uspace/lib/draw/codec/webp.c

   1 /*
   2  * Copyright (c) 2014 Martin Decky
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup draw
  30  * @{
  31  */
  32 /**
  33  * @file
  34  */
  35
  36 #include <stdlib.h>
  37 #include <byteorder.h>
  38 #include <align.h>
  39 #include <stdbool.h>
  40 #include <pixconv.h>
  41 #include <fourcc.h>
  42 #include <stdint.h>
  43 #include <abi/fourcc.h>
  44 #include "webp.h"
  45
  46 /** Check for input buffer overrun condition */
  47 #define CHECK_OVERRUN(state, retval) \
  48         do { \
  49                 if ((state).overrun) \
  50                         return (retval); \
  51         } while (false)
  52
  53 #define SIGNATURE_WEBP_LOSSLESS  UINT8_C(0x2f)
  54
  55 enum {
  56         FOURCC_RIFF          = FOURCC('R', 'I', 'F', 'F'),
  57         FOURCC_WEBP          = FOURCC('W', 'E', 'B', 'P'),
  58         FOURCC_WEBP_LOSSLESS = FOURCC('V', 'P', '8', 'L')
  59 };
  60
  61 typedef enum {
  62         TRANSFORM_PREDICTOR      = 0,
  63         TRANSFORM_COLOR          = 1,
  64         TRANSFORM_SUBTRACT       = 2,
  65         TRANSFORM_COLOR_INDEXING = 3
  66 } webp_transform_t;
  67
  68 typedef struct {
  69         fourcc_t fourcc;
  70         uint32_t payload_size;
  71 } __attribute__((packed)) riff_header_t;
  72
  73 typedef struct {
  74         fourcc_t fourcc;
  75         fourcc_t encoding;
  76         uint32_t stream_size;
  77         uint8_t signature;
  78 } __attribute__((packed)) webp_header_t;
  79
  80 typedef struct {
  81         uint32_t stream_size;
  82         uint16_t width;
  83         uint16_t height;
  84         bool alpha_used;
  85         uint8_t version;
  86
  87         uint8_t *src;     /**< Input buffer */
  88         size_t srclen;    /**< Input buffer size */
  89         size_t srccnt;    /**< Position in the input buffer */
  90
  91         uint32_t bitbuf;  /**< Bit buffer */
  92         size_t bitlen;    /**< Number of bits in the bit buffer */
  93
  94         bool overrun;     /**< Overrun condition */
  95 } webp_t;
  96
  97 /** Get bits from the bit buffer
  98  *
  99  * @param state WebP state.
 100  * @param cnt   Number of bits to return (at most 32).
 101  *
 102  * @return Returned bits.
 103  *
 104  */
 105 static inline uint32_t get_bits(webp_t *state, size_t cnt)
 106 {
 107         /* Bit accumulator for at least 36 bits */
 108         uint64_t val = state->bitbuf;
 109
 110         while (state->bitlen < cnt) {
 111                 if (state->srccnt == state->srclen) {
 112                         state->overrun = true;
 113                         return 0;
 114                 }
 115
 116                 /* Load 8 more bits */
 117                 val |= ((uint64_t) state->src[state->srccnt]) << state->bitlen;
 118                 state->srccnt++;
 119                 state->bitlen += 8;
 120         }
 121
 122         /* Update bits in the buffer */
 123         state->bitbuf = (uint32_t) (val >> cnt);
 124         state->bitlen -= cnt;
 125
 126         return ((uint32_t) (val & ((1 << cnt) - 1)));
 127 }
 128
 129 /** Decode WebP header
 130  *
 131  * @param[in]  data Memory representation of WebP.
 132  * @param[in]  size Size of the representation (in bytes).
 133  * @param[out] webp Decoded WebP.
 134  *
 135  * @return True on succesful decoding.
 136  * @return False on failure.
 137  *
 138  */
 139 static bool decode_webp_header(void *data, size_t size, webp_t *webp)
 140 {
 141         /* Headers sanity check */
 142         if ((size < sizeof(riff_header_t)) ||
 143             (size - sizeof(riff_header_t) < sizeof(webp_header_t)))
 144                 return false;
 145
 146         riff_header_t *riff_header = (riff_header_t *) data;
 147         if (riff_header->fourcc != FOURCC_RIFF)
 148                 return false;
 149
 150         /* Check payload size */
 151         size_t payload_size = uint32_t_le2host(riff_header->payload_size);
 152         if (payload_size + sizeof(riff_header_t) > size)
 153                 return false;
 154
 155         data += sizeof(riff_header_t);
 156         webp_header_t *webp_header = (webp_header_t *) data;
 157         if (webp_header->fourcc != FOURCC_WEBP)
 158                 return false;
 159
 160         /* Only lossless encoding supported so far */
 161         if (webp_header->encoding != FOURCC_WEBP_LOSSLESS)
 162                 return false;
 163
 164         webp->stream_size = uint32_t_le2host(webp_header->stream_size);
 165         if (webp->stream_size + sizeof(riff_header_t) +
 166             sizeof(webp_header_t) > size)
 167                 return false;
 168
 169         if (webp_header->signature != SIGNATURE_WEBP_LOSSLESS)
 170                 return false;
 171
 172         data += sizeof(webp_header_t);
 173
 174         /* Setup decoding state */
 175         webp->src = (uint8_t *) data;
 176         webp->srclen = webp->stream_size - 1;
 177         webp->srccnt = 0;
 178         webp->bitbuf = 0;
 179         webp->bitlen = 0;
 180         webp->overrun = false;
 181
 182         /* Decode the rest of the metadata */
 183         webp->width = get_bits(webp, 14) + 1;
 184         CHECK_OVERRUN(*webp, false);
 185
 186         webp->height = get_bits(webp, 14) + 1;
 187         CHECK_OVERRUN(*webp, false);
 188
 189         webp->alpha_used = get_bits(webp, 1);
 190         CHECK_OVERRUN(*webp, false);
 191
 192         webp->version = get_bits(webp, 3);
 193         CHECK_OVERRUN(*webp, false);
 194
 195         if (webp->version != 0)
 196                 return false;
 197
 198         return true;
 199 }
 200
 201 /** Decode WebP format
 202  *
 203  * Decode WebP format and create a surface from it. The supported
 204  * variants of WebP are currently limited to losslessly compressed
 205  * ARGB images.
 206  *
 207  * @param[in] data  Memory representation of WebP.
 208  * @param[in] size  Size of the representation (in bytes).
 209  * @param[in] flags Surface creation flags.
 210  *
 211  * @return Newly allocated surface with the decoded content.
 212  * @return NULL on error or unsupported format.
 213  *
 214  */
 215 surface_t *decode_webp(void *data, size_t size, surface_flags_t flags)
 216 {
 217         webp_t webp;
 218         if (!decode_webp_header(data, size, &webp))
 219                 return NULL;
 220
 221         bool transform_present = false;
 222
 223         do {
 224                 transform_present = get_bits(&webp, 1);
 225                 CHECK_OVERRUN(webp, NULL);
 226
 227                 if (transform_present) {
 228                         webp_transform_t transform = get_bits(&webp, 2);
 229                         CHECK_OVERRUN(webp, NULL);
 230
 231                         if (transform == TRANSFORM_PREDICTOR) {
 232                                 // FIXME TODO
 233                         } else
 234                                 return NULL;
 235
 236                         // FIXME: decode other transforms
 237                 }
 238         } while (transform_present);
 239
 240         // FIXME: decode image data
 241
 242         return NULL;
 243 }
 244
 245 /** Encode WebP format
 246  *
 247  * Encode WebP format into an array.
 248  *
 249  * @param[in]  surface Surface to be encoded into WebP.
 250  * @param[out] pdata   Pointer to the resulting array.
 251  * @param[out] psize   Pointer to the size of the resulting array.
 252  *
 253  * @return True on succesful encoding.
 254  * @return False on failure.
 255  *
 256  */
 257 bool encode_webp(surface_t *surface, void **pdata, size_t *psize)
 258 {
 259         // TODO
 260         return false;
 261 }
 262
 263 /** @}
 264  */