FFmpeg/libavcodec/dv.h

/*
 * Constants for DV codec
 * Copyright (c) 2002 Fabrice Bellard
 *
 * This file is part of Libav.
 *
 * Libav 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,
 * 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
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * Constants for DV codec.
 */

#ifndef AVCODEC_DV_H
#define AVCODEC_DV_H

#include "avcodec.h"
#include "dv_profile.h"
#include "me_cmp.h"
#include "vlc.h"

typedef struct DVwork_chunk {
    uint16_t buf_offset;
    uint16_t mb_coordinates[5];
} DVwork_chunk;

typedef struct DVVideoContext {
    const AVDVProfile *sys;
    const AVFrame   *frame;
    AVCodecContext  *avctx;
    uint8_t         *buf;

    uint8_t dv_zigzag[2][64];

    void (*get_pixels)(int16_t *block, const uint8_t *pixels, ptrdiff_t linesize);
    void (*fdct[2])(int16_t *block);
    void (*idct_put[2])(uint8_t *dest, ptrdiff_t stride, int16_t *block);
    me_cmp_func ildct_cmp;
    DVwork_chunk work_chunks[4 * 12 * 27];
    uint32_t idct_factor[2 * 4 * 16 * 64];
} DVVideoContext;

enum dv_section_type {
    dv_sect_header  = 0x1f,
    dv_sect_subcode = 0x3f,
    dv_sect_vaux    = 0x56,
    dv_sect_audio   = 0x76,
    dv_sect_video   = 0x96,
};

enum dv_pack_type {
    dv_header525     = 0x3f,  /* see dv_write_pack for important details on */
    dv_header625     = 0xbf,  /* these two packs */
    dv_timecode      = 0x13,
    dv_audio_source  = 0x50,
    dv_audio_control = 0x51,
    dv_audio_recdate = 0x52,
    dv_audio_rectime = 0x53,
    dv_video_source  = 0x60,
    dv_video_control = 0x61,
    dv_video_recdate = 0x62,
    dv_video_rectime = 0x63,
    dv_unknown_pack  = 0xff,
};

#define DV_PROFILE_IS_HD(p) ((p)->video_stype & 0x10)
#define DV_PROFILE_IS_1080i50(p) (((p)->video_stype == 0x14) && ((p)->dsf == 1))
#define DV_PROFILE_IS_720p50(p)  (((p)->video_stype == 0x18) && ((p)->dsf == 1))

/* minimum number of bytes to read from a DV stream in order to
 * determine the profile */
#define DV_PROFILE_BYTES (6 * 80) /* 6 DIF blocks */

/**
 * largest possible DV frame, in bytes (1080i50)
 */
#define DV_MAX_FRAME_SIZE 576000

/**
 * maximum number of blocks per macroblock in any DV format
 */
#define DV_MAX_BPM 8

#define TEX_VLC_BITS 9

extern RL_VLC_ELEM ff_dv_rl_vlc[1184];

int ff_dv_init_dynamic_tables(DVVideoContext *s, const AVDVProfile *d);
int ff_dvvideo_init(AVCodecContext *avctx);

static inline int dv_work_pool_size(const AVDVProfile *d)
{
    int size = d->n_difchan * d->difseg_size * 27;
    if (DV_PROFILE_IS_1080i50(d))
        size -= 3 * 27;
    if (DV_PROFILE_IS_720p50(d))
        size -= 4 * 27;
    return size;
}

static inline void dv_calculate_mb_xy(DVVideoContext *s,
                                      DVwork_chunk *work_chunk,
                                      int m, int *mb_x, int *mb_y)
{
    *mb_x = work_chunk->mb_coordinates[m] & 0xff;
    *mb_y = work_chunk->mb_coordinates[m] >> 8;

    /* We work with 720p frames split in half.
     * The odd half-frame (chan == 2,3) is displaced :-( */
    if (s->sys->height == 720 && !(s->buf[1] & 0x0C))
        /* shifting the Y coordinate down by 72/2 macro blocks */
        *mb_y -= (*mb_y > 17) ? 18 : -72;
}

#endif /* AVCODEC_DV_H */