Adding libwebp: Adding clean copy of libwebp 0.4.0

This commit imports libwebp 0.4.0, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

The patches required to build it in Qt will follow in separate
commit(s).

Task-number: QTBUG-14205
Change-Id: I747918fe2a07716f66cffb795129f7aa5e067759
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 652 insertions, 0 deletions

diff --git a/src/3rdparty/libwebp/src/mux/muxedit.c b/src/3rdparty/libwebp/src/mux/muxedit.c
new file mode 100644
index 0000000..25770b3
--- /dev/null
+++ b/src/3rdparty/libwebp/src/mux/muxedit.c
@@ -0,0 +1,652 @@
+// 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.
+// -----------------------------------------------------------------------------
+//
+// Set and delete APIs for mux.
+//
+// Authors: Urvang (urvang@google.com)
+//          Vikas (vikasa@google.com)
+
+#include <assert.h>
+#include "./muxi.h"
+#include "../utils/utils.h"
+
+//------------------------------------------------------------------------------
+// Life of a mux object.
+
+static void MuxInit(WebPMux* const mux) {
+  if (mux == NULL) return;
+  memset(mux, 0, sizeof(*mux));
+}
+
+WebPMux* WebPNewInternal(int version) {
+  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {
+    return NULL;
+  } else {
+    WebPMux* const mux = (WebPMux*)malloc(sizeof(WebPMux));
+    // If mux is NULL MuxInit is a noop.
+    MuxInit(mux);
+    return mux;
+  }
+}
+
+// Delete all images in 'wpi_list'.
+static void DeleteAllImages(WebPMuxImage** const wpi_list) {
+  while (*wpi_list != NULL) {
+    *wpi_list = MuxImageDelete(*wpi_list);
+  }
+}
+
+static void MuxRelease(WebPMux* const mux) {
+  if (mux == NULL) return;
+  DeleteAllImages(&mux->images_);
+  ChunkListDelete(&mux->vp8x_);
+  ChunkListDelete(&mux->iccp_);
+  ChunkListDelete(&mux->anim_);
+  ChunkListDelete(&mux->exif_);
+  ChunkListDelete(&mux->xmp_);
+  ChunkListDelete(&mux->unknown_);
+}
+
+void WebPMuxDelete(WebPMux* mux) {
+  // If mux is NULL MuxRelease is a noop.
+  MuxRelease(mux);
+  free(mux);
+}
+
+//------------------------------------------------------------------------------
+// Helper method(s).
+
+// Handy MACRO, makes MuxSet() very symmetric to MuxGet().
+#define SWITCH_ID_LIST(INDEX, LIST)                                            \
+  if (idx == (INDEX)) {                                                        \
+    err = ChunkAssignData(&chunk, data, copy_data, tag);                       \
+    if (err == WEBP_MUX_OK) {                                                  \
+      err = ChunkSetNth(&chunk, (LIST), nth);                                  \
+    }                                                                          \
+    return err;                                                                \
+  }
+
+static WebPMuxError MuxSet(WebPMux* const mux, uint32_t tag, uint32_t nth,
+                           const WebPData* const data, int copy_data) {
+  WebPChunk chunk;
+  WebPMuxError err = WEBP_MUX_NOT_FOUND;
+  const CHUNK_INDEX idx = ChunkGetIndexFromTag(tag);
+  assert(mux != NULL);
+  assert(!IsWPI(kChunks[idx].id));
+
+  ChunkInit(&chunk);
+  SWITCH_ID_LIST(IDX_VP8X,    &mux->vp8x_);
+  SWITCH_ID_LIST(IDX_ICCP,    &mux->iccp_);
+  SWITCH_ID_LIST(IDX_ANIM,    &mux->anim_);
+  SWITCH_ID_LIST(IDX_EXIF,    &mux->exif_);
+  SWITCH_ID_LIST(IDX_XMP,     &mux->xmp_);
+  SWITCH_ID_LIST(IDX_UNKNOWN, &mux->unknown_);
+  return err;
+}
+#undef SWITCH_ID_LIST
+
+// Create data for frame/fragment given image data, offsets and duration.
+static WebPMuxError CreateFrameFragmentData(
+    int width, int height, const WebPMuxFrameInfo* const info, int is_frame,
+    WebPData* const frame_frgm) {
+  uint8_t* frame_frgm_bytes;
+  const size_t frame_frgm_size = kChunks[is_frame ? IDX_ANMF : IDX_FRGM].size;
+
+  assert(width > 0 && height > 0 && info->duration >= 0);
+  assert(info->dispose_method == (info->dispose_method & 1));
+  // Note: assertion on upper bounds is done in PutLE24().
+
+  frame_frgm_bytes = (uint8_t*)malloc(frame_frgm_size);
+  if (frame_frgm_bytes == NULL) return WEBP_MUX_MEMORY_ERROR;
+
+  PutLE24(frame_frgm_bytes + 0, info->x_offset / 2);
+  PutLE24(frame_frgm_bytes + 3, info->y_offset / 2);
+
+  if (is_frame) {
+    PutLE24(frame_frgm_bytes + 6, width - 1);
+    PutLE24(frame_frgm_bytes + 9, height - 1);
+    PutLE24(frame_frgm_bytes + 12, info->duration);
+    frame_frgm_bytes[15] =
+        (info->blend_method == WEBP_MUX_NO_BLEND ? 2 : 0) |
+        (info->dispose_method == WEBP_MUX_DISPOSE_BACKGROUND ? 1 : 0);
+  }
+
+  frame_frgm->bytes = frame_frgm_bytes;
+  frame_frgm->size = frame_frgm_size;
+  return WEBP_MUX_OK;
+}
+
+// Outputs image data given a bitstream. The bitstream can either be a
+// single-image WebP file or raw VP8/VP8L data.
+// Also outputs 'is_lossless' to be true if the given bitstream is lossless.
+static WebPMuxError GetImageData(const WebPData* const bitstream,
+                                 WebPData* const image, WebPData* const alpha,
+                                 int* const is_lossless) {
+  WebPDataInit(alpha);  // Default: no alpha.
+  if (bitstream->size < TAG_SIZE ||
+      memcmp(bitstream->bytes, "RIFF", TAG_SIZE)) {
+    // It is NOT webp file data. Return input data as is.
+    *image = *bitstream;
+  } else {
+    // It is webp file data. Extract image data from it.
+    const WebPMuxImage* wpi;
+    WebPMux* const mux = WebPMuxCreate(bitstream, 0);
+    if (mux == NULL) return WEBP_MUX_BAD_DATA;
+    wpi = mux->images_;
+    assert(wpi != NULL && wpi->img_ != NULL);
+    *image = wpi->img_->data_;
+    if (wpi->alpha_ != NULL) {
+      *alpha = wpi->alpha_->data_;
+    }
+    WebPMuxDelete(mux);
+  }
+  *is_lossless = VP8LCheckSignature(image->bytes, image->size);
+  return WEBP_MUX_OK;
+}
+
+static WebPMuxError DeleteChunks(WebPChunk** chunk_list, uint32_t tag) {
+  WebPMuxError err = WEBP_MUX_NOT_FOUND;
+  assert(chunk_list);
+  while (*chunk_list) {
+    WebPChunk* const chunk = *chunk_list;
+    if (chunk->tag_ == tag) {
+      *chunk_list = ChunkDelete(chunk);
+      err = WEBP_MUX_OK;
+    } else {
+      chunk_list = &chunk->next_;
+    }
+  }
+  return err;
+}
+
+static WebPMuxError MuxDeleteAllNamedData(WebPMux* const mux, uint32_t tag) {
+  const WebPChunkId id = ChunkGetIdFromTag(tag);
+  assert(mux != NULL);
+  if (IsWPI(id)) return WEBP_MUX_INVALID_ARGUMENT;
+  return DeleteChunks(MuxGetChunkListFromId(mux, id), tag);
+}
+
+//------------------------------------------------------------------------------
+// Set API(s).
+
+WebPMuxError WebPMuxSetChunk(WebPMux* mux, const char fourcc[4],
+                             const WebPData* chunk_data, int copy_data) {
+  uint32_t tag;
+  WebPMuxError err;
+  if (mux == NULL || fourcc == NULL || chunk_data == NULL ||
+      chunk_data->bytes == NULL || chunk_data->size > MAX_CHUNK_PAYLOAD) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+  tag = ChunkGetTagFromFourCC(fourcc);
+
+  // Delete existing chunk(s) with the same 'fourcc'.
+  err = MuxDeleteAllNamedData(mux, tag);
+  if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;
+
+  // Add the given chunk.
+  return MuxSet(mux, tag, 1, chunk_data, copy_data);
+}
+
+// Creates a chunk from given 'data' and sets it as 1st chunk in 'chunk_list'.
+static WebPMuxError AddDataToChunkList(
+    const WebPData* const data, int copy_data, uint32_t tag,
+    WebPChunk** chunk_list) {
+  WebPChunk chunk;
+  WebPMuxError err;
+  ChunkInit(&chunk);
+  err = ChunkAssignData(&chunk, data, copy_data, tag);
+  if (err != WEBP_MUX_OK) goto Err;
+  err = ChunkSetNth(&chunk, chunk_list, 1);
+  if (err != WEBP_MUX_OK) goto Err;
+  return WEBP_MUX_OK;
+ Err:
+  ChunkRelease(&chunk);
+  return err;
+}
+
+// Extracts image & alpha data from the given bitstream and then sets wpi.alpha_
+// and wpi.img_ appropriately.
+static WebPMuxError SetAlphaAndImageChunks(
+    const WebPData* const bitstream, int copy_data, WebPMuxImage* const wpi) {
+  int is_lossless = 0;
+  WebPData image, alpha;
+  WebPMuxError err = GetImageData(bitstream, &image, &alpha, &is_lossless);
+  const int image_tag =
+      is_lossless ? kChunks[IDX_VP8L].tag : kChunks[IDX_VP8].tag;
+  if (err != WEBP_MUX_OK) return err;
+  if (alpha.bytes != NULL) {
+    err = AddDataToChunkList(&alpha, copy_data, kChunks[IDX_ALPHA].tag,
+                             &wpi->alpha_);
+    if (err != WEBP_MUX_OK) return err;
+  }
+  err = AddDataToChunkList(&image, copy_data, image_tag, &wpi->img_);
+  if (err != WEBP_MUX_OK) return err;
+  return MuxImageFinalize(wpi) ? WEBP_MUX_OK : WEBP_MUX_INVALID_ARGUMENT;
+}
+
+WebPMuxError WebPMuxSetImage(WebPMux* mux, const WebPData* bitstream,
+                             int copy_data) {
+  WebPMuxImage wpi;
+  WebPMuxError err;
+
+  // Sanity checks.
+  if (mux == NULL || bitstream == NULL || bitstream->bytes == NULL ||
+      bitstream->size > MAX_CHUNK_PAYLOAD) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  if (mux->images_ != NULL) {
+    // Only one 'simple image' can be added in mux. So, remove present images.
+    DeleteAllImages(&mux->images_);
+  }
+
+  MuxImageInit(&wpi);
+  err = SetAlphaAndImageChunks(bitstream, copy_data, &wpi);
+  if (err != WEBP_MUX_OK) goto Err;
+
+  // Add this WebPMuxImage to mux.
+  err = MuxImagePush(&wpi, &mux->images_);
+  if (err != WEBP_MUX_OK) goto Err;
+
+  // All is well.
+  return WEBP_MUX_OK;
+
+ Err:  // Something bad happened.
+  MuxImageRelease(&wpi);
+  return err;
+}
+
+WebPMuxError WebPMuxPushFrame(WebPMux* mux, const WebPMuxFrameInfo* frame,
+                              int copy_data) {
+  WebPMuxImage wpi;
+  WebPMuxError err;
+  int is_frame;
+  const WebPData* const bitstream = &frame->bitstream;
+
+  // Sanity checks.
+  if (mux == NULL || frame == NULL) return WEBP_MUX_INVALID_ARGUMENT;
+
+  is_frame = (frame->id == WEBP_CHUNK_ANMF);
+  if (!(is_frame || (frame->id == WEBP_CHUNK_FRGM))) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+#ifndef WEBP_EXPERIMENTAL_FEATURES
+  if (frame->id == WEBP_CHUNK_FRGM) {     // disabled for now.
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+#endif
+
+  if (bitstream->bytes == NULL || bitstream->size > MAX_CHUNK_PAYLOAD) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  if (mux->images_ != NULL) {
+    const WebPMuxImage* const image = mux->images_;
+    const uint32_t image_id = (image->header_ != NULL) ?
+        ChunkGetIdFromTag(image->header_->tag_) : WEBP_CHUNK_IMAGE;
+    if (image_id != frame->id) {
+      return WEBP_MUX_INVALID_ARGUMENT;  // Conflicting frame types.
+    }
+  }
+
+  MuxImageInit(&wpi);
+  err = SetAlphaAndImageChunks(bitstream, copy_data, &wpi);
+  if (err != WEBP_MUX_OK) goto Err;
+  assert(wpi.img_ != NULL);  // As SetAlphaAndImageChunks() was successful.
+
+  {
+    WebPData frame_frgm;
+    const uint32_t tag = kChunks[is_frame ? IDX_ANMF : IDX_FRGM].tag;
+    WebPMuxFrameInfo tmp = *frame;
+    tmp.x_offset &= ~1;  // Snap offsets to even.
+    tmp.y_offset &= ~1;
+    if (!is_frame) {  // Reset unused values.
+      tmp.duration = 1;
+      tmp.dispose_method = WEBP_MUX_DISPOSE_NONE;
+      tmp.blend_method = WEBP_MUX_BLEND;
+    }
+    if (tmp.x_offset < 0 || tmp.x_offset >= MAX_POSITION_OFFSET ||
+        tmp.y_offset < 0 || tmp.y_offset >= MAX_POSITION_OFFSET ||
+        (tmp.duration < 0 || tmp.duration >= MAX_DURATION) ||
+        tmp.dispose_method != (tmp.dispose_method & 1)) {
+      err = WEBP_MUX_INVALID_ARGUMENT;
+      goto Err;
+    }
+    err = CreateFrameFragmentData(wpi.width_, wpi.height_, &tmp, is_frame,
+                                  &frame_frgm);
+    if (err != WEBP_MUX_OK) goto Err;
+    // Add frame/fragment chunk (with copy_data = 1).
+    err = AddDataToChunkList(&frame_frgm, 1, tag, &wpi.header_);
+    WebPDataClear(&frame_frgm);  // frame_frgm owned by wpi.header_ now.
+    if (err != WEBP_MUX_OK) goto Err;
+  }
+
+  // Add this WebPMuxImage to mux.
+  err = MuxImagePush(&wpi, &mux->images_);
+  if (err != WEBP_MUX_OK) goto Err;
+
+  // All is well.
+  return WEBP_MUX_OK;
+
+ Err:  // Something bad happened.
+  MuxImageRelease(&wpi);
+  return err;
+}
+
+WebPMuxError WebPMuxSetAnimationParams(WebPMux* mux,
+                                       const WebPMuxAnimParams* params) {
+  WebPMuxError err;
+  uint8_t data[ANIM_CHUNK_SIZE];
+  const WebPData anim = { data, ANIM_CHUNK_SIZE };
+
+  if (mux == NULL || params == NULL) return WEBP_MUX_INVALID_ARGUMENT;
+  if (params->loop_count < 0 || params->loop_count >= MAX_LOOP_COUNT) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  // Delete any existing ANIM chunk(s).
+  err = MuxDeleteAllNamedData(mux, kChunks[IDX_ANIM].tag);
+  if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;
+
+  // Set the animation parameters.
+  PutLE32(data, params->bgcolor);
+  PutLE16(data + 4, params->loop_count);
+  return MuxSet(mux, kChunks[IDX_ANIM].tag, 1, &anim, 1);
+}
+
+//------------------------------------------------------------------------------
+// Delete API(s).
+
+WebPMuxError WebPMuxDeleteChunk(WebPMux* mux, const char fourcc[4]) {
+  if (mux == NULL || fourcc == NULL) return WEBP_MUX_INVALID_ARGUMENT;
+  return MuxDeleteAllNamedData(mux, ChunkGetTagFromFourCC(fourcc));
+}
+
+WebPMuxError WebPMuxDeleteFrame(WebPMux* mux, uint32_t nth) {
+  if (mux == NULL) return WEBP_MUX_INVALID_ARGUMENT;
+  return MuxImageDeleteNth(&mux->images_, nth);
+}
+
+//------------------------------------------------------------------------------
+// Assembly of the WebP RIFF file.
+
+static WebPMuxError GetFrameFragmentInfo(
+    const WebPChunk* const frame_frgm_chunk,
+    int* const x_offset, int* const y_offset, int* const duration) {
+  const uint32_t tag = frame_frgm_chunk->tag_;
+  const int is_frame = (tag == kChunks[IDX_ANMF].tag);
+  const WebPData* const data = &frame_frgm_chunk->data_;
+  const size_t expected_data_size =
+      is_frame ? ANMF_CHUNK_SIZE : FRGM_CHUNK_SIZE;
+  assert(frame_frgm_chunk != NULL);
+  assert(tag == kChunks[IDX_ANMF].tag || tag ==  kChunks[IDX_FRGM].tag);
+  if (data->size != expected_data_size) return WEBP_MUX_INVALID_ARGUMENT;
+
+  *x_offset = 2 * GetLE24(data->bytes + 0);
+  *y_offset = 2 * GetLE24(data->bytes + 3);
+  if (is_frame) *duration = GetLE24(data->bytes + 12);
+  return WEBP_MUX_OK;
+}
+
+static WebPMuxError GetImageInfo(const WebPMuxImage* const wpi,
+                                 int* const x_offset, int* const y_offset,
+                                 int* const duration,
+                                 int* const width, int* const height) {
+  const WebPChunk* const frame_frgm_chunk = wpi->header_;
+  WebPMuxError err;
+  assert(wpi != NULL);
+  assert(frame_frgm_chunk != NULL);
+
+  // Get offsets and duration from ANMF/FRGM chunk.
+  err = GetFrameFragmentInfo(frame_frgm_chunk, x_offset, y_offset, duration);
+  if (err != WEBP_MUX_OK) return err;
+
+  // Get width and height from VP8/VP8L chunk.
+  if (width != NULL) *width = wpi->width_;
+  if (height != NULL) *height = wpi->height_;
+  return WEBP_MUX_OK;
+}
+
+static WebPMuxError GetImageCanvasWidthHeight(
+    const WebPMux* const mux, uint32_t flags,
+    int* const width, int* const height) {
+  WebPMuxImage* wpi = NULL;
+  assert(mux != NULL);
+  assert(width != NULL && height != NULL);
+
+  wpi = mux->images_;
+  assert(wpi != NULL);
+  assert(wpi->img_ != NULL);
+
+  if (wpi->next_ != NULL) {
+    int max_x = 0;
+    int max_y = 0;
+    int64_t image_area = 0;
+    // if we have a chain of wpi's, header_ is necessarily set
+    assert(wpi->header_ != NULL);
+    // Aggregate the bounding box for animation frames & fragmented images.
+    for (; wpi != NULL; wpi = wpi->next_) {
+      int x_offset = 0, y_offset = 0, duration = 0, w = 0, h = 0;
+      const WebPMuxError err = GetImageInfo(wpi, &x_offset, &y_offset,
+                                            &duration, &w, &h);
+      const int max_x_pos = x_offset + w;
+      const int max_y_pos = y_offset + h;
+      if (err != WEBP_MUX_OK) return err;
+      assert(x_offset < MAX_POSITION_OFFSET);
+      assert(y_offset < MAX_POSITION_OFFSET);
+
+      if (max_x_pos > max_x) max_x = max_x_pos;
+      if (max_y_pos > max_y) max_y = max_y_pos;
+      image_area += w * h;
+    }
+    *width = max_x;
+    *height = max_y;
+    // Crude check to validate that there are no image overlaps/holes for
+    // fragmented images. Check that the aggregated image area for individual
+    // fragments exactly matches the image area of the constructed canvas.
+    // However, the area-match is necessary but not sufficient condition.
+    if ((flags & FRAGMENTS_FLAG) && (image_area != (max_x * max_y))) {
+      *width = 0;
+      *height = 0;
+      return WEBP_MUX_INVALID_ARGUMENT;
+    }
+  } else {
+    // For a single image, canvas dimensions are same as image dimensions.
+    *width = wpi->width_;
+    *height = wpi->height_;
+  }
+  return WEBP_MUX_OK;
+}
+
+// VP8X format:
+// Total Size : 10,
+// Flags  : 4 bytes,
+// Width  : 3 bytes,
+// Height : 3 bytes.
+static WebPMuxError CreateVP8XChunk(WebPMux* const mux) {
+  WebPMuxError err = WEBP_MUX_OK;
+  uint32_t flags = 0;
+  int width = 0;
+  int height = 0;
+  uint8_t data[VP8X_CHUNK_SIZE];
+  const WebPData vp8x = { data, VP8X_CHUNK_SIZE };
+  const WebPMuxImage* images = NULL;
+
+  assert(mux != NULL);
+  images = mux->images_;  // First image.
+  if (images == NULL || images->img_ == NULL ||
+      images->img_->data_.bytes == NULL) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  // If VP8X chunk(s) is(are) already present, remove them (and later add new
+  // VP8X chunk with updated flags).
+  err = MuxDeleteAllNamedData(mux, kChunks[IDX_VP8X].tag);
+  if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;
+
+  // Set flags.
+  if (mux->iccp_ != NULL && mux->iccp_->data_.bytes != NULL) {
+    flags |= ICCP_FLAG;
+  }
+  if (mux->exif_ != NULL && mux->exif_->data_.bytes != NULL) {
+    flags |= EXIF_FLAG;
+  }
+  if (mux->xmp_ != NULL && mux->xmp_->data_.bytes != NULL) {
+    flags |= XMP_FLAG;
+  }
+  if (images->header_ != NULL) {
+    if (images->header_->tag_ == kChunks[IDX_FRGM].tag) {
+      // This is a fragmented image.
+      flags |= FRAGMENTS_FLAG;
+    } else if (images->header_->tag_ == kChunks[IDX_ANMF].tag) {
+      // This is an image with animation.
+      flags |= ANIMATION_FLAG;
+    }
+  }
+  if (MuxImageCount(images, WEBP_CHUNK_ALPHA) > 0) {
+    flags |= ALPHA_FLAG;  // Some images have an alpha channel.
+  }
+
+  if (flags == 0) {
+    // For Simple Image, VP8X chunk should not be added.
+    return WEBP_MUX_OK;
+  }
+
+  err = GetImageCanvasWidthHeight(mux, flags, &width, &height);
+  if (err != WEBP_MUX_OK) return err;
+
+  if (width <= 0 || height <= 0) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+  if (width > MAX_CANVAS_SIZE || height > MAX_CANVAS_SIZE) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  if (MuxHasAlpha(images)) {
+    // This means some frames explicitly/implicitly contain alpha.
+    // Note: This 'flags' update must NOT be done for a lossless image
+    // without a VP8X chunk!
+    flags |= ALPHA_FLAG;
+  }
+
+  PutLE32(data + 0, flags);   // VP8X chunk flags.
+  PutLE24(data + 4, width - 1);   // canvas width.
+  PutLE24(data + 7, height - 1);  // canvas height.
+
+  return MuxSet(mux, kChunks[IDX_VP8X].tag, 1, &vp8x, 1);
+}
+
+// Cleans up 'mux' by removing any unnecessary chunks.
+static WebPMuxError MuxCleanup(WebPMux* const mux) {
+  int num_frames;
+  int num_fragments;
+  int num_anim_chunks;
+
+  // If we have an image with single fragment or frame, convert it to a
+  // non-animated non-fragmented image (to avoid writing FRGM/ANMF chunk
+  // unnecessarily).
+  WebPMuxError err = WebPMuxNumChunks(mux, kChunks[IDX_ANMF].id, &num_frames);
+  if (err != WEBP_MUX_OK) return err;
+  err = WebPMuxNumChunks(mux, kChunks[IDX_FRGM].id, &num_fragments);
+  if (err != WEBP_MUX_OK) return err;
+  if (num_frames == 1 || num_fragments == 1) {
+    WebPMuxImage* frame_frag;
+    err = MuxImageGetNth((const WebPMuxImage**)&mux->images_, 1, &frame_frag);
+    assert(err == WEBP_MUX_OK);  // We know that one frame/fragment does exist.
+    if (frame_frag->header_ != NULL) {
+      assert(frame_frag->header_->tag_ == kChunks[IDX_ANMF].tag ||
+             frame_frag->header_->tag_ == kChunks[IDX_FRGM].tag);
+      ChunkDelete(frame_frag->header_);  // Removes ANMF/FRGM chunk.
+      frame_frag->header_ = NULL;
+    }
+    num_frames = 0;
+    num_fragments = 0;
+  }
+  // Remove ANIM chunk if this is a non-animated image.
+  err = WebPMuxNumChunks(mux, kChunks[IDX_ANIM].id, &num_anim_chunks);
+  if (err != WEBP_MUX_OK) return err;
+  if (num_anim_chunks >= 1 && num_frames == 0) {
+    err = MuxDeleteAllNamedData(mux, kChunks[IDX_ANIM].tag);
+    if (err != WEBP_MUX_OK) return err;
+  }
+  return WEBP_MUX_OK;
+}
+
+// Total size of a list of images.
+static size_t ImageListDiskSize(const WebPMuxImage* wpi_list) {
+  size_t size = 0;
+  while (wpi_list != NULL) {
+    size += MuxImageDiskSize(wpi_list);
+    wpi_list = wpi_list->next_;
+  }
+  return size;
+}
+
+// Write out the given list of images into 'dst'.
+static uint8_t* ImageListEmit(const WebPMuxImage* wpi_list, uint8_t* dst) {
+  while (wpi_list != NULL) {
+    dst = MuxImageEmit(wpi_list, dst);
+    wpi_list = wpi_list->next_;
+  }
+  return dst;
+}
+
+WebPMuxError WebPMuxAssemble(WebPMux* mux, WebPData* assembled_data) {
+  size_t size = 0;
+  uint8_t* data = NULL;
+  uint8_t* dst = NULL;
+  WebPMuxError err;
+
+  if (mux == NULL || assembled_data == NULL) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  // Finalize mux.
+  err = MuxCleanup(mux);
+  if (err != WEBP_MUX_OK) return err;
+  err = CreateVP8XChunk(mux);
+  if (err != WEBP_MUX_OK) return err;
+
+  // Allocate data.
+  size = ChunkListDiskSize(mux->vp8x_) + ChunkListDiskSize(mux->iccp_)
+       + ChunkListDiskSize(mux->anim_) + ImageListDiskSize(mux->images_)
+       + ChunkListDiskSize(mux->exif_) + ChunkListDiskSize(mux->xmp_)
+       + ChunkListDiskSize(mux->unknown_) + RIFF_HEADER_SIZE;
+
+  data = (uint8_t*)malloc(size);
+  if (data == NULL) return WEBP_MUX_MEMORY_ERROR;
+
+  // Emit header & chunks.
+  dst = MuxEmitRiffHeader(data, size);
+  dst = ChunkListEmit(mux->vp8x_, dst);
+  dst = ChunkListEmit(mux->iccp_, dst);
+  dst = ChunkListEmit(mux->anim_, dst);
+  dst = ImageListEmit(mux->images_, dst);
+  dst = ChunkListEmit(mux->exif_, dst);
+  dst = ChunkListEmit(mux->xmp_, dst);
+  dst = ChunkListEmit(mux->unknown_, dst);
+  assert(dst == data + size);
+
+  // Validate mux.
+  err = MuxValidate(mux);
+  if (err != WEBP_MUX_OK) {
+    free(data);
+    data = NULL;
+    size = 0;
+  }
+
+  // Finalize data.
+  assembled_data->bytes = data;
+  assembled_data->size = size;
+
+  return err;
+}
+
+//------------------------------------------------------------------------------
+