Fix 32-bit dropouts: enable AVX2 and bound the render-ahead

kernel/joc_kernel.vcxproj

@@ -113,18 +113,19 @@
   </ItemDefinitionGroup>
 
   <!--
-    SIMD units, mirroring CMakeLists.txt (the JOC_SIMD_* block) exactly.
+    SIMD units, mirroring CMakeLists.txt (the JOC_SIMD_* block).
 
     The ISA in the file name, one translation unit per ISA, each compiled with
     its own /arch because MSVC has no function-level ISA attribute; dispatch.cpp
-    (a baseline unit) picks one at run time from CPUID/XGETBV.  The kernel
-    enables SIMD only for x86_64 and aarch64, so:
+    (a baseline unit) picks one at run time from CPUID/XGETBV.
 
-      * Win32 (x86) gets NO SIMD unit and NO SIMD define: the scalar reference
-        and the probe/dispatch baseline are all it builds, exactly as
-        CMAKE_SIZEOF_VOID_P EQUAL 8 gates them out upstream;
       * x64 gets the AVX2 and AVX-512 units, JOC_SIMD_HAVE_SSE2 / _AVX2 /
         _AVX512, and a per-file /arch for those two files only;
+      * Win32 (x86) gets the AVX2 unit and JOC_SIMD_HAVE_AVX2.  AVX2 is not an
+        x86-64-only ISA and MSVC accepts /arch:AVX2 for x86, so gating it on the
+        pointer size left the 32-bit component on the scalar reference, which is
+        too slow to hold a 4096-frame read inside its own 85.3 ms of audio.
+        AVX-512 stays x64-only: 32-bit mode addresses ZMM0-7 only.
       * src\simd\kernels_intrin_neon.cpp is excluded everywhere here: the CMake
         build lists it only for aarch64 (CMakeLists.txt lines 177-180), which no
         configuration of this project targets.
@@ -134,6 +135,11 @@
       <PreprocessorDefinitions>JOC_SIMD_HAVE_SSE2=1;JOC_SIMD_HAVE_AVX2=1;JOC_SIMD_HAVE_AVX512=1;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
   </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Platform)'=='Win32'">
+    <ClCompile>
+      <PreprocessorDefinitions>JOC_SIMD_HAVE_AVX2=1;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+    </ClCompile>
+  </ItemDefinitionGroup>
 
   <ItemGroup>
     <!-- Verbatim copies of the upstream native library (JOC_REUSED_SOURCES). -->
@@ -203,6 +209,12 @@
     </ClCompile>
   </ItemGroup>
 
+  <ItemGroup Condition="'$(Platform)'=='Win32'">
+    <ClCompile Include="src\simd\kernels_intrin_avx2.cpp">
+      <AdditionalOptions>/arch:AVX2 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+  </ItemGroup>
+
   <ItemGroup>
     <ClInclude Include="include\eac3joc_core.h" />
     <ClInclude Include="include\joc_core.h" />

kernel/src/simd/cpu_probe.cpp

@@ -7,10 +7,10 @@
 
 #include "simd/cpu_probe.h"
 
-#if defined(_M_X64)
+#if defined(_M_X64) || defined(_M_IX86)
 #include <immintrin.h>
 #include <intrin.h>
-#elif defined(__x86_64__)
+#elif defined(__x86_64__) || defined(__i386__)
 #include <cpuid.h>
 #endif
 
@@ -21,10 +21,13 @@
 namespace joc::simd {
 namespace {
 
-// ------------------------------------------------------------------- x86-64 --
-#if defined(_M_X64) || defined(__x86_64__)
+// ---------------------------------------------------------------------- x86 --
+// Both pointer sizes are probed: AVX2 is not an x86-64-only ISA, and gating this
+// 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)
+#if defined(_M_X64) || defined(_M_IX86)
 
 // CPUID tells us what the silicon can do; XCR0 tells us whether the OS saves the
 // state the wider registers need.  Both have to agree, or the first AVX
@@ -53,7 +56,7 @@ CpuFeatures probe_x86() noexcept {
     return features;
 }
 
-#else  // GCC/Clang on x86-64
+#else  // GCC/Clang on x86
 
 // The compiler runtime performs the same CPUID + XGETBV probe (libgcc's cpuinfo
 // checks XCR0 before it reports AVX), which keeps this file free of inline

kernel/src/stream/stream.cpp

@@ -221,7 +221,7 @@ Status Stream::push_eac3(const std::uint8_t* data, std::size_t size, std::size_t
         }
         metadata_.push_back(entry);
     }
-    return process_ready_frames();
+    return process_ready_frames(false);
 }
 
 Status Stream::push_bed(const float* interleaved6, std::size_t samples, std::size_t* consumed) {
@@ -235,7 +235,7 @@ Status Stream::push_bed(const float* interleaved6, std::size_t samples, std::siz
         bed_pending_.insert(bed_pending_.end(), interleaved6,
                             interleaved6 + samples * kBedChannels);
     }
-    return process_ready_frames();
+    return process_ready_frames(false);
 }
 
 Status Stream::push_objects16(const float* planar16, std::size_t samples, std::size_t* consumed) {
@@ -267,8 +267,13 @@ Status Stream::push_objects16(const float* planar16, std::size_t samples, std::s
     return Status::success();
 }
 
-Status Stream::process_ready_frames() {
+Status Stream::process_ready_frames(bool drain_all) {
     while (bed_pending_.size() / kBedChannels >= kFrameSamples && !metadata_.empty()) {
+        // Stop before rendering what the caller is not about to take: the frames
+        // stay queued, in order, and are rendered by a later push or by flush().
+        if (!drain_all && buffered_samples() >= kMaxRenderAheadSamples) {
+            break;
+        }
         const FrameMetadata entry = metadata_.front();
         metadata_.pop_front();
 
@@ -429,6 +434,13 @@ 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:
+    // every frame still queued has to reach the renderer before its tail is
+    // drained, or the end of the file would be dropped.
+    const Status remaining = process_ready_frames(true);
+    if (!remaining.ok()) {
+        return remaining;
+    }
     if (binaural_ready_) {
         std::vector<double> tail;
         const Status drained =

kernel/src/stream/stream.h

@@ -85,8 +85,18 @@ public:
                    : 0u;
     }
 
+    // A push renders every frame it makes ready, and the caller decides how far
+    // its demuxer runs ahead of playback.  Without a bound, a demuxer that runs
+    // 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:
-    Status process_ready_frames();
+    // `drain_all` ignores kMaxRenderAheadSamples and renders every ready frame.
+    Status process_ready_frames(bool drain_all);
     Status render_objects16(const std::vector<float>& objects16);
     Status render_rosella_objects16(const std::vector<float>& objects16);
     // Moves at most `limit` rendered stereo samples per channel out of the FIFO

src/joc_decode.cpp

@@ -20,6 +20,16 @@ namespace joc_decode {
 namespace {
 
 constexpr std::size_t kEac3Chunk = 96u * 1024u;      // bytes read per push
+// The core renders every frame it is handed, and it renders it during the push,
+// so a read must not queue more frames than the caller is about to take: a 96 KB
+// read is around thirty syncframes, i.e. a second of audio rendered to satisfy
+// one 4096-frame read.  This is that read (2.67 syncframes) rounded up, so each
+// read hands the core about as much as it is about to consume.
+constexpr std::uint64_t kEac3FramesPerRead = 3u;
+// Rendered audio the caller has not taken yet.  Once this much is waiting there
+// is nothing to gain from queueing more input: the core would render it now and
+// the caller would not ask for it for several more reads.
+constexpr std::size_t kMaxRenderedAheadSamples = 4096u;
 constexpr std::size_t kBedFramesChunk = 8192u;       // staging capacity, in frames
 constexpr std::size_t kBedChannels = 6;              // ffmpeg -ac 6
 // A read on an anonymous pipe only completes once the whole request is available,
@@ -974,7 +984,23 @@ std::size_t Engine::read(float* destination, std::size_t frames, std::string* er
             impl.eac3_eof = true;
         }
 
-        if (!impl.eac3_eof && impl.frames_queued <= impl.bed_frames_pushed + 2u &&
+        // The core renders during the push, so input is queued only while the
+        // caller still has less than one read's worth of rendered audio waiting.
+        // Pushing past that is what turns a single read into a second of work:
+        // the samples are rendered early rather than wrongly, and the read that
+        // pays for them overruns its own audio.
+        std::size_t rendered_ahead = 0;
+        {
+            joc_stream_status_info pending{};
+            pending.struct_size = sizeof(pending);
+            pending.struct_version = 1;
+            if (impl.api.status(impl.stream, &pending) == JOC_OK) {
+                rendered_ahead = static_cast<std::size_t>(pending.buffered_samples);
+            }
+        }
+
+        if (!impl.eac3_eof && rendered_ahead < kMaxRenderedAheadSamples &&
+            impl.frames_queued <= impl.bed_frames_pushed + 2u &&
             (impl.settings.input_frame_limit == 0 ||
              impl.frames_queued < impl.settings.input_frame_limit)) {
             // The tail of a chunk is usually the head of the next syncframe.  It
@@ -1023,17 +1049,24 @@ std::size_t Engine::read(float* destination, std::size_t frames, std::string* er
                     offset += bytes;
                     ++complete;
                 }
-                // With an input limit the chunk is cut at a frame boundary: the
+                // The chunk is cut at a frame boundary for two independent
+                // reasons: a configured input limit has to stop exactly where it
+                // says, and a read must not queue more frames than it is about to
+                // consume.  Both cuts land on a frame boundary because the
                 // renderer's output depends on how many frames it was given, so a
-                // limit that overshoots to the end of the read buffer would not
-                // reproduce a run that stopped earlier.
-                std::size_t push_bytes = offset;
-                std::uint64_t pushed_frames = complete;
+                // cut that overshoots would not reproduce a run that stopped
+                // earlier.
+                std::uint64_t allowed = complete;
                 if (impl.settings.input_frame_limit != 0) {
                     const std::uint64_t room =
                         impl.settings.input_frame_limit - impl.frames_queued;
-                    if (complete > room) {
-                        pushed_frames = room;
+                    if (allowed > room) allowed = room;
+                }
+                if (allowed > kEac3FramesPerRead) allowed = kEac3FramesPerRead;
+                std::size_t push_bytes = offset;
+                std::uint64_t pushed_frames = complete;
+                if (allowed < complete) {
+                    pushed_frames = allowed;
                     std::size_t walk = 0;
                     for (std::uint64_t index = 0; index < pushed_frames; ++index) {
                         const std::size_t bytes = joc_eac3::frame_bytes_at(
@@ -1043,7 +1076,6 @@ std::size_t Engine::read(float* destination, std::size_t frames, std::string* er
                     }
                     push_bytes = walk;
                 }
-                }
                 joc_stream_buffer input{};
                 input.struct_size = sizeof(input);
                 input.struct_version = 1;
@@ -1064,7 +1096,11 @@ std::size_t Engine::read(float* destination, std::size_t frames, std::string* er
                     std::memmove(impl.eac3_buffer.data(), impl.eac3_buffer.data() + push_bytes,
                                  impl.eac3_carry);
                 }
-                if (got == 0) impl.eac3_eof = true;
+                // The pipe can end while complete syncframes are still waiting in
+                // the buffer: they are queued by the next pass, so the input is
+                // only over once nothing but a partial frame is left.  Ending here
+                // instead would drop them, and with them the end of the file.
+                if (got == 0 && pushed_frames >= complete) impl.eac3_eof = true;
             }
         }
 

src/main.cpp

@@ -12,7 +12,7 @@
 
 // Kept in one place: the string reported to foobar2000 and written to the log
 // must not drift apart.
-#define JOC_VERSION "0.2.2"
+#define JOC_VERSION "0.3.0"
 
 DECLARE_COMPONENT_VERSION("JOC decoder (E-AC-3 JOC)", JOC_VERSION,
                           "Plays E-AC-3 JOC (Dolby Atmos) files: the JOC objects are "