diff options
Diffstat (limited to 'libavutil/pixdesc.h')
-rw-r--r-- | libavutil/pixdesc.h | 260 |
1 files changed, 170 insertions, 90 deletions
diff --git a/libavutil/pixdesc.h b/libavutil/pixdesc.h index 4e8a29e607..ea046033a3 100644 --- a/libavutil/pixdesc.h +++ b/libavutil/pixdesc.h @@ -2,20 +2,20 @@ * pixel format descriptor * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -26,6 +26,7 @@ #include "attributes.h" #include "pixfmt.h" +#include "version.h" typedef struct AVComponentDescriptor { /** @@ -105,14 +106,11 @@ typedef struct AVPixFmtDescriptor { uint64_t flags; /** - * Parameters that describe how pixels are packed. If the format - * has chroma components, they must be stored in comp[1] and - * comp[2]. - * If the format is RGB-like, the first component is R, followed - * by G and B. - * - * If the format is YUV-like, the first component is Y, followed - * by U and V. + * 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. */ @@ -148,88 +146,42 @@ typedef struct AVPixFmtDescriptor { * 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 Libav treats it as - * paletted internally, but the palette is generated by the decoder and is not - * stored in the file. - */ -#define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6) -/** - * The pixel format has an alpha channel. - */ -#define AV_PIX_FMT_FLAG_ALPHA (1 << 7) - -/** - * 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 + * 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 */ -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); +#define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6) /** - * Return the pixel format corresponding to name. + * 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. * - * 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". + * The alpha is always straight, never pre-multiplied. * - * Finally if no pixel format has been found, returns PIX_FMT_NONE. + * 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. */ -enum AVPixelFormat av_get_pix_fmt(const char *name); +#define AV_PIX_FMT_FLAG_ALPHA (1 << 7) /** - * 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() + * The pixel format is following a Bayer pattern */ -const char *av_get_pix_fmt_name(enum AVPixelFormat pix_fmt); +#define AV_PIX_FMT_FLAG_BAYER (1 << 8) /** - * Print in buf the string corresponding to the pixel format with - * number pix_fmt, or an 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. + * 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). */ -char *av_get_pix_fmt_string(char *buf, int buf_size, - enum AVPixelFormat pix_fmt); +#define AV_PIX_FMT_FLAG_FLOAT (1 << 9) /** * Return the number of bits per pixel used by the pixel format @@ -243,6 +195,12 @@ char *av_get_pix_fmt_string(char *buf, int buf_size, 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. */ @@ -283,16 +241,6 @@ int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt); /** - * 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); - -/** * @return the name for provided color range or NULL if unknown. */ const char *av_color_range_name(enum AVColorRange range); @@ -342,4 +290,136 @@ const char *av_chroma_location_name(enum AVChromaLocation location); */ 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 */ |