diff options
Diffstat (limited to 'simd/arm/common/jdsample-neon.c')
| -rw-r--r-- | simd/arm/common/jdsample-neon.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/simd/arm/common/jdsample-neon.c b/simd/arm/common/jdsample-neon.c index 8f4fd7c5..e4f5129d 100644 --- a/simd/arm/common/jdsample-neon.c +++ b/simd/arm/common/jdsample-neon.c @@ -513,3 +513,45 @@ void jsimd_h2v1_upsample_neon(int max_v_samp_factor, } } } + + +/* + * The diagram below shows the operation of h2v2 (simple) upsampling. Each + * sample in the row is duplicated to form two output pixel channel values. + * This horizontally-upsampled row is then also duplicated. + * + * p0 p1 p2 p3 + * +-----+-----+ +-----+-----+-----+-----+ + * | s0 | s1 | -> | s0 | s0 | s1 | s1 | + * +-----+-----+ +-----+-----+-----+-----+ + * | s0 | s0 | s1 | s1 | + * +-----+-----+-----+-----+ + */ + +void jsimd_h2v2_upsample_neon(int max_v_samp_factor, + JDIMENSION output_width, + JSAMPARRAY input_data, + JSAMPARRAY *output_data_ptr) +{ + JSAMPARRAY output_data = *output_data_ptr; + JSAMPROW inptr, outptr0, outptr1; + + for (int inrow = 0, outrow = 0; outrow < max_v_samp_factor; inrow++) { + inptr = input_data[inrow]; + outptr0 = output_data[outrow++]; + outptr1 = output_data[outrow++]; + + for (unsigned colctr = 0; 2 * colctr < output_width; colctr += 16) { + uint8x16_t samples = vld1q_u8(inptr + colctr); + /* Duplicate the samples - the store interleaves them to produce the */ + /* pattern in the diagram above. */ + uint8x16x2_t output_pixels = { samples, samples }; + /* Store pixel values to memory for both output rows. */ + /* Due to the way sample buffers are allocated, we don't need to worry */ + /* about tail cases when output_width is not a multiple of 32. */ + /* See "Creation of 2-D sample arrays" in jmemmgr.c for details. */ + vst2q_u8(outptr0 + 2 * colctr, output_pixels); + vst2q_u8(outptr1 + 2 * colctr, output_pixels); + } + } +} |