FFmpeg/libavcodec/dvdata.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_DVDATA_H
#define AVCODEC_DVDATA_H

#include "libavutil/rational.h"
#include "avcodec.h"

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

/*
 * DVprofile is used to express the differences between various
 * DV flavors. For now it's primarily used for differentiating
 * 525/60 and 625/50, but the plans are to use it for various
 * DV specs as well (e.g. SMPTE314M vs. IEC 61834).
 */
typedef struct DVprofile {
    int              dsf;                   /* value of the dsf in the DV header */
    int              video_stype;           /* stype for VAUX source pack */
    int              frame_size;            /* total size of one frame in bytes */
    int              difseg_size;           /* number of DIF segments per DIF channel */
    int              n_difchan;             /* number of DIF channels per frame */
    AVRational       time_base;             /* 1/framerate */
    int              ltc_divisor;           /* FPS from the LTS standpoint */
    int              height;                /* picture height in pixels */
    int              width;                 /* picture width in pixels */
    AVRational       sar[2];                /* sample aspect ratios for 4:3 and 16:9 */
    DVwork_chunk    *work_chunks;           /* each thread gets its own chunk of frame to work on */
    uint32_t        *idct_factor;           /* set of iDCT factor tables */
    enum PixelFormat pix_fmt;               /* picture pixel format */
    int              bpm;                   /* blocks per macroblock */
    const uint8_t   *block_sizes;           /* AC block sizes, in bits */
    int              audio_stride;          /* size of audio_shuffle table */
    int              audio_min_samples[3];  /* min amount of audio samples */
                                            /* for 48kHz, 44.1kHz and 32kHz */
    int              audio_samples_dist[5]; /* how many samples are supposed to be */
                                            /* in each frame in a 5 frames window */
    const uint8_t  (*audio_shuffle)[9];     /* PCM shuffling table */
} DVprofile;

static const uint8_t dv_audio_shuffle525[10][9] = {
  {  0, 30, 60, 20, 50, 80, 10, 40, 70 }, /* 1st channel */
  {  6, 36, 66, 26, 56, 86, 16, 46, 76 },
  { 12, 42, 72,  2, 32, 62, 22, 52, 82 },
  { 18, 48, 78,  8, 38, 68, 28, 58, 88 },
  { 24, 54, 84, 14, 44, 74,  4, 34, 64 },

  {  1, 31, 61, 21, 51, 81, 11, 41, 71 }, /* 2nd channel */
  {  7, 37, 67, 27, 57, 87, 17, 47, 77 },
  { 13, 43, 73,  3, 33, 63, 23, 53, 83 },
  { 19, 49, 79,  9, 39, 69, 29, 59, 89 },
  { 25, 55, 85, 15, 45, 75,  5, 35, 65 },
};

static const uint8_t dv_audio_shuffle625[12][9] = {
  {   0,  36,  72,  26,  62,  98,  16,  52,  88}, /* 1st channel */
  {   6,  42,  78,  32,  68, 104,  22,  58,  94},
  {  12,  48,  84,   2,  38,  74,  28,  64, 100},
  {  18,  54,  90,   8,  44,  80,  34,  70, 106},
  {  24,  60,  96,  14,  50,  86,   4,  40,  76},
  {  30,  66, 102,  20,  56,  92,  10,  46,  82},

  {   1,  37,  73,  27,  63,  99,  17,  53,  89}, /* 2nd channel */
  {   7,  43,  79,  33,  69, 105,  23,  59,  95},
  {  13,  49,  85,   3,  39,  75,  29,  65, 101},
  {  19,  55,  91,   9,  45,  81,  35,  71, 107},
  {  25,  61,  97,  15,  51,  87,   5,  41,  77},
  {  31,  67, 103,  21,  57,  93,  11,  47,  83},
};

static const av_unused int dv_audio_frequency[3] = {
    48000, 44100, 32000,
};

/* macroblock bit budgets */
static const uint8_t block_sizes_dv2550[8] = {
    112, 112, 112, 112, 80, 80, 0, 0,
};

static const uint8_t block_sizes_dv100[8] = {
    80, 80, 80, 80, 80, 80, 64, 64,
};

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

const DVprofile* avpriv_dv_frame_profile(const DVprofile *sys,
                                         const uint8_t* frame, unsigned buf_size);
const DVprofile* avpriv_dv_codec_profile(AVCodecContext* codec);

#endif /* AVCODEC_DVDATA_H */