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LibGfx/WebP: Make decode_webp_chunk_VP8L() return a Bitmap

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...instead of setting it on the context. We'll need this to decode
animation frames.
This commit is contained in:
Nico Weber 2023-05-06 06:00:49 -04:00 • committed by Andreas Kling
parent 1334bac548
commit 0b70ecb7e6
1 changed files with 16 additions and 16 deletions
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32
Userland/Libraries/LibGfx/ImageFormats/WebPLoader.cpp
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@ -1212,23 +1212,13 @@ ErrorOr<NonnullRefPtr<Bitmap>> ColorIndexingTransform::transform(NonnullRefPtr<B
// https://developers.google.com/speed/webp/docs/riff_container#simple_file_format_lossless // 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 // 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) static ErrorOr<NonnullRefPtr<Bitmap>> decode_webp_chunk_VP8L(WebPLoadingContext& context, Chunk const& vp8l_chunk)
{ {
VERIFY(context.first_chunk->type == FourCC("VP8L") || context.first_chunk->type == FourCC("VP8X")); VERIFY(context.first_chunk->type == FourCC("VP8L") || context.first_chunk->type == FourCC("VP8X"));
VERIFY(vp8l_chunk.type == FourCC("VP8L")); VERIFY(vp8l_chunk.type == FourCC("VP8L"));
auto vp8l_header = TRY(decode_webp_chunk_VP8L_header(context, vp8l_chunk)); 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) }; FixedMemoryStream memory_stream { vp8l_chunk.data.slice(5) };
LittleEndianInputBitStream bit_stream { MaybeOwned<Stream>(memory_stream) }; LittleEndianInputBitStream bit_stream { MaybeOwned<Stream>(memory_stream) };
@ -1237,7 +1227,7 @@ static ErrorOr<void> decode_webp_chunk_VP8L(WebPLoadingContext& context, Chunk c
// https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#4_transformations // 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 // https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#72_structure_of_transforms
auto stored_size = context.size.value(); auto stored_size = IntSize { vp8l_header.width, vp8l_header.height };
// optional-transform = (%b1 transform optional-transform) / %b0 // optional-transform = (%b1 transform optional-transform) / %b0
// "Each transform is allowed to be used only once." // "Each transform is allowed to be used only once."
@ -1290,14 +1280,14 @@ static ErrorOr<void> decode_webp_chunk_VP8L(WebPLoadingContext& context, Chunk c
} }
auto format = vp8l_header.is_alpha_used ? BitmapFormat::BGRA8888 : BitmapFormat::BGRx8888; auto format = vp8l_header.is_alpha_used ? BitmapFormat::BGRA8888 : BitmapFormat::BGRx8888;
context.bitmap = TRY(decode_webp_chunk_VP8L_image(context, ImageKind::SpatiallyCoded, format, stored_size, bit_stream)); auto bitmap = TRY(decode_webp_chunk_VP8L_image(context, ImageKind::SpatiallyCoded, format, stored_size, bit_stream));
// Transforms have to be applied in the reverse order they appear in in the file. // Transforms have to be applied in the reverse order they appear in in the file.
// (As far as I can tell, this isn't mentioned in the spec.) // (As far as I can tell, this isn't mentioned in the spec.)
for (auto const& transform : transforms.in_reverse()) for (auto const& transform : transforms.in_reverse())
context.bitmap = TRY(transform->transform(context.bitmap.release_nonnull())); bitmap = TRY(transform->transform(bitmap));
return {}; return bitmap;
} }
static ErrorOr<VP8XHeader> decode_webp_chunk_VP8X(WebPLoadingContext& context, Chunk const& vp8x_chunk) static ErrorOr<VP8XHeader> decode_webp_chunk_VP8X(WebPLoadingContext& context, Chunk const& vp8x_chunk)
@ -1668,7 +1658,17 @@ ErrorOr<ImageFrameDescriptor> WebPImageDecoderPlugin::frame(size_t index)
if (m_context->image_data.image_data_chunk.has_value() && m_context->image_data.image_data_chunk->type == FourCC("VP8L")) { if (m_context->image_data.image_data_chunk.has_value() && m_context->image_data.image_data_chunk->type == FourCC("VP8L")) {
if (m_context->state < WebPLoadingContext::State::BitmapDecoded) { if (m_context->state < WebPLoadingContext::State::BitmapDecoded) {
TRY(decode_webp_chunk_VP8L(*m_context, m_context->image_data.image_data_chunk.value())); auto bitmap = TRY(decode_webp_chunk_VP8L(*m_context, m_context->image_data.image_data_chunk.value()));
// Check that size in VP8X chunk matches dimensions in VP8L chunk if both are present.
if (m_context->first_chunk->type == FourCC("VP8X")) {
if (static_cast<u32>(bitmap->width()) != m_context->vp8x_header.width)
return m_context->error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different widths");
if (static_cast<u32>(bitmap->height()) != m_context->vp8x_header.height)
return m_context->error("WebPImageDecoderPlugin: VP8X and VP8L chunks store different heights");
}
m_context->bitmap = move(bitmap);
m_context->state = WebPLoadingContext::State::BitmapDecoded; m_context->state = WebPLoadingContext::State::BitmapDecoded;
} }