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| author | Nico Weber <thakis@chromium.org> | 2023-04-03 19:31:41 -0400 |
|---|---|---|
| committer | Linus Groh <mail@linusgroh.de> | 2023-04-06 00:16:52 +0100 |
| commit | e8f5e699fe0a9eb08a4bf3ced9cf153cc928e8ff (patch) | |
| tree | eb0bacdf85a392a59bca3a84fd14a837d2f4a58b | |
| parent | 8e6911c8f64bcbdb6fc7036a281236b1d626c131 (diff) | |
| download | serenity-e8f5e699fe0a9eb08a4bf3ced9cf153cc928e8ff.zip | |
LibGfx: Read transform type in webp lossless decoder
Doesn't do anything with it yet, so this only makes the
"not yet implemented" message a bit more detailed.
| -rw-r--r-- | Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp b/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp index 9193e852c1..bd8fb9864a 100644 --- a/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp +++ b/Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp @@ -463,8 +463,38 @@ static ErrorOr<void> decode_webp_chunk_VP8L(WebPLoadingContext& context, Chunk c // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#72_structure_of_transforms // optional-transform = (%b1 transform optional-transform) / %b0 - if (TRY(bit_stream.read_bits(1))) - return context.error("WebPImageDecoderPlugin: VP8L transform handling not yet implemented"); + 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"); + } + } // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#623_decoding_entropy-coded_image_data // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#523_color_cache_coding |