diff options
author | Nico Weber <thakis@chromium.org> | 2023-04-04 09:34:16 -0400 |
---|---|---|
committer | Linus Groh <mail@linusgroh.de> | 2023-04-06 00:16:52 +0100 |
commit | 4bd7090bc5550c1fecf28cc3b3e2a9195098a262 (patch) | |
tree | 338630a3886610cd249c20e070ae05ccc68b4be3 /Userland | |
parent | f21af311c26a30881ddeb14edfc5b253e1a29c45 (diff) | |
download | serenity-4bd7090bc5550c1fecf28cc3b3e2a9195098a262.zip |
LibGfx: Move webp image decoding function up a bit
Pure code move, no changes (except that this allows removing the
explicit prototype for this function, so it removes that).
Diffstat (limited to 'Userland')
-rw-r--r-- | Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp | 133 |
1 files changed, 65 insertions, 68 deletions
diff --git a/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp b/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp index 244d7fcc33..3ca1a04924 100644 --- a/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp +++ b/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp @@ -443,74 +443,6 @@ static ErrorOr<PrefixCodeGroup> decode_webp_chunk_VP8L_prefix_code_group(WebPLoa return group; } - -static ErrorOr<NonnullRefPtr<Bitmap>> decode_webp_chunk_VP8L_image(WebPLoadingContext&, VP8LHeader const& vp8l_header, LittleEndianInputBitStream&); - -// https://developers.google.com/speed/webp/docs/riff_container#simple_file_format_lossless -// https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#7_overall_structure_of_the_format -static ErrorOr<void> decode_webp_chunk_VP8L(WebPLoadingContext& context, Chunk const& vp8l_chunk) -{ - VERIFY(context.first_chunk->type == FourCC("VP8L") || context.first_chunk->type == FourCC("VP8X")); - VERIFY(vp8l_chunk.type == FourCC("VP8L")); - - auto vp8l_header = TRY(decode_webp_chunk_VP8L_header(context, vp8l_chunk)); - - // Check that size in VP8X chunk matches dimensions in VP8L chunk if both are present. - if (context.first_chunk->type == FourCC("VP8X")) { - if (vp8l_header.width != context.vp8x_header.width) - return context.error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different widths"); - if (vp8l_header.height != context.vp8x_header.height) - return context.error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different heights"); - if (vp8l_header.is_alpha_used != context.vp8x_header.has_alpha) - return context.error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different alpha"); - } - - FixedMemoryStream memory_stream { vp8l_chunk.data.slice(5) }; - LittleEndianInputBitStream bit_stream { MaybeOwned<Stream>(memory_stream) }; - - // image-stream = optional-transform spatially-coded-image - - // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#4_transformations - // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#72_structure_of_transforms - - // optional-transform = (%b1 transform optional-transform) / %b0 - while (TRY(bit_stream.read_bits(1))) { - // transform = predictor-tx / color-tx / subtract-green-tx - // transform =/ color-indexing-tx - - enum TransformType { - // predictor-tx = %b00 predictor-image - PREDICTOR_TRANSFORM = 0, - - // color-tx = %b01 color-image - COLOR_TRANSFORM = 1, - - // subtract-green-tx = %b10 - SUBTRACT_GREEN_TRANSFORM = 2, - - // color-indexing-tx = %b11 color-indexing-image - COLOR_INDEXING_TRANSFORM = 3, - }; - - TransformType transform_type = static_cast<TransformType>(TRY(bit_stream.read_bits(2))); - dbgln_if(WEBP_DEBUG, "transform type {}", (int)transform_type); - - switch (transform_type) { - case PREDICTOR_TRANSFORM: - return context.error("WebPImageDecoderPlugin: VP8L PREDICTOR_TRANSFORM handling not yet implemented"); - case COLOR_TRANSFORM: - return context.error("WebPImageDecoderPlugin: VP8L COLOR_TRANSFORM handling not yet implemented"); - case SUBTRACT_GREEN_TRANSFORM: - return context.error("WebPImageDecoderPlugin: VP8L SUBTRACT_GREEN_TRANSFORM handling not yet implemented"); - case COLOR_INDEXING_TRANSFORM: - return context.error("WebPImageDecoderPlugin: VP8L COLOR_INDEXING_TRANSFORM handling not yet implemented"); - } - } - - context.bitmap = TRY(decode_webp_chunk_VP8L_image(context, vp8l_header, bit_stream)); - return {}; -} - static ErrorOr<NonnullRefPtr<Bitmap>> decode_webp_chunk_VP8L_image(WebPLoadingContext& context, VP8LHeader const& vp8l_header, LittleEndianInputBitStream& bit_stream) { // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#623_decoding_entropy-coded_image_data @@ -680,6 +612,71 @@ static ErrorOr<NonnullRefPtr<Bitmap>> decode_webp_chunk_VP8L_image(WebPLoadingCo return bitmap; } +// https://developers.google.com/speed/webp/docs/riff_container#simple_file_format_lossless +// https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#7_overall_structure_of_the_format +static ErrorOr<void> decode_webp_chunk_VP8L(WebPLoadingContext& context, Chunk const& vp8l_chunk) +{ + VERIFY(context.first_chunk->type == FourCC("VP8L") || context.first_chunk->type == FourCC("VP8X")); + VERIFY(vp8l_chunk.type == FourCC("VP8L")); + + auto vp8l_header = TRY(decode_webp_chunk_VP8L_header(context, vp8l_chunk)); + + // Check that size in VP8X chunk matches dimensions in VP8L chunk if both are present. + if (context.first_chunk->type == FourCC("VP8X")) { + if (vp8l_header.width != context.vp8x_header.width) + return context.error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different widths"); + if (vp8l_header.height != context.vp8x_header.height) + return context.error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different heights"); + if (vp8l_header.is_alpha_used != context.vp8x_header.has_alpha) + return context.error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different alpha"); + } + + FixedMemoryStream memory_stream { vp8l_chunk.data.slice(5) }; + LittleEndianInputBitStream bit_stream { MaybeOwned<Stream>(memory_stream) }; + + // image-stream = optional-transform spatially-coded-image + + // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#4_transformations + // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#72_structure_of_transforms + + // optional-transform = (%b1 transform optional-transform) / %b0 + while (TRY(bit_stream.read_bits(1))) { + // transform = predictor-tx / color-tx / subtract-green-tx + // transform =/ color-indexing-tx + + enum TransformType { + // predictor-tx = %b00 predictor-image + PREDICTOR_TRANSFORM = 0, + + // color-tx = %b01 color-image + COLOR_TRANSFORM = 1, + + // subtract-green-tx = %b10 + SUBTRACT_GREEN_TRANSFORM = 2, + + // color-indexing-tx = %b11 color-indexing-image + COLOR_INDEXING_TRANSFORM = 3, + }; + + TransformType transform_type = static_cast<TransformType>(TRY(bit_stream.read_bits(2))); + dbgln_if(WEBP_DEBUG, "transform type {}", (int)transform_type); + + switch (transform_type) { + case PREDICTOR_TRANSFORM: + return context.error("WebPImageDecoderPlugin: VP8L PREDICTOR_TRANSFORM handling not yet implemented"); + case COLOR_TRANSFORM: + return context.error("WebPImageDecoderPlugin: VP8L COLOR_TRANSFORM handling not yet implemented"); + case SUBTRACT_GREEN_TRANSFORM: + return context.error("WebPImageDecoderPlugin: VP8L SUBTRACT_GREEN_TRANSFORM handling not yet implemented"); + case COLOR_INDEXING_TRANSFORM: + return context.error("WebPImageDecoderPlugin: VP8L COLOR_INDEXING_TRANSFORM handling not yet implemented"); + } + } + + context.bitmap = TRY(decode_webp_chunk_VP8L_image(context, vp8l_header, bit_stream)); + return {}; +} + static ErrorOr<VP8XHeader> decode_webp_chunk_VP8X(WebPLoadingContext& context, Chunk const& vp8x_chunk) { VERIFY(vp8x_chunk.type == FourCC("VP8X")); |