Cross Reference: /external/webp/src/dec/alpha.c

Lines Matching refs:dec
27   ALPHDecoder* const dec = (ALPHDecoder*)WebPSafeCalloc(1ULL, sizeof(*dec));
28   return dec;
31 void ALPHDelete(ALPHDecoder* const dec) {
32   if (dec != NULL) {
33     VP8LDelete(dec->vp8l_dec_);
34     dec->vp8l_dec_ = NULL;
35     WebPSafeFree(dec);
46 static int ALPHInit(ALPHDecoder* const dec, const uint8_t* data,
56   dec->width_ = width;
57   dec->height_ = height;
63   dec->method_ = (data[0] >> 0) & 0x03;
64   dec->filter_ = (data[0] >> 2) & 0x03;
65   dec->pre_processing_ = (data[0] >> 4) & 0x03;
67   if (dec->method_ < ALPHA_NO_COMPRESSION ||
68       dec->method_ > ALPHA_LOSSLESS_COMPRESSION ||
69       dec->filter_ >= WEBP_FILTER_LAST ||
70       dec->pre_processing_ > ALPHA_PREPROCESSED_LEVELS ||
75   if (dec->method_ == ALPHA_NO_COMPRESSION) {
76     const size_t alpha_decoded_size = dec->width_ * dec->height_;
79     assert(dec->method_ == ALPHA_LOSSLESS_COMPRESSION);
80     ok = VP8LDecodeAlphaHeader(dec, alpha_data, alpha_data_size, output);
90 static int ALPHDecode(VP8Decoder* const dec, int row, int num_rows) {
91   ALPHDecoder* const alph_dec = dec->alph_dec_;
95   uint8_t* const output = dec->alpha_plane_;
99     assert(dec->alpha_data_size_ >= ALPHA_HEADER_LEN + offset + num_pixels);
100     memcpy(dec->alpha_plane_ + offset,
101            dec->alpha_data_ + ALPHA_HEADER_LEN + offset, num_pixels);
113   if (row + num_rows == dec->pic_hdr_.height_) {
114     dec->is_alpha_decoded_ = 1;
122 const uint8_t* VP8DecompressAlphaRows(VP8Decoder* const dec,
124   const int width = dec->pic_hdr_.width_;
125   const int height = dec->pic_hdr_.height_;
133     assert(dec->alpha_plane_ != NULL);
134     dec->alph_dec_ = ALPHNew();
135     if (dec->alph_dec_ == NULL) return NULL;
136     if (!ALPHInit(dec->alph_dec_, dec->alpha_data_, dec->alpha_data_size_,
137                   width, height, dec->alpha_plane_)) {
138       ALPHDelete(dec->alph_dec_);
139       dec->alph_dec_ = NULL;
143     if (dec->alph_dec_->pre_processing_ != ALPHA_PREPROCESSED_LEVELS) {
144       dec->alpha_dithering_ = 0;  // disable dithering
150   if (!dec->is_alpha_decoded_) {
152     assert(dec->alph_dec_ != NULL);
153     ok = ALPHDecode(dec, row, num_rows);
154     if (ok && dec->alpha_dithering_ > 0) {
155       ok = WebPDequantizeLevels(dec->alpha_plane_, width, height,
156                                 dec->alpha_dithering_);
158     if (!ok || dec->is_alpha_decoded_) {
159       ALPHDelete(dec->alph_dec_);
160       dec->alph_dec_ = NULL;
166   return dec->alpha_plane_ + row * width;