+#ifdef __SSE2__
+
+// Returns the number of bytes consumed.
+size_t memcpy_interleaved_fastpath(uint8_t *dest1, uint8_t *dest2, const uint8_t *src, size_t n)
+{
+ const uint8_t *limit = src + n;
+ size_t consumed = 0;
+
+ // Align end to 32 bytes.
+ limit = (const uint8_t *)(intptr_t(limit) & ~31);
+
+ if (src >= limit) {
+ return 0;
+ }
+
+ // Process [0,31] bytes, such that start gets aligned to 32 bytes.
+ const uint8_t *aligned_src = (const uint8_t *)(intptr_t(src + 31) & ~31);
+ if (aligned_src != src) {
+ size_t n2 = aligned_src - src;
+ memcpy_interleaved(dest1, dest2, src, n2);
+ dest1 += n2 / 2;
+ dest2 += n2 / 2;
+ if (n2 % 2) {
+ swap(dest1, dest2);
+ }
+ src = aligned_src;
+ consumed += n2;
+ }
+
+ // Make the length a multiple of 64.
+ if (((limit - src) % 64) != 0) {
+ limit -= 32;
+ }
+ assert(((limit - src) % 64) == 0);
+
+#if __AVX2__
+ const __m256i * __restrict in = (const __m256i *)src;
+ __m256i * __restrict out1 = (__m256i *)dest1;
+ __m256i * __restrict out2 = (__m256i *)dest2;
+
+ __m256i shuffle_cw = _mm256_set_epi8(
+ 15, 13, 11, 9, 7, 5, 3, 1, 14, 12, 10, 8, 6, 4, 2, 0,
+ 15, 13, 11, 9, 7, 5, 3, 1, 14, 12, 10, 8, 6, 4, 2, 0);
+ while (in < (const __m256i *)limit) {
+ // Note: For brevity, comments show lanes as if they were 2x64-bit (they're actually 2x128).
+ __m256i data1 = _mm256_stream_load_si256(in); // AaBbCcDd EeFfGgHh
+ __m256i data2 = _mm256_stream_load_si256(in + 1); // IiJjKkLl MmNnOoPp
+
+ data1 = _mm256_shuffle_epi8(data1, shuffle_cw); // ABCDabcd EFGHefgh
+ data2 = _mm256_shuffle_epi8(data2, shuffle_cw); // IJKLijkl MNOPmnop
+
+ data1 = _mm256_permute4x64_epi64(data1, 0b11011000); // ABCDEFGH abcdefgh
+ data2 = _mm256_permute4x64_epi64(data2, 0b11011000); // IJKLMNOP ijklmnop
+
+ __m256i lo = _mm256_permute2x128_si256(data1, data2, 0b00100000);
+ __m256i hi = _mm256_permute2x128_si256(data1, data2, 0b00110001);
+
+ _mm256_storeu_si256(out1, lo);
+ _mm256_storeu_si256(out2, hi);
+
+ in += 2;
+ ++out1;
+ ++out2;
+ consumed += 64;
+ }
+#else
+ const __m128i * __restrict in = (const __m128i *)src;
+ __m128i * __restrict out1 = (__m128i *)dest1;
+ __m128i * __restrict out2 = (__m128i *)dest2;
+
+ __m128i mask_lower_byte = _mm_set1_epi16(0x00ff);
+ while (in < (const __m128i *)limit) {
+ __m128i data1 = _mm_load_si128(in);
+ __m128i data2 = _mm_load_si128(in + 1);
+ __m128i data1_lo = _mm_and_si128(data1, mask_lower_byte);
+ __m128i data2_lo = _mm_and_si128(data2, mask_lower_byte);
+ __m128i data1_hi = _mm_srli_epi16(data1, 8);
+ __m128i data2_hi = _mm_srli_epi16(data2, 8);
+ __m128i lo = _mm_packus_epi16(data1_lo, data2_lo);
+ _mm_storeu_si128(out1, lo);
+ __m128i hi = _mm_packus_epi16(data1_hi, data2_hi);
+ _mm_storeu_si128(out2, hi);
+
+ in += 2;
+ ++out1;
+ ++out2;
+ consumed += 32;
+ }
+#endif
+
+ return consumed;
+}
+
+#endif // __SSE2__
+
+BMDPixelFormat pixel_format_to_bmd(PixelFormat pixel_format)
+{
+ switch (pixel_format) {
+ case PixelFormat_8BitYCbCr:
+ return bmdFormat8BitYUV;
+ case PixelFormat_10BitYCbCr:
+ return bmdFormat10BitYUV;
+ default:
+ assert(false);
+ }
+}
+