2.0.0: Fixed potential audio-mixer bug which could happen when parallel loop was...

[casparcg] / core / mixer / audio / audio_mixer.cpp

diff --git a/core/mixer/audio/audio_mixer.cpp b/core/mixer/audio/audio_mixer.cpp
index 50ce413c4f707393c78215358209cdba00482129..5a695e61c4e79a456c93df2e71600fc1a67e1f76 100644 (file)
--- a/core/mixer/audio/audio_mixer.cpp
+++ b/core/mixer/audio/audio_mixer.cpp
@@ -92,12 +92,16 @@ public:
        \r
        audio_buffer mix()\r
        {       \r
+               // NOTE: auto data should be larger than format_desc_.audio_samples_per_frame to allow sse to read/write beyond size.\r
+\r
                auto intermediate = std::vector<float, tbb::cache_aligned_allocator<float>>(format_desc_.audio_samples_per_frame+128, 0.0f);\r
 \r
                std::map<const void*, core::frame_transform> next_frame_transforms;\r
+               \r
+               tbb::affinity_partitioner ap;\r
 \r
                BOOST_FOREACH(auto& item, items)\r
-               {                               \r
+               {                       \r
                        const auto next = item.transform;\r
                        auto prev = next;\r
 \r
@@ -106,7 +110,7 @@ public:
                                prev = it->second;\r
                                \r
                        next_frame_transforms[item.tag] = next; // Store all active tags, inactive tags will be removed at the end.\r
-                               \r
+\r
                        if(next.volume < 0.001 && prev.volume < 0.001)\r
                                continue;\r
                                                                        \r
@@ -118,38 +122,37 @@ public:
                                                \r
                        const float prev_volume = static_cast<float>(prev.volume);\r
                        const float next_volume = static_cast<float>(next.volume);\r
-                       const float delta               = 1.0f/static_cast<float>(format_desc_.audio_samples_per_frame/2);\r
-                       \r
-                       tbb::parallel_for\r
-                       (\r
-                               tbb::blocked_range<size_t>(0, format_desc_.audio_samples_per_frame/4),\r
-                               [&](const tbb::blocked_range<size_t>& r)\r
-                               {\r
-                                       for(size_t n = r.begin(); n < r.end(); ++n)\r
-                                       {\r
-                                               const float alpha0      = (n*2) * delta;\r
-                                               const float volume0     = prev_volume * (1.0f - alpha0) + next_volume * alpha0;\r
-                                               const float volume1     = prev_volume * (1.0f - alpha0 + delta) + next_volume * (alpha0 + delta);\r
-\r
-                                               auto sample_epi32       = _mm_load_si128(reinterpret_cast<__m128i*>(&item.audio_data[n*4]));\r
-                                               auto res_sample_ps      = _mm_load_ps(&intermediate[n*4]);\r
-\r
-                                               auto sample_ps          = _mm_cvtepi32_ps(sample_epi32);                                                                                                \r
-                                               sample_ps                       = _mm_mul_ps(sample_ps, _mm_setr_ps(volume1, volume1, volume0, volume0));       \r
-                                               res_sample_ps           = _mm_add_ps(sample_ps, res_sample_ps); \r
-\r
-                                               _mm_store_ps(&intermediate[n*4], res_sample_ps);\r
-                                       }\r
-                               }\r
-                       );\r
+                       const float delta               = 1.0f/static_cast<float>(format_desc_.audio_samples_per_frame/format_desc_.audio_channels);\r
+                                               \r
+                       auto alpha_ps   = _mm_setr_ps(delta, delta, 0.0f, 0.0f);\r
+                       auto delta2_ps  = _mm_set_ps1(delta*2.0f);\r
+                       auto prev_ps    = _mm_set_ps1(prev_volume);\r
+                       auto next_ps    = _mm_set_ps1(next_volume);     \r
+\r
+                       for(size_t n = 0; n < format_desc_.audio_samples_per_frame/4; ++n)\r
+                       {               \r
+                               auto next2_ps           = _mm_mul_ps(next_ps, alpha_ps);\r
+                               auto prev2_ps           = _mm_sub_ps(prev_ps, _mm_mul_ps(prev_ps, alpha_ps));\r
+                               auto volume_ps          = _mm_add_ps(next2_ps, prev2_ps);\r
+\r
+                               auto sample_ps          = _mm_cvtepi32_ps(_mm_load_si128(reinterpret_cast<__m128i*>(&item.audio_data[n*4])));\r
+                               auto res_sample_ps      = _mm_load_ps(&intermediate[n*4]);                                                                                      \r
+                               sample_ps                       = _mm_mul_ps(sample_ps, volume_ps);     \r
+                               res_sample_ps           = _mm_add_ps(sample_ps, res_sample_ps); \r
+\r
+                               alpha_ps                        = _mm_add_ps(alpha_ps, delta2_ps);\r
+\r
+                               _mm_store_ps(&intermediate[n*4], res_sample_ps);\r
+                       }\r
                }\r
                \r
-               auto result = audio_buffer(format_desc_.audio_samples_per_frame+128, 0);        \r
-\r
+               auto result = audio_buffer(format_desc_.audio_samples_per_frame+128);   \r
+                       \r
                auto intermediate_128 = reinterpret_cast<__m128i*>(intermediate.data());\r
                auto result_128           = reinterpret_cast<__m128i*>(result.data());\r
+                               \r
                for(size_t n = 0; n < format_desc_.audio_samples_per_frame/32; ++n)\r
-               {\r
+               {       \r
                        auto xmm0 = _mm_load_ps(reinterpret_cast<float*>(intermediate_128++));\r
                        auto xmm1 = _mm_load_ps(reinterpret_cast<float*>(intermediate_128++));\r
                        auto xmm2 = _mm_load_ps(reinterpret_cast<float*>(intermediate_128++));\r