libwebp: update to v0.5.1

third_party/libwebp/dec/idec.c

 // Copyright 2011 Google Inc. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the COPYING file in the root of the source
 // tree. An additional intellectual property rights grant can be found
 // in the file PATENTS. All contributing project authors may
 // be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 // Incremental decoding
@@ skipping 52 matching lines @@
 } MemBuffer;
 
 struct WebPIDecoder {
   DecState state_;         // current decoding state
   WebPDecParams params_;   // Params to store output info
   int is_lossless_;        // for down-casting 'dec_'.
   void* dec_;              // either a VP8Decoder or a VP8LDecoder instance
   VP8Io io_;
 
   MemBuffer mem_;          // input memory buffer.
-  WebPDecBuffer output_;   // output buffer (when no external one is supplied)
+  WebPDecBuffer output_;   // output buffer (when no external one is supplied,
+                           // or if the external one has slow-memory)
+  WebPDecBuffer* final_output_;  // Slow-memory output to copy to eventually.
   size_t chunk_size_;      // Compressed VP8/VP8L size extracted from Header.
 
   int last_mb_y_;          // last row reached for intra-mode decoding
 };
 
 // MB context to restore in case VP8DecodeMB() fails
 typedef struct {
   VP8MB left_;
   VP8MB info_;
   VP8BitReader token_br_;
@@ skipping 27 matching lines @@
   MemBuffer* const mem = &idec->mem_;
   const uint8_t* const new_base = mem->buf_ + mem->start_;
   // note: for VP8, setting up idec->io_ is only really needed at the beginning
   // of the decoding, till partition #0 is complete.
   idec->io_.data = new_base;
   idec->io_.data_size = MemDataSize(mem);
 
   if (idec->dec_ != NULL) {
     if (!idec->is_lossless_) {
       VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
-      const int last_part = dec->num_parts_ - 1;
+      const uint32_t last_part = dec->num_parts_minus_one_;
       if (offset != 0) {
-        int p;
+        uint32_t p;
         for (p = 0; p <= last_part; ++p) {
           VP8RemapBitReader(dec->parts_ + p, offset);
         }
         // Remap partition #0 data pointer to new offset, but only in MAP
         // mode (in APPEND mode, partition #0 is copied into a fixed memory).
         if (mem->mode_ == MEM_MODE_MAP) {
           VP8RemapBitReader(&dec->br_, offset);
         }
       }
       {
         const uint8_t* const last_start = dec->parts_[last_part].buf_;
-        assert(last_part >= 0);
         VP8BitReaderSetBuffer(&dec->parts_[last_part], last_start,
                               mem->buf_ + mem->end_ - last_start);
       }
       if (NeedCompressedAlpha(idec)) {
         ALPHDecoder* const alph_dec = dec->alph_dec_;
         dec->alpha_data_ += offset;
         if (alph_dec != NULL) {
           if (alph_dec->method_ == ALPHA_LOSSLESS_COMPRESSION) {
             VP8LDecoder* const alph_vp8l_dec = alph_dec->vp8l_dec_;
             assert(alph_vp8l_dec != NULL);
@@ skipping 96 matching lines @@
   return 1;
 }
 
 // To be called last.
 static VP8StatusCode FinishDecoding(WebPIDecoder* const idec) {
   const WebPDecoderOptions* const options = idec->params_.options;
   WebPDecBuffer* const output = idec->params_.output;
 
   idec->state_ = STATE_DONE;
   if (options != NULL && options->flip) {
-    return WebPFlipBuffer(output);
-  } else {
-    return VP8_STATUS_OK;
+    const VP8StatusCode status = WebPFlipBuffer(output);
+    if (status != VP8_STATUS_OK) return status;
   }
+  if (idec->final_output_ != NULL) {
+    WebPCopyDecBufferPixels(output, idec->final_output_);  // do the slow-copy
+    WebPFreeDecBuffer(&idec->output_);
+    *output = *idec->final_output_;
+    idec->final_output_ = NULL;
+  }
+  return VP8_STATUS_OK;
 }
 
 //------------------------------------------------------------------------------
 // Macroblock-decoding contexts
 
 static void SaveContext(const VP8Decoder* dec, const VP8BitReader* token_br,
                         MBContext* const context) {
   context->left_ = dec->mb_info_[-1];
   context->info_ = dec->mb_info_[dec->mb_x_];
   context->token_br_ = *token_br;
@@ skipping 184 matching lines @@
       if (!VP8ParseIntraModeRow(&dec->br_, dec)) {
         // note: normally, error shouldn't occur since we already have the whole
         // partition0 available here in DecodeRemaining(). Reaching EOF while
         // reading intra modes really means a BITSTREAM_ERROR.
         return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
       }
       idec->last_mb_y_ = dec->mb_y_;
     }
     for (; dec->mb_x_ < dec->mb_w_; ++dec->mb_x_) {
       VP8BitReader* const token_br =
-          &dec->parts_[dec->mb_y_ & (dec->num_parts_ - 1)];
+          &dec->parts_[dec->mb_y_ & dec->num_parts_minus_one_];
       MBContext context;
       SaveContext(dec, token_br, &context);
       if (!VP8DecodeMB(dec, token_br)) {
         // We shouldn't fail when MAX_MB data was available
-        if (dec->num_parts_ == 1 && MemDataSize(&idec->mem_) > MAX_MB_SIZE) {
+        if (dec->num_parts_minus_one_ == 0 &&
+            MemDataSize(&idec->mem_) > MAX_MB_SIZE) {
           return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
         }
         RestoreContext(&context, dec, token_br);
         return VP8_STATUS_SUSPENDED;
       }
       // Release buffer only if there is only one partition
-      if (dec->num_parts_ == 1) {
+      if (dec->num_parts_minus_one_ == 0) {
         idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_;
         assert(idec->mem_.start_ <= idec->mem_.end_);
       }
     }
     VP8InitScanline(dec);   // Prepare for next scanline
 
     // Reconstruct, filter and emit the row.
     if (!VP8ProcessRow(dec, io)) {
       return IDecError(idec, VP8_STATUS_USER_ABORT);
     }
@@ skipping 85 matching lines @@
   if (idec->state_ == STATE_VP8L_HEADER) {
     status = DecodeVP8LHeader(idec);
   }
   if (idec->state_ == STATE_VP8L_DATA) {
     status = DecodeVP8LData(idec);
   }
   return status;
 }
 
 //------------------------------------------------------------------------------
-// Public functions
+// Internal constructor
 
-WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) {
+static WebPIDecoder* NewDecoder(WebPDecBuffer* const output_buffer,
+                                const WebPBitstreamFeatures* const features) {
   WebPIDecoder* idec = (WebPIDecoder*)WebPSafeCalloc(1ULL, sizeof(*idec));
   if (idec == NULL) {
     return NULL;
   }
 
   idec->state_ = STATE_WEBP_HEADER;
   idec->chunk_size_ = 0;
 
   idec->last_mb_y_ = -1;
 
   InitMemBuffer(&idec->mem_);
   WebPInitDecBuffer(&idec->output_);
   VP8InitIo(&idec->io_);
 
   WebPResetDecParams(&idec->params_);
-  idec->params_.output = (output_buffer != NULL) ? output_buffer
-                                                 : &idec->output_;
+  if (output_buffer == NULL || WebPAvoidSlowMemory(output_buffer, features)) {
+    idec->params_.output = &idec->output_;
+    idec->final_output_ = output_buffer;
+    if (output_buffer != NULL) {
+      idec->params_.output->colorspace = output_buffer->colorspace;
+    }
+  } else {
+    idec->params_.output = output_buffer;
+    idec->final_output_ = NULL;
+  }
   WebPInitCustomIo(&idec->params_, &idec->io_);  // Plug the I/O functions.
 
   return idec;
 }
 
+//------------------------------------------------------------------------------
+// Public functions
+
+WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) {
+  return NewDecoder(output_buffer, NULL);
+}
+
 WebPIDecoder* WebPIDecode(const uint8_t* data, size_t data_size,
                           WebPDecoderConfig* config) {
   WebPIDecoder* idec;
+  WebPBitstreamFeatures tmp_features;
+  WebPBitstreamFeatures* const features =
+      (config == NULL) ? &tmp_features : &config->input;
+  memset(&tmp_features, 0, sizeof(tmp_features));
 
   // Parse the bitstream's features, if requested:
-  if (data != NULL && data_size > 0 && config != NULL) {
-    if (WebPGetFeatures(data, data_size, &config->input) != VP8_STATUS_OK) {
+  if (data != NULL && data_size > 0) {
+    if (WebPGetFeatures(data, data_size, features) != VP8_STATUS_OK) {
       return NULL;
     }
   }
+
   // Create an instance of the incremental decoder
-  idec = WebPINewDecoder(config ? &config->output : NULL);
+  idec = (config != NULL) ? NewDecoder(&config->output, features)
+                          : NewDecoder(NULL, features);
   if (idec == NULL) {
     return NULL;
   }
   // Finish initialization
   if (config != NULL) {
     idec->params_.options = &config->options;
   }
   return idec;
 }
 
@@ skipping 13 matching lines @@
   ClearMemBuffer(&idec->mem_);
   WebPFreeDecBuffer(&idec->output_);
   WebPSafeFree(idec);
 }
 
 //------------------------------------------------------------------------------
 // Wrapper toward WebPINewDecoder
 
 WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer,
                           size_t output_buffer_size, int output_stride) {
-  const int is_external_memory = (output_buffer != NULL);
+  const int is_external_memory = (output_buffer != NULL) ? 1 : 0;
   WebPIDecoder* idec;
 
   if (mode >= MODE_YUV) return NULL;
-  if (!is_external_memory) {    // Overwrite parameters to sane values.
+  if (is_external_memory == 0) {    // Overwrite parameters to sane values.
     output_buffer_size = 0;
     output_stride = 0;
   } else {  // A buffer was passed. Validate the other params.
     if (output_stride == 0 || output_buffer_size == 0) {
       return NULL;   // invalid parameter.
     }
   }
   idec = WebPINewDecoder(NULL);
   if (idec == NULL) return NULL;
   idec->output_.colorspace = mode;
   idec->output_.is_external_memory = is_external_memory;
   idec->output_.u.RGBA.rgba = output_buffer;
   idec->output_.u.RGBA.stride = output_stride;
   idec->output_.u.RGBA.size = output_buffer_size;
   return idec;
 }
 
 WebPIDecoder* WebPINewYUVA(uint8_t* luma, size_t luma_size, int luma_stride,
                            uint8_t* u, size_t u_size, int u_stride,
                            uint8_t* v, size_t v_size, int v_stride,
                            uint8_t* a, size_t a_size, int a_stride) {
-  const int is_external_memory = (luma != NULL);
+  const int is_external_memory = (luma != NULL) ? 1 : 0;
   WebPIDecoder* idec;
   WEBP_CSP_MODE colorspace;
 
-  if (!is_external_memory) {    // Overwrite parameters to sane values.
+  if (is_external_memory == 0) {    // Overwrite parameters to sane values.
     luma_size = u_size = v_size = a_size = 0;
     luma_stride = u_stride = v_stride = a_stride = 0;
     u = v = a = NULL;
     colorspace = MODE_YUVA;
   } else {  // A luma buffer was passed. Validate the other parameters.
     if (u == NULL || v == NULL) return NULL;
     if (luma_size == 0 || u_size == 0 || v_size == 0) return NULL;
     if (luma_stride == 0 || u_stride == 0 || v_stride == 0) return NULL;
     if (a != NULL) {
       if (a_size == 0 || a_stride == 0) return NULL;
@@ skipping 87 matching lines @@
 
 //------------------------------------------------------------------------------
 
 static const WebPDecBuffer* GetOutputBuffer(const WebPIDecoder* const idec) {
   if (idec == NULL || idec->dec_ == NULL) {
     return NULL;
   }
   if (idec->state_ <= STATE_VP8_PARTS0) {
     return NULL;
   }
+  if (idec->final_output_ != NULL) {
+    return NULL;   // not yet slow-copied
+  }
   return idec->params_.output;
 }
 
 const WebPDecBuffer* WebPIDecodedArea(const WebPIDecoder* idec,
                                       int* left, int* top,
                                       int* width, int* height) {
   const WebPDecBuffer* const src = GetOutputBuffer(idec);
   if (left != NULL) *left = 0;
   if (top != NULL) *top = 0;
-  if (src) {
+  if (src != NULL) {
     if (width != NULL) *width = src->width;
     if (height != NULL) *height = idec->params_.last_y;
   } else {
     if (width != NULL) *width = 0;
     if (height != NULL) *height = 0;
   }
   return src;
 }
 
 uint8_t* WebPIDecGetRGB(const WebPIDecoder* idec, int* last_y,
@@ skipping 44 matching lines @@
     return 0;
   }
 
   idec->io_.put = put;
   idec->io_.setup = setup;
   idec->io_.teardown = teardown;
   idec->io_.opaque = user_data;
 
   return 1;
 }