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LibVideo: Add VideoFrame class for decoded video frames

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The class is virtual and has one subclass, SubsampledYUVFrame, which
is used by the VP9 decoder to return a single frame. The
output_to_bitmap(Bitmap&) function can be used to set pixels on an
existing bitmap of the correct size to the RGB values that
should be displayed. The to_bitmap() function will allocate a new bitmap
and fill it using output_to_bitmap.

This new class also implements bilinear scaling of the subsampled U and
V planes so that subsampled videos' colors will appear smoother.
This commit is contained in:
Zaggy1024 2022-10-08 18:36:57 -05:00 • committed by Andreas Kling
parent 30189186e9
commit 074f771b59
8 changed files with 244 additions and 70 deletions
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67
Userland/Libraries/LibVideo/VP9/Decoder.cpp
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@ -19,7 +19,7 @@ Decoder::Decoder()
{
}
DecoderErrorOr<void> Decoder::decode(Span<const u8> chunk_data)
DecoderErrorOr<void> Decoder::receive_sample(Span<u8 const> chunk_data)
{
auto superframe_sizes = m_parser->parse_superframe_sizes(chunk_data);
@ -42,9 +42,9 @@ DecoderErrorOr<void> Decoder::decode(Span<const u8> chunk_data)
return {};
}
DecoderErrorOr<void> Decoder::decode(ByteBuffer const& chunk_data)
DecoderErrorOr<void> Decoder::receive_sample(ByteBuffer const& chunk_data)
{
return decode(chunk_data.span());
return receive_sample(chunk_data.span());
}
void Decoder::dump_frame_info()
@ -57,7 +57,7 @@ inline size_t index_from_row_and_column(u32 row, u32 column, u32 stride)
return row * stride + column;
}
DecoderErrorOr<void> Decoder::decode_frame(Span<const u8> frame_data)
DecoderErrorOr<void> Decoder::decode_frame(Span<u8 const> frame_data)
{
// 1. The syntax elements for the coded frame are extracted as specified in sections 6 and 7. The syntax
// tables include function calls indicating when the block decode processes should be triggered.
@ -130,27 +130,7 @@ Vector<u16>& Decoder::get_output_buffer(u8 plane)
return m_buffers.output[plane];
}
Vector<u16> const& Decoder::get_output_buffer_for_plane(u8 plane) const
{
return m_buffers.output[plane];
}
Gfx::Size<size_t> Decoder::get_y_plane_size()
{
return m_parser->get_decoded_size_for_plane(0);
}
bool Decoder::get_uv_subsampling_y()
{
return m_parser->m_subsampling_y;
}
bool Decoder::get_uv_subsampling_x()
{
return m_parser->m_subsampling_x;
}
CodingIndependentCodePoints Decoder::get_cicp_color_space()
inline CodingIndependentCodePoints Decoder::get_cicp_color_space()
{
ColorPrimaries color_primaries;
TransferCharacteristics transfer_characteristics;
@ -209,9 +189,42 @@ CodingIndependentCodePoints Decoder::get_cicp_color_space()
return { color_primaries, transfer_characteristics, matrix_coefficients, m_parser->m_color_range };
}
u8 Decoder::get_bit_depth()
DecoderErrorOr<NonnullOwnPtr<VideoFrame>> Decoder::get_decoded_frame()
{
return m_parser->m_bit_depth;
size_t decoded_y_width = m_parser->m_mi_cols * 8;
Gfx::Size<size_t> output_y_size = {
m_parser->m_frame_width,
m_parser->m_frame_height,
};
auto decoded_uv_width = decoded_y_width >> m_parser->m_subsampling_x;
Gfx::Size<size_t> output_uv_size = {
output_y_size.width() >> m_parser->m_subsampling_x,
output_y_size.height() >> m_parser->m_subsampling_y,
};
Array<FixedArray<u16>, 3> output_buffers = {
DECODER_TRY_ALLOC(FixedArray<u16>::try_create(output_y_size.width() * output_y_size.height())),
DECODER_TRY_ALLOC(FixedArray<u16>::try_create(output_uv_size.width() * output_uv_size.height())),
DECODER_TRY_ALLOC(FixedArray<u16>::try_create(output_uv_size.width() * output_uv_size.height())),
};
for (u8 plane = 0; plane < 3; plane++) {
auto& buffer = output_buffers[plane];
auto decoded_width = plane == 0 ? decoded_y_width : decoded_uv_width;
auto output_size = plane == 0 ? output_y_size : output_uv_size;
auto const& decoded_buffer = get_output_buffer(plane);
for (u32 row = 0; row < output_size.height(); row++) {
memcpy(
buffer.data() + row * output_size.width(),
decoded_buffer.data() + row * decoded_width,
output_size.width() * sizeof(*buffer.data()));
}
}
return DECODER_TRY_ALLOC(adopt_nonnull_own_or_enomem(new (nothrow) SubsampledYUVFrame(
{ output_y_size.width(), output_y_size.height() },
m_parser->m_bit_depth, get_cicp_color_space(),
m_parser->m_subsampling_x, m_parser->m_subsampling_y,
output_buffers[0], output_buffers[1], output_buffers[2])));
}
u8 Decoder::merge_prob(u8 pre_prob, u8 count_0, u8 count_1, u8 count_sat, u8 max_update_factor)