void add_output(const ImageFormat &format, OutputAlphaFormat alpha_format);
// Adds an YCbCr output. Note that you can only have at most two Y'CbCr
- // outputs, and they must have the same <ycbcr_format>.
+ // outputs, and they must have the same <ycbcr_format> and <type>.
// (This limitation may be lifted in the future, to allow e.g. simultaneous
// 8- and 10-bit output. Currently, multiple Y'CbCr outputs are only
// useful in some very limited circumstances, like if one texture goes
//
// Only 4:4:4 output is supported due to fragment shader limitations,
// so chroma_subsampling_x and chroma_subsampling_y must both be 1.
+ // <type> should match the data type of the FBO you are rendering to,
+ // so that if you use 16-bit output (GL_UNSIGNED_SHORT), you will get
+ // 8-, 10- or 12-bit output correctly as determined by <ycbcr_format.num_levels>.
+ // Using e.g. ycbcr_format.num_levels == 1024 with GL_UNSIGNED_BYTE is
+ // nonsensical and invokes undefined behavior.
//
// If you have both RGBA and Y'CbCr output(s), the RGBA output will come
// in the last draw buffer. Also, <format> and <alpha_format> must be
// identical between the two.
void add_ycbcr_output(const ImageFormat &format, OutputAlphaFormat alpha_format,
const YCbCrFormat &ycbcr_format,
- YCbCrOutputSplitting output_splitting = YCBCR_OUTPUT_INTERLEAVED);
+ YCbCrOutputSplitting output_splitting = YCBCR_OUTPUT_INTERLEAVED,
+ GLenum output_type = GL_UNSIGNED_BYTE);
// Change Y'CbCr output format. (This can be done also after finalize()).
// Note that you are not allowed to change subsampling parameters;
// Set number of output bits, to scale the dither.
// 8 is the right value for most outputs.
+ //
+ // Special note for 10- and 12-bit Y'CbCr packed into GL_UNSIGNED_SHORT:
+ // This is relative to the actual output, not the logical one, so you should
+ // specify 16 here, not 10 or 12.
+ //
// The default, 0, is a special value that means no dither.
void set_dither_bits(unsigned num_bits)
{
bool output_color_rgba;
int num_output_color_ycbcr; // Max 2.
YCbCrFormat output_ycbcr_format; // If num_output_color_ycbcr is > 0.
+ GLenum output_ycbcr_type; // If num_output_color_ycbcr is > 0.
YCbCrOutputSplitting output_ycbcr_splitting[2]; // If num_output_color_ycbcr is > N.
std::vector<Node *> nodes;