diff lib/libavutil/pixdesc.h @ 2134:992d2e6f907d

preparation for libavcodec
author zipi
date Tue, 31 Dec 2013 14:52:14 +0000
parents
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libavutil/pixdesc.h	Tue Dec 31 14:52:14 2013 +0000
@@ -0,0 +1,289 @@
+/*
+ * 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 <stdint.h>
+#include "pixfmt.h"
+
+typedef struct AVComponentDescriptor{
+    uint16_t plane        :2;            ///< which of the 4 planes contains the component
+
+    /**
+     * Number of elements between 2 horizontally consecutive pixels minus 1.
+     * Elements are bits for bitstream formats, bytes otherwise.
+     */
+    uint16_t step_minus1  :3;
+
+    /**
+     * Number of elements before the component of the first pixel plus 1.
+     * Elements are bits for bitstream formats, bytes otherwise.
+     */
+    uint16_t offset_plus1 :3;
+    uint16_t shift        :3;            ///< number of least significant bits that must be shifted away to get the value
+    uint16_t depth_minus1 :4;            ///< number of bits in the component minus 1
+}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 = -((-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;      ///< chroma_width = -((-luma_width )>>log2_chroma_w)
+
+    /**
+     * Amount to shift the luma height right to find the chroma height.
+     * For YV12 this is 1 for example.
+     * chroma_height= -((-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;
+    uint8_t flags;
+
+    /**
+     * Parameters that describe how pixels are packed.
+     * If the format has 2 or 4 components, then alpha is last.
+     * 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.
+     */
+    AVComponentDescriptor comp[4];
+}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 FFmpeg 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)
+
+#if FF_API_PIX_FMT
+/**
+ * @deprecate use the AV_PIX_FMT_FLAG_* flags
+ */
+#define PIX_FMT_BE        AV_PIX_FMT_FLAG_BE
+#define PIX_FMT_PAL       AV_PIX_FMT_FLAG_PAL
+#define PIX_FMT_BITSTREAM AV_PIX_FMT_FLAG_BITSTREAM
+#define PIX_FMT_HWACCEL   AV_PIX_FMT_FLAG_HWACCEL
+#define PIX_FMT_PLANAR    AV_PIX_FMT_FLAG_PLANAR
+#define PIX_FMT_RGB       AV_PIX_FMT_FLAG_RGB
+#define PIX_FMT_PSEUDOPAL AV_PIX_FMT_FLAG_PSEUDOPAL
+#define PIX_FMT_ALPHA     AV_PIX_FMT_FLAG_ALPHA
+#endif
+
+#if FF_API_PIX_FMT_DESC
+/**
+ * The array of all the pixel format descriptors.
+ */
+extern const AVPixFmtDescriptor av_pix_fmt_descriptors[];
+#endif
+
+/**
+ * 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);
+
+/**
+ * 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 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.
+ */
+char *av_get_pix_fmt_string (char *buf, int buf_size, enum AVPixelFormat pix_fmt);
+
+/**
+ * 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 avcodec_get_chroma_sub_sample() for a function that asserts a
+ * valid pixel format instead of returning an error code.
+ * Its recommanded 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
+ * @param[out] v_shift store log2_chroma_h
+ *
+ * @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);
+
+void ff_check_pixfmt_descriptors(void);
+
+/**
+ * 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);
+
+
+#endif /* AVUTIL_PIXDESC_H */