ffmpeg colorkey_options中的black對應的十六進制

 

 

libavfilter/vf_colorkey.c

typedef struct ColorkeyContext {
    const AVClass *class;

    /* color offsets rgba */
    int co[4];

    uint8_t colorkey_rgba[4];
    float similarity;
    float blend;
} ColorkeyContext;



#define OFFSET(x) offsetof(ColorkeyContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

static const AVOption colorkey_options[] = {
    { "color", "set the colorkey key color", OFFSET(colorkey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
    { "similarity", "set the colorkey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
    { "blend", "set the colorkey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
    { NULL }
};

AVFILTER_DEFINE_CLASS(colorkey);

AVFilter ff_vf_colorkey = {
    .name          = "colorkey",
    .description   = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on RGB colors."),
    .priv_size     = sizeof(ColorkeyContext),
    .priv_class    = &colorkey_class,
    .query_formats = query_formats,
    .inputs        = colorkey_inputs,
    .outputs       = colorkey_outputs,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
};

 

 

libavutil/parseutils.c

typedef struct ColorEntry {
    const char *name;            ///< a string representing the name of the color
    uint8_t     rgb_color[3];    ///< RGB values for the color
} ColorEntry;

static const ColorEntry color_table[] = {
    { "AliceBlue",            { 0xF0, 0xF8, 0xFF } },
    { "AntiqueWhite",         { 0xFA, 0xEB, 0xD7 } },
    { "Aqua",                 { 0x00, 0xFF, 0xFF } },
    { "Aquamarine",           { 0x7F, 0xFF, 0xD4 } },
    { "Azure",                { 0xF0, 0xFF, 0xFF } },
    { "Beige",                { 0xF5, 0xF5, 0xDC } },
    { "Bisque",               { 0xFF, 0xE4, 0xC4 } },
    { "Black",                { 0x00, 0x00, 0x00 } },
    { "BlanchedAlmond",       { 0xFF, 0xEB, 0xCD } },
    { "Blue",                 { 0x00, 0x00, 0xFF } },
    { "BlueViolet",           { 0x8A, 0x2B, 0xE2 } },
    { "Brown",                { 0xA5, 0x2A, 0x2A } },
    { "BurlyWood",            { 0xDE, 0xB8, 0x87 } },
    { "CadetBlue",            { 0x5F, 0x9E, 0xA0 } },
    { "Chartreuse",           { 0x7F, 0xFF, 0x00 } },
    { "Chocolate",            { 0xD2, 0x69, 0x1E } },
    { "Coral",                { 0xFF, 0x7F, 0x50 } },
    { "CornflowerBlue",       { 0x64, 0x95, 0xED } },
    { "Cornsilk",             { 0xFF, 0xF8, 0xDC } },
    { "Crimson",              { 0xDC, 0x14, 0x3C } },
    { "Cyan",                 { 0x00, 0xFF, 0xFF } },
    { "DarkBlue",             { 0x00, 0x00, 0x8B } },
    { "DarkCyan",             { 0x00, 0x8B, 0x8B } },
    { "DarkGoldenRod",        { 0xB8, 0x86, 0x0B } },
    { "DarkGray",             { 0xA9, 0xA9, 0xA9 } },
    { "DarkGreen",            { 0x00, 0x64, 0x00 } },
    { "DarkKhaki",            { 0xBD, 0xB7, 0x6B } },
    { "DarkMagenta",          { 0x8B, 0x00, 0x8B } },
    { "DarkOliveGreen",       { 0x55, 0x6B, 0x2F } },
    { "Darkorange",           { 0xFF, 0x8C, 0x00 } },
    { "DarkOrchid",           { 0x99, 0x32, 0xCC } },
    { "DarkRed",              { 0x8B, 0x00, 0x00 } },
    { "DarkSalmon",           { 0xE9, 0x96, 0x7A } },
    { "DarkSeaGreen",         { 0x8F, 0xBC, 0x8F } },
    { "DarkSlateBlue",        { 0x48, 0x3D, 0x8B } },
    { "DarkSlateGray",        { 0x2F, 0x4F, 0x4F } },
    { "DarkTurquoise",        { 0x00, 0xCE, 0xD1 } },
    { "DarkViolet",           { 0x94, 0x00, 0xD3 } },
    { "DeepPink",             { 0xFF, 0x14, 0x93 } },
    { "DeepSkyBlue",          { 0x00, 0xBF, 0xFF } },
    { "DimGray",              { 0x69, 0x69, 0x69 } },
    { "DodgerBlue",           { 0x1E, 0x90, 0xFF } },
    { "FireBrick",            { 0xB2, 0x22, 0x22 } },
    { "FloralWhite",          { 0xFF, 0xFA, 0xF0 } },
    { "ForestGreen",          { 0x22, 0x8B, 0x22 } },
    { "Fuchsia",              { 0xFF, 0x00, 0xFF } },
    { "Gainsboro",            { 0xDC, 0xDC, 0xDC } },
    { "GhostWhite",           { 0xF8, 0xF8, 0xFF } },
    { "Gold",                 { 0xFF, 0xD7, 0x00 } },
    { "GoldenRod",            { 0xDA, 0xA5, 0x20 } },
    { "Gray",                 { 0x80, 0x80, 0x80 } },
    { "Green",                { 0x00, 0x80, 0x00 } },
    { "GreenYellow",          { 0xAD, 0xFF, 0x2F } },
    { "HoneyDew",             { 0xF0, 0xFF, 0xF0 } },
    { "HotPink",              { 0xFF, 0x69, 0xB4 } },
    { "IndianRed",            { 0xCD, 0x5C, 0x5C } },
    { "Indigo",               { 0x4B, 0x00, 0x82 } },
    { "Ivory",                { 0xFF, 0xFF, 0xF0 } },
    { "Khaki",                { 0xF0, 0xE6, 0x8C } },
    { "Lavender",             { 0xE6, 0xE6, 0xFA } },
    { "LavenderBlush",        { 0xFF, 0xF0, 0xF5 } },
    { "LawnGreen",            { 0x7C, 0xFC, 0x00 } },
    { "LemonChiffon",         { 0xFF, 0xFA, 0xCD } },
    { "LightBlue",            { 0xAD, 0xD8, 0xE6 } },
    { "LightCoral",           { 0xF0, 0x80, 0x80 } },
    { "LightCyan",            { 0xE0, 0xFF, 0xFF } },
    { "LightGoldenRodYellow", { 0xFA, 0xFA, 0xD2 } },
    { "LightGreen",           { 0x90, 0xEE, 0x90 } },
    { "LightGrey",            { 0xD3, 0xD3, 0xD3 } },
    { "LightPink",            { 0xFF, 0xB6, 0xC1 } },
    { "LightSalmon",          { 0xFF, 0xA0, 0x7A } },
    { "LightSeaGreen",        { 0x20, 0xB2, 0xAA } },
    { "LightSkyBlue",         { 0x87, 0xCE, 0xFA } },
    { "LightSlateGray",       { 0x77, 0x88, 0x99 } },
    { "LightSteelBlue",       { 0xB0, 0xC4, 0xDE } },
    { "LightYellow",          { 0xFF, 0xFF, 0xE0 } },
    { "Lime",                 { 0x00, 0xFF, 0x00 } },
    { "LimeGreen",            { 0x32, 0xCD, 0x32 } },
    { "Linen",                { 0xFA, 0xF0, 0xE6 } },
    { "Magenta",              { 0xFF, 0x00, 0xFF } },
    { "Maroon",               { 0x80, 0x00, 0x00 } },
    { "MediumAquaMarine",     { 0x66, 0xCD, 0xAA } },
    { "MediumBlue",           { 0x00, 0x00, 0xCD } },
    { "MediumOrchid",         { 0xBA, 0x55, 0xD3 } },
    { "MediumPurple",         { 0x93, 0x70, 0xD8 } },
    { "MediumSeaGreen",       { 0x3C, 0xB3, 0x71 } },
    { "MediumSlateBlue",      { 0x7B, 0x68, 0xEE } },
    { "MediumSpringGreen",    { 0x00, 0xFA, 0x9A } },
    { "MediumTurquoise",      { 0x48, 0xD1, 0xCC } },
    { "MediumVioletRed",      { 0xC7, 0x15, 0x85 } },
    { "MidnightBlue",         { 0x19, 0x19, 0x70 } },
    { "MintCream",            { 0xF5, 0xFF, 0xFA } },
    { "MistyRose",            { 0xFF, 0xE4, 0xE1 } },
    { "Moccasin",             { 0xFF, 0xE4, 0xB5 } },
    { "NavajoWhite",          { 0xFF, 0xDE, 0xAD } },
    { "Navy",                 { 0x00, 0x00, 0x80 } },
    { "OldLace",              { 0xFD, 0xF5, 0xE6 } },
    { "Olive",                { 0x80, 0x80, 0x00 } },
    { "OliveDrab",            { 0x6B, 0x8E, 0x23 } },
    { "Orange",               { 0xFF, 0xA5, 0x00 } },
    { "OrangeRed",            { 0xFF, 0x45, 0x00 } },
    { "Orchid",               { 0xDA, 0x70, 0xD6 } },
    { "PaleGoldenRod",        { 0xEE, 0xE8, 0xAA } },
    { "PaleGreen",            { 0x98, 0xFB, 0x98 } },
    { "PaleTurquoise",        { 0xAF, 0xEE, 0xEE } },
    { "PaleVioletRed",        { 0xD8, 0x70, 0x93 } },
    { "PapayaWhip",           { 0xFF, 0xEF, 0xD5 } },
    { "PeachPuff",            { 0xFF, 0xDA, 0xB9 } },
    { "Peru",                 { 0xCD, 0x85, 0x3F } },
    { "Pink",                 { 0xFF, 0xC0, 0xCB } },
    { "Plum",                 { 0xDD, 0xA0, 0xDD } },
    { "PowderBlue",           { 0xB0, 0xE0, 0xE6 } },
    { "Purple",               { 0x80, 0x00, 0x80 } },
    { "Red",                  { 0xFF, 0x00, 0x00 } },
    { "RosyBrown",            { 0xBC, 0x8F, 0x8F } },
    { "RoyalBlue",            { 0x41, 0x69, 0xE1 } },
    { "SaddleBrown",          { 0x8B, 0x45, 0x13 } },
    { "Salmon",               { 0xFA, 0x80, 0x72 } },
    { "SandyBrown",           { 0xF4, 0xA4, 0x60 } },
    { "SeaGreen",             { 0x2E, 0x8B, 0x57 } },
    { "SeaShell",             { 0xFF, 0xF5, 0xEE } },
    { "Sienna",               { 0xA0, 0x52, 0x2D } },
    { "Silver",               { 0xC0, 0xC0, 0xC0 } },
    { "SkyBlue",              { 0x87, 0xCE, 0xEB } },
    { "SlateBlue",            { 0x6A, 0x5A, 0xCD } },
    { "SlateGray",            { 0x70, 0x80, 0x90 } },
    { "Snow",                 { 0xFF, 0xFA, 0xFA } },
    { "SpringGreen",          { 0x00, 0xFF, 0x7F } },
    { "SteelBlue",            { 0x46, 0x82, 0xB4 } },
    { "Tan",                  { 0xD2, 0xB4, 0x8C } },
    { "Teal",                 { 0x00, 0x80, 0x80 } },
    { "Thistle",              { 0xD8, 0xBF, 0xD8 } },
    { "Tomato",               { 0xFF, 0x63, 0x47 } },
    { "Turquoise",            { 0x40, 0xE0, 0xD0 } },
    { "Violet",               { 0xEE, 0x82, 0xEE } },
    { "Wheat",                { 0xF5, 0xDE, 0xB3 } },
    { "White",                { 0xFF, 0xFF, 0xFF } },
    { "WhiteSmoke",           { 0xF5, 0xF5, 0xF5 } },
    { "Yellow",               { 0xFF, 0xFF, 0x00 } },
    { "YellowGreen",          { 0x9A, 0xCD, 0x32 } },
};

 

 

其中AVOption在libavutil/opt.h定義

enum AVOptionType{
    AV_OPT_TYPE_FLAGS,
    AV_OPT_TYPE_INT,
    AV_OPT_TYPE_INT64,
    AV_OPT_TYPE_DOUBLE,
    AV_OPT_TYPE_FLOAT,
    AV_OPT_TYPE_STRING,
    AV_OPT_TYPE_RATIONAL,
    AV_OPT_TYPE_BINARY,  ///< offset must point to a pointer immediately followed by an int for the length
    AV_OPT_TYPE_DICT,
    AV_OPT_TYPE_CONST = 128,
    AV_OPT_TYPE_IMAGE_SIZE = MKBETAG('S','I','Z','E'), ///< offset must point to two consecutive integers
    AV_OPT_TYPE_PIXEL_FMT  = MKBETAG('P','F','M','T'),
    AV_OPT_TYPE_SAMPLE_FMT = MKBETAG('S','F','M','T'),
    AV_OPT_TYPE_VIDEO_RATE = MKBETAG('V','R','A','T'), ///< offset must point to AVRational
    AV_OPT_TYPE_DURATION   = MKBETAG('D','U','R',' '),
    AV_OPT_TYPE_COLOR      = MKBETAG('C','O','L','R'),
    AV_OPT_TYPE_CHANNEL_LAYOUT = MKBETAG('C','H','L','A'),
    AV_OPT_TYPE_BOOL           = MKBETAG('B','O','O','L'),
};

/**
 * AVOption
 */
typedef struct AVOption {
    const char *name;

    /**
     * short English help text
     * @todo What about other languages?
     */
    const char *help;

    /**
     * The offset relative to the context structure where the option
     * value is stored. It should be 0 for named constants.
     */
    int offset;
    enum AVOptionType type;

    /**
     * the default value for scalar options
     */
    union {
        int64_t i64;
        double dbl;
        const char *str;
        /* TODO those are unused now */
        AVRational q;
    } default_val;
    double min;                 ///< minimum valid value for the option
    double max;                 ///< maximum valid value for the option

    int flags;
#define AV_OPT_FLAG_ENCODING_PARAM  1   ///< a generic parameter which can be set by the user for muxing or encoding
#define AV_OPT_FLAG_DECODING_PARAM  2   ///< a generic parameter which can be set by the user for demuxing or decoding
#if FF_API_OPT_TYPE_METADATA
#define AV_OPT_FLAG_METADATA        4   ///< some data extracted or inserted into the file like title, comment, ...
#endif
#define AV_OPT_FLAG_AUDIO_PARAM     8
#define AV_OPT_FLAG_VIDEO_PARAM     16
#define AV_OPT_FLAG_SUBTITLE_PARAM  32
/**
 * The option is inteded for exporting values to the caller.
 */
#define AV_OPT_FLAG_EXPORT          64
/**
 * The option may not be set through the AVOptions API, only read.
 * This flag only makes sense when AV_OPT_FLAG_EXPORT is also set.
 */
#define AV_OPT_FLAG_READONLY        128
#define AV_OPT_FLAG_FILTERING_PARAM (1<<16) ///< a generic parameter which can be set by the user for filtering
//FIXME think about enc-audio, ... style flags

    /**
     * The logical unit to which the option belongs. Non-constant
     * options and corresponding named constants share the same
     * unit. May be NULL.
     */
    const char *unit;
} AVOption;

因此經過名稱能夠找到對應的十六進制數字。