/* * pixel format descriptor * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVUTIL_PIXDESC_H #define AVUTIL_PIXDESC_H #include <inttypes.h> #include "attributes.h" #include "pixfmt.h" #include "version.h" typedef struct AVComponentDescriptor { /** * Which of the 4 planes contains the component. */ int plane; /** * Number of elements between 2 horizontally consecutive pixels. * Elements are bits for bitstream formats, bytes otherwise. */ int step; /** * Number of elements before the component of the first pixel. * Elements are bits for bitstream formats, bytes otherwise. */ int offset; /** * Number of least significant bits that must be shifted away * to get the value. */ int shift; /** * Number of bits in the component. */ int depth; #if FF_API_PLUS1_MINUS1 /** deprecated, use step instead */ attribute_deprecated int step_minus1; /** deprecated, use depth instead */ attribute_deprecated int depth_minus1; /** deprecated, use offset instead */ attribute_deprecated int offset_plus1; #endif } AVComponentDescriptor; /** * Descriptor that unambiguously describes how the bits of a pixel are * stored in the up to 4 data planes of an image. It also stores the * subsampling factors and number of components. * * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV * and all the YUV variants) AVPixFmtDescriptor just stores how values * are stored not what these values represent. */ typedef struct AVPixFmtDescriptor { const char *name; uint8_t nb_components; ///< The number of components each pixel has, (1-4) /** * Amount to shift the luma width right to find the chroma width. * For YV12 this is 1 for example. * chroma_width = AV_CEIL_RSHIFT(luma_width, log2_chroma_w) * The note above is needed to ensure rounding up. * This value only refers to the chroma components. */ uint8_t log2_chroma_w; /** * Amount to shift the luma height right to find the chroma height. * For YV12 this is 1 for example. * chroma_height= AV_CEIL_RSHIFT(luma_height, log2_chroma_h) * The note above is needed to ensure rounding up. * This value only refers to the chroma components. */ uint8_t log2_chroma_h; /** * Combination of AV_PIX_FMT_FLAG_... flags. */ uint64_t flags; /** * Parameters that describe how pixels are packed. * If the format has 1 or 2 components, then luma is 0. * If the format has 3 or 4 components: * if the RGB flag is set then 0 is red, 1 is green and 2 is blue; * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V. * * If present, the Alpha channel is always the last component. */ AVComponentDescriptor comp[4]; /** * Alternative comma-separated names. */ const char *alias; } AVPixFmtDescriptor; /** * Pixel format is big-endian. */ #define AV_PIX_FMT_FLAG_BE (1 << 0) /** * Pixel format has a palette in data[1], values are indexes in this palette. */ #define AV_PIX_FMT_FLAG_PAL (1 << 1) /** * All values of a component are bit-wise packed end to end. */ #define AV_PIX_FMT_FLAG_BITSTREAM (1 << 2) /** * Pixel format is an HW accelerated format. */ #define AV_PIX_FMT_FLAG_HWACCEL (1 << 3) /** * At least one pixel component is not in the first data plane. */ #define AV_PIX_FMT_FLAG_PLANAR (1 << 4) /** * The pixel format contains RGB-like data (as opposed to YUV/grayscale). */ #define AV_PIX_FMT_FLAG_RGB (1 << 5) /** * The pixel format is "pseudo-paletted". This means that it contains a * fixed palette in the 2nd plane but the palette is fixed/constant for each * PIX_FMT. This allows interpreting the data as if it was PAL8, which can * in some cases be simpler. Or the data can be interpreted purely based on * the pixel format without using the palette. * An example of a pseudo-paletted format is AV_PIX_FMT_GRAY8 */ #define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6) /** * The pixel format has an alpha channel. This is set on all formats that * support alpha in some way. The exception is AV_PIX_FMT_PAL8, which can * carry alpha as part of the palette. Details are explained in the * AVPixelFormat enum, and are also encoded in the corresponding * AVPixFmtDescriptor. * * The alpha is always straight, never pre-multiplied. * * If a codec or a filter does not support alpha, it should set all alpha to * opaque, or use the equivalent pixel formats without alpha component, e.g. * AV_PIX_FMT_RGB0 (or AV_PIX_FMT_RGB24 etc.) instead of AV_PIX_FMT_RGBA. */ #define AV_PIX_FMT_FLAG_ALPHA (1 << 7) /** * The pixel format is following a Bayer pattern */ #define AV_PIX_FMT_FLAG_BAYER (1 << 8) /** * The pixel format contains IEEE-754 floating point values. Precision (double, * single, or half) should be determined by the pixel size (64, 32, or 16 bits). */ #define AV_PIX_FMT_FLAG_FLOAT (1 << 9) /** * Return the number of bits per pixel used by the pixel format * described by pixdesc. Note that this is not the same as the number * of bits per sample. * * The returned number of bits refers to the number of bits actually * used for storing the pixel information, that is padding bits are * not counted. */ int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc); /** * Return the number of bits per pixel for the pixel format * described by pixdesc, including any padding or unused bits. */ int av_get_padded_bits_per_pixel(const AVPixFmtDescriptor *pixdesc); /** * @return a pixel format descriptor for provided pixel format or NULL if * this pixel format is unknown. */ const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt); /** * Iterate over all pixel format descriptors known to libavutil. * * @param prev previous descriptor. NULL to get the first descriptor. * * @return next descriptor or NULL after the last descriptor */ const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev); /** * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc * is not a valid pointer to a pixel format descriptor. */ enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc); /** * Utility function to access log2_chroma_w log2_chroma_h from * the pixel format AVPixFmtDescriptor. * * See av_get_chroma_sub_sample() for a function that asserts a * valid pixel format instead of returning an error code. * Its recommended that you use avcodec_get_chroma_sub_sample unless * you do check the return code! * * @param[in] pix_fmt the pixel format * @param[out] h_shift store log2_chroma_w (horizontal/width shift) * @param[out] v_shift store log2_chroma_h (vertical/height shift) * * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format */ int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift); /** * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a * valid pixel format. */ int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt); /** * @return the name for provided color range or NULL if unknown. */ const char *av_color_range_name(enum AVColorRange range); /** * @return the AVColorRange value for name or an AVError if not found. */ int av_color_range_from_name(const char *name); /** * @return the name for provided color primaries or NULL if unknown. */ const char *av_color_primaries_name(enum AVColorPrimaries primaries); /** * @return the AVColorPrimaries value for name or an AVError if not found. */ int av_color_primaries_from_name(const char *name); /** * @return the name for provided color transfer or NULL if unknown. */ const char *av_color_transfer_name(enum AVColorTransferCharacteristic transfer); /** * @return the AVColorTransferCharacteristic value for name or an AVError if not found. */ int av_color_transfer_from_name(const char *name); /** * @return the name for provided color space or NULL if unknown. */ const char *av_color_space_name(enum AVColorSpace space); /** * @return the AVColorSpace value for name or an AVError if not found. */ int av_color_space_from_name(const char *name); /** * @return the name for provided chroma location or NULL if unknown. */ const char *av_chroma_location_name(enum AVChromaLocation location); /** * @return the AVChromaLocation value for name or an AVError if not found. */ int av_chroma_location_from_name(const char *name); /** * Return the pixel format corresponding to name. * * If there is no pixel format with name name, then looks for a * pixel format with the name corresponding to the native endian * format of name. * For example in a little-endian system, first looks for "gray16", * then for "gray16le". * * Finally if no pixel format has been found, returns AV_PIX_FMT_NONE. */ enum AVPixelFormat av_get_pix_fmt(const char *name); /** * Return the short name for a pixel format, NULL in case pix_fmt is * unknown. * * @see av_get_pix_fmt(), av_get_pix_fmt_string() */ const char *av_get_pix_fmt_name(enum AVPixelFormat pix_fmt); /** * Print in buf the string corresponding to the pixel format with * number pix_fmt, or a header if pix_fmt is negative. * * @param buf the buffer where to write the string * @param buf_size the size of buf * @param pix_fmt the number of the pixel format to print the * corresponding info string, or a negative value to print the * corresponding header. */ char *av_get_pix_fmt_string(char *buf, int buf_size, enum AVPixelFormat pix_fmt); /** * Read a line from an image, and write the values of the * pixel format component c to dst. * * @param data the array containing the pointers to the planes of the image * @param linesize the array containing the linesizes of the image * @param desc the pixel format descriptor for the image * @param x the horizontal coordinate of the first pixel to read * @param y the vertical coordinate of the first pixel to read * @param w the width of the line to read, that is the number of * values to write to dst * @param read_pal_component if not zero and the format is a paletted * format writes the values corresponding to the palette * component c in data[1] to dst, rather than the palette indexes in * data[0]. The behavior is undefined if the format is not paletted. */ void av_read_image_line(uint16_t *dst, const uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w, int read_pal_component); /** * Write the values from src to the pixel format component c of an * image line. * * @param src array containing the values to write * @param data the array containing the pointers to the planes of the * image to write into. It is supposed to be zeroed. * @param linesize the array containing the linesizes of the image * @param desc the pixel format descriptor for the image * @param x the horizontal coordinate of the first pixel to write * @param y the vertical coordinate of the first pixel to write * @param w the width of the line to write, that is the number of * values to write to the image line */ void av_write_image_line(const uint16_t *src, uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w); /** * Utility function to swap the endianness of a pixel format. * * @param[in] pix_fmt the pixel format * * @return pixel format with swapped endianness if it exists, * otherwise AV_PIX_FMT_NONE */ enum AVPixelFormat av_pix_fmt_swap_endianness(enum AVPixelFormat pix_fmt); #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */ #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */ #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */ #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */ #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */ #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */ /** * Compute what kind of losses will occur when converting from one specific * pixel format to another. * When converting from one pixel format to another, information loss may occur. * For example, when converting from RGB24 to GRAY, the color information will * be lost. Similarly, other losses occur when converting from some formats to * other formats. These losses can involve loss of chroma, but also loss of * resolution, loss of color depth, loss due to the color space conversion, loss * of the alpha bits or loss due to color quantization. * av_get_fix_fmt_loss() informs you about the various types of losses * which will occur when converting from one pixel format to another. * * @param[in] dst_pix_fmt destination pixel format * @param[in] src_pix_fmt source pixel format * @param[in] has_alpha Whether the source pixel format alpha channel is used. * @return Combination of flags informing you what kind of losses will occur * (maximum loss for an invalid dst_pix_fmt). */ int av_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt, int has_alpha); /** * Compute what kind of losses will occur when converting from one specific * pixel format to another. * When converting from one pixel format to another, information loss may occur. * For example, when converting from RGB24 to GRAY, the color information will * be lost. Similarly, other losses occur when converting from some formats to * other formats. These losses can involve loss of chroma, but also loss of * resolution, loss of color depth, loss due to the color space conversion, loss * of the alpha bits or loss due to color quantization. * av_get_fix_fmt_loss() informs you about the various types of losses * which will occur when converting from one pixel format to another. * * @param[in] dst_pix_fmt destination pixel format * @param[in] src_pix_fmt source pixel format * @param[in] has_alpha Whether the source pixel format alpha channel is used. * @return Combination of flags informing you what kind of losses will occur * (maximum loss for an invalid dst_pix_fmt). */ enum AVPixelFormat av_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2, enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr); #endif /* AVUTIL_PIXDESC_H */