VideoFrame

Remarks

One allocation, not one per plane. The planes live end to end in a single array, which is what lets the whole frame reach the GPU as one memcpy into a staging buffer and one copy per plane out of it. Three arrays would mean three copies and three things for a pool to keep in step.

Rows are tightly packed. Stride is the plane's width in bytes and nothing else — there is no alignment padding, because the only consumer that would want it is the upload path, and a staging buffer is written by this code rather than by a driver. A codec that decodes into padded rows copies out; that cost is the codec's, and it is what every codec does anyway when it hands a picture over.

A frame is mutable and reused. It is rented from a VideoFramePool, decoded into, shown, and returned. Holding one past Return is a use-after-free that the type cannot prevent and the player is careful about — see VideoPlayer, where the queue owns every frame it has not handed out.

Fields and properties (6)

• public VideoFormat Format

  What the frame holds and how to read it.

• public TimeSpan Timestamp

  When it should be shown, measured from the start of the stream.

• public TimeSpan Duration

  How long it stays on screen, or Zero if nothing said.

• public bool IsKeyFrame

  Whether the stream could be joined at this frame.

• public int Size

  How many bytes of Pixels the picture occupies.

• public ReadOnlySpan<byte> Pixels

  Every plane, end to end.

Methods (7)

• public void Reset(in VideoFormat format)

  Points the frame at a format, allocating if what it has will not do.

• public int Stride(int plane)

  How many bytes one row of a plane takes.

• public int Offset(int plane)

  Where a plane starts within Pixels.

• public Span<byte> Plane(int plane)

  A plane, to write into.

• public Span<byte> Row(int plane, int row)

  One row of a plane, to write into.

• public void CopyFrom(VideoFrame source)

  Copies another frame's pixels and timing into this one.

• public void Clear()

  Fills the frame with black.

Used by (21)

• ColourRoundTripTestsVixen.Video.Tests
• CountingCodecVixen.Video.Tests
• IVideoCodecVixen.Video
• IVideoStreamDecoderVixen.Video
• MatroskaAudioTestsVixen.Video.Tests
• OpusAudioTrackTestsVixen.Video.Codecs.Tests
• StarvedDecoderVixen.Video.Tests
• StepDecoderVixen.Video.Tests
• UncompressedVideoCodecVixen.Video
• VideoColourConversionVixen.Video
• VideoColourConversionTestsVixen.Video.Tests
• VideoConstantsTestsVixen.Video.Rendering.Tests
• VideoFramePoolVixen.Video
• VideoFrameTestsVixen.Video.Tests
• VideoPlayerVixen.Video
• VideoPlayerTestsVixen.Video.Tests
• VideoRendererTestsVixen.Video.Rendering.Tests
• VideoTextureVixen.Video
• VideoTextureTestsVixen.Video.Tests
• WebMVideoStreamDecoderVixen.Video
• WebMVideoStreamDecoderTestsVixen.Video.Tests