Optimizations to ma_deinterleave_pcm_frames() for stereo.

2026-04-21 15:56:58 +02:00 · 2026-02-15 21:54:29 +10:00
parent 01e5042bfb
commit 242cbf4d8c
3 changed files with 360 additions and 5 deletions
@@ -883,6 +883,9 @@ if(MINIAUDIO_BUILD_TESTS)
    add_miniaudio_test(miniaudio_generation generation/generation.c)
    add_test(NAME miniaudio_generation COMMAND miniaudio_generation)

+    add_miniaudio_test(miniaudio_profiling profiling/profiling.c)
+    #add_test(NAME miniaudio_profiling COMMAND miniaudio_profiling)
+
    add_miniaudio_test(miniaudio_resampling resampling/resampling.c)
    #add_test(NAME miniaudio_resampling COMMAND miniaudio_resampling)
    if(TARGET samplerate)
@@ -52899,6 +52899,16 @@ MA_API void ma_deinterleave_pcm_frames(ma_format format, ma_uint32 channels, ma_
        return; /* Invalid args. */
    }

+    /*
+    You shouldn't really be calling this for mono streams, but I can imagine a situation where it is called
+    generically without the caller explicitly checking the channel count. We'll implement this in as a
+    memcpy() to keep it fast.
+    */
+    if (channels == 1) {
+        MA_COPY_MEMORY(ppDeinterleavedPCMFrames[0], pInterleavedPCMFrames, frameCount * ma_get_bytes_per_frame(format, channels));
+        return;
+    }
+
    /* For efficiency we do this per format. */
    switch (format) {
        case ma_format_u8:
@@ -52906,7 +52916,64 @@ MA_API void ma_deinterleave_pcm_frames(ma_format format, ma_uint32 channels, ma_
            const ma_uint8* pSrcU8 = (const ma_uint8*)pInterleavedPCMFrames;
            ma_uint64 iPCMFrame;

-            for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+            iPCMFrame = 0;
+
+            /* Specialization for stereo. We can do 4 frames at a time here. */
+            if (channels == 2) {
+                ma_uint32* pDstU32_0 = (ma_uint32*)ppDeinterleavedPCMFrames[0];
+                ma_uint32* pDstU32_1 = (ma_uint32*)ppDeinterleavedPCMFrames[1];
+                ma_uint64 frameCount4 = frameCount >> 2;
+                
+                /* Check alignment of buffers. Use aligned fast path only if all buffers are 4-byte aligned. */
+                if (((ma_uintptr)pSrcU8 & 3) == 0 && ((ma_uintptr)pDstU32_0 & 3) == 0 && ((ma_uintptr)pDstU32_1 & 3) == 0) {
+                    #if 1
+                    {
+                        const ma_uint32* pSrcU32Running = (const ma_uint32*)pSrcU8;
+
+                        for (iPCMFrame = 0; iPCMFrame < frameCount4; iPCMFrame += 1) {
+                            ma_uint32 src0;
+                            ma_uint32 src1;
+                            ma_uint32 dst0;
+                            ma_uint32 dst1;
+
+                            src0 = pSrcU32Running[0];
+                            src1 = pSrcU32Running[1];
+
+                            dst0 = ((src0 & 0x00FF0000) >>  8) | ((src0 & 0x000000FF) >> 0) | ((src1 & 0x00FF0000) << 8) | ((src1 & 0x000000FF) << 16);
+                            dst1 = ((src0 & 0xFF000000) >> 16) | ((src0 & 0x0000FF00) >> 8) | ((src1 & 0xFF000000) << 0) | ((src1 & 0x0000FF00) <<  8);
+
+                            pDstU32_0[iPCMFrame] = dst0;
+                            pDstU32_1[iPCMFrame] = dst1;
+
+                            pSrcU32Running += 2;
+                        }
+
+                        iPCMFrame *= 4;
+                    }
+                    #else
+                    {
+                        const ma_uint8* pSrcU8Running = (const ma_uint8*)pSrcU8;
+
+                        for (iPCMFrame = 0; iPCMFrame + 4 < frameCount; iPCMFrame += 4) {
+                            ma_uint32 dst0;
+                            ma_uint32 dst1;
+
+                            dst0 = (pSrcU8Running[0] << 0) | (pSrcU8Running[2] << 8) | (pSrcU8Running[4] << 16) | (pSrcU8Running[6] << 24);
+                            dst1 = (pSrcU8Running[1] << 0) | (pSrcU8Running[3] << 8) | (pSrcU8Running[5] << 16) | (pSrcU8Running[7] << 24);
+
+                            *pDstU32_0 = dst0;
+                            *pDstU32_1 = dst1;
+
+                            pSrcU8Running += 4 * 2;
+                            pDstU32_0 += 1;
+                            pDstU32_1 += 1;
+                        }
+                    }
+                    #endif
+                }
+            }
+
+            for (; iPCMFrame < frameCount; iPCMFrame += 1) {
                ma_uint32 iChannel;
                for (iChannel = 0; iChannel < channels; iChannel += 1) {
                    ma_uint8* pDstU8 = (ma_uint8*)ppDeinterleavedPCMFrames[iChannel];
@@ -52919,7 +52986,65 @@ MA_API void ma_deinterleave_pcm_frames(ma_format format, ma_uint32 channels, ma_
        {
            const ma_int16* pSrcS16 = (const ma_int16*)pInterleavedPCMFrames;
            ma_uint64 iPCMFrame;
-            for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+
+            iPCMFrame = 0;
+
+            /* Specialization for stereo. We can do 2 frames at a time here. */
+            if (channels == 2) {
+                ma_uint32* pDstU32_0 = (ma_uint32*)ppDeinterleavedPCMFrames[0];
+                ma_uint32* pDstU32_1 = (ma_uint32*)ppDeinterleavedPCMFrames[1];
+                ma_uint64 frameCount2 = frameCount >> 1;
+
+                /* Check alignment of buffers. Use aligned fast path only if all buffers are 4-byte aligned. */
+                if (((ma_uintptr)pSrcS16 & 3) == 0 && ((ma_uintptr)pDstU32_0 & 3) == 0 && ((ma_uintptr)pDstU32_1 & 3) == 0) {
+                    #if 1
+                    {
+                        const ma_uint32* pSrcU32Running = (const ma_uint32*)pSrcS16;
+
+                        for (iPCMFrame = 0; iPCMFrame < frameCount2; iPCMFrame += 1) {
+                            ma_uint32 src0;
+                            ma_uint32 src1;
+                            ma_uint32 dst0;
+                            ma_uint32 dst1;
+
+                            src0 = pSrcU32Running[0];
+                            src1 = pSrcU32Running[1];
+
+                            dst0 = ((src0 & 0x0000FFFF) <<  0) | ((src1 & 0x0000FFFF) << 16);
+                            dst1 = ((src0 & 0xFFFF0000) >> 16) | ((src1 & 0xFFFF0000) >>  0);
+
+                            pDstU32_0[iPCMFrame] = dst0;
+                            pDstU32_1[iPCMFrame] = dst1;
+
+                            pSrcU32Running += 2;
+                        }
+
+                        iPCMFrame *= 2;
+                    }
+                    #else
+                    {
+                        const ma_uint16* pSrcU16Running = (const ma_uint16*)pSrcS16;
+
+                        for (iPCMFrame = 0; iPCMFrame + 2 < frameCount; iPCMFrame += 2) {
+                            ma_uint32 dst0;
+                            ma_uint32 dst1;
+
+                            dst0 = (pSrcU16Running[0] << 0) | (pSrcU16Running[2] << 16);
+                            dst1 = (pSrcU16Running[1] << 0) | (pSrcU16Running[3] << 16);
+
+                            *pDstU32_0 = dst0;
+                            *pDstU32_1 = dst1;
+
+                            pSrcU16Running += 2 * 2;
+                            pDstU32_0 += 1;
+                            pDstU32_1 += 1;
+                        }
+                    }
+                    #endif
+                }
+            }
+
+            for (; iPCMFrame < frameCount; iPCMFrame += 1) {
                ma_uint32 iChannel;
                for (iChannel = 0; iChannel < channels; iChannel += 1) {
                    ma_int16* pDstS16 = (ma_int16*)ppDeinterleavedPCMFrames[iChannel];
@@ -52932,7 +53057,24 @@ MA_API void ma_deinterleave_pcm_frames(ma_format format, ma_uint32 channels, ma_
        {
            const float* pSrcF32 = (const float*)pInterleavedPCMFrames;
            ma_uint64 iPCMFrame;
-            for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+
+            iPCMFrame = 0;
+
+            /* Specialization for stereo. */
+            if (channels == 2) {
+                float* pDstF32_0 = (float*)ppDeinterleavedPCMFrames[0];
+                float* pDstF32_1 = (float*)ppDeinterleavedPCMFrames[1];
+                const float* pSrcF32Running = (const float*)pSrcF32;
+
+                for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+                    pDstF32_0[iPCMFrame] = pSrcF32Running[0];
+                    pDstF32_1[iPCMFrame] = pSrcF32Running[1];
+
+                    pSrcF32Running += 2;
+                }
+            }
+
+            for (; iPCMFrame < frameCount; iPCMFrame += 1) {
                ma_uint32 iChannel;
                for (iChannel = 0; iChannel < channels; iChannel += 1) {
                    float* pDstF32 = (float*)ppDeinterleavedPCMFrames[iChannel];
@@ -52945,7 +53087,24 @@ MA_API void ma_deinterleave_pcm_frames(ma_format format, ma_uint32 channels, ma_
        {
            const ma_int32* pSrcS32 = (const ma_int32*)pInterleavedPCMFrames;
            ma_uint64 iPCMFrame;
-            for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+
+            iPCMFrame = 0;
+
+            /* Specialization for stereo. */
+            if (channels == 2) {
+                ma_uint32* pDstU32_0 = (ma_uint32*)ppDeinterleavedPCMFrames[0];
+                ma_uint32* pDstU32_1 = (ma_uint32*)ppDeinterleavedPCMFrames[1];
+                const ma_uint32* pSrcU32Running = (const ma_uint32*)pSrcS32;
+
+                for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+                    pDstU32_0[iPCMFrame] = pSrcU32Running[0];
+                    pDstU32_1[iPCMFrame] = pSrcU32Running[1];
+
+                    pSrcU32Running += 2;
+                }
+            }
+
+            for (; iPCMFrame < frameCount; iPCMFrame += 1) {
                ma_uint32 iChannel;
                for (iChannel = 0; iChannel < channels; iChannel += 1) {
                    ma_int32* pDstS32 = (ma_int32*)ppDeinterleavedPCMFrames[iChannel];
@@ -52958,7 +53117,30 @@ MA_API void ma_deinterleave_pcm_frames(ma_format format, ma_uint32 channels, ma_
        {
            const ma_uint8* pSrcS24 = (const ma_uint8*)pInterleavedPCMFrames;
            ma_uint64 iPCMFrame;
-            for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+
+            iPCMFrame = 0;
+
+            if (channels == 2) {
+                ma_uint8* pDstS24_0 = (ma_uint8*)ppDeinterleavedPCMFrames[0];
+                ma_uint8* pDstS24_1 = (ma_uint8*)ppDeinterleavedPCMFrames[1];
+                const ma_uint8* pSrcS24Running = (const ma_uint8*)pSrcS24;
+
+                for (; iPCMFrame < frameCount; iPCMFrame += 1) {
+                    pDstS24_0[0] = pSrcS24Running[0];
+                    pDstS24_0[1] = pSrcS24Running[1];
+                    pDstS24_0[2] = pSrcS24Running[2];
+
+                    pDstS24_1[0] = pSrcS24Running[3];
+                    pDstS24_1[1] = pSrcS24Running[4];
+                    pDstS24_1[2] = pSrcS24Running[5];
+
+                    pSrcS24Running += 6;
+                    pDstS24_0 += 3;
+                    pDstS24_1 += 3;
+                }
+            }
+
+            for (; iPCMFrame < frameCount; iPCMFrame += 1) {
                ma_uint32 iChannel;
                for (iChannel = 0; iChannel < channels; iChannel += 1) {
                    ma_uint8* pDstS24 = (ma_uint8*)ppDeinterleavedPCMFrames[iChannel];
@@ -0,0 +1,170 @@
+#if 1
+#include "../../miniaudio.c"
+#else
+#define MINIAUDIO_IMPLEMENTATION
+#include "../../miniaudio-11.h"
+#endif
+
+const char* format_short_name(ma_format format)
+{
+    switch (format)
+    {
+        case ma_format_u8:  return "u8";
+        case ma_format_s16: return "s16";
+        case ma_format_s32: return "s32";
+        case ma_format_s24: return "s24";
+        case ma_format_f32: return "f32";
+        default: return "unknown";
+    }
+}
+
+void deinterleave_reference(ma_format format, ma_uint32 channels, ma_uint64 frameCount, const void* pInterleavedPCMFrames, void** ppDeinterleavedPCMFrames)
+{
+    ma_uint32 sampleSizeInBytes = ma_get_bytes_per_sample(format);
+    ma_uint64 iPCMFrame;
+    for (iPCMFrame = 0; iPCMFrame < frameCount; iPCMFrame += 1) {
+        ma_uint32 iChannel;
+        for (iChannel = 0; iChannel < channels; iChannel += 1) {
+                    void* pDst = ma_offset_ptr(ppDeinterleavedPCMFrames[iChannel], iPCMFrame*sampleSizeInBytes);
+            const void* pSrc = ma_offset_ptr(pInterleavedPCMFrames, (iPCMFrame*channels+iChannel)*sampleSizeInBytes);
+            memcpy(pDst, pSrc, sampleSizeInBytes);
+        }
+    }
+}
+
+void fill_debug_frames(void* pBuffer, ma_format format, ma_uint32 channels, ma_uint32 frameCount)
+{
+    ma_uint8 v = 0;
+    ma_uint32 bpf = ma_get_bytes_per_frame(format, channels);
+    ma_uint32 iByte;
+
+    /* Just fill byte-by-byte. */
+    for (iByte = 0; iByte < frameCount * bpf; iByte += 1) {
+        ((ma_uint8*)pBuffer)[iByte] = v;
+        v += 1; /* Just let this overflow. */
+    }
+}
+
+ma_bool32 verify_deinterleaving_by_format(ma_format format, ma_uint32 channels)
+{
+    ma_uint64 frameCount = 1023;    /* <-- Make this odd so we can test that the tail is handled properly from internal loop unrolling. */
+    ma_uint32 bpf = ma_get_bytes_per_frame(format, channels);
+    void* pInterleavedReference;
+    void* pDeinterleavedReference[MA_MAX_CHANNELS];
+    void* pInterleavedOptimized;
+    void* pDeinterleavedOptimized[MA_MAX_CHANNELS];
+    ma_uint32 iChannel;
+
+    pInterleavedReference = ma_malloc(frameCount * bpf, NULL);
+    pInterleavedOptimized = ma_malloc(frameCount * bpf, NULL);
+    
+    for (iChannel = 0; iChannel < channels; iChannel += 1) {
+        pDeinterleavedReference[iChannel] = ma_malloc(frameCount * ma_get_bytes_per_sample(format), NULL);
+        pDeinterleavedOptimized[iChannel] = ma_malloc(frameCount * ma_get_bytes_per_sample(format), NULL);
+    }
+
+    fill_debug_frames(pInterleavedReference, frameCount, format, channels);
+    MA_COPY_MEMORY(pInterleavedOptimized, pInterleavedReference, frameCount * bpf);
+
+
+    deinterleave_reference    (format, channels, frameCount, pInterleavedReference, pDeinterleavedReference);
+    ma_deinterleave_pcm_frames(format, channels, frameCount, pInterleavedOptimized, pDeinterleavedOptimized);
+
+    for (iChannel = 0; iChannel < channels; iChannel += 1) {
+        if (memcmp(pDeinterleavedReference[iChannel], pDeinterleavedOptimized[iChannel], frameCount * ma_get_bytes_per_sample(format)) != 0) {
+            return MA_FALSE;
+        }
+    }
+
+
+    for (iChannel = 0; iChannel < channels; iChannel += 1) {
+        ma_free(pDeinterleavedReference[iChannel], NULL);
+        ma_free(pDeinterleavedOptimized[iChannel], NULL);
+    }
+
+    ma_free(pInterleavedReference, NULL);
+    ma_free(pInterleavedOptimized, NULL);
+
+    return MA_TRUE;
+}
+
+void profile_deinterleaving_by_format(ma_format format, ma_uint32 channels)
+{
+    ma_uint64 frameCount = 1024 * 1024;
+    ma_uint32 iterationCount = 1000;
+    ma_uint32 bpf = ma_get_bytes_per_frame(format, channels);
+    void* pInterleaved;
+    void* pDeinterleaved[MA_MAX_CHANNELS];
+    ma_uint32 iChannel;
+    ma_timer timer;
+    double startTime;
+
+    printf("%s %u: ", format_short_name(format), channels);
+
+    if (verify_deinterleaving_by_format(format, channels) == MA_FALSE) {
+        printf("FAILED\n");
+        return;
+    }
+
+
+    ma_timer_init(&timer);
+
+    pInterleaved = ma_malloc(frameCount * bpf, NULL);
+    
+    for (iChannel = 0; iChannel < channels; iChannel += 1) {
+        pDeinterleaved[iChannel] = ma_malloc(frameCount * ma_get_bytes_per_sample(format), NULL);
+    }
+
+    ma_debug_fill_pcm_frames_with_sine_wave((float*)pInterleaved, frameCount, format, channels, 48000); /* The float* cast is to work around an API bug in miniaudio v0.11. It's harmless. */
+
+
+    startTime = ma_timer_get_time_in_seconds(&timer);
+    {
+        ma_uint32 i;
+        for (i = 0; i < iterationCount; i += 1) {
+            ma_deinterleave_pcm_frames(format, channels, frameCount, pInterleaved, pDeinterleaved);
+        }
+    }
+    printf("%f\n", ma_timer_get_time_in_seconds(&timer) - startTime);
+
+
+    for (iChannel = 0; iChannel < channels; iChannel += 1) {
+        ma_free(pDeinterleaved[iChannel], NULL);
+    }
+
+    ma_free(pInterleaved, NULL);
+}
+
+void profile_deinterleaving(void)
+{
+    /* Stereo has an optimized code path. */
+    profile_deinterleaving_by_format(ma_format_u8,  2);
+    profile_deinterleaving_by_format(ma_format_s16, 2);
+    profile_deinterleaving_by_format(ma_format_f32, 2);
+    profile_deinterleaving_by_format(ma_format_s32, 2);
+    profile_deinterleaving_by_format(ma_format_s24, 2);
+
+    /* We have a special case for mono streams so make sure we have coverage of that case. */
+    profile_deinterleaving_by_format(ma_format_u8,  1);
+    profile_deinterleaving_by_format(ma_format_s16, 1);
+    profile_deinterleaving_by_format(ma_format_f32, 1);
+    profile_deinterleaving_by_format(ma_format_s32, 1);
+    profile_deinterleaving_by_format(ma_format_s24, 1);
+
+    /* Channels > 2 run on a generic code path. */
+    profile_deinterleaving_by_format(ma_format_u8,  3);
+    profile_deinterleaving_by_format(ma_format_s16, 3);
+    profile_deinterleaving_by_format(ma_format_f32, 3);
+    profile_deinterleaving_by_format(ma_format_s32, 3);
+    profile_deinterleaving_by_format(ma_format_s24, 3);
+}
+
+int main(int argc, char** argv)
+{
+    profile_deinterleaving();
+
+    (void)argc;
+    (void)argv;
+
+    return 0;
+}