Struct mozjpeg_sys::jpeg_decompress_struct [−] [src]

#[repr(C)]

pub struct jpeg_decompress_struct {
    pub common: jpeg_common_struct,
    pub src: *mut jpeg_source_mgr,
    pub image_width: JDIMENSION,
    pub image_height: JDIMENSION,
    pub num_components: c_int,
    pub jpeg_color_space: J_COLOR_SPACE,
    pub out_color_space: J_COLOR_SPACE,
    pub scale_num: c_uint,
    pub scale_denom: c_uint,
    pub output_gamma: f64,
    pub buffered_image: boolean,
    pub raw_data_out: boolean,
    pub dct_method: J_DCT_METHOD,
    pub do_fancy_upsampling: boolean,
    pub do_block_smoothing: boolean,
    pub quantize_colors: boolean,
    pub dither_mode: J_DITHER_MODE,
    pub two_pass_quantize: boolean,
    pub desired_number_of_colors: c_int,
    pub enable_1pass_quant: boolean,
    pub enable_external_quant: boolean,
    pub enable_2pass_quant: boolean,
    pub output_width: JDIMENSION,
    pub output_height: JDIMENSION,
    pub out_color_components: c_int,
    pub output_components: c_int,
    pub rec_outbuf_height: c_int,
    pub actual_number_of_colors: c_int,
    pub colormap: JSAMPARRAY_MUT,
    pub output_scanline: JDIMENSION,
    pub input_scan_number: c_int,
    pub input_iMCU_row: JDIMENSION,
    pub output_scan_number: c_int,
    pub output_iMCU_row: JDIMENSION,
    pub coef_bits: *mut c_void,
    pub quant_tbl_ptrs: [*mut JQUANT_TBL; 4],
    pub comp_info: *mut jpeg_component_info,
    pub marker_list: *mut jpeg_marker_struct,
    pub max_h_samp_factor: c_int,
    pub max_v_samp_factor: c_int,
    // some fields omitted
}

Fields

Basic description of image --- filled in by jpeg_read_header()

Decompression processing parameters --- these fields must be set before calling jpeg_start_decompress(). Note that jpeg_read_header() initializes them to default values.

image gamma wanted in output

TRUE=downsampled data wanted

Description of actual output image that will be returned to application. These fields are computed by jpeg_start_decompress(). You can also use jpeg_calc_output_dimensions() to determine these values in advance of calling jpeg_start_decompress().

min recommended height of scanline buffer If the buffer passed to jpeg_read_scanlines() is less than this many rows high, space and time will be wasted due to unnecessary data copying. Usually rec_outbuf_height will be 1 or 2, at most 4.

Row index of next scanline to be read from jpeg_read_scanlines(). Application may use this to control its processing loop, e.g., "while (output_scanline < output_height)".

Current input scan number and number of iMCU rows completed in scan. These indicate the progress of the decompressor input side.

Current progression status. coef_bits[c][i] indicates the precision with which component c's DCT coefficient i (in zigzag order) is known. It is -1 when no data has yet been received, otherwise it is the point transform (shift) value for the most recent scan of the coefficient (thus, 0 at completion of the progression). This pointer is NULL when reading a non-progressive file.

Internal JPEG parameters --- the application usually need not look at these fields. Note that the decompressor output side may not use any parameters that can change between scans.

These fields are computed during decompression startup