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Diffstat (limited to 'drivers/webpold/format_constants.h')
| -rw-r--r-- | drivers/webpold/format_constants.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/webpold/format_constants.h b/drivers/webpold/format_constants.h new file mode 100644 index 0000000000..7ce498f672 --- /dev/null +++ b/drivers/webpold/format_constants.h @@ -0,0 +1,90 @@ +// Copyright 2012 Google Inc. All Rights Reserved. +// +// This code is licensed under the same terms as WebM: +// Software License Agreement: http://www.webmproject.org/license/software/ +// Additional IP Rights Grant: http://www.webmproject.org/license/additional/ +// ----------------------------------------------------------------------------- +// +// Internal header for constants related to WebP file format. +// +// Author: Urvang (urvang@google.com) + +#ifndef WEBP_WEBP_FORMAT_CONSTANTS_H_ +#define WEBP_WEBP_FORMAT_CONSTANTS_H_ + +// VP8 related constants. +#define VP8_SIGNATURE 0x9d012a // Signature in VP8 data. +#define VP8_MAX_PARTITION0_SIZE (1 << 19) // max size of mode partition +#define VP8_MAX_PARTITION_SIZE (1 << 24) // max size for token partition +#define VP8_FRAME_HEADER_SIZE 10 // Size of the frame header within VP8 data. + +// VP8L related constants. +#define VP8L_SIGNATURE_SIZE 1 // VP8L signature size. +#define VP8L_MAGIC_BYTE 0x2f // VP8L signature byte. +#define VP8L_IMAGE_SIZE_BITS 14 // Number of bits used to store + // width and height. +#define VP8L_VERSION_BITS 3 // 3 bits reserved for version. +#define VP8L_VERSION 0 // version 0 +#define VP8L_FRAME_HEADER_SIZE 5 // Size of the VP8L frame header. + +#define MAX_PALETTE_SIZE 256 +#define MAX_CACHE_BITS 11 +#define HUFFMAN_CODES_PER_META_CODE 5 +#define ARGB_BLACK 0xff000000 + +#define DEFAULT_CODE_LENGTH 8 +#define MAX_ALLOWED_CODE_LENGTH 15 + +#define NUM_LITERAL_CODES 256 +#define NUM_LENGTH_CODES 24 +#define NUM_DISTANCE_CODES 40 +#define CODE_LENGTH_CODES 19 + +#define MIN_HUFFMAN_BITS 2 // min number of Huffman bits +#define MAX_HUFFMAN_BITS 9 // max number of Huffman bits + +#define TRANSFORM_PRESENT 1 // The bit to be written when next data + // to be read is a transform. +#define NUM_TRANSFORMS 4 // Maximum number of allowed transform + // in a bitstream. +typedef enum { + PREDICTOR_TRANSFORM = 0, + CROSS_COLOR_TRANSFORM = 1, + SUBTRACT_GREEN = 2, + COLOR_INDEXING_TRANSFORM = 3 +} VP8LImageTransformType; + +// Alpha related constants. +#define ALPHA_HEADER_LEN 1 +#define ALPHA_NO_COMPRESSION 0 +#define ALPHA_LOSSLESS_COMPRESSION 1 +#define ALPHA_PREPROCESSED_LEVELS 1 + +// Mux related constants. +#define TAG_SIZE 4 // Size of a chunk tag (e.g. "VP8L"). +#define CHUNK_SIZE_BYTES 4 // Size needed to store chunk's size. +#define CHUNK_HEADER_SIZE 8 // Size of a chunk header. +#define RIFF_HEADER_SIZE 12 // Size of the RIFF header ("RIFFnnnnWEBP"). +#define FRAME_CHUNK_SIZE 15 // Size of a FRM chunk. +#define LOOP_CHUNK_SIZE 2 // Size of a LOOP chunk. +#define TILE_CHUNK_SIZE 6 // Size of a TILE chunk. +#define VP8X_CHUNK_SIZE 10 // Size of a VP8X chunk. + +#define TILING_FLAG_BIT 0x01 // Set if tiles are possibly used. +#define ANIMATION_FLAG_BIT 0x02 // Set if some animation is expected +#define ICC_FLAG_BIT 0x04 // Whether ICC is present or not. +#define METADATA_FLAG_BIT 0x08 // Set if some META chunk is possibly present. +#define ALPHA_FLAG_BIT 0x10 // Should be same as the ALPHA_FLAG in mux.h +#define ROTATION_FLAG_BITS 0xe0 // all 3 bits for rotation + symmetry + +#define MAX_CANVAS_SIZE (1 << 24) // 24-bit max for VP8X width/height. +#define MAX_IMAGE_AREA (1ULL << 32) // 32-bit max for width x height. +#define MAX_LOOP_COUNT (1 << 16) // maximum value for loop-count +#define MAX_DURATION (1 << 24) // maximum duration +#define MAX_POSITION_OFFSET (1 << 24) // maximum frame/tile x/y offset + +// Maximum chunk payload is such that adding the header and padding won't +// overflow a uint32_t. +#define MAX_CHUNK_PAYLOAD (~0U - CHUNK_HEADER_SIZE - 1) + +#endif /* WEBP_WEBP_FORMAT_CONSTANTS_H_ */ |