start]{
+                               return frame_queue.empty() || frame_queue.front().local_pts != frame_start;
+                       });
+                       if (aborted) {
+                               // clear_queue() happened, so don't play this frame after all.
+                               continue;
+                       }
+                       qf = move(frame_queue.front());
                        frame_queue.pop_front();
                }
 
                if (qf.type == QueuedFrame::ORIGINAL) {
                        // Send the JPEG frame on, unchanged.
-                       string jpeg = read_file(filename_for_frame(qf.stream_idx, qf.input_first_pts));
+                       string jpeg = frame_reader.read_frame(qf.frame1);
                        AVPacket pkt;
                        av_init_packet(&pkt);
                        pkt.stream_index = 0;
@@ -544,7 +578,7 @@ void VideoStream::encode_thread_func()
                } else if (qf.type == QueuedFrame::FADED) {
                        glClientWaitSync(qf.fence.get(), /*flags=*/0, GL_TIMEOUT_IGNORED);
 
-                       shared_ptr<Frame> frame = frame_from_pbo(qf.resources.pbo_contents, 1280, 720);
+                       shared_ptr<Frame> frame = frame_from_pbo(qf.resources->pbo_contents, 1280, 720);
 
                        // Now JPEG encode it, and send it on to the stream.
                        vector<uint8_t> jpeg = encode_jpeg(frame->y.get(), frame->cb.get(), frame->cr.get(), 1280, 720);
@@ -556,16 +590,14 @@ void VideoStream::encode_thread_func()
                        pkt.size = jpeg.size();
                        stream_mux->add_packet(pkt, qf.output_pts, qf.output_pts);
                        last_frame = move(jpeg);
-
-                       // Put the frame resources back.
-                       unique_lock<mutex> lock(queue_lock);
-                       interpolate_resources.push_back(qf.resources);
                } else if (qf.type == QueuedFrame::INTERPOLATED || qf.type == QueuedFrame::FADED_INTERPOLATED) {
                        glClientWaitSync(qf.fence.get(), /*flags=*/0, GL_TIMEOUT_IGNORED);
 
-                       // Send a copy of the frame on to display.
-                       shared_ptr<Frame> frame = frame_from_pbo(qf.resources.pbo_contents, 1280, 720);
-                       JPEGFrameView::insert_interpolated_frame(qf.id, frame);
+                       // Send it on to display.
+                       shared_ptr<Frame> frame = frame_from_pbo(qf.resources->pbo_contents, 1280, 720);
+                       if (qf.display_decoded_func != nullptr) {
+                               qf.display_decoded_func(frame);
+                       }
 
                        // Now JPEG encode it, and send it on to the stream.
                        vector<uint8_t> jpeg = encode_jpeg(frame->y.get(), frame->cb.get(), frame->cr.get(), 1280, 720);
@@ -582,13 +614,19 @@ void VideoStream::encode_thread_func()
                        pkt.size = jpeg.size();
                        stream_mux->add_packet(pkt, qf.output_pts, qf.output_pts);
                        last_frame = move(jpeg);
-
-                       // Put the frame resources back.
-                       unique_lock<mutex> lock(queue_lock);
-                       interpolate_resources.push_back(qf.resources);
+               } else if (qf.type == QueuedFrame::REFRESH) {
+                       AVPacket pkt;
+                       av_init_packet(&pkt);
+                       pkt.stream_index = 0;
+                       pkt.data = (uint8_t *)last_frame.data();
+                       pkt.size = last_frame.size();
+                       stream_mux->add_packet(pkt, qf.output_pts, qf.output_pts);
                } else {
                        assert(false);
                }
+               if (qf.display_func != nullptr) {
+                       qf.display_func();
+               }
        }
 }