| // Copyright 2024 The Wuffs Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| // |
| // SPDX-License-Identifier: Apache-2.0 OR MIT |
| |
| use "std/vp8" |
| |
| pub status "#bad Huffman code (over-subscribed)" |
| pub status "#bad Huffman code (under-subscribed)" |
| pub status "#bad Huffman code" |
| pub status "#bad back-reference" |
| pub status "#bad color cache" |
| pub status "#bad header" |
| pub status "#bad transform" |
| pub status "#short chunk" |
| pub status "#truncated input" |
| pub status "#unsupported number of Huffman groups" |
| pub status "#unsupported transform after color indexing transform" |
| pub status "#unsupported WebP file" |
| |
| pri status "#internal error: inconsistent Huffman code" |
| pri status "#internal error: inconsistent dst buffer" |
| pri status "#internal error: inconsistent n_bits" |
| |
| pub const DECODER_WORKBUF_LEN_MAX_INCL_WORST_CASE : base.u64 = 0 |
| |
| pub struct decoder? implements base.image_decoder( |
| pixfmt : base.u32, |
| width : base.u32[..= 0x4000], |
| height : base.u32[..= 0x4000], |
| |
| // The call sequence state machine is discussed in |
| // (/doc/std/image-decoders-call-sequence.md). |
| call_sequence : base.u8, |
| |
| code_length_code_lengths : array[19] base.u8[..= 7], |
| |
| sub_chunk_has_padding : base.bool, |
| |
| is_vp8_lossy : base.bool, |
| |
| frame_config_io_position : base.u64, |
| |
| riff_chunk_length : base.u32, |
| sub_chunk_length : base.u32, |
| |
| bits : base.u32, |
| n_bits : base.u32[..= 31], |
| |
| seen_transform : array[4] base.bool, |
| transform_type : array[4] base.u8[..= 3], |
| transform_tile_size_log2 : array[4] base.u8[..= 9], |
| n_transforms : base.u32[..= 4], |
| |
| color_cache_bits : base.u32[..= 11], |
| overall_color_cache_bits : base.u32[..= 11], |
| overall_tile_size_log2 : base.u32[..= 9], |
| overall_n_huffman_groups : base.u32[..= 256], |
| |
| ht_n_symbols : base.u32[..= 2328], |
| ht_code_lengths_remaining : base.u32, |
| |
| color_indexing_palette_size : base.u32[..= 256], |
| color_indexing_width : base.u32[..= 0x4000], |
| |
| // The 0th element is for the Meta (Huffman Group) selectors. |
| // The 1st element is for the Predictor transform. |
| // The 2nd element is for the Cross Color transform. |
| // The 3rd element is overall workbuf length. |
| workbuf_offset_for_transform : array[4] base.u32[..= 0x4C00_0000], |
| |
| // If the Color Indexing transform is present then workbuf[i .. j] |
| // holds the pre-transformed pixel data (the Green component of the |
| // pixel's bgra data holds color indexes) and workbuf[0 .. j] holds the |
| // post-transformed data: |
| // |
| // - i is workbuf_offset_for_color_indexing |
| // - j is workbuf_offset_for_transform[0] |
| // |
| // i is calculated as: |
| // |
| // - if there are 8 bits per color index then i is 0. |
| // - if there are 4 bits per color index then i is j*1/2, roughly. |
| // - if there are 2 bits per color index then i is j*3/4, roughly. |
| // - if there are 1 bits per color index then i is j*7/8, roughly. |
| // |
| // The two slices (workbuf[i .. j] and workbuf[0 .. j]) overlap. |
| // apply_transform_color_indexing modifies the pixel buffer in-place. |
| workbuf_offset_for_color_indexing : base.u32[..= 0x4000_0000], |
| |
| vp8 : vp8.decoder, |
| |
| swizzler : base.pixel_swizzler, |
| util : base.utility, |
| ) + ( |
| palette : array[4 * 256] base.u8, |
| color_cache : array[2048] base.u32, |
| |
| codes : array[2328] base.u16, |
| code_lengths : array[2328] base.u16, |
| |
| // Each node is a base.u16 whose bit patterns are: |
| // |
| // - 0000_0000_0000_0000 Invalid. |
| // - 0CCC_CCCC_CCCC_CCCC Branch node (children_offset is CCC). |
| // - 1SSS_SSSS_SSSS_SSSS Leaf node (symbol is SSS, it may be zero). |
| code_lengths_huffman_nodes : array[37] base.u16, |
| |
| // A Huffman group has five (5) Huffman trees. |
| // |
| // Start .. End Size |
| // 0x064C .. 0x187B 0x122F (1) Green, back-ref length, color cache. |
| // 0x0000 .. 0x01FF 0x01FF (2) Red. |
| // 0x01FF .. 0x03FE 0x01FF (3) Blue. |
| // 0x03FE .. 0x05FD 0x01FF (4) Alpha. |
| // 0x05FD .. 0x064C 0x004F (5) Back-ref distance. |
| // |
| // The Green+etc tree is last (in terms of start offset) because it's |
| // by far the largest (worst case) and its color cache component has |
| // variable length. |
| // |
| // 0x122F = 4655 = ((2 * 2328) - 1) and the same 2328 turns up in func |
| // decoder.decode_huffman_tree. |
| // |
| // 2328 is (256 + 24 + 2048), combining 256 Green values, 24 back-ref |
| // lengths and up to 2048 = (1 << 11) color cache keys. |
| // |
| // 0x01FF = 511 = ((2 * 256) - 1) is for 256 Red (Blue, Alpha) values. |
| // |
| // 0x004F = 79 = ((2 * 40) - 1) is for 40 back-ref distances. |
| // |
| // 0x187B = 6267 and (0x187B * sizeof(u16)) = 12534. Overall, this |
| // field takes 0x30_F600 = 3_208704 bytes of memory. |
| // |
| // The base.u16's bits are the same as for code_lengths_huffman_nodes. |
| huffman_nodes : array[256] array[0x187B] base.u16, |
| ) |
| |
| pub func decoder.get_quirk(key: base.u32) base.u64 { |
| return 0 |
| } |
| |
| pub func decoder.set_quirk!(key: base.u32, value: base.u64) base.status { |
| return base."#unsupported option" |
| } |
| |
| pub func decoder.decode_image_config?(dst: nptr base.image_config, src: base.io_reader) { |
| var status : base.status |
| |
| while true { |
| status =? this.do_decode_image_config?(dst: args.dst, src: args.src) |
| if (status == base."$short read") and args.src.is_closed() { |
| return "#truncated input" |
| } |
| yield? status |
| } |
| } |
| |
| pri func decoder.do_decode_image_config?(dst: nptr base.image_config, src: base.io_reader) { |
| var c32 : base.u32 |
| var r_mark : base.u64 |
| var status : base.status |
| |
| if this.call_sequence <> 0x00 { |
| return base."#bad call sequence" |
| } |
| |
| c32 = args.src.read_u32le?() |
| if c32 <> 'RIFF'le { |
| return "#bad header" |
| } |
| this.riff_chunk_length = args.src.read_u32le?() |
| if (this.riff_chunk_length & 1) <> 0 { |
| return "#bad header" |
| } |
| |
| while true { |
| io_limit (io: args.src, limit: this.riff_chunk_length as base.u64) { |
| r_mark = args.src.mark() |
| status =? this.do_decode_image_config_limited?(dst: args.dst, src: args.src) |
| this.riff_chunk_length ~sat-= |
| (args.src.count_since(mark: r_mark) & 0xFFFF_FFFF) as base.u32 |
| } |
| |
| if status.is_ok() { |
| break |
| } else if not status.is_suspension() { |
| return status |
| } else if (status == base."$short read") and (this.riff_chunk_length == 0) { |
| return "#short chunk" |
| } |
| yield? status |
| } |
| |
| this.frame_config_io_position = args.src.position() |
| |
| if (not this.is_vp8_lossy) and (args.dst <> nullptr) { |
| args.dst.set!( |
| pixfmt: this.pixfmt, |
| pixsub: 0, |
| width: this.width, |
| height: this.height, |
| first_frame_io_position: this.frame_config_io_position, |
| first_frame_is_opaque: false) |
| } |
| |
| this.call_sequence = 0x20 |
| } |
| |
| pri func decoder.do_decode_image_config_limited?(dst: nptr base.image_config, src: base.io_reader) { |
| var c32 : base.u32 |
| var r_mark : base.u64 |
| var status : base.status |
| |
| c32 = args.src.read_u32le?() |
| if c32 <> 'WEBP'le { |
| return "#bad header" |
| } |
| |
| c32 = args.src.read_u32le?() |
| if c32 == 'VP8 'le { |
| this.is_vp8_lossy = true |
| } else if c32 == 'VP8L'le { |
| // No-op. |
| } else if c32 == 'VP8X'le { |
| return "#unsupported WebP file" |
| } else { |
| return "#bad header" |
| } |
| |
| this.sub_chunk_length = args.src.read_u32le?() |
| if this.sub_chunk_length < 4 { |
| return "#bad header" |
| } |
| this.sub_chunk_has_padding = (this.sub_chunk_length & 1) <> 0 |
| |
| while true { |
| io_limit (io: args.src, limit: this.sub_chunk_length as base.u64) { |
| r_mark = args.src.mark() |
| if this.is_vp8_lossy { |
| status =? this.vp8.decode_image_config?(dst: args.dst, src: args.src) |
| } else { |
| status =? this.do_decode_image_config_limited_vp8l?(src: args.src) |
| } |
| this.sub_chunk_length ~sat-= |
| (args.src.count_since(mark: r_mark) & 0xFFFF_FFFF) as base.u32 |
| } |
| |
| if status.is_ok() { |
| break |
| } else if not status.is_suspension() { |
| return status |
| } else if (status == base."$short read") and (this.sub_chunk_length == 0) { |
| return "#short chunk" |
| } |
| yield? status |
| } |
| } |
| |
| pri func decoder.do_decode_image_config_limited_vp8l?(src: base.io_reader) { |
| var c32 : base.u32 |
| var transform_size : base.u32[..= 0x400_0000] |
| |
| c32 = args.src.read_u8_as_u32?() |
| if c32 <> 0x2F { |
| return "#bad header" |
| } |
| c32 = args.src.read_u32le?() |
| this.width = (c32 & 0x3FFF) + 1 |
| c32 >>= 14 |
| this.height = (c32 & 0x3FFF) + 1 |
| c32 >>= 14 |
| this.pixfmt = base.PIXEL_FORMAT__BGRX |
| if (c32 & 1) <> 0 { |
| this.pixfmt = base.PIXEL_FORMAT__BGRA_NONPREMUL |
| } |
| c32 >>= 1 |
| if c32 <> 0 { |
| return "#bad header" |
| } |
| |
| transform_size = 4 * ((this.width + 3) >> 2) * ((this.height + 3) >> 2) |
| this.workbuf_offset_for_transform[0] = (4 * this.width * this.height) + (0 * transform_size) |
| this.workbuf_offset_for_transform[1] = (4 * this.width * this.height) + (1 * transform_size) |
| this.workbuf_offset_for_transform[2] = (4 * this.width * this.height) + (2 * transform_size) |
| this.workbuf_offset_for_transform[3] = (4 * this.width * this.height) + (3 * transform_size) |
| } |
| |
| pub func decoder.decode_frame_config?(dst: nptr base.frame_config, src: base.io_reader) { |
| var status : base.status |
| |
| while true { |
| if this.is_vp8_lossy { |
| status =? this.vp8.decode_frame_config?(dst: args.dst, src: args.src) |
| } else { |
| status =? this.do_decode_frame_config?(dst: args.dst, src: args.src) |
| } |
| if (status == base."$short read") and args.src.is_closed() { |
| return "#truncated input" |
| } |
| yield? status |
| } |
| } |
| |
| pri func decoder.do_decode_frame_config?(dst: nptr base.frame_config, src: base.io_reader) { |
| var pixfmt : base.pixel_format |
| |
| if this.call_sequence == 0x20 { |
| // No-op. |
| } else if this.call_sequence < 0x20 { |
| this.do_decode_image_config?(dst: nullptr, src: args.src) |
| } else if this.call_sequence == 0x28 { |
| if this.frame_config_io_position <> args.src.position() { |
| return base."#bad restart" |
| } |
| } else if this.call_sequence == 0x40 { |
| this.call_sequence = 0x60 |
| return base."@end of data" |
| } else { |
| return base."@end of data" |
| } |
| |
| if args.dst <> nullptr { |
| pixfmt = this.util.make_pixel_format(repr: this.pixfmt) |
| args.dst.set!(bounds: this.util.make_rect_ie_u32( |
| min_incl_x: 0, |
| min_incl_y: 0, |
| max_excl_x: this.width, |
| max_excl_y: this.height), |
| duration: 0, |
| index: 0, |
| io_position: this.frame_config_io_position, |
| disposal: 0, |
| opaque_within_bounds: false, |
| overwrite_instead_of_blend: false, |
| background_color: pixfmt.default_background_color()) |
| } |
| |
| this.call_sequence = 0x40 |
| } |
| |
| pub func decoder.decode_frame?(dst: ptr base.pixel_buffer, src: base.io_reader, blend: base.pixel_blend, workbuf: slice base.u8, opts: nptr base.decode_frame_options) { |
| var status : base.status |
| |
| while true { |
| if this.is_vp8_lossy { |
| status =? this.vp8.decode_frame?(dst: args.dst, src: args.src, blend: args.blend, workbuf: args.workbuf, opts: args.opts) |
| } else { |
| status =? this.do_decode_frame?(dst: args.dst, src: args.src, blend: args.blend, workbuf: args.workbuf, opts: args.opts) |
| } |
| if (status == base."$short read") and args.src.is_closed() { |
| return "#truncated input" |
| } |
| yield? status |
| } |
| } |
| |
| pri func decoder.do_decode_frame?(dst: ptr base.pixel_buffer, src: base.io_reader, blend: base.pixel_blend, workbuf: slice base.u8, opts: nptr base.decode_frame_options) { |
| var c8 : base.u8 |
| var has_more : base.u32[..= 1] |
| var width : base.u32[..= 0x4000] |
| var dst : slice base.u8 |
| var tile_data : roslice base.u8 |
| var status : base.status |
| var pix : slice base.u8 |
| var which : base.u32[..= 4] |
| var transform_type : base.u32[..= 3] |
| var ti : base.u64 |
| var tj : base.u64 |
| |
| if this.call_sequence == 0x40 { |
| // No-op. |
| } else if this.call_sequence < 0x40 { |
| this.do_decode_frame_config?(dst: nullptr, src: args.src) |
| } else { |
| return base."@end of data" |
| } |
| |
| this.seen_transform[0] = false |
| this.seen_transform[1] = false |
| this.seen_transform[2] = false |
| this.seen_transform[3] = false |
| this.n_transforms = 0 |
| |
| while true { |
| if this.n_bits < 1 { |
| c8 = args.src.read_u8?() |
| this.bits = (c8 as base.u32) |
| this.n_bits = 8 |
| assert this.n_bits >= 1 |
| } |
| has_more = this.bits & 1 |
| this.bits >>= 1 |
| this.n_bits -= 1 |
| |
| if has_more == 0 { |
| break |
| } |
| this.decode_transform?(src: args.src, workbuf: args.workbuf) |
| } |
| |
| width = this.width |
| if this.seen_transform[3] { |
| width = this.color_indexing_width |
| } |
| |
| this.decode_color_cache_parameters?(src: args.src) |
| this.overall_color_cache_bits = this.color_cache_bits |
| this.decode_hg_table?(src: args.src, width: width, workbuf: args.workbuf) |
| this.color_cache_bits = this.overall_color_cache_bits |
| this.decode_huffman_groups?(src: args.src, n_huffman_groups: this.overall_n_huffman_groups) |
| |
| while true { |
| if ((this.workbuf_offset_for_color_indexing as base.u64) > (this.workbuf_offset_for_transform[0] as base.u64)) or |
| ((this.workbuf_offset_for_transform[0] as base.u64) > (this.workbuf_offset_for_transform[1] as base.u64)) or |
| ((this.workbuf_offset_for_transform[1] as base.u64) > args.workbuf.length()) or |
| ((this.workbuf_offset_for_transform[0] as base.u64) > args.workbuf.length()) { |
| return base."#bad workbuf length" |
| } |
| dst = args.workbuf[ |
| (this.workbuf_offset_for_color_indexing as base.u64) .. |
| (this.workbuf_offset_for_transform[0] as base.u64)] |
| tile_data = args.workbuf[ |
| (this.workbuf_offset_for_transform[0] as base.u64) .. |
| (this.workbuf_offset_for_transform[1] as base.u64)] |
| status =? this.decode_pixels?( |
| dst: dst, |
| src: args.src, |
| width: width, |
| height: this.height, |
| tile_data: tile_data, |
| tile_size_log2: this.overall_tile_size_log2) |
| if status.is_ok() { |
| break |
| } |
| yield? status |
| } |
| |
| if (this.workbuf_offset_for_transform[0] as base.u64) > args.workbuf.length() { |
| return base."#bad workbuf length" |
| } |
| pix = args.workbuf[.. (this.workbuf_offset_for_transform[0] as base.u64)] |
| |
| which = this.n_transforms |
| while which > 0 { |
| which -= 1 |
| transform_type = this.transform_type[which] as base.u32 |
| |
| tile_data = this.util.empty_slice_u8() |
| if transform_type < 2 { |
| ti = this.workbuf_offset_for_transform[transform_type + 1] as base.u64 |
| tj = this.workbuf_offset_for_transform[transform_type + 2] as base.u64 |
| if (ti <= tj) and (tj <= args.workbuf.length()) { |
| tile_data = args.workbuf[ti .. tj] |
| } |
| } |
| |
| if transform_type == 0 { |
| this.apply_transform_predictor!(pix: pix, tile_data: tile_data) |
| } else if transform_type == 1 { |
| this.apply_transform_cross_color!(pix: pix, tile_data: tile_data) |
| } else if transform_type == 2 { |
| this.apply_transform_subtract_green!(pix: pix) |
| } else { |
| this.apply_transform_color_indexing!(pix: pix) |
| width = this.width |
| } |
| } |
| |
| status = this.swizzle!( |
| dst: args.dst, |
| src: pix, |
| blend: args.blend) |
| if not status.is_ok() { |
| return status |
| } |
| |
| this.call_sequence = 0x60 |
| } |
| |
| pri func decoder.decode_transform?(src: base.io_reader, workbuf: slice base.u8) { |
| var status : base.status |
| var c8 : base.u8 |
| var transform_type : base.u32[..= 3] |
| var tile_size_log2 : base.u32[..= 9] |
| var p : slice base.u8 |
| |
| if this.n_bits < 2 { |
| c8 = args.src.read_u8?() |
| if this.n_bits >= 2 { |
| return "#internal error: inconsistent n_bits" |
| } |
| this.bits |= (c8 as base.u32) << this.n_bits |
| this.n_bits += 8 |
| assert this.n_bits >= 2 |
| } |
| transform_type = this.bits & 3 |
| this.bits >>= 2 |
| this.n_bits -= 2 |
| |
| if this.seen_transform[transform_type] or (this.n_transforms >= 4) { |
| return "#bad transform" |
| } else if this.seen_transform[3] { |
| return "#unsupported transform after color indexing transform" |
| } |
| this.seen_transform[transform_type] = true |
| this.transform_type[this.n_transforms] = transform_type as base.u8 |
| this.n_transforms += 1 |
| |
| if transform_type < 2 { // Predictor, Cross Color transform. |
| if this.n_bits < 3 { |
| c8 = args.src.read_u8?() |
| if this.n_bits >= 3 { |
| return "#internal error: inconsistent n_bits" |
| } |
| this.bits |= (c8 as base.u32) << this.n_bits |
| this.n_bits += 8 |
| assert this.n_bits >= 3 |
| } |
| tile_size_log2 = (this.bits & 7) + 2 |
| this.transform_tile_size_log2[transform_type] = tile_size_log2 as base.u8 |
| this.bits >>= 3 |
| this.n_bits -= 3 |
| |
| this.decode_color_cache_parameters?(src: args.src) |
| this.decode_huffman_groups?(src: args.src, n_huffman_groups: 1) |
| |
| while true, |
| inv transform_type < 2, |
| inv tile_size_log2 >= 2, |
| { |
| if ((this.workbuf_offset_for_transform[transform_type + 1] as base.u64) > (this.workbuf_offset_for_transform[transform_type + 2] as base.u64)) or |
| ((this.workbuf_offset_for_transform[transform_type + 2] as base.u64) > args.workbuf.length()) { |
| return base."#bad workbuf length" |
| } |
| status =? this.decode_pixels?( |
| dst: args.workbuf[ |
| (this.workbuf_offset_for_transform[transform_type + 1] as base.u64) .. |
| (this.workbuf_offset_for_transform[transform_type + 2] as base.u64)], |
| src: args.src, |
| width: (this.width + (((1 as base.u32) << tile_size_log2) - 1)) >> tile_size_log2, |
| height: (this.height + (((1 as base.u32) << tile_size_log2) - 1)) >> tile_size_log2, |
| tile_data: this.util.empty_slice_u8(), |
| tile_size_log2: 0) |
| if status.is_ok() { |
| break |
| } |
| yield? status |
| } |
| |
| } else if transform_type == 2 { // Subtract Green transform. |
| // No-op. |
| |
| } else { // Color Indexing transform. |
| if this.n_bits < 8 { |
| c8 = args.src.read_u8?() |
| if this.n_bits >= 8 { |
| return "#internal error: inconsistent n_bits" |
| } |
| this.bits |= (c8 as base.u32) << this.n_bits |
| this.n_bits += 8 |
| assert this.n_bits >= 8 |
| } |
| this.color_indexing_palette_size = (this.bits & 0xFF) + 1 |
| this.bits >>= 8 |
| this.n_bits -= 8 |
| |
| if this.color_indexing_palette_size <= 2 { |
| this.color_indexing_width = (this.width + 7) / 8 |
| this.transform_tile_size_log2[3] = 3 |
| } else if this.color_indexing_palette_size <= 4 { |
| this.color_indexing_width = (this.width + 3) / 4 |
| this.transform_tile_size_log2[3] = 2 |
| } else if this.color_indexing_palette_size <= 16 { |
| this.color_indexing_width = (this.width + 1) / 2 |
| this.transform_tile_size_log2[3] = 1 |
| } else { |
| this.color_indexing_width = this.width |
| this.transform_tile_size_log2[3] = 0 |
| } |
| |
| if this.width >= this.color_indexing_width { |
| this.workbuf_offset_for_color_indexing = 4 * (this.width - this.color_indexing_width) * this.height |
| } |
| |
| this.decode_color_cache_parameters?(src: args.src) |
| this.decode_huffman_groups?(src: args.src, n_huffman_groups: 1) |
| |
| this.decode_pixels?( |
| dst: this.palette[.. 4 * this.color_indexing_palette_size], |
| src: args.src, |
| width: this.color_indexing_palette_size, |
| height: 1, |
| tile_data: this.util.empty_slice_u8(), |
| tile_size_log2: 0) |
| this.palette[4 * this.color_indexing_palette_size .. 1024].bulk_memset!(byte_value: 0) |
| |
| p = this.palette[.. 4 * this.color_indexing_palette_size] |
| while p.length() >= 8 { |
| p[4] ~mod+= p[0] |
| p[5] ~mod+= p[1] |
| p[6] ~mod+= p[2] |
| p[7] ~mod+= p[3] |
| p = p[4 ..] |
| } |
| } |
| } |
| |
| pri func decoder.decode_color_cache_parameters?(src: base.io_reader) { |
| var c8 : base.u8 |
| var use_color_cache : base.u32[..= 1] |
| var color_cache_bits : base.u32[..= 15] |
| |
| if this.n_bits < 1 { |
| c8 = args.src.read_u8?() |
| this.bits = (c8 as base.u32) |
| this.n_bits = 8 |
| assert this.n_bits >= 1 |
| } |
| use_color_cache = this.bits & 1 |
| this.bits >>= 1 |
| this.n_bits -= 1 |
| |
| this.color_cache_bits = 0 |
| if use_color_cache <> 0 { |
| if this.n_bits < 4 { |
| c8 = args.src.read_u8?() |
| if this.n_bits >= 4 { |
| return "#internal error: inconsistent n_bits" |
| } |
| this.bits |= (c8 as base.u32) << this.n_bits |
| this.n_bits += 8 |
| assert this.n_bits >= 4 |
| } |
| color_cache_bits = this.bits & 15 |
| this.bits >>= 4 |
| this.n_bits -= 4 |
| |
| if (color_cache_bits < 1) or (11 < color_cache_bits) { |
| return "#bad color cache" |
| } |
| this.color_cache_bits = color_cache_bits |
| } |
| } |
| |
| pri func decoder.decode_hg_table?(src: base.io_reader, width: base.u32[..= 0x4000], workbuf: slice base.u8) { |
| var status : base.status |
| var c8 : base.u8 |
| var use_hg_table : base.u32[..= 1] |
| var tile_size_log2 : base.u32[..= 9] |
| var hg_pixels : slice base.u8 |
| var n : base.u64 |
| var p : roslice base.u8 |
| var hg_plus_1 : base.u32[..= 256] |
| |
| if this.n_bits < 1 { |
| c8 = args.src.read_u8?() |
| this.bits = (c8 as base.u32) |
| this.n_bits = 8 |
| assert this.n_bits >= 1 |
| } |
| use_hg_table = this.bits & 1 |
| this.bits >>= 1 |
| this.n_bits -= 1 |
| |
| if use_hg_table == 0 { |
| this.overall_n_huffman_groups = 1 |
| this.overall_tile_size_log2 = 0 |
| if ((this.workbuf_offset_for_transform[0] as base.u64) > (this.workbuf_offset_for_transform[1] as base.u64)) or |
| ((this.workbuf_offset_for_transform[1] as base.u64) > args.workbuf.length()) { |
| return base."#bad workbuf length" |
| } |
| hg_pixels = args.workbuf[ |
| this.workbuf_offset_for_transform[0] as base.u64 .. |
| this.workbuf_offset_for_transform[1] as base.u64] |
| if hg_pixels.length() >= 4 { |
| hg_pixels[0] = 0x00 |
| hg_pixels[1] = 0x00 |
| hg_pixels[2] = 0x00 |
| hg_pixels[3] = 0x00 |
| } |
| return ok |
| } |
| |
| if this.n_bits < 3 { |
| c8 = args.src.read_u8?() |
| if this.n_bits >= 3 { |
| return "#internal error: inconsistent n_bits" |
| } |
| this.bits |= (c8 as base.u32) << this.n_bits |
| this.n_bits += 8 |
| assert this.n_bits >= 3 |
| } |
| tile_size_log2 = (this.bits & 7) + 2 |
| this.bits >>= 3 |
| this.n_bits -= 3 |
| |
| this.overall_tile_size_log2 = tile_size_log2 |
| |
| this.decode_color_cache_parameters?(src: args.src) |
| this.decode_huffman_groups?(src: args.src, n_huffman_groups: 1) |
| while true, |
| inv tile_size_log2 >= 2, |
| { |
| if ((this.workbuf_offset_for_transform[0] as base.u64) > (this.workbuf_offset_for_transform[1] as base.u64)) or |
| ((this.workbuf_offset_for_transform[1] as base.u64) > args.workbuf.length()) { |
| return base."#bad workbuf length" |
| } |
| status =? this.decode_pixels?( |
| dst: args.workbuf[ |
| (this.workbuf_offset_for_transform[0] as base.u64) .. |
| (this.workbuf_offset_for_transform[1] as base.u64)], |
| src: args.src, |
| width: (args.width + (((1 as base.u32) << tile_size_log2) - 1)) >> tile_size_log2, |
| height: (this.height + (((1 as base.u32) << tile_size_log2) - 1)) >> tile_size_log2, |
| tile_data: this.util.empty_slice_u8(), |
| tile_size_log2: 0) |
| if status.is_ok() { |
| break |
| } |
| yield? status |
| } |
| |
| this.overall_n_huffman_groups = 1 |
| if ((this.workbuf_offset_for_transform[0] as base.u64) > (this.workbuf_offset_for_transform[1] as base.u64)) or |
| ((this.workbuf_offset_for_transform[1] as base.u64) > args.workbuf.length()) { |
| return base."#bad workbuf length" |
| } |
| hg_pixels = args.workbuf[ |
| this.workbuf_offset_for_transform[0] as base.u64 .. |
| this.workbuf_offset_for_transform[1] as base.u64] |
| n = (((args.width + (((1 as base.u32) << tile_size_log2) - 1)) >> tile_size_log2) * |
| ((this.height + (((1 as base.u32) << tile_size_log2) - 1)) >> tile_size_log2) * |
| 4) as base.u64 |
| if n > hg_pixels.length() { |
| return base."#bad workbuf length" |
| } |
| p = hg_pixels[.. n] |
| while p.length() >= 4 { |
| if p[2] <> 0 { |
| return "#unsupported number of Huffman groups" |
| } |
| hg_plus_1 = (p[1] as base.u32) + 1 |
| if this.overall_n_huffman_groups < hg_plus_1 { |
| this.overall_n_huffman_groups = hg_plus_1 |
| } |
| p = p[4 ..] |
| } |
| } |
| |
| pri func decoder.decode_pixels?(dst: slice base.u8, src: base.io_reader, width: base.u32[..= 0x4000], height: base.u32[..= 0x4000], tile_data: roslice base.u8, tile_size_log2: base.u32[..= 9]) { |
| var i : base.u32 |
| var n : base.u32[..= 2048] |
| |
| i = 0 |
| n = (1 as base.u32) << this.color_cache_bits |
| while i < n { |
| assert i < 2048 via "a < b: a < c; c <= b"(c: n) |
| this.color_cache[i] = 0 |
| i += 1 |
| } |
| |
| this.decode_pixels_slow?( |
| dst: args.dst, |
| src: args.src, |
| width: args.width, |
| height: args.height, |
| tile_data: args.tile_data, |
| tile_size_log2: args.tile_size_log2) |
| } |
| |
| pri func decoder.swizzle!(dst: ptr base.pixel_buffer, src: roslice base.u8, blend: base.pixel_blend) base.status { |
| var status : base.status |
| var dst_pixfmt : base.pixel_format |
| var dst_bits_per_pixel : base.u32[..= 256] |
| var dst_bytes_per_pixel : base.u32[..= 32] |
| var dst_bytes_per_row : base.u64 |
| var dst_palette : slice base.u8 |
| var tab : table base.u8 |
| var src_bytes_per_row : base.u64 |
| var dst : slice base.u8 |
| var y : base.u32 |
| |
| status = this.swizzler.prepare!( |
| dst_pixfmt: args.dst.pixel_format(), |
| dst_palette: args.dst.palette_or_else(fallback: this.palette[..]), |
| src_pixfmt: this.util.make_pixel_format(repr: this.pixfmt), |
| src_palette: this.util.empty_slice_u8(), |
| blend: args.blend) |
| if not status.is_ok() { |
| return status |
| } |
| |
| // TODO: the dst_pixfmt variable shouldn't be necessary. We should be able |
| // to chain the two calls: "args.dst.pixel_format().bits_per_pixel()". |
| dst_pixfmt = args.dst.pixel_format() |
| dst_bits_per_pixel = dst_pixfmt.bits_per_pixel() |
| if (dst_bits_per_pixel & 7) <> 0 { |
| return base."#unsupported option" |
| } |
| dst_bytes_per_pixel = dst_bits_per_pixel / 8 |
| dst_bytes_per_row = (this.width * dst_bytes_per_pixel) as base.u64 |
| dst_palette = args.dst.palette_or_else(fallback: this.palette[..]) |
| tab = args.dst.plane(p: 0) |
| src_bytes_per_row = (this.width * 4) as base.u64 |
| |
| while src_bytes_per_row <= args.src.length() { |
| dst = tab.row_u32(y: y) |
| if dst_bytes_per_row < dst.length() { |
| dst = dst[.. dst_bytes_per_row] |
| } |
| |
| this.swizzler.swizzle_interleaved_from_slice!( |
| dst: dst, |
| dst_palette: dst_palette, |
| src: args.src[.. src_bytes_per_row]) |
| |
| args.src = args.src[src_bytes_per_row ..] |
| y ~mod+= 1 |
| } |
| |
| return ok |
| } |
| |
| pub func decoder.frame_dirty_rect() base.rect_ie_u32 { |
| if this.is_vp8_lossy { |
| return this.vp8.frame_dirty_rect() |
| } |
| return this.util.make_rect_ie_u32( |
| min_incl_x: 0, |
| min_incl_y: 0, |
| max_excl_x: this.width, |
| max_excl_y: this.height) |
| } |
| |
| pub func decoder.num_animation_loops() base.u32 { |
| return 0 |
| } |
| |
| pub func decoder.num_decoded_frame_configs() base.u64 { |
| if this.is_vp8_lossy { |
| return this.vp8.num_decoded_frame_configs() |
| } |
| if this.call_sequence > 0x20 { |
| return 1 |
| } |
| return 0 |
| } |
| |
| pub func decoder.num_decoded_frames() base.u64 { |
| if this.is_vp8_lossy { |
| return this.vp8.num_decoded_frames() |
| } |
| if this.call_sequence > 0x40 { |
| return 1 |
| } |
| return 0 |
| } |
| |
| pub func decoder.restart_frame!(index: base.u64, io_position: base.u64) base.status { |
| var status : base.status |
| |
| if this.is_vp8_lossy { |
| status = this.vp8.restart_frame!(index: args.index, io_position: args.io_position) |
| return status |
| } |
| if this.call_sequence < 0x20 { |
| return base."#bad call sequence" |
| } |
| if (args.index <> 0) or (args.io_position <> this.frame_config_io_position) { |
| return base."#bad argument" |
| } |
| this.call_sequence = 0x28 |
| return ok |
| } |
| |
| pub func decoder.set_report_metadata!(fourcc: base.u32, report: base.bool) { |
| // No-op. |
| } |
| |
| pub func decoder.tell_me_more?(dst: base.io_writer, minfo: nptr base.more_information, src: base.io_reader) { |
| return base."#no more information" |
| } |
| |
| pub func decoder.workbuf_len() base.range_ii_u64 { |
| if this.is_vp8_lossy { |
| return this.vp8.workbuf_len() |
| } |
| return this.util.make_range_ii_u64( |
| min_incl: this.workbuf_offset_for_transform[3] as base.u64, |
| max_incl: this.workbuf_offset_for_transform[3] as base.u64) |
| } |
| |
| pri const DISTANCE_MAP : roarray[120] base.u8 = [ |
| 0x18, 0x07, 0x17, 0x19, 0x28, 0x06, 0x27, 0x29, 0x16, 0x1A, |
| 0x26, 0x2A, 0x38, 0x05, 0x37, 0x39, 0x15, 0x1B, 0x36, 0x3A, |
| 0x25, 0x2B, 0x48, 0x04, 0x47, 0x49, 0x14, 0x1C, 0x35, 0x3B, |
| 0x46, 0x4A, 0x24, 0x2C, 0x58, 0x45, 0x4B, 0x34, 0x3C, 0x03, |
| 0x57, 0x59, 0x13, 0x1D, 0x56, 0x5A, 0x23, 0x2D, 0x44, 0x4C, |
| 0x55, 0x5B, 0x33, 0x3D, 0x68, 0x02, 0x67, 0x69, 0x12, 0x1E, |
| 0x66, 0x6A, 0x22, 0x2E, 0x54, 0x5C, 0x43, 0x4D, 0x65, 0x6B, |
| 0x32, 0x3E, 0x78, 0x01, 0x77, 0x79, 0x53, 0x5D, 0x11, 0x1F, |
| 0x64, 0x6C, 0x42, 0x4E, 0x76, 0x7A, 0x21, 0x2F, 0x75, 0x7B, |
| 0x31, 0x3F, 0x63, 0x6D, 0x52, 0x5E, 0x00, 0x74, 0x7C, 0x41, |
| 0x4F, 0x10, 0x20, 0x62, 0x6E, 0x30, 0x73, 0x7D, 0x51, 0x5F, |
| 0x40, 0x72, 0x7E, 0x61, 0x6F, 0x50, 0x71, 0x7F, 0x60, 0x70, |
| ] |
