Fix the objects16 input layout and bound its render-ahead

CMakeLists.txt

@@ -260,7 +260,9 @@ endif()
 if(JOC_BUILD_TESTS)
     enable_testing()
     add_executable(joc_tests tests/test_core.cpp)
-    target_link_libraries(joc_tests PRIVATE joc_core_impl)
+    # The stream tests reach the core the shared library exports, so the static
+    # library alone is not enough to link them.
+    target_link_libraries(joc_tests PRIVATE joc_core_impl joc_core)
     target_include_directories(joc_tests PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/src")
     add_test(NAME core COMMAND joc_tests)
     # The public headers must stay valid C and C++: these targets exist to prove it.

include/joc_stream.h

@@ -39,12 +39,12 @@ typedef struct joc_stream joc_stream;
 
 typedef enum joc_stream_input {
     JOC_STREAM_IN_EAC3 = 0,          /* bare E-AC-3 syncframes (the metadata stream) */
-    JOC_STREAM_IN_PCM_OBJECTS16 = 1, /* 16-channel objects16, decoded by the host   */
+    JOC_STREAM_IN_PCM_OBJECTS16 = 1, /* objects16 frames, planar [16][1536] each    */
     JOC_STREAM_IN_CORE_PCM = 3       /* the 5.1 core PCM of the pushed E-AC-3 frames */
 } joc_stream_input;
 
 typedef enum joc_stream_output {
-    JOC_STREAM_OUT_PCM_OBJECTS16 = 0, /* planar [16][samples] float32        */
+    JOC_STREAM_OUT_PCM_OBJECTS16 = 0, /* objects16 frames, planar [16][1536] each    */
     JOC_STREAM_OUT_SPEAKER = 1,       /* interleaved [samples][channels] f32         */
     JOC_STREAM_OUT_BINAURAL = 2       /* interleaved [samples][2] f32                */
 } joc_stream_output;

src/simd/cpu_probe.cpp

@@ -22,9 +22,7 @@ namespace joc::simd {
 namespace {
 
 // ---------------------------------------------------------------------- x86 --
-// Both pointer sizes are probed: AVX2 is not an x86-64-only ISA, and gating this
+// AVX2 is not an x86-64-only ISA, so both pointer sizes are probed.
-// on _M_X64 / __x86_64__ left every 32-bit x86 build reporting "no features",
-// which pinned the dispatcher to the scalar kernels.
 #if defined(_M_X64) || defined(_M_IX86) || defined(__x86_64__) || defined(__i386__)
 
 #if defined(_M_X64) || defined(_M_IX86)

src/stream/stream.cpp

@@ -38,7 +38,10 @@ void Stream::reset_state() {
     reader_ = eac3::FrameReader();
     metadata_.clear();
     bed_pending_.clear();
+    bed_read_offset_ = 0;
     objects16_.clear();
+    objects_pending_.clear();
+    objects_read_offset_ = 0;
     output_.clear();
     read_offset_ = 0;
     info_ = Info();
@@ -245,54 +248,82 @@ Status Stream::push_objects16(const float* planar16, std::size_t samples, std::s
     if (planar16 == nullptr || samples == 0u) {
         return Status::success();
     }
-    // Rendered immediately: the host has already done the JOC rebuild.
+    // Queued as whole frames, each planar [16][kFrameSamples]: the shape the
+    // objects16 output writes, so a host can feed a batch back unchanged.
+    constexpr std::size_t kFrameValues =
+        static_cast<std::size_t>(JOC_OUTPUT_CHANNELS) * kFrameSamples;
     for (std::size_t offset = 0; offset < samples; offset += kFrameSamples) {
         const std::size_t count = std::min(kFrameSamples, samples - offset);
-        std::vector<float> frame(static_cast<std::size_t>(JOC_OUTPUT_CHANNELS) * kFrameSamples,
+        const std::size_t base = objects_pending_.size();
-                                 0.0f);
+        const float* frame = planar16 + (offset / kFrameSamples) * kFrameValues;
+        objects_pending_.resize(base + kFrameValues, 0.0f);
         for (std::size_t channel = 0; channel < JOC_OUTPUT_CHANNELS; ++channel) {
-            std::memcpy(frame.data() + channel * kFrameSamples,
+            std::memcpy(objects_pending_.data() + base + channel * kFrameSamples,
-                        planar16 + channel * samples + offset, count * sizeof(float));
+                        frame + channel * kFrameSamples, count * sizeof(float));
         }
-        ++info_.frames_in;
+    }
-        info_.samples_in += count;
+    return process_objects16_frames(false);
-        const Status rendered = render_objects16(frame);
+}
+
+Status Stream::process_objects16_frames(bool drain_all) {
+    constexpr std::size_t kFrameValues =
+        static_cast<std::size_t>(JOC_OUTPUT_CHANNELS) * kFrameSamples;
+    while (objects_pending_.size() - objects_read_offset_ >= kFrameValues) {
+        // Leave the rest queued, in order, for a later push or for flush().
+        if (!drain_all && buffered_samples() >= kMaxRenderAheadSamples) {
+            break;
+        }
+        const auto first = objects_pending_.begin() +
+                           static_cast<std::ptrdiff_t>(objects_read_offset_);
+        objects_frame_.assign(first, first + static_cast<std::ptrdiff_t>(kFrameValues));
+        objects_read_offset_ += kFrameValues;
+        const Status rendered = render_objects16(objects_frame_);
         if (!rendered.ok()) {
             return rendered;
         }
-        if (count != kFrameSamples) {
+        ++info_.frames_in;
-            break;  // a partial frame is dropped; the host should push whole frames
+        info_.samples_in += kFrameSamples;
     }
+    if (objects_read_offset_ == objects_pending_.size()) {
+        objects_pending_.clear();
+        objects_read_offset_ = 0;
+    } else if (objects_read_offset_ >= (1u << 20)) {
+        // Erasing from the front moves the remainder, so it is only worth doing
+        // once the consumed prefix is large enough to pay for the move.
+        objects_pending_.erase(
+            objects_pending_.begin(),
+            objects_pending_.begin() + static_cast<std::ptrdiff_t>(objects_read_offset_));
+        objects_read_offset_ = 0;
     }
     return Status::success();
 }
 
 Status Stream::process_ready_frames(bool drain_all) {
-    while (bed_pending_.size() / kBedChannels >= kFrameSamples && !metadata_.empty()) {
+    while (bed_pending_.size() - bed_read_offset_ >= kFrameSamples * kBedChannels &&
-        // Stop before rendering what the caller is not about to take: the frames
+           !metadata_.empty()) {
-        // stay queued, in order, and are rendered by a later push or by flush().
+        // Leave the rest queued, in order, for a later push or for flush().
         if (!drain_all && buffered_samples() >= kMaxRenderAheadSamples) {
             break;
         }
         const FrameMetadata entry = metadata_.front();
         metadata_.pop_front();
 
-        std::vector<float> bed5(static_cast<std::size_t>(JOC_CORE_CHANNELS) * kFrameSamples, 0.0f);
+        const float* bed = bed_pending_.data() + bed_read_offset_;
-        std::vector<float> lfe(kFrameSamples, 0.0f);
+        bed5_.resize(static_cast<std::size_t>(JOC_CORE_CHANNELS) * kFrameSamples);
+        lfe_.resize(kFrameSamples);
         for (std::size_t sample = 0; sample < kFrameSamples; ++sample) {
             for (std::size_t channel = 0; channel < JOC_CORE_CHANNELS; ++channel) {
-                bed5[channel * kFrameSamples + sample] =
+                bed5_[channel * kFrameSamples + sample] =
-                    bed_pending_[sample * kBedChannels + kCoreChannels[channel]];
+                    bed[sample * kBedChannels + kCoreChannels[channel]];
             }
-            lfe[sample] = bed_pending_[sample * kBedChannels + kLfeChannel];
+            lfe_[sample] = bed[sample * kBedChannels + kLfeChannel];
         }
-        bed_pending_.erase(bed_pending_.begin(),
+        bed_read_offset_ += kFrameSamples * kBedChannels;
-                           bed_pending_.begin() + static_cast<std::ptrdiff_t>(kFrameSamples *
+        compact_bed_pending();
-                                                                             kBedChannels));
 
         std::string error;
-        const Status rebuilt = joc::rebuild_objects16(rebuilder_, entry.params, bed5.data(),
+        const Status rebuilt = joc::rebuild_objects16(rebuilder_, entry.params, bed5_.data(),
-                                                      lfe.data(), gain_, &objects16_, &error);
+                                                      lfe_.data(), gain_, &objects16_, &error);
         if (!rebuilt.ok()) {
             return Status::fail(rebuilt.code(), stage::kDsp, error);
         }
@@ -307,6 +338,22 @@ Status Stream::process_ready_frames(bool drain_all) {
     return Status::success();
 }
 
+void Stream::compact_bed_pending() {
+    if (bed_read_offset_ == 0) {
+        return;
+    }
+    if (bed_read_offset_ == bed_pending_.size()) {
+        bed_pending_.clear();
+        bed_read_offset_ = 0;
+    } else if (bed_read_offset_ >= (1u << 20)) {
+        // Erasing from the front moves the remainder, so it is only worth doing
+        // once the consumed prefix is large enough to pay for the move.
+        bed_pending_.erase(bed_pending_.begin(),
+                           bed_pending_.begin() + static_cast<std::ptrdiff_t>(bed_read_offset_));
+        bed_read_offset_ = 0;
+    }
+}
+
 Status Stream::render_objects16(const std::vector<float>& objects16) {
     if (config_.output == JOC_STREAM_OUT_PCM_OBJECTS16) {
         output_.insert(output_.end(), objects16.begin(), objects16.end());
@@ -324,6 +371,7 @@ Status Stream::render_objects16(const std::vector<float>& objects16) {
         if (!stepped.ok()) {
             return Status::fail(stepped.code(), stage::kRender, error);
         }
+        output_.reserve(output_.size() + speaker_.output.size());
         for (const double value : speaker_.output) {
             output_.push_back(static_cast<float>(value));
         }
@@ -344,13 +392,13 @@ Status Stream::render_objects16(const std::vector<float>& objects16) {
     if (!submitted.ok()) {
         return submitted;
     }
-    std::vector<double> produced;
+    binaural_.take_output(&produced_);
-    binaural_.take_output(&produced);
+    output_.reserve(output_.size() + produced_.size());
-    for (const double value : produced) {
+    for (const double value : produced_) {
         output_.push_back(static_cast<float>(value));
     }
     info_.frames_out++;
-    info_.samples_out += produced.size() / 2u;
+    info_.samples_out += produced_.size() / 2u;
     return Status::success();
 }
 
@@ -371,16 +419,15 @@ Status Stream::render_rosella_objects16(const std::vector<float>& objects16) {
     if (!submitted.ok()) {
         return submitted;
     }
-    std::vector<double> produced;
+    rosella_.take_output(&produced_);
-    rosella_.take_output(&produced);
+    if (!produced_.empty()) {
-    if (!produced.empty()) {
+        rosella_pending_.insert(rosella_pending_.end(), produced_.begin(), produced_.end());
-        rosella_pending_.insert(rosella_pending_.end(), produced.begin(), produced.end());
     }
     release_rosella_output(kFrameSamples);
     info_.frames_out++;
     // Counted as the runtime produces it, which is also how the SOFA path counts:
     // the totals are identical, only the frame they appear on differs.
-    info_.samples_out += produced.size() / 2u;
+    info_.samples_out += produced_.size() / 2u;
     return Status::success();
 }
 
@@ -393,6 +440,7 @@ void Stream::release_rosella_output(std::size_t limit) {
         return;
     }
     const std::size_t values = count * 2u;
+    output_.reserve(output_.size() + values);
     for (std::size_t index = 0; index < values; ++index) {
         output_.push_back(static_cast<float>(rosella_pending_[rosella_read_offset_ + index]));
     }
@@ -434,13 +482,16 @@ Status Stream::pull(float* destination, std::size_t capacity_samples, std::size_
 }
 
 Status Stream::flush() {
-    // Input has ended, so the render-ahead bound has nothing left to wait for:
+    // Input has ended, so drain what the cap held back: nothing else will
-    // every frame still queued has to reach the renderer before its tail is
+    // trigger rendering.
-    // drained, or the end of the file would be dropped.
     const Status remaining = process_ready_frames(true);
     if (!remaining.ok()) {
         return remaining;
     }
+    const Status objects = process_objects16_frames(true);
+    if (!objects.ok()) {
+        return objects;
+    }
     if (binaural_ready_) {
         std::vector<double> tail;
         const Status drained =
@@ -448,6 +499,7 @@ Status Stream::flush() {
         if (!drained.ok()) {
             return drained;
         }
+        output_.reserve(output_.size() + tail.size());
         for (const double value : tail) {
             output_.push_back(static_cast<float>(value));
         }
@@ -464,6 +516,7 @@ Status Stream::flush() {
         // tail only sounds after it.  The program samples were already counted by
         // render_rosella_objects16, so only the tail is added here.
         release_rosella_output(rosella_pending_samples());
+        output_.reserve(output_.size() + tail.size());
         for (const double value : tail) {
             output_.push_back(static_cast<float>(value));
         }

src/stream/stream.h

@@ -85,13 +85,8 @@ public:
                    : 0u;
     }
 
-    // A push renders every frame it makes ready, and the caller decides how far
+    // Cap on rendered samples that have not been pulled.  A push renders what it
-    // its demuxer runs ahead of playback.  Without a bound, a demuxer that runs
+    // makes ready, so a caller that feeds faster than it pulls renders ahead.
-    // far ahead turns its whole read-ahead burst into latency on whichever pull()
-    // happens to follow it: the samples are not wasted, but they are rendered at
-    // the worst possible moment.  Rendering therefore stops once this many
-    // samples are rendered and unpulled; flush() lifts the bound so the frames
-    // still waiting when the input ends are drained rather than dropped.
     static constexpr std::size_t kMaxRenderAheadSamples = 16384;
 
 private:
@@ -106,6 +101,10 @@ private:
         return rosella_ready_ ? (rosella_pending_.size() - rosella_read_offset_) / 2u : 0u;
     }
     void reset_state();
+    // Drops the bed samples that have already been rendered, keeping the rest.
+    void compact_bed_pending();
+    // Renders the queued objects16 frames, bounded by kMaxRenderAheadSamples.
+    Status process_objects16_frames(bool drain_all);
 
     Config config_;
     Info info_;
@@ -113,7 +112,12 @@ private:
     std::deque<FrameMetadata> metadata_;
     FrameMetadata pending_metadata_;
     std::vector<float> bed_pending_;
-    std::vector<std::uint8_t> frame_copy_;
+    std::size_t bed_read_offset_ = 0;
+    std::vector<float> bed5_;
+    std::vector<float> lfe_;
+    std::vector<float> objects_pending_;
+    std::size_t objects_read_offset_ = 0;
+    std::vector<float> objects_frame_;
     std::vector<float> objects16_;
     std::vector<float> output_;
     std::size_t read_offset_ = 0;
@@ -125,6 +129,7 @@ private:
     hrtf::RosellaRuntime rosella_;
     std::vector<double> rosella_pending_;
     std::size_t rosella_read_offset_ = 0;
+    std::vector<double> produced_;
     bool speaker_enabled_ = false;
     bool binaural_enabled_ = false;
     bool binaural_ready_ = false;

tests/test_core.cpp

@@ -1,5 +1,6 @@
 // Unit tests for the engine's self-contained parts: no test data files, no
 // reference implementation, no external framework.  Run with `ctest` or directly.
+#include <algorithm>
 #include <cmath>
 #include <filesystem>
 #include <cstdint>
@@ -30,6 +31,7 @@
 #include "io/wav_writer.h"
 #include "io/zip_reader.h"
 #include "oamd/oamd_parser.h"
+#include "stream/stream.h"
 
 namespace {
 
@@ -707,6 +709,83 @@ void test_builtin_kernel_tables() {
           "f5beb3220e4530fcf28e7f4da7f07e821074265d118c911d61a590e00753a573");
 }
 
+// Drives one objects16 stream over `block` and returns what it renders.  With
+// `frame_at_a_time` each push carries a single frame; otherwise the whole batch
+// goes in at once.  `peak` reports the largest backlog a push left behind.
+std::vector<float> drive_objects16_stream(const std::vector<float>& block, std::size_t frames,
+                                          bool frame_at_a_time, std::size_t* peak) {
+    constexpr std::size_t kFrameValues = JOC_OUTPUT_CHANNELS * JOC_FRAME_SAMPLES;
+    joc::stream::Stream stream;
+    joc::stream::Config config;
+    config.input = JOC_STREAM_IN_PCM_OBJECTS16;
+    config.output = JOC_STREAM_OUT_SPEAKER;
+    config.layout = "5.1";
+    const joc::Status created = stream.create(config);
+    CHECK(created.ok());
+    if (!created.ok()) {
+        return {};
+    }
+    const std::size_t channels = stream.info().output_channels;
+    CHECK(channels != 0u);
+    std::vector<float> pulled(4096u * channels);
+    std::vector<float> rendered;
+    const auto drain = [&] {
+        for (;;) {
+            std::size_t produced = 0;
+            const joc::Status status = stream.pull(pulled.data(), 4096u, &produced);
+            CHECK(status.ok());
+            if (!status.ok() || produced == 0u) {
+                return;
+            }
+            rendered.insert(rendered.end(), pulled.begin(),
+                            pulled.begin() + static_cast<std::ptrdiff_t>(produced * channels));
+        }
+    };
+
+    std::size_t consumed = 0;
+    while (consumed < frames) {
+        const std::size_t count = frame_at_a_time ? 1u : frames - consumed;
+        std::size_t taken = 0;
+        const joc::Status pushed = stream.push_objects16(
+            block.data() + consumed * kFrameValues, count * JOC_FRAME_SAMPLES, &taken);
+        CHECK(pushed.ok());
+        if (!pushed.ok()) {
+            return rendered;
+        }
+        // A push takes everything it is given; only the rendering is bounded.
+        CHECK(taken == count * JOC_FRAME_SAMPLES);
+        *peak = std::max(*peak, stream.buffered_samples());
+        consumed += taken / JOC_FRAME_SAMPLES;
+        drain();
+    }
+    CHECK(stream.flush().ok());
+    drain();
+    return rendered;
+}
+
+// A push renders every frame it makes ready, so the stream bounds how far ahead of
+// the caller it renders.  A batch pushed at once must therefore leave a bounded
+// backlog, and it must render the same samples as pushing one frame at a time.
+void test_stream_render_ahead() {
+    constexpr std::size_t kFrames = 32;
+    constexpr std::size_t kFrameValues = JOC_OUTPUT_CHANNELS * JOC_FRAME_SAMPLES;
+    std::vector<float> block(kFrames * kFrameValues);
+    for (std::size_t index = 0; index < block.size(); ++index) {
+        block[index] = static_cast<float>(std::sin(static_cast<double>(index) * 0.0007) * 0.25);
+    }
+
+    std::size_t frame_peak = 0;
+    const std::vector<float> reference =
+        drive_objects16_stream(block, kFrames, true, &frame_peak);
+    std::size_t batch_peak = 0;
+    const std::vector<float> batched = drive_objects16_stream(block, kFrames, false, &batch_peak);
+
+    CHECK(!reference.empty());
+    CHECK(batched == reference);
+    // The batch is larger than the bound, so it cannot all be rendered at once.
+    CHECK(batch_peak < kFrames * JOC_FRAME_SAMPLES / 2u);
+}
+
 }  // namespace
 
 int main() {
@@ -728,6 +807,7 @@ int main() {
     test_sofa_reader_errors();
     test_hrtf_cache_policy();
     test_rosella_model_errors();
+    test_stream_render_ahead();
     std::printf("%d checks, %d failure(s)\n", g_checks, g_failures);
     return g_failures == 0 ? 0 : 1;
 }