diff options
Diffstat (limited to 'drivers/webp/mux/anim_encode.c')
| -rw-r--r-- | drivers/webp/mux/anim_encode.c | 1534 |
1 files changed, 0 insertions, 1534 deletions
diff --git a/drivers/webp/mux/anim_encode.c b/drivers/webp/mux/anim_encode.c deleted file mode 100644 index 2226febf13..0000000000 --- a/drivers/webp/mux/anim_encode.c +++ /dev/null @@ -1,1534 +0,0 @@ -// Copyright 2014 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. -// ----------------------------------------------------------------------------- -// -// AnimEncoder implementation. -// - -#include <assert.h> -#include <limits.h> -#include <math.h> // for pow() -#include <stdio.h> -#include <stdlib.h> // for abs() - -#include "../utils/utils.h" -#include "webp/decode.h" -#include "webp/encode.h" -#include "webp/format_constants.h" -#include "webp/mux.h" - -#if defined(_MSC_VER) && _MSC_VER < 1900 -#define snprintf _snprintf -#endif - -#define ERROR_STR_MAX_LENGTH 100 - -//------------------------------------------------------------------------------ -// Internal structs. - -// Stores frame rectangle dimensions. -typedef struct { - int x_offset_, y_offset_, width_, height_; -} FrameRect; - -// Used to store two candidates of encoded data for an animation frame. One of -// the two will be chosen later. -typedef struct { - WebPMuxFrameInfo sub_frame_; // Encoded frame rectangle. - WebPMuxFrameInfo key_frame_; // Encoded frame if it is a key-frame. - int is_key_frame_; // True if 'key_frame' has been chosen. -} EncodedFrame; - -struct WebPAnimEncoder { - const int canvas_width_; // Canvas width. - const int canvas_height_; // Canvas height. - const WebPAnimEncoderOptions options_; // Global encoding options. - - FrameRect prev_rect_; // Previous WebP frame rectangle. - WebPConfig last_config_; // Cached in case a re-encode is needed. - WebPConfig last_config_reversed_; // If 'last_config_' uses lossless, then - // this config uses lossy and vice versa; - // only valid if 'options_.allow_mixed' - // is true. - - WebPPicture* curr_canvas_; // Only pointer; we don't own memory. - - // Canvas buffers. - WebPPicture curr_canvas_copy_; // Possibly modified current canvas. - int curr_canvas_copy_modified_; // True if pixels in 'curr_canvas_copy_' - // differ from those in 'curr_canvas_'. - - WebPPicture prev_canvas_; // Previous canvas. - WebPPicture prev_canvas_disposed_; // Previous canvas disposed to background. - - // Encoded data. - EncodedFrame* encoded_frames_; // Array of encoded frames. - size_t size_; // Number of allocated frames. - size_t start_; // Frame start index. - size_t count_; // Number of valid frames. - size_t flush_count_; // If >0, 'flush_count' frames starting from - // 'start' are ready to be added to mux. - - // key-frame related. - int64_t best_delta_; // min(canvas size - frame size) over the frames. - // Can be negative in certain cases due to - // transparent pixels in a frame. - int keyframe_; // Index of selected key-frame relative to 'start_'. - int count_since_key_frame_; // Frames seen since the last key-frame. - - int first_timestamp_; // Timestamp of the first frame. - int prev_timestamp_; // Timestamp of the last added frame. - int prev_candidate_undecided_; // True if it's not yet decided if previous - // frame would be a sub-frame or a key-frame. - - // Misc. - int is_first_frame_; // True if first frame is yet to be added/being added. - int got_null_frame_; // True if WebPAnimEncoderAdd() has already been called - // with a NULL frame. - - size_t in_frame_count_; // Number of input frames processed so far. - size_t out_frame_count_; // Number of frames added to mux so far. This may be - // different from 'in_frame_count_' due to merging. - - WebPMux* mux_; // Muxer to assemble the WebP bitstream. - char error_str_[ERROR_STR_MAX_LENGTH]; // Error string. Empty if no error. -}; - -// ----------------------------------------------------------------------------- -// Life of WebPAnimEncoder object. - -#define DELTA_INFINITY (1ULL << 32) -#define KEYFRAME_NONE (-1) - -// Reset the counters in the WebPAnimEncoder. -static void ResetCounters(WebPAnimEncoder* const enc) { - enc->start_ = 0; - enc->count_ = 0; - enc->flush_count_ = 0; - enc->best_delta_ = DELTA_INFINITY; - enc->keyframe_ = KEYFRAME_NONE; -} - -static void DisableKeyframes(WebPAnimEncoderOptions* const enc_options) { - enc_options->kmax = INT_MAX; - enc_options->kmin = enc_options->kmax - 1; -} - -#define MAX_CACHED_FRAMES 30 - -static void SanitizeEncoderOptions(WebPAnimEncoderOptions* const enc_options) { - int print_warning = enc_options->verbose; - - if (enc_options->minimize_size) { - DisableKeyframes(enc_options); - } - - if (enc_options->kmin <= 0) { - DisableKeyframes(enc_options); - print_warning = 0; - } - if (enc_options->kmax <= 0) { // All frames will be key-frames. - enc_options->kmin = 0; - enc_options->kmax = 0; - return; - } - - if (enc_options->kmin >= enc_options->kmax) { - enc_options->kmin = enc_options->kmax - 1; - if (print_warning) { - fprintf(stderr, "WARNING: Setting kmin = %d, so that kmin < kmax.\n", - enc_options->kmin); - } - } else { - const int kmin_limit = enc_options->kmax / 2 + 1; - if (enc_options->kmin < kmin_limit && kmin_limit < enc_options->kmax) { - // This ensures that enc.keyframe + kmin >= kmax is always true. So, we - // can flush all the frames in the 'count_since_key_frame == kmax' case. - enc_options->kmin = kmin_limit; - if (print_warning) { - fprintf(stderr, - "WARNING: Setting kmin = %d, so that kmin >= kmax / 2 + 1.\n", - enc_options->kmin); - } - } - } - // Limit the max number of frames that are allocated. - if (enc_options->kmax - enc_options->kmin > MAX_CACHED_FRAMES) { - enc_options->kmin = enc_options->kmax - MAX_CACHED_FRAMES; - if (print_warning) { - fprintf(stderr, - "WARNING: Setting kmin = %d, so that kmax - kmin <= %d.\n", - enc_options->kmin, MAX_CACHED_FRAMES); - } - } - assert(enc_options->kmin < enc_options->kmax); -} - -#undef MAX_CACHED_FRAMES - -static void DefaultEncoderOptions(WebPAnimEncoderOptions* const enc_options) { - enc_options->anim_params.loop_count = 0; - enc_options->anim_params.bgcolor = 0xffffffff; // White. - enc_options->minimize_size = 0; - DisableKeyframes(enc_options); - enc_options->allow_mixed = 0; - enc_options->verbose = 0; -} - -int WebPAnimEncoderOptionsInitInternal(WebPAnimEncoderOptions* enc_options, - int abi_version) { - if (enc_options == NULL || - WEBP_ABI_IS_INCOMPATIBLE(abi_version, WEBP_MUX_ABI_VERSION)) { - return 0; - } - DefaultEncoderOptions(enc_options); - return 1; -} - -// This starting value is more fit to WebPCleanupTransparentAreaLossless(). -#define TRANSPARENT_COLOR 0x00000000 - -static void ClearRectangle(WebPPicture* const picture, - int left, int top, int width, int height) { - int j; - for (j = top; j < top + height; ++j) { - uint32_t* const dst = picture->argb + j * picture->argb_stride; - int i; - for (i = left; i < left + width; ++i) { - dst[i] = TRANSPARENT_COLOR; - } - } -} - -static void WebPUtilClearPic(WebPPicture* const picture, - const FrameRect* const rect) { - if (rect != NULL) { - ClearRectangle(picture, rect->x_offset_, rect->y_offset_, - rect->width_, rect->height_); - } else { - ClearRectangle(picture, 0, 0, picture->width, picture->height); - } -} - -static void MarkNoError(WebPAnimEncoder* const enc) { - enc->error_str_[0] = '\0'; // Empty string. -} - -static void MarkError(WebPAnimEncoder* const enc, const char* str) { - if (snprintf(enc->error_str_, ERROR_STR_MAX_LENGTH, "%s.", str) < 0) { - assert(0); // FIX ME! - } -} - -static void MarkError2(WebPAnimEncoder* const enc, - const char* str, int error_code) { - if (snprintf(enc->error_str_, ERROR_STR_MAX_LENGTH, "%s: %d.", str, - error_code) < 0) { - assert(0); // FIX ME! - } -} - -WebPAnimEncoder* WebPAnimEncoderNewInternal( - int width, int height, const WebPAnimEncoderOptions* enc_options, - int abi_version) { - WebPAnimEncoder* enc; - - if (WEBP_ABI_IS_INCOMPATIBLE(abi_version, WEBP_MUX_ABI_VERSION)) { - return NULL; - } - if (width <= 0 || height <= 0 || - (width * (uint64_t)height) >= MAX_IMAGE_AREA) { - return NULL; - } - - enc = (WebPAnimEncoder*)WebPSafeCalloc(1, sizeof(*enc)); - if (enc == NULL) return NULL; - // sanity inits, so we can call WebPAnimEncoderDelete(): - enc->encoded_frames_ = NULL; - enc->mux_ = NULL; - MarkNoError(enc); - - // Dimensions and options. - *(int*)&enc->canvas_width_ = width; - *(int*)&enc->canvas_height_ = height; - if (enc_options != NULL) { - *(WebPAnimEncoderOptions*)&enc->options_ = *enc_options; - SanitizeEncoderOptions((WebPAnimEncoderOptions*)&enc->options_); - } else { - DefaultEncoderOptions((WebPAnimEncoderOptions*)&enc->options_); - } - - // Canvas buffers. - if (!WebPPictureInit(&enc->curr_canvas_copy_) || - !WebPPictureInit(&enc->prev_canvas_) || - !WebPPictureInit(&enc->prev_canvas_disposed_)) { - goto Err; - } - enc->curr_canvas_copy_.width = width; - enc->curr_canvas_copy_.height = height; - enc->curr_canvas_copy_.use_argb = 1; - if (!WebPPictureAlloc(&enc->curr_canvas_copy_) || - !WebPPictureCopy(&enc->curr_canvas_copy_, &enc->prev_canvas_) || - !WebPPictureCopy(&enc->curr_canvas_copy_, &enc->prev_canvas_disposed_)) { - goto Err; - } - WebPUtilClearPic(&enc->prev_canvas_, NULL); - enc->curr_canvas_copy_modified_ = 1; - - // Encoded frames. - ResetCounters(enc); - // Note: one extra storage is for the previous frame. - enc->size_ = enc->options_.kmax - enc->options_.kmin + 1; - // We need space for at least 2 frames. But when kmin, kmax are both zero, - // enc->size_ will be 1. So we handle that special case below. - if (enc->size_ < 2) enc->size_ = 2; - enc->encoded_frames_ = - (EncodedFrame*)WebPSafeCalloc(enc->size_, sizeof(*enc->encoded_frames_)); - if (enc->encoded_frames_ == NULL) goto Err; - - enc->mux_ = WebPMuxNew(); - if (enc->mux_ == NULL) goto Err; - - enc->count_since_key_frame_ = 0; - enc->first_timestamp_ = 0; - enc->prev_timestamp_ = 0; - enc->prev_candidate_undecided_ = 0; - enc->is_first_frame_ = 1; - enc->got_null_frame_ = 0; - - return enc; // All OK. - - Err: - WebPAnimEncoderDelete(enc); - return NULL; -} - -// Release the data contained by 'encoded_frame'. -static void FrameRelease(EncodedFrame* const encoded_frame) { - if (encoded_frame != NULL) { - WebPDataClear(&encoded_frame->sub_frame_.bitstream); - WebPDataClear(&encoded_frame->key_frame_.bitstream); - memset(encoded_frame, 0, sizeof(*encoded_frame)); - } -} - -void WebPAnimEncoderDelete(WebPAnimEncoder* enc) { - if (enc != NULL) { - WebPPictureFree(&enc->curr_canvas_copy_); - WebPPictureFree(&enc->prev_canvas_); - WebPPictureFree(&enc->prev_canvas_disposed_); - if (enc->encoded_frames_ != NULL) { - size_t i; - for (i = 0; i < enc->size_; ++i) { - FrameRelease(&enc->encoded_frames_[i]); - } - WebPSafeFree(enc->encoded_frames_); - } - WebPMuxDelete(enc->mux_); - WebPSafeFree(enc); - } -} - -// ----------------------------------------------------------------------------- -// Frame addition. - -// Returns cached frame at the given 'position'. -static EncodedFrame* GetFrame(const WebPAnimEncoder* const enc, - size_t position) { - assert(enc->start_ + position < enc->size_); - return &enc->encoded_frames_[enc->start_ + position]; -} - -typedef int (*ComparePixelsFunc)(const uint32_t*, int, const uint32_t*, int, - int, int); - -// Returns true if 'length' number of pixels in 'src' and 'dst' are equal, -// assuming the given step sizes between pixels. -// 'max_allowed_diff' is unused and only there to allow function pointer use. -static WEBP_INLINE int ComparePixelsLossless(const uint32_t* src, int src_step, - const uint32_t* dst, int dst_step, - int length, int max_allowed_diff) { - (void)max_allowed_diff; - assert(length > 0); - while (length-- > 0) { - if (*src != *dst) { - return 0; - } - src += src_step; - dst += dst_step; - } - return 1; -} - -// Helper to check if each channel in 'src' and 'dst' is at most off by -// 'max_allowed_diff'. -static WEBP_INLINE int PixelsAreSimilar(uint32_t src, uint32_t dst, - int max_allowed_diff) { - const int src_a = (src >> 24) & 0xff; - const int src_r = (src >> 16) & 0xff; - const int src_g = (src >> 8) & 0xff; - const int src_b = (src >> 0) & 0xff; - const int dst_a = (dst >> 24) & 0xff; - const int dst_r = (dst >> 16) & 0xff; - const int dst_g = (dst >> 8) & 0xff; - const int dst_b = (dst >> 0) & 0xff; - - return (abs(src_r * src_a - dst_r * dst_a) <= (max_allowed_diff * 255)) && - (abs(src_g * src_a - dst_g * dst_a) <= (max_allowed_diff * 255)) && - (abs(src_b * src_a - dst_b * dst_a) <= (max_allowed_diff * 255)) && - (abs(src_a - dst_a) <= max_allowed_diff); -} - -// Returns true if 'length' number of pixels in 'src' and 'dst' are within an -// error bound, assuming the given step sizes between pixels. -static WEBP_INLINE int ComparePixelsLossy(const uint32_t* src, int src_step, - const uint32_t* dst, int dst_step, - int length, int max_allowed_diff) { - assert(length > 0); - while (length-- > 0) { - if (!PixelsAreSimilar(*src, *dst, max_allowed_diff)) { - return 0; - } - src += src_step; - dst += dst_step; - } - return 1; -} - -static int IsEmptyRect(const FrameRect* const rect) { - return (rect->width_ == 0) || (rect->height_ == 0); -} - -static int QualityToMaxDiff(float quality) { - const double val = pow(quality / 100., 0.5); - const double max_diff = 31 * (1 - val) + 1 * val; - return (int)(max_diff + 0.5); -} - -// Assumes that an initial valid guess of change rectangle 'rect' is passed. -static void MinimizeChangeRectangle(const WebPPicture* const src, - const WebPPicture* const dst, - FrameRect* const rect, - int is_lossless, float quality) { - int i, j; - const ComparePixelsFunc compare_pixels = - is_lossless ? ComparePixelsLossless : ComparePixelsLossy; - const int max_allowed_diff_lossy = QualityToMaxDiff(quality); - const int max_allowed_diff = is_lossless ? 0 : max_allowed_diff_lossy; - - // Sanity checks. - assert(src->width == dst->width && src->height == dst->height); - assert(rect->x_offset_ + rect->width_ <= dst->width); - assert(rect->y_offset_ + rect->height_ <= dst->height); - - // Left boundary. - for (i = rect->x_offset_; i < rect->x_offset_ + rect->width_; ++i) { - const uint32_t* const src_argb = - &src->argb[rect->y_offset_ * src->argb_stride + i]; - const uint32_t* const dst_argb = - &dst->argb[rect->y_offset_ * dst->argb_stride + i]; - if (compare_pixels(src_argb, src->argb_stride, dst_argb, dst->argb_stride, - rect->height_, max_allowed_diff)) { - --rect->width_; // Redundant column. - ++rect->x_offset_; - } else { - break; - } - } - if (rect->width_ == 0) goto NoChange; - - // Right boundary. - for (i = rect->x_offset_ + rect->width_ - 1; i >= rect->x_offset_; --i) { - const uint32_t* const src_argb = - &src->argb[rect->y_offset_ * src->argb_stride + i]; - const uint32_t* const dst_argb = - &dst->argb[rect->y_offset_ * dst->argb_stride + i]; - if (compare_pixels(src_argb, src->argb_stride, dst_argb, dst->argb_stride, - rect->height_, max_allowed_diff)) { - --rect->width_; // Redundant column. - } else { - break; - } - } - if (rect->width_ == 0) goto NoChange; - - // Top boundary. - for (j = rect->y_offset_; j < rect->y_offset_ + rect->height_; ++j) { - const uint32_t* const src_argb = - &src->argb[j * src->argb_stride + rect->x_offset_]; - const uint32_t* const dst_argb = - &dst->argb[j * dst->argb_stride + rect->x_offset_]; - if (compare_pixels(src_argb, 1, dst_argb, 1, rect->width_, - max_allowed_diff)) { - --rect->height_; // Redundant row. - ++rect->y_offset_; - } else { - break; - } - } - if (rect->height_ == 0) goto NoChange; - - // Bottom boundary. - for (j = rect->y_offset_ + rect->height_ - 1; j >= rect->y_offset_; --j) { - const uint32_t* const src_argb = - &src->argb[j * src->argb_stride + rect->x_offset_]; - const uint32_t* const dst_argb = - &dst->argb[j * dst->argb_stride + rect->x_offset_]; - if (compare_pixels(src_argb, 1, dst_argb, 1, rect->width_, - max_allowed_diff)) { - --rect->height_; // Redundant row. - } else { - break; - } - } - if (rect->height_ == 0) goto NoChange; - - if (IsEmptyRect(rect)) { - NoChange: - rect->x_offset_ = 0; - rect->y_offset_ = 0; - rect->width_ = 0; - rect->height_ = 0; - } -} - -// Snap rectangle to even offsets (and adjust dimensions if needed). -static WEBP_INLINE void SnapToEvenOffsets(FrameRect* const rect) { - rect->width_ += (rect->x_offset_ & 1); - rect->height_ += (rect->y_offset_ & 1); - rect->x_offset_ &= ~1; - rect->y_offset_ &= ~1; -} - -typedef struct { - int should_try_; // Should try this set of parameters. - int empty_rect_allowed_; // Frame with empty rectangle can be skipped. - FrameRect rect_ll_; // Frame rectangle for lossless compression. - WebPPicture sub_frame_ll_; // Sub-frame pic for lossless compression. - FrameRect rect_lossy_; // Frame rectangle for lossy compression. - // Could be smaller than rect_ll_ as pixels - // with small diffs can be ignored. - WebPPicture sub_frame_lossy_; // Sub-frame pic for lossless compression. -} SubFrameParams; - -static int SubFrameParamsInit(SubFrameParams* const params, - int should_try, int empty_rect_allowed) { - params->should_try_ = should_try; - params->empty_rect_allowed_ = empty_rect_allowed; - if (!WebPPictureInit(¶ms->sub_frame_ll_) || - !WebPPictureInit(¶ms->sub_frame_lossy_)) { - return 0; - } - return 1; -} - -static void SubFrameParamsFree(SubFrameParams* const params) { - WebPPictureFree(¶ms->sub_frame_ll_); - WebPPictureFree(¶ms->sub_frame_lossy_); -} - -// Given previous and current canvas, picks the optimal rectangle for the -// current frame based on 'is_lossless' and other parameters. Assumes that the -// initial guess 'rect' is valid. -static int GetSubRect(const WebPPicture* const prev_canvas, - const WebPPicture* const curr_canvas, int is_key_frame, - int is_first_frame, int empty_rect_allowed, - int is_lossless, float quality, FrameRect* const rect, - WebPPicture* const sub_frame) { - if (!is_key_frame || is_first_frame) { // Optimize frame rectangle. - // Note: This behaves as expected for first frame, as 'prev_canvas' is - // initialized to a fully transparent canvas in the beginning. - MinimizeChangeRectangle(prev_canvas, curr_canvas, rect, - is_lossless, quality); - } - - if (IsEmptyRect(rect)) { - if (empty_rect_allowed) { // No need to get 'sub_frame'. - return 1; - } else { // Force a 1x1 rectangle. - rect->width_ = 1; - rect->height_ = 1; - assert(rect->x_offset_ == 0); - assert(rect->y_offset_ == 0); - } - } - - SnapToEvenOffsets(rect); - return WebPPictureView(curr_canvas, rect->x_offset_, rect->y_offset_, - rect->width_, rect->height_, sub_frame); -} - -// Picks optimal frame rectangle for both lossless and lossy compression. The -// initial guess for frame rectangles will be the full canvas. -static int GetSubRects(const WebPPicture* const prev_canvas, - const WebPPicture* const curr_canvas, int is_key_frame, - int is_first_frame, float quality, - SubFrameParams* const params) { - // Lossless frame rectangle. - params->rect_ll_.x_offset_ = 0; - params->rect_ll_.y_offset_ = 0; - params->rect_ll_.width_ = curr_canvas->width; - params->rect_ll_.height_ = curr_canvas->height; - if (!GetSubRect(prev_canvas, curr_canvas, is_key_frame, is_first_frame, - params->empty_rect_allowed_, 1, quality, - ¶ms->rect_ll_, ¶ms->sub_frame_ll_)) { - return 0; - } - // Lossy frame rectangle. - params->rect_lossy_ = params->rect_ll_; // seed with lossless rect. - return GetSubRect(prev_canvas, curr_canvas, is_key_frame, is_first_frame, - params->empty_rect_allowed_, 0, quality, - ¶ms->rect_lossy_, ¶ms->sub_frame_lossy_); -} - -static void DisposeFrameRectangle(int dispose_method, - const FrameRect* const rect, - WebPPicture* const curr_canvas) { - assert(rect != NULL); - if (dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) { - WebPUtilClearPic(curr_canvas, rect); - } -} - -static uint32_t RectArea(const FrameRect* const rect) { - return (uint32_t)rect->width_ * rect->height_; -} - -static int IsLosslessBlendingPossible(const WebPPicture* const src, - const WebPPicture* const dst, - const FrameRect* const rect) { - int i, j; - assert(src->width == dst->width && src->height == dst->height); - assert(rect->x_offset_ + rect->width_ <= dst->width); - assert(rect->y_offset_ + rect->height_ <= dst->height); - for (j = rect->y_offset_; j < rect->y_offset_ + rect->height_; ++j) { - for (i = rect->x_offset_; i < rect->x_offset_ + rect->width_; ++i) { - const uint32_t src_pixel = src->argb[j * src->argb_stride + i]; - const uint32_t dst_pixel = dst->argb[j * dst->argb_stride + i]; - const uint32_t dst_alpha = dst_pixel >> 24; - if (dst_alpha != 0xff && src_pixel != dst_pixel) { - // In this case, if we use blending, we can't attain the desired - // 'dst_pixel' value for this pixel. So, blending is not possible. - return 0; - } - } - } - return 1; -} - -static int IsLossyBlendingPossible(const WebPPicture* const src, - const WebPPicture* const dst, - const FrameRect* const rect, - float quality) { - const int max_allowed_diff_lossy = QualityToMaxDiff(quality); - int i, j; - assert(src->width == dst->width && src->height == dst->height); - assert(rect->x_offset_ + rect->width_ <= dst->width); - assert(rect->y_offset_ + rect->height_ <= dst->height); - for (j = rect->y_offset_; j < rect->y_offset_ + rect->height_; ++j) { - for (i = rect->x_offset_; i < rect->x_offset_ + rect->width_; ++i) { - const uint32_t src_pixel = src->argb[j * src->argb_stride + i]; - const uint32_t dst_pixel = dst->argb[j * dst->argb_stride + i]; - const uint32_t dst_alpha = dst_pixel >> 24; - if (dst_alpha != 0xff && - !PixelsAreSimilar(src_pixel, dst_pixel, max_allowed_diff_lossy)) { - // In this case, if we use blending, we can't attain the desired - // 'dst_pixel' value for this pixel. So, blending is not possible. - return 0; - } - } - } - return 1; -} - -// For pixels in 'rect', replace those pixels in 'dst' that are same as 'src' by -// transparent pixels. -// Returns true if at least one pixel gets modified. -static int IncreaseTransparency(const WebPPicture* const src, - const FrameRect* const rect, - WebPPicture* const dst) { - int i, j; - int modified = 0; - assert(src != NULL && dst != NULL && rect != NULL); - assert(src->width == dst->width && src->height == dst->height); - for (j = rect->y_offset_; j < rect->y_offset_ + rect->height_; ++j) { - const uint32_t* const psrc = src->argb + j * src->argb_stride; - uint32_t* const pdst = dst->argb + j * dst->argb_stride; - for (i = rect->x_offset_; i < rect->x_offset_ + rect->width_; ++i) { - if (psrc[i] == pdst[i] && pdst[i] != TRANSPARENT_COLOR) { - pdst[i] = TRANSPARENT_COLOR; - modified = 1; - } - } - } - return modified; -} - -#undef TRANSPARENT_COLOR - -// Replace similar blocks of pixels by a 'see-through' transparent block -// with uniform average color. -// Assumes lossy compression is being used. -// Returns true if at least one pixel gets modified. -static int FlattenSimilarBlocks(const WebPPicture* const src, - const FrameRect* const rect, - WebPPicture* const dst, float quality) { - const int max_allowed_diff_lossy = QualityToMaxDiff(quality); - int i, j; - int modified = 0; - const int block_size = 8; - const int y_start = (rect->y_offset_ + block_size) & ~(block_size - 1); - const int y_end = (rect->y_offset_ + rect->height_) & ~(block_size - 1); - const int x_start = (rect->x_offset_ + block_size) & ~(block_size - 1); - const int x_end = (rect->x_offset_ + rect->width_) & ~(block_size - 1); - assert(src != NULL && dst != NULL && rect != NULL); - assert(src->width == dst->width && src->height == dst->height); - assert((block_size & (block_size - 1)) == 0); // must be a power of 2 - // Iterate over each block and count similar pixels. - for (j = y_start; j < y_end; j += block_size) { - for (i = x_start; i < x_end; i += block_size) { - int cnt = 0; - int avg_r = 0, avg_g = 0, avg_b = 0; - int x, y; - const uint32_t* const psrc = src->argb + j * src->argb_stride + i; - uint32_t* const pdst = dst->argb + j * dst->argb_stride + i; - for (y = 0; y < block_size; ++y) { - for (x = 0; x < block_size; ++x) { - const uint32_t src_pixel = psrc[x + y * src->argb_stride]; - const int alpha = src_pixel >> 24; - if (alpha == 0xff && - PixelsAreSimilar(src_pixel, pdst[x + y * dst->argb_stride], - max_allowed_diff_lossy)) { - ++cnt; - avg_r += (src_pixel >> 16) & 0xff; - avg_g += (src_pixel >> 8) & 0xff; - avg_b += (src_pixel >> 0) & 0xff; - } - } - } - // If we have a fully similar block, we replace it with an - // average transparent block. This compresses better in lossy mode. - if (cnt == block_size * block_size) { - const uint32_t color = (0x00 << 24) | - ((avg_r / cnt) << 16) | - ((avg_g / cnt) << 8) | - ((avg_b / cnt) << 0); - for (y = 0; y < block_size; ++y) { - for (x = 0; x < block_size; ++x) { - pdst[x + y * dst->argb_stride] = color; - } - } - modified = 1; - } - } - } - return modified; -} - -static int EncodeFrame(const WebPConfig* const config, WebPPicture* const pic, - WebPMemoryWriter* const memory) { - pic->use_argb = 1; - pic->writer = WebPMemoryWrite; - pic->custom_ptr = memory; - if (!WebPEncode(config, pic)) { - return 0; - } - return 1; -} - -// Struct representing a candidate encoded frame including its metadata. -typedef struct { - WebPMemoryWriter mem_; - WebPMuxFrameInfo info_; - FrameRect rect_; - int evaluate_; // True if this candidate should be evaluated. -} Candidate; - -// Generates a candidate encoded frame given a picture and metadata. -static WebPEncodingError EncodeCandidate(WebPPicture* const sub_frame, - const FrameRect* const rect, - const WebPConfig* const encoder_config, - int use_blending, - Candidate* const candidate) { - WebPConfig config = *encoder_config; - WebPEncodingError error_code = VP8_ENC_OK; - assert(candidate != NULL); - memset(candidate, 0, sizeof(*candidate)); - - // Set frame rect and info. - candidate->rect_ = *rect; - candidate->info_.id = WEBP_CHUNK_ANMF; - candidate->info_.x_offset = rect->x_offset_; - candidate->info_.y_offset = rect->y_offset_; - candidate->info_.dispose_method = WEBP_MUX_DISPOSE_NONE; // Set later. - candidate->info_.blend_method = - use_blending ? WEBP_MUX_BLEND : WEBP_MUX_NO_BLEND; - candidate->info_.duration = 0; // Set in next call to WebPAnimEncoderAdd(). - - // Encode picture. - WebPMemoryWriterInit(&candidate->mem_); - - if (!config.lossless && use_blending) { - // Disable filtering to avoid blockiness in reconstructed frames at the - // time of decoding. - config.autofilter = 0; - config.filter_strength = 0; - } - if (!EncodeFrame(&config, sub_frame, &candidate->mem_)) { - error_code = sub_frame->error_code; - goto Err; - } - - candidate->evaluate_ = 1; - return error_code; - - Err: - WebPMemoryWriterClear(&candidate->mem_); - return error_code; -} - -static void CopyCurrentCanvas(WebPAnimEncoder* const enc) { - if (enc->curr_canvas_copy_modified_) { - WebPCopyPixels(enc->curr_canvas_, &enc->curr_canvas_copy_); - enc->curr_canvas_copy_.progress_hook = enc->curr_canvas_->progress_hook; - enc->curr_canvas_copy_.user_data = enc->curr_canvas_->user_data; - enc->curr_canvas_copy_modified_ = 0; - } -} - -enum { - LL_DISP_NONE = 0, - LL_DISP_BG, - LOSSY_DISP_NONE, - LOSSY_DISP_BG, - CANDIDATE_COUNT -}; - -#define MIN_COLORS_LOSSY 31 // Don't try lossy below this threshold. -#define MAX_COLORS_LOSSLESS 194 // Don't try lossless above this threshold. - -// Generates candidates for a given dispose method given pre-filled sub-frame -// 'params'. -static WebPEncodingError GenerateCandidates( - WebPAnimEncoder* const enc, Candidate candidates[CANDIDATE_COUNT], - WebPMuxAnimDispose dispose_method, int is_lossless, int is_key_frame, - SubFrameParams* const params, - const WebPConfig* const config_ll, const WebPConfig* const config_lossy) { - WebPEncodingError error_code = VP8_ENC_OK; - const int is_dispose_none = (dispose_method == WEBP_MUX_DISPOSE_NONE); - Candidate* const candidate_ll = - is_dispose_none ? &candidates[LL_DISP_NONE] : &candidates[LL_DISP_BG]; - Candidate* const candidate_lossy = is_dispose_none - ? &candidates[LOSSY_DISP_NONE] - : &candidates[LOSSY_DISP_BG]; - WebPPicture* const curr_canvas = &enc->curr_canvas_copy_; - const WebPPicture* const prev_canvas = - is_dispose_none ? &enc->prev_canvas_ : &enc->prev_canvas_disposed_; - int use_blending_ll; - int use_blending_lossy; - - CopyCurrentCanvas(enc); - use_blending_ll = - !is_key_frame && - IsLosslessBlendingPossible(prev_canvas, curr_canvas, ¶ms->rect_ll_); - use_blending_lossy = - !is_key_frame && - IsLossyBlendingPossible(prev_canvas, curr_canvas, ¶ms->rect_lossy_, - config_lossy->quality); - - // Pick candidates to be tried. - if (!enc->options_.allow_mixed) { - candidate_ll->evaluate_ = is_lossless; - candidate_lossy->evaluate_ = !is_lossless; - } else { // Use a heuristic for trying lossless and/or lossy compression. - const int num_colors = WebPGetColorPalette(¶ms->sub_frame_ll_, NULL); - candidate_ll->evaluate_ = (num_colors < MAX_COLORS_LOSSLESS); - candidate_lossy->evaluate_ = (num_colors >= MIN_COLORS_LOSSY); - } - - // Generate candidates. - if (candidate_ll->evaluate_) { - CopyCurrentCanvas(enc); - if (use_blending_ll) { - enc->curr_canvas_copy_modified_ = - IncreaseTransparency(prev_canvas, ¶ms->rect_ll_, curr_canvas); - } - error_code = EncodeCandidate(¶ms->sub_frame_ll_, ¶ms->rect_ll_, - config_ll, use_blending_ll, candidate_ll); - if (error_code != VP8_ENC_OK) return error_code; - } - if (candidate_lossy->evaluate_) { - CopyCurrentCanvas(enc); - if (use_blending_lossy) { - enc->curr_canvas_copy_modified_ = - FlattenSimilarBlocks(prev_canvas, ¶ms->rect_lossy_, curr_canvas, - config_lossy->quality); - } - error_code = - EncodeCandidate(¶ms->sub_frame_lossy_, ¶ms->rect_lossy_, - config_lossy, use_blending_lossy, candidate_lossy); - if (error_code != VP8_ENC_OK) return error_code; - enc->curr_canvas_copy_modified_ = 1; - } - return error_code; -} - -#undef MIN_COLORS_LOSSY -#undef MAX_COLORS_LOSSLESS - -static void GetEncodedData(const WebPMemoryWriter* const memory, - WebPData* const encoded_data) { - encoded_data->bytes = memory->mem; - encoded_data->size = memory->size; -} - -// Sets dispose method of the previous frame to be 'dispose_method'. -static void SetPreviousDisposeMethod(WebPAnimEncoder* const enc, - WebPMuxAnimDispose dispose_method) { - const size_t position = enc->count_ - 2; - EncodedFrame* const prev_enc_frame = GetFrame(enc, position); - assert(enc->count_ >= 2); // As current and previous frames are in enc. - - if (enc->prev_candidate_undecided_) { - assert(dispose_method == WEBP_MUX_DISPOSE_NONE); - prev_enc_frame->sub_frame_.dispose_method = dispose_method; - prev_enc_frame->key_frame_.dispose_method = dispose_method; - } else { - WebPMuxFrameInfo* const prev_info = prev_enc_frame->is_key_frame_ - ? &prev_enc_frame->key_frame_ - : &prev_enc_frame->sub_frame_; - prev_info->dispose_method = dispose_method; - } -} - -static int IncreasePreviousDuration(WebPAnimEncoder* const enc, int duration) { - const size_t position = enc->count_ - 1; - EncodedFrame* const prev_enc_frame = GetFrame(enc, position); - int new_duration; - - assert(enc->count_ >= 1); - assert(prev_enc_frame->sub_frame_.duration == - prev_enc_frame->key_frame_.duration); - assert(prev_enc_frame->sub_frame_.duration == - (prev_enc_frame->sub_frame_.duration & (MAX_DURATION - 1))); - assert(duration == (duration & (MAX_DURATION - 1))); - - new_duration = prev_enc_frame->sub_frame_.duration + duration; - if (new_duration >= MAX_DURATION) { // Special case. - // Separate out previous frame from earlier merged frames to avoid overflow. - // We add a 1x1 transparent frame for the previous frame, with blending on. - const FrameRect rect = { 0, 0, 1, 1 }; - const uint8_t lossless_1x1_bytes[] = { - 0x52, 0x49, 0x46, 0x46, 0x14, 0x00, 0x00, 0x00, 0x57, 0x45, 0x42, 0x50, - 0x56, 0x50, 0x38, 0x4c, 0x08, 0x00, 0x00, 0x00, 0x2f, 0x00, 0x00, 0x00, - 0x10, 0x88, 0x88, 0x08 - }; - const WebPData lossless_1x1 = { - lossless_1x1_bytes, sizeof(lossless_1x1_bytes) - }; - const uint8_t lossy_1x1_bytes[] = { - 0x52, 0x49, 0x46, 0x46, 0x40, 0x00, 0x00, 0x00, 0x57, 0x45, 0x42, 0x50, - 0x56, 0x50, 0x38, 0x58, 0x0a, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x41, 0x4c, 0x50, 0x48, 0x02, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x56, 0x50, 0x38, 0x20, 0x18, 0x00, 0x00, 0x00, - 0x30, 0x01, 0x00, 0x9d, 0x01, 0x2a, 0x01, 0x00, 0x01, 0x00, 0x02, 0x00, - 0x34, 0x25, 0xa4, 0x00, 0x03, 0x70, 0x00, 0xfe, 0xfb, 0xfd, 0x50, 0x00 - }; - const WebPData lossy_1x1 = { lossy_1x1_bytes, sizeof(lossy_1x1_bytes) }; - const int can_use_lossless = - (enc->last_config_.lossless || enc->options_.allow_mixed); - EncodedFrame* const curr_enc_frame = GetFrame(enc, enc->count_); - curr_enc_frame->is_key_frame_ = 0; - curr_enc_frame->sub_frame_.id = WEBP_CHUNK_ANMF; - curr_enc_frame->sub_frame_.x_offset = 0; - curr_enc_frame->sub_frame_.y_offset = 0; - curr_enc_frame->sub_frame_.dispose_method = WEBP_MUX_DISPOSE_NONE; - curr_enc_frame->sub_frame_.blend_method = WEBP_MUX_BLEND; - curr_enc_frame->sub_frame_.duration = duration; - if (!WebPDataCopy(can_use_lossless ? &lossless_1x1 : &lossy_1x1, - &curr_enc_frame->sub_frame_.bitstream)) { - return 0; - } - ++enc->count_; - ++enc->count_since_key_frame_; - enc->flush_count_ = enc->count_ - 1; - enc->prev_candidate_undecided_ = 0; - enc->prev_rect_ = rect; - } else { // Regular case. - // Increase duration of the previous frame by 'duration'. - prev_enc_frame->sub_frame_.duration = new_duration; - prev_enc_frame->key_frame_.duration = new_duration; - } - return 1; -} - -// Pick the candidate encoded frame with smallest size and release other -// candidates. -// TODO(later): Perhaps a rough SSIM/PSNR produced by the encoder should -// also be a criteria, in addition to sizes. -static void PickBestCandidate(WebPAnimEncoder* const enc, - Candidate* const candidates, int is_key_frame, - EncodedFrame* const encoded_frame) { - int i; - int best_idx = -1; - size_t best_size = ~0; - for (i = 0; i < CANDIDATE_COUNT; ++i) { - if (candidates[i].evaluate_) { - const size_t candidate_size = candidates[i].mem_.size; - if (candidate_size < best_size) { - best_idx = i; - best_size = candidate_size; - } - } - } - assert(best_idx != -1); - for (i = 0; i < CANDIDATE_COUNT; ++i) { - if (candidates[i].evaluate_) { - if (i == best_idx) { - WebPMuxFrameInfo* const dst = is_key_frame - ? &encoded_frame->key_frame_ - : &encoded_frame->sub_frame_; - *dst = candidates[i].info_; - GetEncodedData(&candidates[i].mem_, &dst->bitstream); - if (!is_key_frame) { - // Note: Previous dispose method only matters for non-keyframes. - // Also, we don't want to modify previous dispose method that was - // selected when a non key-frame was assumed. - const WebPMuxAnimDispose prev_dispose_method = - (best_idx == LL_DISP_NONE || best_idx == LOSSY_DISP_NONE) - ? WEBP_MUX_DISPOSE_NONE - : WEBP_MUX_DISPOSE_BACKGROUND; - SetPreviousDisposeMethod(enc, prev_dispose_method); - } - enc->prev_rect_ = candidates[i].rect_; // save for next frame. - } else { - WebPMemoryWriterClear(&candidates[i].mem_); - candidates[i].evaluate_ = 0; - } - } - } -} - -// Depending on the configuration, tries different compressions -// (lossy/lossless), dispose methods, blending methods etc to encode the current -// frame and outputs the best one in 'encoded_frame'. -// 'frame_skipped' will be set to true if this frame should actually be skipped. -static WebPEncodingError SetFrame(WebPAnimEncoder* const enc, - const WebPConfig* const config, - int is_key_frame, - EncodedFrame* const encoded_frame, - int* const frame_skipped) { - int i; - WebPEncodingError error_code = VP8_ENC_OK; - const WebPPicture* const curr_canvas = &enc->curr_canvas_copy_; - const WebPPicture* const prev_canvas = &enc->prev_canvas_; - Candidate candidates[CANDIDATE_COUNT]; - const int is_lossless = config->lossless; - const int is_first_frame = enc->is_first_frame_; - - // First frame cannot be skipped as there is no 'previous frame' to merge it - // to. So, empty rectangle is not allowed for the first frame. - const int empty_rect_allowed_none = !is_first_frame; - - // Even if there is exact pixel match between 'disposed previous canvas' and - // 'current canvas', we can't skip current frame, as there may not be exact - // pixel match between 'previous canvas' and 'current canvas'. So, we don't - // allow empty rectangle in this case. - const int empty_rect_allowed_bg = 0; - - // If current frame is a key-frame, dispose method of previous frame doesn't - // matter, so we don't try dispose to background. - // Also, if key-frame insertion is on, and previous frame could be picked as - // either a sub-frame or a key-frame, then we can't be sure about what frame - // rectangle would be disposed. In that case too, we don't try dispose to - // background. - const int dispose_bg_possible = - !is_key_frame && !enc->prev_candidate_undecided_; - - SubFrameParams dispose_none_params; - SubFrameParams dispose_bg_params; - - WebPConfig config_ll = *config; - WebPConfig config_lossy = *config; - config_ll.lossless = 1; - config_lossy.lossless = 0; - enc->last_config_ = *config; - enc->last_config_reversed_ = config->lossless ? config_lossy : config_ll; - *frame_skipped = 0; - - if (!SubFrameParamsInit(&dispose_none_params, 1, empty_rect_allowed_none) || - !SubFrameParamsInit(&dispose_bg_params, 0, empty_rect_allowed_bg)) { - return VP8_ENC_ERROR_INVALID_CONFIGURATION; - } - - for (i = 0; i < CANDIDATE_COUNT; ++i) { - candidates[i].evaluate_ = 0; - } - - // Change-rectangle assuming previous frame was DISPOSE_NONE. - if (!GetSubRects(prev_canvas, curr_canvas, is_key_frame, is_first_frame, - config_lossy.quality, &dispose_none_params)) { - error_code = VP8_ENC_ERROR_INVALID_CONFIGURATION; - goto Err; - } - - if ((is_lossless && IsEmptyRect(&dispose_none_params.rect_ll_)) || - (!is_lossless && IsEmptyRect(&dispose_none_params.rect_lossy_))) { - // Don't encode the frame at all. Instead, the duration of the previous - // frame will be increased later. - assert(empty_rect_allowed_none); - *frame_skipped = 1; - goto End; - } - - if (dispose_bg_possible) { - // Change-rectangle assuming previous frame was DISPOSE_BACKGROUND. - WebPPicture* const prev_canvas_disposed = &enc->prev_canvas_disposed_; - WebPCopyPixels(prev_canvas, prev_canvas_disposed); - DisposeFrameRectangle(WEBP_MUX_DISPOSE_BACKGROUND, &enc->prev_rect_, - prev_canvas_disposed); - - if (!GetSubRects(prev_canvas_disposed, curr_canvas, is_key_frame, - is_first_frame, config_lossy.quality, - &dispose_bg_params)) { - error_code = VP8_ENC_ERROR_INVALID_CONFIGURATION; - goto Err; - } - assert(!IsEmptyRect(&dispose_bg_params.rect_ll_)); - assert(!IsEmptyRect(&dispose_bg_params.rect_lossy_)); - - if (enc->options_.minimize_size) { // Try both dispose methods. - dispose_bg_params.should_try_ = 1; - dispose_none_params.should_try_ = 1; - } else if ((is_lossless && - RectArea(&dispose_bg_params.rect_ll_) < - RectArea(&dispose_none_params.rect_ll_)) || - (!is_lossless && - RectArea(&dispose_bg_params.rect_lossy_) < - RectArea(&dispose_none_params.rect_lossy_))) { - dispose_bg_params.should_try_ = 1; // Pick DISPOSE_BACKGROUND. - dispose_none_params.should_try_ = 0; - } - } - - if (dispose_none_params.should_try_) { - error_code = GenerateCandidates( - enc, candidates, WEBP_MUX_DISPOSE_NONE, is_lossless, is_key_frame, - &dispose_none_params, &config_ll, &config_lossy); - if (error_code != VP8_ENC_OK) goto Err; - } - - if (dispose_bg_params.should_try_) { - assert(!enc->is_first_frame_); - assert(dispose_bg_possible); - error_code = GenerateCandidates( - enc, candidates, WEBP_MUX_DISPOSE_BACKGROUND, is_lossless, is_key_frame, - &dispose_bg_params, &config_ll, &config_lossy); - if (error_code != VP8_ENC_OK) goto Err; - } - - PickBestCandidate(enc, candidates, is_key_frame, encoded_frame); - - goto End; - - Err: - for (i = 0; i < CANDIDATE_COUNT; ++i) { - if (candidates[i].evaluate_) { - WebPMemoryWriterClear(&candidates[i].mem_); - } - } - - End: - SubFrameParamsFree(&dispose_none_params); - SubFrameParamsFree(&dispose_bg_params); - return error_code; -} - -// Calculate the penalty incurred if we encode given frame as a key frame -// instead of a sub-frame. -static int64_t KeyFramePenalty(const EncodedFrame* const encoded_frame) { - return ((int64_t)encoded_frame->key_frame_.bitstream.size - - encoded_frame->sub_frame_.bitstream.size); -} - -static int CacheFrame(WebPAnimEncoder* const enc, - const WebPConfig* const config) { - int ok = 0; - int frame_skipped = 0; - WebPEncodingError error_code = VP8_ENC_OK; - const size_t position = enc->count_; - EncodedFrame* const encoded_frame = GetFrame(enc, position); - - ++enc->count_; - - if (enc->is_first_frame_) { // Add this as a key-frame. - error_code = SetFrame(enc, config, 1, encoded_frame, &frame_skipped); - if (error_code != VP8_ENC_OK) goto End; - assert(frame_skipped == 0); // First frame can't be skipped, even if empty. - assert(position == 0 && enc->count_ == 1); - encoded_frame->is_key_frame_ = 1; - enc->flush_count_ = 0; - enc->count_since_key_frame_ = 0; - enc->prev_candidate_undecided_ = 0; - } else { - ++enc->count_since_key_frame_; - if (enc->count_since_key_frame_ <= enc->options_.kmin) { - // Add this as a frame rectangle. - error_code = SetFrame(enc, config, 0, encoded_frame, &frame_skipped); - if (error_code != VP8_ENC_OK) goto End; - if (frame_skipped) goto Skip; - encoded_frame->is_key_frame_ = 0; - enc->flush_count_ = enc->count_ - 1; - enc->prev_candidate_undecided_ = 0; - } else { - int64_t curr_delta; - - // Add this as a frame rectangle to enc. - error_code = SetFrame(enc, config, 0, encoded_frame, &frame_skipped); - if (error_code != VP8_ENC_OK) goto End; - if (frame_skipped) goto Skip; - - // Add this as a key-frame to enc, too. - error_code = SetFrame(enc, config, 1, encoded_frame, &frame_skipped); - if (error_code != VP8_ENC_OK) goto End; - assert(frame_skipped == 0); // Key-frame cannot be an empty rectangle. - - // Analyze size difference of the two variants. - curr_delta = KeyFramePenalty(encoded_frame); - if (curr_delta <= enc->best_delta_) { // Pick this as the key-frame. - if (enc->keyframe_ != KEYFRAME_NONE) { - EncodedFrame* const old_keyframe = GetFrame(enc, enc->keyframe_); - assert(old_keyframe->is_key_frame_); - old_keyframe->is_key_frame_ = 0; - } - encoded_frame->is_key_frame_ = 1; - enc->keyframe_ = (int)position; - enc->best_delta_ = curr_delta; - enc->flush_count_ = enc->count_ - 1; // We can flush previous frames. - } else { - encoded_frame->is_key_frame_ = 0; - } - // Note: We need '>=' below because when kmin and kmax are both zero, - // count_since_key_frame will always be > kmax. - if (enc->count_since_key_frame_ >= enc->options_.kmax) { - enc->flush_count_ = enc->count_ - 1; - enc->count_since_key_frame_ = 0; - enc->keyframe_ = KEYFRAME_NONE; - enc->best_delta_ = DELTA_INFINITY; - } - enc->prev_candidate_undecided_ = 1; - } - } - - // Update previous to previous and previous canvases for next call. - WebPCopyPixels(enc->curr_canvas_, &enc->prev_canvas_); - enc->is_first_frame_ = 0; - - Skip: - ok = 1; - ++enc->in_frame_count_; - - End: - if (!ok || frame_skipped) { - FrameRelease(encoded_frame); - // We reset some counters, as the frame addition failed/was skipped. - --enc->count_; - if (!enc->is_first_frame_) --enc->count_since_key_frame_; - if (!ok) { - MarkError2(enc, "ERROR adding frame. WebPEncodingError", error_code); - } - } - enc->curr_canvas_->error_code = error_code; // report error_code - assert(ok || error_code != VP8_ENC_OK); - return ok; -} - -static int FlushFrames(WebPAnimEncoder* const enc) { - while (enc->flush_count_ > 0) { - WebPMuxError err; - EncodedFrame* const curr = GetFrame(enc, 0); - const WebPMuxFrameInfo* const info = - curr->is_key_frame_ ? &curr->key_frame_ : &curr->sub_frame_; - assert(enc->mux_ != NULL); - err = WebPMuxPushFrame(enc->mux_, info, 1); - if (err != WEBP_MUX_OK) { - MarkError2(enc, "ERROR adding frame. WebPMuxError", err); - return 0; - } - if (enc->options_.verbose) { - fprintf(stderr, "INFO: Added frame. offset:%d,%d dispose:%d blend:%d\n", - info->x_offset, info->y_offset, info->dispose_method, - info->blend_method); - } - ++enc->out_frame_count_; - FrameRelease(curr); - ++enc->start_; - --enc->flush_count_; - --enc->count_; - if (enc->keyframe_ != KEYFRAME_NONE) --enc->keyframe_; - } - - if (enc->count_ == 1 && enc->start_ != 0) { - // Move enc->start to index 0. - const int enc_start_tmp = (int)enc->start_; - EncodedFrame temp = enc->encoded_frames_[0]; - enc->encoded_frames_[0] = enc->encoded_frames_[enc_start_tmp]; - enc->encoded_frames_[enc_start_tmp] = temp; - FrameRelease(&enc->encoded_frames_[enc_start_tmp]); - enc->start_ = 0; - } - return 1; -} - -#undef DELTA_INFINITY -#undef KEYFRAME_NONE - -int WebPAnimEncoderAdd(WebPAnimEncoder* enc, WebPPicture* frame, int timestamp, - const WebPConfig* encoder_config) { - WebPConfig config; - int ok; - - if (enc == NULL) { - return 0; - } - MarkNoError(enc); - - if (!enc->is_first_frame_) { - // Make sure timestamps are non-decreasing (integer wrap-around is OK). - const uint32_t prev_frame_duration = - (uint32_t)timestamp - enc->prev_timestamp_; - if (prev_frame_duration >= MAX_DURATION) { - if (frame != NULL) { - frame->error_code = VP8_ENC_ERROR_INVALID_CONFIGURATION; - } - MarkError(enc, "ERROR adding frame: timestamps must be non-decreasing"); - return 0; - } - if (!IncreasePreviousDuration(enc, (int)prev_frame_duration)) { - return 0; - } - } else { - enc->first_timestamp_ = timestamp; - } - - if (frame == NULL) { // Special: last call. - enc->got_null_frame_ = 1; - enc->prev_timestamp_ = timestamp; - return 1; - } - - if (frame->width != enc->canvas_width_ || - frame->height != enc->canvas_height_) { - frame->error_code = VP8_ENC_ERROR_INVALID_CONFIGURATION; - MarkError(enc, "ERROR adding frame: Invalid frame dimensions"); - return 0; - } - - if (!frame->use_argb) { // Convert frame from YUV(A) to ARGB. - if (enc->options_.verbose) { - fprintf(stderr, "WARNING: Converting frame from YUV(A) to ARGB format; " - "this incurs a small loss.\n"); - } - if (!WebPPictureYUVAToARGB(frame)) { - MarkError(enc, "ERROR converting frame from YUV(A) to ARGB"); - return 0; - } - } - - if (encoder_config != NULL) { - if (!WebPValidateConfig(encoder_config)) { - MarkError(enc, "ERROR adding frame: Invalid WebPConfig"); - return 0; - } - config = *encoder_config; - } else { - WebPConfigInit(&config); - config.lossless = 1; - } - assert(enc->curr_canvas_ == NULL); - enc->curr_canvas_ = frame; // Store reference. - assert(enc->curr_canvas_copy_modified_ == 1); - CopyCurrentCanvas(enc); - - ok = CacheFrame(enc, &config) && FlushFrames(enc); - - enc->curr_canvas_ = NULL; - enc->curr_canvas_copy_modified_ = 1; - if (ok) { - enc->prev_timestamp_ = timestamp; - } - return ok; -} - -// ----------------------------------------------------------------------------- -// Bitstream assembly. - -static int DecodeFrameOntoCanvas(const WebPMuxFrameInfo* const frame, - WebPPicture* const canvas) { - const WebPData* const image = &frame->bitstream; - WebPPicture sub_image; - WebPDecoderConfig config; - WebPInitDecoderConfig(&config); - WebPUtilClearPic(canvas, NULL); - if (WebPGetFeatures(image->bytes, image->size, &config.input) != - VP8_STATUS_OK) { - return 0; - } - if (!WebPPictureView(canvas, frame->x_offset, frame->y_offset, - config.input.width, config.input.height, &sub_image)) { - return 0; - } - config.output.is_external_memory = 1; - config.output.colorspace = MODE_BGRA; - config.output.u.RGBA.rgba = (uint8_t*)sub_image.argb; - config.output.u.RGBA.stride = sub_image.argb_stride * 4; - config.output.u.RGBA.size = config.output.u.RGBA.stride * sub_image.height; - - if (WebPDecode(image->bytes, image->size, &config) != VP8_STATUS_OK) { - return 0; - } - return 1; -} - -static int FrameToFullCanvas(WebPAnimEncoder* const enc, - const WebPMuxFrameInfo* const frame, - WebPData* const full_image) { - WebPPicture* const canvas_buf = &enc->curr_canvas_copy_; - WebPMemoryWriter mem1, mem2; - WebPMemoryWriterInit(&mem1); - WebPMemoryWriterInit(&mem2); - - if (!DecodeFrameOntoCanvas(frame, canvas_buf)) goto Err; - if (!EncodeFrame(&enc->last_config_, canvas_buf, &mem1)) goto Err; - GetEncodedData(&mem1, full_image); - - if (enc->options_.allow_mixed) { - if (!EncodeFrame(&enc->last_config_reversed_, canvas_buf, &mem2)) goto Err; - if (mem2.size < mem1.size) { - GetEncodedData(&mem2, full_image); - WebPMemoryWriterClear(&mem1); - } else { - WebPMemoryWriterClear(&mem2); - } - } - return 1; - - Err: - WebPMemoryWriterClear(&mem1); - WebPMemoryWriterClear(&mem2); - return 0; -} - -// Convert a single-frame animation to a non-animated image if appropriate. -// TODO(urvang): Can we pick one of the two heuristically (based on frame -// rectangle and/or presence of alpha)? -static WebPMuxError OptimizeSingleFrame(WebPAnimEncoder* const enc, - WebPData* const webp_data) { - WebPMuxError err = WEBP_MUX_OK; - int canvas_width, canvas_height; - WebPMuxFrameInfo frame; - WebPData full_image; - WebPData webp_data2; - WebPMux* const mux = WebPMuxCreate(webp_data, 0); - if (mux == NULL) return WEBP_MUX_BAD_DATA; - assert(enc->out_frame_count_ == 1); - WebPDataInit(&frame.bitstream); - WebPDataInit(&full_image); - WebPDataInit(&webp_data2); - - err = WebPMuxGetFrame(mux, 1, &frame); - if (err != WEBP_MUX_OK) goto End; - if (frame.id != WEBP_CHUNK_ANMF) goto End; // Non-animation: nothing to do. - err = WebPMuxGetCanvasSize(mux, &canvas_width, &canvas_height); - if (err != WEBP_MUX_OK) goto End; - if (!FrameToFullCanvas(enc, &frame, &full_image)) { - err = WEBP_MUX_BAD_DATA; - goto End; - } - err = WebPMuxSetImage(mux, &full_image, 1); - if (err != WEBP_MUX_OK) goto End; - err = WebPMuxAssemble(mux, &webp_data2); - if (err != WEBP_MUX_OK) goto End; - - if (webp_data2.size < webp_data->size) { // Pick 'webp_data2' if smaller. - WebPDataClear(webp_data); - *webp_data = webp_data2; - WebPDataInit(&webp_data2); - } - - End: - WebPDataClear(&frame.bitstream); - WebPDataClear(&full_image); - WebPMuxDelete(mux); - WebPDataClear(&webp_data2); - return err; -} - -int WebPAnimEncoderAssemble(WebPAnimEncoder* enc, WebPData* webp_data) { - WebPMux* mux; - WebPMuxError err; - - if (enc == NULL) { - return 0; - } - MarkNoError(enc); - - if (webp_data == NULL) { - MarkError(enc, "ERROR assembling: NULL input"); - return 0; - } - - if (enc->in_frame_count_ == 0) { - MarkError(enc, "ERROR: No frames to assemble"); - return 0; - } - - if (!enc->got_null_frame_ && enc->in_frame_count_ > 1 && enc->count_ > 0) { - // set duration of the last frame to be avg of durations of previous frames. - const double delta_time = enc->prev_timestamp_ - enc->first_timestamp_; - const int average_duration = (int)(delta_time / (enc->in_frame_count_ - 1)); - if (!IncreasePreviousDuration(enc, average_duration)) { - return 0; - } - } - - // Flush any remaining frames. - enc->flush_count_ = enc->count_; - if (!FlushFrames(enc)) { - return 0; - } - - // Set definitive canvas size. - mux = enc->mux_; - err = WebPMuxSetCanvasSize(mux, enc->canvas_width_, enc->canvas_height_); - if (err != WEBP_MUX_OK) goto Err; - - err = WebPMuxSetAnimationParams(mux, &enc->options_.anim_params); - if (err != WEBP_MUX_OK) goto Err; - - // Assemble into a WebP bitstream. - err = WebPMuxAssemble(mux, webp_data); - if (err != WEBP_MUX_OK) goto Err; - - if (enc->out_frame_count_ == 1) { - err = OptimizeSingleFrame(enc, webp_data); - if (err != WEBP_MUX_OK) goto Err; - } - return 1; - - Err: - MarkError2(enc, "ERROR assembling WebP", err); - return 0; -} - -const char* WebPAnimEncoderGetError(WebPAnimEncoder* enc) { - if (enc == NULL) return NULL; - return enc->error_str_; -} - -// ----------------------------------------------------------------------------- |