mpegpicture.h

Go to the documentation of this file.

/*
 * Mpeg video formats-related defines and utility functions
 *
 * 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 AVCODEC_MPEGPICTURE_H
#define AVCODEC_MPEGPICTURE_H

#include <stdint.h>

#include "libavutil/frame.h"

#include "avcodec.h"
#include "motion_est.h"
#include "thread.h"

#define MAX_PICTURE_COUNT 36
#define EDGE_WIDTH 16

typedef struct ScratchpadContext {
    uint8_t *edge_emu_buffer;     ///< temporary buffer for if MVs point to out-of-frame data
    uint8_t *rd_scratchpad;       ///< scratchpad for rate distortion mb decision
    uint8_t *obmc_scratchpad;
    uint8_t *b_scratchpad;        ///< scratchpad used for writing into write only buffers
} ScratchpadContext;

/**
 * Picture.
 */
typedef struct Picture {
    struct AVFrame *f;
    ThreadFrame tf;

    AVBufferRef *qscale_table_buf;
    int8_t *qscale_table;

    AVBufferRef *motion_val_buf[2];
    int16_t (*motion_val[2])[2];

    AVBufferRef *mb_type_buf;
    uint32_t *mb_type;          ///< types and macros are defined in mpegutils.h

    AVBufferRef *mbskip_table_buf;
    uint8_t *mbskip_table;

    AVBufferRef *ref_index_buf[2];
    int8_t *ref_index[2];

    AVBufferRef *mb_var_buf;
    uint16_t *mb_var;           ///< Table for MB variances

    AVBufferRef *mc_mb_var_buf;
    uint16_t *mc_mb_var;        ///< Table for motion compensated MB variances

    int alloc_mb_width;         ///< mb_width used to allocate tables
    int alloc_mb_height;        ///< mb_height used to allocate tables

    AVBufferRef *mb_mean_buf;
    uint8_t *mb_mean;           ///< Table for MB luminance

    AVBufferRef *hwaccel_priv_buf;
    void *hwaccel_picture_private; ///< Hardware accelerator private data

    int field_picture;          ///< whether or not the picture was encoded in separate fields

    int64_t mb_var_sum;         ///< sum of MB variance for current frame
    int64_t mc_mb_var_sum;      ///< motion compensated MB variance for current frame

    int b_frame_score;
    int needs_realloc;          ///< Picture needs to be reallocated (eg due to a frame size change)

    int reference;
    int shared;

    uint64_t encoding_error[AV_NUM_DATA_POINTERS];
} Picture;

/**
 * Allocate a Picture.
 * The pixels are allocated/set by calling get_buffer() if shared = 0.
 */
int ff_alloc_picture(AVCodecContext *avctx, Picture *pic, MotionEstContext *me,
                     ScratchpadContext *sc, int shared, int encoding,
                     int chroma_x_shift, int chroma_y_shift, int out_format,
                     int mb_stride, int mb_width, int mb_height, int b8_stride,
                     ptrdiff_t *linesize, ptrdiff_t *uvlinesize);

int ff_mpeg_framesize_alloc(AVCodecContext *avctx, MotionEstContext *me,
                            ScratchpadContext *sc, int linesize);

int ff_mpeg_ref_picture(AVCodecContext *avctx, Picture *dst, Picture *src);
void ff_mpeg_unref_picture(AVCodecContext *avctx, Picture *picture);

void ff_free_picture_tables(Picture *pic);
int ff_update_picture_tables(Picture *dst, Picture *src);

int ff_find_unused_picture(AVCodecContext *avctx, Picture *picture, int shared);

#endif /* AVCODEC_MPEGPICTURE_H */