3rdparty/libwebp/mux/muxinternal.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
WebPGetMuxVersion
ChunkInit
ChunkRelease
ChunkGetIndexFromTag
ChunkGetIdFromTag
ChunkGetTagFromFourCC
ChunkGetIndexFromFourCC
ChunkSearchNextInList
ChunkSearchList
ChunkSearchListToSet
ChunkAssignData
ChunkSetNth
ChunkDelete
ChunksListDiskSize
ChunkEmit
ChunkListEmit
MuxImageInit
MuxImageRelease
MuxImageCount
SearchImageToGetOrDelete
MuxImagePush
MuxImageDelete
MuxImageDeleteAll
MuxImageDeleteNth
MuxImageGetNth
MuxImageDiskSize
MuxImageListDiskSize
ChunkEmitSpecial
MuxImageEmit
MuxImageListEmit
MuxHasLosslessImages
MuxEmitRiffHeader
MuxGetChunkListFromId
MuxValidateForImage
IsNotCompatible
ValidateChunk
MuxValidate
// 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.
// -----------------------------------------------------------------------------
//
// Internal objects and utils for mux.
//
// Authors: Urvang (urvang@google.com)
//          Vikas (vikasa@google.com)

#include <assert.h>
#include "./muxi.h"
#include "../utils/utils.h"

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

#define UNDEFINED_CHUNK_SIZE (-1)

const ChunkInfo kChunks[] = {
  { MKFOURCC('V', 'P', '8', 'X'),  WEBP_CHUNK_VP8X,    VP8X_CHUNK_SIZE },
  { MKFOURCC('I', 'C', 'C', 'P'),  WEBP_CHUNK_ICCP,    UNDEFINED_CHUNK_SIZE },
  { MKFOURCC('A', 'N', 'I', 'M'),  WEBP_CHUNK_ANIM,    ANIM_CHUNK_SIZE },
  { MKFOURCC('A', 'N', 'M', 'F'),  WEBP_CHUNK_ANMF,    ANMF_CHUNK_SIZE },
  { MKFOURCC('F', 'R', 'G', 'M'),  WEBP_CHUNK_FRGM,    FRGM_CHUNK_SIZE },
  { MKFOURCC('A', 'L', 'P', 'H'),  WEBP_CHUNK_ALPHA,   UNDEFINED_CHUNK_SIZE },
  { MKFOURCC('V', 'P', '8', ' '),  WEBP_CHUNK_IMAGE,   UNDEFINED_CHUNK_SIZE },
  { MKFOURCC('V', 'P', '8', 'L'),  WEBP_CHUNK_IMAGE,   UNDEFINED_CHUNK_SIZE },
  { MKFOURCC('E', 'X', 'I', 'F'),  WEBP_CHUNK_EXIF,    UNDEFINED_CHUNK_SIZE },
  { MKFOURCC('X', 'M', 'P', ' '),  WEBP_CHUNK_XMP,     UNDEFINED_CHUNK_SIZE },
  { MKFOURCC('U', 'N', 'K', 'N'),  WEBP_CHUNK_UNKNOWN, UNDEFINED_CHUNK_SIZE },

  { NIL_TAG,                       WEBP_CHUNK_NIL,     UNDEFINED_CHUNK_SIZE }
};

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

int WebPGetMuxVersion(void) {
  return (MUX_MAJ_VERSION << 16) | (MUX_MIN_VERSION << 8) | MUX_REV_VERSION;
}

//------------------------------------------------------------------------------
// Life of a chunk object.

void ChunkInit(WebPChunk* const chunk) {
  assert(chunk);
  memset(chunk, 0, sizeof(*chunk));
  chunk->tag_ = NIL_TAG;
}

WebPChunk* ChunkRelease(WebPChunk* const chunk) {
  WebPChunk* next;
  if (chunk == NULL) return NULL;
  if (chunk->owner_) {
    WebPDataClear(&chunk->data_);
  }
  next = chunk->next_;
  ChunkInit(chunk);
  return next;
}

//------------------------------------------------------------------------------
// Chunk misc methods.

CHUNK_INDEX ChunkGetIndexFromTag(uint32_t tag) {
  int i;
  for (i = 0; kChunks[i].tag != NIL_TAG; ++i) {
    if (tag == kChunks[i].tag) return i;
  }
  return IDX_NIL;
}

WebPChunkId ChunkGetIdFromTag(uint32_t tag) {
  int i;
  for (i = 0; kChunks[i].tag != NIL_TAG; ++i) {
    if (tag == kChunks[i].tag) return kChunks[i].id;
  }
  return WEBP_CHUNK_NIL;
}

uint32_t ChunkGetTagFromFourCC(const char fourcc[4]) {
  return MKFOURCC(fourcc[0], fourcc[1], fourcc[2], fourcc[3]);
}

CHUNK_INDEX ChunkGetIndexFromFourCC(const char fourcc[4]) {
  const uint32_t tag = ChunkGetTagFromFourCC(fourcc);
  const CHUNK_INDEX idx = ChunkGetIndexFromTag(tag);
  return (idx == IDX_NIL) ? IDX_UNKNOWN : idx;
}

//------------------------------------------------------------------------------
// Chunk search methods.

// Returns next chunk in the chunk list with the given tag.
static WebPChunk* ChunkSearchNextInList(WebPChunk* chunk, uint32_t tag) {
  while (chunk != NULL && chunk->tag_ != tag) {
    chunk = chunk->next_;
  }
  return chunk;
}

WebPChunk* ChunkSearchList(WebPChunk* first, uint32_t nth, uint32_t tag) {
  uint32_t iter = nth;
  first = ChunkSearchNextInList(first, tag);
  if (first == NULL) return NULL;

  while (--iter != 0) {
    WebPChunk* next_chunk = ChunkSearchNextInList(first->next_, tag);
    if (next_chunk == NULL) break;
    first = next_chunk;
  }
  return ((nth > 0) && (iter > 0)) ? NULL : first;
}

// Outputs a pointer to 'prev_chunk->next_',
//   where 'prev_chunk' is the pointer to the chunk at position (nth - 1).
// Returns true if nth chunk was found.
static int ChunkSearchListToSet(WebPChunk** chunk_list, uint32_t nth,
                                WebPChunk*** const location) {
  uint32_t count = 0;
  assert(chunk_list != NULL);
  *location = chunk_list;

  while (*chunk_list != NULL) {
    WebPChunk* const cur_chunk = *chunk_list;
    ++count;
    if (count == nth) return 1;  // Found.
    chunk_list = &cur_chunk->next_;
    *location = chunk_list;
  }

  // *chunk_list is ok to be NULL if adding at last location.
  return (nth == 0 || (count == nth - 1)) ? 1 : 0;
}

//------------------------------------------------------------------------------
// Chunk writer methods.

WebPMuxError ChunkAssignData(WebPChunk* chunk, const WebPData* const data,
                             int copy_data, uint32_t tag) {
  // For internally allocated chunks, always copy data & make it owner of data.
  if (tag == kChunks[IDX_VP8X].tag || tag == kChunks[IDX_ANIM].tag) {
    copy_data = 1;
  }

  ChunkRelease(chunk);

  if (data != NULL) {
    if (copy_data) {        // Copy data.
      if (!WebPDataCopy(data, &chunk->data_)) return WEBP_MUX_MEMORY_ERROR;
      chunk->owner_ = 1;    // Chunk is owner of data.
    } else {                // Don't copy data.
      chunk->data_ = *data;
    }
  }
  chunk->tag_ = tag;
  return WEBP_MUX_OK;
}

WebPMuxError ChunkSetNth(WebPChunk* chunk, WebPChunk** chunk_list,
                         uint32_t nth) {
  WebPChunk* new_chunk;

  if (!ChunkSearchListToSet(chunk_list, nth, &chunk_list)) {
    return WEBP_MUX_NOT_FOUND;
  }

  new_chunk = (WebPChunk*)malloc(sizeof(*new_chunk));
  if (new_chunk == NULL) return WEBP_MUX_MEMORY_ERROR;
  *new_chunk = *chunk;
  chunk->owner_ = 0;
  new_chunk->next_ = *chunk_list;
  *chunk_list = new_chunk;
  return WEBP_MUX_OK;
}

//------------------------------------------------------------------------------
// Chunk deletion method(s).

WebPChunk* ChunkDelete(WebPChunk* const chunk) {
  WebPChunk* const next = ChunkRelease(chunk);
  free(chunk);
  return next;
}

//------------------------------------------------------------------------------
// Chunk serialization methods.

size_t ChunksListDiskSize(const WebPChunk* chunk_list) {
  size_t size = 0;
  while (chunk_list != NULL) {
    size += ChunkDiskSize(chunk_list);
    chunk_list = chunk_list->next_;
  }
  return size;
}

static uint8_t* ChunkEmit(const WebPChunk* const chunk, uint8_t* dst) {
  const size_t chunk_size = chunk->data_.size;
  assert(chunk);
  assert(chunk->tag_ != NIL_TAG);
  PutLE32(dst + 0, chunk->tag_);
  PutLE32(dst + TAG_SIZE, (uint32_t)chunk_size);
  assert(chunk_size == (uint32_t)chunk_size);
  memcpy(dst + CHUNK_HEADER_SIZE, chunk->data_.bytes, chunk_size);
  if (chunk_size & 1)
    dst[CHUNK_HEADER_SIZE + chunk_size] = 0;  // Add padding.
  return dst + ChunkDiskSize(chunk);
}

uint8_t* ChunkListEmit(const WebPChunk* chunk_list, uint8_t* dst) {
  while (chunk_list != NULL) {
    dst = ChunkEmit(chunk_list, dst);
    chunk_list = chunk_list->next_;
  }
  return dst;
}

//------------------------------------------------------------------------------
// Life of a MuxImage object.

void MuxImageInit(WebPMuxImage* const wpi) {
  assert(wpi);
  memset(wpi, 0, sizeof(*wpi));
}

WebPMuxImage* MuxImageRelease(WebPMuxImage* const wpi) {
  WebPMuxImage* next;
  if (wpi == NULL) return NULL;
  ChunkDelete(wpi->header_);
  ChunkDelete(wpi->alpha_);
  ChunkDelete(wpi->img_);

  next = wpi->next_;
  MuxImageInit(wpi);
  return next;
}

//------------------------------------------------------------------------------
// MuxImage search methods.

int MuxImageCount(const WebPMuxImage* wpi_list, WebPChunkId id) {
  int count = 0;
  const WebPMuxImage* current;
  for (current = wpi_list; current != NULL; current = current->next_) {
    if (id == WEBP_CHUNK_NIL) {
      ++count;  // Special case: count all images.
    } else {
      const WebPChunk* const wpi_chunk = *MuxImageGetListFromId(current, id);
      if (wpi_chunk != NULL) {
        const WebPChunkId wpi_chunk_id = ChunkGetIdFromTag(wpi_chunk->tag_);
        if (wpi_chunk_id == id) ++count;  // Count images with a matching 'id'.
      }
    }
  }
  return count;
}

// Outputs a pointer to 'prev_wpi->next_',
//   where 'prev_wpi' is the pointer to the image at position (nth - 1).
// Returns true if nth image was found.
static int SearchImageToGetOrDelete(WebPMuxImage** wpi_list, uint32_t nth,
                                    WebPMuxImage*** const location) {
  uint32_t count = 0;
  assert(wpi_list);
  *location = wpi_list;

  if (nth == 0) {
    nth = MuxImageCount(*wpi_list, WEBP_CHUNK_NIL);
    if (nth == 0) return 0;  // Not found.
  }

  while (*wpi_list != NULL) {
    WebPMuxImage* const cur_wpi = *wpi_list;
    ++count;
    if (count == nth) return 1;  // Found.
    wpi_list = &cur_wpi->next_;
    *location = wpi_list;
  }
  return 0;  // Not found.
}

//------------------------------------------------------------------------------
// MuxImage writer methods.

WebPMuxError MuxImagePush(const WebPMuxImage* wpi, WebPMuxImage** wpi_list) {
  WebPMuxImage* new_wpi;

  while (*wpi_list != NULL) {
    WebPMuxImage* const cur_wpi = *wpi_list;
    if (cur_wpi->next_ == NULL) break;
    wpi_list = &cur_wpi->next_;
  }

  new_wpi = (WebPMuxImage*)malloc(sizeof(*new_wpi));
  if (new_wpi == NULL) return WEBP_MUX_MEMORY_ERROR;
  *new_wpi = *wpi;
  new_wpi->next_ = NULL;

  if (*wpi_list != NULL) {
    (*wpi_list)->next_ = new_wpi;
  } else {
    *wpi_list = new_wpi;
  }
  return WEBP_MUX_OK;
}

//------------------------------------------------------------------------------
// MuxImage deletion methods.

WebPMuxImage* MuxImageDelete(WebPMuxImage* const wpi) {
  // Delete the components of wpi. If wpi is NULL this is a noop.
  WebPMuxImage* const next = MuxImageRelease(wpi);
  free(wpi);
  return next;
}

void MuxImageDeleteAll(WebPMuxImage** const wpi_list) {
  while (*wpi_list != NULL) {
    *wpi_list = MuxImageDelete(*wpi_list);
  }
}

WebPMuxError MuxImageDeleteNth(WebPMuxImage** wpi_list, uint32_t nth) {
  assert(wpi_list);
  if (!SearchImageToGetOrDelete(wpi_list, nth, &wpi_list)) {
    return WEBP_MUX_NOT_FOUND;
  }
  *wpi_list = MuxImageDelete(*wpi_list);
  return WEBP_MUX_OK;
}

//------------------------------------------------------------------------------
// MuxImage reader methods.

WebPMuxError MuxImageGetNth(const WebPMuxImage** wpi_list, uint32_t nth,
                            WebPMuxImage** wpi) {
  assert(wpi_list);
  assert(wpi);
  if (!SearchImageToGetOrDelete((WebPMuxImage**)wpi_list, nth,
                                (WebPMuxImage***)&wpi_list)) {
    return WEBP_MUX_NOT_FOUND;
  }
  *wpi = (WebPMuxImage*)*wpi_list;
  return WEBP_MUX_OK;
}

//------------------------------------------------------------------------------
// MuxImage serialization methods.

// Size of an image.
size_t MuxImageDiskSize(const WebPMuxImage* const wpi) {
  size_t size = 0;
  if (wpi->header_ != NULL) size += ChunkDiskSize(wpi->header_);
  if (wpi->alpha_ != NULL) size += ChunkDiskSize(wpi->alpha_);
  if (wpi->img_ != NULL) size += ChunkDiskSize(wpi->img_);
  return size;
}

size_t MuxImageListDiskSize(const WebPMuxImage* wpi_list) {
  size_t size = 0;
  while (wpi_list != NULL) {
    size += MuxImageDiskSize(wpi_list);
    wpi_list = wpi_list->next_;
  }
  return size;
}

// Special case as ANMF/FRGM chunk encapsulates other image chunks.
static uint8_t* ChunkEmitSpecial(const WebPChunk* const header,
                                 size_t total_size, uint8_t* dst) {
  const size_t header_size = header->data_.size;
  const size_t offset_to_next = total_size - CHUNK_HEADER_SIZE;
  assert(header->tag_ == kChunks[IDX_ANMF].tag ||
         header->tag_ == kChunks[IDX_FRGM].tag);
  PutLE32(dst + 0, header->tag_);
  PutLE32(dst + TAG_SIZE, (uint32_t)offset_to_next);
  assert(header_size == (uint32_t)header_size);
  memcpy(dst + CHUNK_HEADER_SIZE, header->data_.bytes, header_size);
  if (header_size & 1) {
    dst[CHUNK_HEADER_SIZE + header_size] = 0;  // Add padding.
  }
  return dst + ChunkDiskSize(header);
}

uint8_t* MuxImageEmit(const WebPMuxImage* const wpi, uint8_t* dst) {
  // Ordering of chunks to be emitted is strictly as follows:
  // 1. ANMF/FRGM chunk (if present).
  // 2. ALPH chunk (if present).
  // 3. VP8/VP8L chunk.
  assert(wpi);
  if (wpi->header_ != NULL) {
    dst = ChunkEmitSpecial(wpi->header_, MuxImageDiskSize(wpi), dst);
  }
  if (wpi->alpha_ != NULL) dst = ChunkEmit(wpi->alpha_, dst);
  if (wpi->img_ != NULL) dst = ChunkEmit(wpi->img_, dst);
  return dst;
}

uint8_t* MuxImageListEmit(const WebPMuxImage* wpi_list, uint8_t* dst) {
  while (wpi_list != NULL) {
    dst = MuxImageEmit(wpi_list, dst);
    wpi_list = wpi_list->next_;
  }
  return dst;
}

//------------------------------------------------------------------------------
// Helper methods for mux.

int MuxHasLosslessImages(const WebPMuxImage* images) {
  while (images != NULL) {
    assert(images->img_ != NULL);
    if (images->img_->tag_ == kChunks[IDX_VP8L].tag) {
      return 1;
    }
    images = images->next_;
  }
  return 0;
}

uint8_t* MuxEmitRiffHeader(uint8_t* const data, size_t size) {
  PutLE32(data + 0, MKFOURCC('R', 'I', 'F', 'F'));
  PutLE32(data + TAG_SIZE, (uint32_t)size - CHUNK_HEADER_SIZE);
  assert(size == (uint32_t)size);
  PutLE32(data + TAG_SIZE + CHUNK_SIZE_BYTES, MKFOURCC('W', 'E', 'B', 'P'));
  return data + RIFF_HEADER_SIZE;
}

WebPChunk** MuxGetChunkListFromId(const WebPMux* mux, WebPChunkId id) {
  assert(mux != NULL);
  switch (id) {
    case WEBP_CHUNK_VP8X:    return (WebPChunk**)&mux->vp8x_;
    case WEBP_CHUNK_ICCP:    return (WebPChunk**)&mux->iccp_;
    case WEBP_CHUNK_ANIM:    return (WebPChunk**)&mux->anim_;
    case WEBP_CHUNK_EXIF:    return (WebPChunk**)&mux->exif_;
    case WEBP_CHUNK_XMP:     return (WebPChunk**)&mux->xmp_;
    case WEBP_CHUNK_UNKNOWN: return (WebPChunk**)&mux->unknown_;
    default: return NULL;
  }
}

WebPMuxError MuxValidateForImage(const WebPMux* const mux) {
  const int num_images = MuxImageCount(mux->images_, WEBP_CHUNK_IMAGE);
  const int num_frames = MuxImageCount(mux->images_, WEBP_CHUNK_ANMF);
  const int num_fragments = MuxImageCount(mux->images_, WEBP_CHUNK_FRGM);

  if (num_images == 0) {
    // No images in mux.
    return WEBP_MUX_NOT_FOUND;
  } else if (num_images == 1 && num_frames == 0 && num_fragments == 0) {
    // Valid case (single image).
    return WEBP_MUX_OK;
  } else {
    // Frame/Fragment case OR an invalid mux.
    return WEBP_MUX_INVALID_ARGUMENT;
  }
}

static int IsNotCompatible(int feature, int num_items) {
  return (feature != 0) != (num_items > 0);
}

#define NO_FLAG 0

// Test basic constraints:
// retrieval, maximum number of chunks by index (use -1 to skip)
// and feature incompatibility (use NO_FLAG to skip).
// On success returns WEBP_MUX_OK and stores the chunk count in *num.
static WebPMuxError ValidateChunk(const WebPMux* const mux, CHUNK_INDEX idx,
                                  WebPFeatureFlags feature,
                                  WebPFeatureFlags vp8x_flags,
                                  int max, int* num) {
  const WebPMuxError err =
      WebPMuxNumChunks(mux, kChunks[idx].id, num);
  if (err != WEBP_MUX_OK) return err;
  if (max > -1 && *num > max) return WEBP_MUX_INVALID_ARGUMENT;
  if (feature != NO_FLAG && IsNotCompatible(vp8x_flags & feature, *num)) {
    return WEBP_MUX_INVALID_ARGUMENT;
  }
  return WEBP_MUX_OK;
}

WebPMuxError MuxValidate(const WebPMux* const mux) {
  int num_iccp;
  int num_exif;
  int num_xmp;
  int num_anim;
  int num_frames;
  int num_fragments;
  int num_vp8x;
  int num_images;
  int num_alpha;
  uint32_t flags;
  WebPMuxError err;

  // Verify mux is not NULL.
  if (mux == NULL) return WEBP_MUX_INVALID_ARGUMENT;

  // Verify mux has at least one image.
  if (mux->images_ == NULL) return WEBP_MUX_INVALID_ARGUMENT;

  err = WebPMuxGetFeatures(mux, &flags);
  if (err != WEBP_MUX_OK) return err;

  // At most one color profile chunk.
  err = ValidateChunk(mux, IDX_ICCP, ICCP_FLAG, flags, 1, &num_iccp);
  if (err != WEBP_MUX_OK) return err;

  // At most one EXIF metadata.
  err = ValidateChunk(mux, IDX_EXIF, EXIF_FLAG, flags, 1, &num_exif);
  if (err != WEBP_MUX_OK) return err;

  // At most one XMP metadata.
  err = ValidateChunk(mux, IDX_XMP, XMP_FLAG, flags, 1, &num_xmp);
  if (err != WEBP_MUX_OK) return err;

  // Animation: ANIMATION_FLAG, ANIM chunk and ANMF chunk(s) are consistent.
  // At most one ANIM chunk.
  err = ValidateChunk(mux, IDX_ANIM, NO_FLAG, flags, 1, &num_anim);
  if (err != WEBP_MUX_OK) return err;
  err = ValidateChunk(mux, IDX_ANMF, NO_FLAG, flags, -1, &num_frames);
  if (err != WEBP_MUX_OK) return err;

  {
    const int has_animation = !!(flags & ANIMATION_FLAG);
    if (has_animation && (num_anim == 0 || num_frames == 0)) {
      return WEBP_MUX_INVALID_ARGUMENT;
    }
    if (!has_animation && (num_anim == 1 || num_frames > 0)) {
      return WEBP_MUX_INVALID_ARGUMENT;
    }
  }

  // Fragmentation: FRAGMENTS_FLAG and FRGM chunk(s) are consistent.
  err = ValidateChunk(mux, IDX_FRGM, FRAGMENTS_FLAG, flags, -1, &num_fragments);
  if (err != WEBP_MUX_OK) return err;

  // Verify either VP8X chunk is present OR there is only one elem in
  // mux->images_.
  err = ValidateChunk(mux, IDX_VP8X, NO_FLAG, flags, 1, &num_vp8x);
  if (err != WEBP_MUX_OK) return err;
  err = ValidateChunk(mux, IDX_VP8, NO_FLAG, flags, -1, &num_images);
  if (err != WEBP_MUX_OK) return err;
  if (num_vp8x == 0 && num_images != 1) return WEBP_MUX_INVALID_ARGUMENT;

  // ALPHA_FLAG & alpha chunk(s) are consistent.
  if (MuxHasLosslessImages(mux->images_)) {
    if (num_vp8x > 0) {
      // Special case: we have a VP8X chunk as well as some lossless images.
      if (!(flags & ALPHA_FLAG)) return WEBP_MUX_INVALID_ARGUMENT;
    }
  } else {
      err = ValidateChunk(mux, IDX_ALPHA, ALPHA_FLAG, flags, -1, &num_alpha);
      if (err != WEBP_MUX_OK) return err;
  }

  // num_fragments & num_images are consistent.
  if (num_fragments > 0 && num_images != num_fragments) {
    return WEBP_MUX_INVALID_ARGUMENT;
  }

  return WEBP_MUX_OK;
}

#undef NO_FLAG

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

#if defined(__cplusplus) || defined(c_plusplus)
}    // extern "C"
#endif
/* [<][>][^][v][top][bottom][index][help] */
root/3rdparty/libwebp/mux/muxinternal.c

DEFINITIONS
