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Diffstat (limited to 'gpr/source/lib/vc5_decoder/wavelet.c')
| -rwxr-xr-x | gpr/source/lib/vc5_decoder/wavelet.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/gpr/source/lib/vc5_decoder/wavelet.c b/gpr/source/lib/vc5_decoder/wavelet.c new file mode 100755 index 0000000..a60eb0a --- /dev/null +++ b/gpr/source/lib/vc5_decoder/wavelet.c @@ -0,0 +1,173 @@ +/*! @file wavelet.c + * + * @brief Implementation of the module for wavelet data structures and transforms + * + * @version 1.0.0 + * + * (C) Copyright 2018 GoPro Inc (http://gopro.com/). + * + * Licensed under either: + * - Apache License, Version 2.0, http://www.apache.org/licenses/LICENSE-2.0 + * - MIT license, http://opensource.org/licenses/MIT + * at your option. + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "headers.h" + +/*! + @brief Apply the inverse wavelet transform to reconstruct a lowpass band + + This routine reconstructs the lowpass band in the output wavelet from the + decoded bands in the input wavelet. The prescale argument is used to undo + scaling that may have been performed during encoding to prevent overflow. + + @todo Replace the two different routines for different prescale shifts with + a single routine that can handle any prescale shift. +*/ +CODEC_ERROR TransformInverseSpatialQuantLowpass(gpr_allocator *allocator, WAVELET *input, WAVELET *output, uint16_t prescale) +{ + // Dimensions of each wavelet band + DIMENSION input_width = input->width; + DIMENSION input_height = input->height; + + // The output width may be less than twice the input width if the output width is odd + DIMENSION output_width = output->width; + + // The output height may be less than twice the input height if the output height is odd + DIMENSION output_height = output->height; + + // Check that a valid input image has been provided + assert(input != NULL); + assert(input->data[0] != NULL); + assert(input->data[1] != NULL); + assert(input->data[2] != NULL); + assert(input->data[3] != NULL); + + // Check that the output image is a gray image or a lowpass wavelet band + assert(output->data[0] != NULL); + + // Check for valid quantization values + if (input->quant[0] == 0) { + input->quant[0] = 1; + } + + assert(input->quant[0] > 0); + assert(input->quant[1] > 0); + assert(input->quant[2] > 0); + assert(input->quant[3] > 0); + + if (prescale > 1) + { + // This is a spatial transform for the lowpass temporal band + assert(prescale == 2); + + // Apply the inverse spatial transform for a lowpass band that is not prescaled + InvertSpatialQuantDescale16s(allocator, + (PIXEL *)input->data[0], input->pitch, + (PIXEL *)input->data[1], input->pitch, + (PIXEL *)input->data[2], input->pitch, + (PIXEL *)input->data[3], input->pitch, + output->data[0], output->pitch, + input_width, input_height, + output_width, output_height, + prescale, input->quant); + } + else + { + // This case does not handle any prescaling applied during encoding + assert(prescale == 0); + + // Apply the inverse spatial transform for a lowpass band that is not prescaled + InvertSpatialQuant16s(allocator, + (PIXEL *)input->data[0], input->pitch, + (PIXEL *)input->data[1], input->pitch, + (PIXEL *)input->data[2], input->pitch, + (PIXEL *)input->data[3], input->pitch, + output->data[0], output->pitch, + input_width, input_height, + output_width, output_height, + input->quant); + } + + return CODEC_ERROR_OKAY; +} + +/*! + @brief Apply the inverse wavelet transform to reconstruct a component array + + This routine reconstructs the lowpass band in the output wavelet from the + decoded bands in the input wavelet. The prescale argument is used to undo + scaling that may have been performed during encoding to prevent overflow. +*/ +CODEC_ERROR TransformInverseSpatialQuantArray(gpr_allocator *allocator, + WAVELET *input, + COMPONENT_VALUE *output_buffer, + DIMENSION output_width, + DIMENSION output_height, + size_t output_pitch, + PRESCALE prescale) +{ + // Dimensions of each wavelet band + DIMENSION input_width = input->width; + DIMENSION input_height = input->height; + + // Check that a valid input image has been provided + assert(input != NULL); + assert(input->data[0] != NULL); + assert(input->data[1] != NULL); + assert(input->data[2] != NULL); + assert(input->data[3] != NULL); + + // Check for valid quantization values + if (input->quant[0] == 0) { + input->quant[0] = 1; + } + + assert(input->quant[0] > 0); + assert(input->quant[1] > 0); + assert(input->quant[2] > 0); + assert(input->quant[3] > 0); + + assert(output_width > 0 && output_height > 0 && output_pitch > 0 && output_buffer != NULL); + + if (prescale > 1) + { + // This is a spatial transform for the lowpass temporal band + assert(prescale == 2); + + // Apply the inverse spatial transform for a lowpass band that is not prescaled + InvertSpatialQuantDescale16s(allocator, + (PIXEL *)input->data[0], input->pitch, + (PIXEL *)input->data[1], input->pitch, + (PIXEL *)input->data[2], input->pitch, + (PIXEL *)input->data[3], input->pitch, + (PIXEL *)output_buffer, (int)output_pitch, + input_width, input_height, + output_width, output_height, + prescale, input->quant); + } + else + { + // This case does not handle any prescaling applied during encoding + assert(prescale == 0); + + // Apply the inverse spatial transform for a lowpass band that is not prescaled + InvertSpatialQuant16s(allocator, + (PIXEL *)input->data[0], input->pitch, + (PIXEL *)input->data[1], input->pitch, + (PIXEL *)input->data[2], input->pitch, + (PIXEL *)input->data[3], input->pitch, + (PIXEL *)output_buffer, (int)output_pitch, + input_width, input_height, + output_width, output_height, + input->quant); + } + + return CODEC_ERROR_OKAY; +} |