diff --git a/examples/gif2webp.c b/examples/gif2webp.c
index eeed97b4..060e466d 100644
--- a/examples/gif2webp.c
+++ b/examples/gif2webp.c
@@ -442,14 +442,21 @@ int main(int argc, const char *argv[]) {
gif->SWidth, gif->SHeight);
}
}
- // Allocate current buffer
+ // Set definitive canvas size.
+ err = WebPMuxSetCanvasSize(mux, gif->SWidth, gif->SHeight);
+ if (err != WEBP_MUX_OK) {
+ fprintf(stderr, "Invalid canvas size %d x %d\n",
+ gif->SWidth, gif->SHeight);
+ goto End;
+ }
+ // Allocate current buffer.
frame.width = gif->SWidth;
frame.height = gif->SHeight;
frame.use_argb = 1;
if (!WebPPictureAlloc(&frame)) goto End;
WebPUtilClearPic(&frame, NULL);
- // Initialize cache
+ // Initialize cache.
cache = WebPFrameCacheNew(frame.width, frame.height,
kmin, kmax, allow_mixed);
if (cache == NULL) goto End;
diff --git a/src/mux/muxedit.c b/src/mux/muxedit.c
index 2c6c5f9a..26b19249 100644
--- a/src/mux/muxedit.c
+++ b/src/mux/muxedit.c
@@ -20,8 +20,10 @@
// Life of a mux object.
static void MuxInit(WebPMux* const mux) {
- if (mux == NULL) return;
+ assert(mux != NULL);
memset(mux, 0, sizeof(*mux));
+ mux->canvas_width_ = 0; // just to be explicit
+ mux->canvas_height_ = 0;
}
WebPMux* WebPNewInternal(int version) {
@@ -29,8 +31,7 @@ WebPMux* WebPNewInternal(int version) {
return NULL;
} else {
WebPMux* const mux = (WebPMux*)WebPSafeMalloc(1ULL, sizeof(WebPMux));
- // If mux is NULL MuxInit is a noop.
- MuxInit(mux);
+ if (mux != NULL) MuxInit(mux);
return mux;
}
}
@@ -43,7 +44,7 @@ static void DeleteAllImages(WebPMuxImage** const wpi_list) {
}
static void MuxRelease(WebPMux* const mux) {
- if (mux == NULL) return;
+ assert(mux != NULL);
DeleteAllImages(&mux->images_);
ChunkListDelete(&mux->vp8x_);
ChunkListDelete(&mux->iccp_);
@@ -54,9 +55,10 @@ static void MuxRelease(WebPMux* const mux) {
}
void WebPMuxDelete(WebPMux* mux) {
- // If mux is NULL MuxRelease is a noop.
- MuxRelease(mux);
- WebPSafeFree(mux);
+ if (mux != NULL) {
+ MuxRelease(mux);
+ WebPSafeFree(mux);
+ }
}
//------------------------------------------------------------------------------
@@ -360,6 +362,32 @@ WebPMuxError WebPMuxSetAnimationParams(WebPMux* mux,
return MuxSet(mux, kChunks[IDX_ANIM].tag, 1, &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).
@@ -413,9 +441,10 @@ static WebPMuxError GetImageInfo(const WebPMuxImage* const wpi,
return WEBP_MUX_OK;
}
-static WebPMuxError GetImageCanvasWidthHeight(
- const WebPMux* const mux, uint32_t flags,
- int* const width, int* const height) {
+// Returns the tightest dimension for the canvas considering the image list.
+static WebPMuxError GetAdjustedCanvasSize(const WebPMux* const mux,
+ uint32_t flags,
+ int* const width, int* const height) {
WebPMuxImage* wpi = NULL;
assert(mux != NULL);
assert(width != NULL && height != NULL);
@@ -513,12 +542,7 @@ static WebPMuxError CreateVP8XChunk(WebPMux* const mux) {
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);
+ err = GetAdjustedCanvasSize(mux, flags, &width, &height);
if (err != WEBP_MUX_OK) return err;
if (width <= 0 || height <= 0) {
@@ -528,6 +552,19 @@ static WebPMuxError CreateVP8XChunk(WebPMux* const mux) {
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) {
+ // For Simple Image, 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
@@ -603,7 +640,13 @@ WebPMuxError WebPMuxAssemble(WebPMux* mux, WebPData* assembled_data) {
uint8_t* dst = NULL;
WebPMuxError err;
- if (mux == NULL || assembled_data == NULL) {
+ 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;
}
@@ -649,4 +692,3 @@ WebPMuxError WebPMuxAssemble(WebPMux* mux, WebPData* assembled_data) {
}
//------------------------------------------------------------------------------
-
diff --git a/src/mux/muxi.h b/src/mux/muxi.h
index 277d5fba..6a410232 100644
--- a/src/mux/muxi.h
+++ b/src/mux/muxi.h
@@ -65,7 +65,9 @@ struct WebPMux {
WebPChunk* anim_;
WebPChunk* vp8x_;
- WebPChunk* unknown_;
+ WebPChunk* unknown_;
+ int canvas_width_;
+ int canvas_height_;
};
// CHUNK_INDEX enum: used for indexing within 'kChunks' (defined below) only.
diff --git a/src/mux/muxread.c b/src/mux/muxread.c
index db51cf12..bba09a5d 100644
--- a/src/mux/muxread.c
+++ b/src/mux/muxread.c
@@ -264,6 +264,10 @@ WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data,
// getting all chunks of an image.
chunk_list = MuxGetChunkListFromId(mux, id); // List to add this chunk.
if (ChunkSetNth(&chunk, chunk_list, 0) != WEBP_MUX_OK) goto Err;
+ if (id == WEBP_CHUNK_VP8X) { // grab global specs
+ mux->canvas_width_ = GetLE24(data + 12) + 1;
+ mux->canvas_height_ = GetLE24(data + 15) + 1;
+ }
break;
}
data += data_size;
@@ -320,14 +324,20 @@ static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux,
f = GetLE32(data.bytes + 0);
w = GetLE24(data.bytes + 4) + 1;
h = GetLE24(data.bytes + 7) + 1;
- } else { // Single image case.
+ } else {
const WebPMuxImage* const wpi = mux->images_;
- WebPMuxError err = ValidateForSingleImage(mux);
- if (err != WEBP_MUX_OK) return err;
- assert(wpi != NULL);
- w = wpi->width_;
- h = wpi->height_;
- if (wpi->has_alpha_) f |= ALPHA_FLAG;
+ // Grab user-forced canvas size as default.
+ w = mux->canvas_width_;
+ h = mux->canvas_height_;
+ if (w == 0 && h == 0 && ValidateForSingleImage(mux) == WEBP_MUX_OK) {
+ // single image and not forced canvas size => use dimension of first frame
+ assert(wpi != NULL);
+ w = wpi->width_;
+ h = wpi->height_;
+ }
+ if (wpi != NULL) {
+ if (wpi->has_alpha_) f |= ALPHA_FLAG;
+ }
}
if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA;
@@ -537,4 +547,3 @@ WebPMuxError WebPMuxNumChunks(const WebPMux* mux,
}
//------------------------------------------------------------------------------
-
diff --git a/src/webp/mux.h b/src/webp/mux.h
index eb57f51c..578d9e02 100644
--- a/src/webp/mux.h
+++ b/src/webp/mux.h
@@ -55,7 +55,7 @@
extern "C" {
#endif
-#define WEBP_MUX_ABI_VERSION 0x0101 // MAJOR(8b) + MINOR(8b)
+#define WEBP_MUX_ABI_VERSION 0x0102 // MAJOR(8b) + MINOR(8b)
// Note: forward declaring enumerations is not allowed in (strict) C and C++,
// the types are left here for reference.
@@ -105,6 +105,7 @@ WEBP_EXTERN(WebPMux*) WebPNewInternal(int);
// Creates an empty mux object.
// Returns:
// A pointer to the newly created empty mux object.
+// Or NULL in case of memory error.
static WEBP_INLINE WebPMux* WebPMuxNew(void) {
return WebPNewInternal(WEBP_MUX_ABI_VERSION);
}
@@ -309,6 +310,24 @@ WEBP_EXTERN(WebPMuxError) WebPMuxGetAnimationParams(
//------------------------------------------------------------------------------
// Misc Utilities.
+// Sets the canvas size for the mux object. The width and height can be
+// specified explicitly or left as zero (0, 0).
+// * When width and height are specified explicitly, then this frame bound is
+// enforced during subsequent calls to WebPMuxAssemble() and an error is
+// reported if any animated frame does not completely fit within the canvas.
+// * When unspecified (0, 0), the constructed canvas will get the frame bounds
+// from the bounding-box over all frames after calling WebPMuxAssemble().
+// Parameters:
+// mux - (in) object to which the canvas size is to be set
+// width - (in) canvas width
+// height - (in) canvas height
+// Returns:
+// WEBP_MUX_INVALID_ARGUMENT - if mux is NULL; or
+// width or height are invalid or out of bounds
+// WEBP_MUX_OK - on success.
+WEBP_EXTERN(WebPMuxError) WebPMuxSetCanvasSize(WebPMux* mux,
+ int width, int height);
+
// Gets the canvas size from the mux object.
// Note: This method assumes that the VP8X chunk, if present, is up-to-date.
// That is, the mux object hasn't been modified since the last call to
@@ -356,7 +375,8 @@ WEBP_EXTERN(WebPMuxError) WebPMuxNumChunks(const WebPMux* mux,
// Note: The content of 'assembled_data' will be ignored and overwritten.
// Also, the content of 'assembled_data' is allocated using malloc(), and NOT
// owned by the 'mux' object. It MUST be deallocated by the caller by calling
-// WebPDataClear().
+// WebPDataClear(). It's always safe to call WebPDataClear() upon return,
+// even in case of error.
// Parameters:
// mux - (in/out) object whose chunks are to be assembled
// assembled_data - (out) assembled WebP data