// 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 <stddef.h>

#include <string.h>

#include "src/dec/vp8_dec.h"

#include "src/mux/muxi.h"

#include "src/utils/utils.h"

#include "src/webp/format_constants.h"

#include "src/webp/mux.h"

#include "src/webp/mux_types.h"

#include "src/webp/types.h"

//------------------------------------------------------------------------------

// Life of a mux object.

static void MuxInit(WebPMux* const mux) {

  assert(mux != NULL);

  memset(mux, 0, sizeof(*mux));

  mux->canvas_width = 0;  // just to be explicit

  mux->canvas_height = 0;

}

WebPMux* WebPNewInternal(int version) {

  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {

    return NULL;

  } else {

    WebPMux* const mux = (WebPMux*)WebPSafeMalloc(1ULL, sizeof(WebPMux));

    if (mux != NULL) 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) {

  assert(mux != NULL);

  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 != NULL) {

    MuxRelease(mux);

    WebPSafeFree(mux);

  }

}

//------------------------------------------------------------------------------

// Helper method(s).

// Handy MACRO, makes MuxSet() very symmetric to MuxGet().

#define SWITCH_ID_LIST(INDEX, LIST)                        \

  do {                                                     \

    if (idx == (INDEX)) {                                  \

      err = ChunkAssignData(&chunk, data, copy_data, tag); \

      if (err == WEBP_MUX_OK) {                            \

        err = ChunkSetHead(&chunk, (LIST));                \

        if (err != WEBP_MUX_OK) ChunkRelease(&chunk);      \

      }                                                    \

      return err;                                          \

    }                                                      \

  } while (0)

static WebPMuxError MuxSet(WebPMux* const mux, uint32_t tag,

                           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 given image data, offsets and duration.

static WebPMuxError CreateFrameData(int width, int height,

                                    const WebPMuxFrameInfo* const info,

                                    WebPData* const frame) {

  uint8_t* frame_bytes;

  const size_t frame_size = kChunks[IDX_ANMF].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_bytes = (uint8_t*)WebPSafeMalloc(1ULL, frame_size);

  if (frame_bytes == NULL) return WEBP_MUX_MEMORY_ERROR;

  PutLE24(frame_bytes + 0, info->x_offset / 2);

  PutLE24(frame_bytes + 3, info->y_offset / 2);

  PutLE24(frame_bytes + 6, width - 1);

  PutLE24(frame_bytes + 9, height - 1);

  PutLE24(frame_bytes + 12, info->duration);

  frame_bytes[15] =

      (info->blend_method == WEBP_MUX_NO_BLEND ? 2 : 0) |

      (info->dispose_method == WEBP_MUX_DISPOSE_BACKGROUND ? 1 : 0);

  frame->bytes = frame_bytes;

  frame->size = frame_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, 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 = ChunkSetHead(&chunk, chunk_list);

  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;

  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* info,

                              int copy_data) {

  WebPMuxImage wpi;

  WebPMuxError err;

  if (mux == NULL || info == NULL) return WEBP_MUX_INVALID_ARGUMENT;

  if (info->id != WEBP_CHUNK_ANMF) return WEBP_MUX_INVALID_ARGUMENT;

  if (info->bitstream.bytes == NULL ||

      info->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 != info->id) {

      return WEBP_MUX_INVALID_ARGUMENT;  // Conflicting frame types.

    }

  }

  MuxImageInit(&wpi);

  err = SetAlphaAndImageChunks(&info->bitstream, copy_data, &wpi);

  if (err != WEBP_MUX_OK) goto Err;

  assert(wpi.img != NULL);  // As SetAlphaAndImageChunks() was successful.

  {

    WebPData frame;

    const uint32_t tag = kChunks[IDX_ANMF].tag;

    WebPMuxFrameInfo tmp = *info;

    tmp.x_offset &= ~1;  // Snap offsets to even.

    tmp.y_offset &= ~1;

    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 = CreateFrameData(wpi.width, wpi.height, &tmp, &frame);

    if (err != WEBP_MUX_OK) goto Err;

    // Add frame chunk (with copy_data = 1).

    err = AddDataToChunkList(&frame, 1, tag, &wpi.header);

    WebPDataClear(&frame);  // frame 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, &anim, 1);

}

WebPMuxError WebPMuxSetCanvasSize(WebPMux* mux, int width, int height) {

  WebPMuxError err;

  if (mux == NULL) {

    return WEBP_MUX_INVALID_ARGUMENT;

  }

  if (width < 0 || height < 0 || width > MAX_CANVAS_SIZE ||

      height > MAX_CANVAS_SIZE) {

    return WEBP_MUX_INVALID_ARGUMENT;

  }

  if (width * (uint64_t)height >= MAX_IMAGE_AREA) {

    return WEBP_MUX_INVALID_ARGUMENT;

  }

  if ((width * height) == 0 && (width | height) != 0) {

    // one of width / height is zero, but not both -> invalid!

    return WEBP_MUX_INVALID_ARGUMENT;

  }

  // If we already assembled a VP8X chunk, invalidate it.

  err = MuxDeleteAllNamedData(mux, kChunks[IDX_VP8X].tag);

  if (err != WEBP_MUX_OK && err != WEBP_MUX_NOT_FOUND) return err;

  mux->canvas_width = width;

  mux->canvas_height = height;

  return WEBP_MUX_OK;

}

//------------------------------------------------------------------------------

// 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 GetFrameInfo(const WebPChunk* const frame_chunk,

                                 int* const x_offset, int* const y_offset,

                                 int* const duration) {

  const WebPData* const data = &frame_chunk->data;

  const size_t expected_data_size = ANMF_CHUNK_SIZE;

  assert(frame_chunk->tag == kChunks[IDX_ANMF].tag);

  assert(frame_chunk != NULL);

  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);

  *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_chunk = wpi->header;

  WebPMuxError err;

  assert(wpi != NULL);

  assert(frame_chunk != NULL);

  // Get offsets and duration from ANMF chunk.

  err = GetFrameInfo(frame_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;

}

// Returns the tightest dimension for the canvas considering the image list.

static WebPMuxError GetAdjustedCanvasSize(const WebPMux* const mux,

                                          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, max_y = 0;

    // if we have a chain of wpi's, header is necessarily set

    assert(wpi->header != NULL);

    // Aggregate the bounding box for animation frames.

    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;

    }

    *width = max_x;

    *height = max_y;

  } 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_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.

  }

  err = GetAdjustedCanvasSize(mux, &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 (mux->canvas_width != 0 || mux->canvas_height != 0) {

    if (width > mux->canvas_width || height > mux->canvas_height) {

      return WEBP_MUX_INVALID_ARGUMENT;

    }

    width = mux->canvas_width;

    height = mux->canvas_height;

  }

  if (flags == 0 && mux->unknown == NULL) {

    // For simple file format, VP8X chunk should not be added.

    return WEBP_MUX_OK;

  }

  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, &vp8x, 1);

}

// Cleans up 'mux' by removing any unnecessary chunks.

static WebPMuxError MuxCleanup(WebPMux* const mux) {

  int num_frames;

  int num_anim_chunks;

  // If we have an image with a single frame, and its rectangle

  // covers the whole canvas, convert it to a non-animated image

  // (to avoid writing ANMF chunk unnecessarily).

  WebPMuxError err = WebPMuxNumChunks(mux, kChunks[IDX_ANMF].id, &num_frames);

  if (err != WEBP_MUX_OK) return err;

  if (num_frames == 1) {

    WebPMuxImage* frame = NULL;

    err = MuxImageGetNth((const WebPMuxImage**)&mux->images, 1, &frame);

    if (err != WEBP_MUX_OK) return err;

    // We know that one frame does exist.

    assert(frame != NULL);

    if (frame->header != NULL &&

        ((mux->canvas_width == 0 && mux->canvas_height == 0) ||

         (frame->width == mux->canvas_width &&

          frame->height == mux->canvas_height))) {

      assert(frame->header->tag == kChunks[IDX_ANMF].tag);

      ChunkDelete(frame->header);  // Removes ANMF chunk.

      frame->header = NULL;

      num_frames = 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 (assembled_data == NULL) {

    return WEBP_MUX_INVALID_ARGUMENT;

  }

  // Clean up returned data, in case something goes wrong.

  memset(assembled_data, 0, sizeof(*assembled_data));

  if (mux == 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*)WebPSafeMalloc(1ULL, 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) {

    WebPSafeFree(data);

    data = NULL;

    size = 0;

  }

  // Finalize data.

  assembled_data->bytes = data;

  assembled_data->size = size;

  return err;

}

//------------------------------------------------------------------------------