FFmpeg/libavcodec/mjpegenc.c

/*
 * MJPEG encoder
 * Copyright (c) 2000 Gerard Lantau.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <stdlib.h>
#include <stdio.h>
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"

typedef struct MJpegContext {
    UINT8 huff_size_dc_luminance[12];
    UINT16 huff_code_dc_luminance[12];
    UINT8 huff_size_dc_chrominance[12];
    UINT16 huff_code_dc_chrominance[12];

    UINT8 huff_size_ac_luminance[256];
    UINT16 huff_code_ac_luminance[256];
    UINT8 huff_size_ac_chrominance[256];
    UINT16 huff_code_ac_chrominance[256];
} MJpegContext;

#define SOF0 0xc0
#define SOI 0xd8
#define EOI 0xd9
#define DQT 0xdb
#define DHT 0xc4
#define SOS 0xda

#if 0
/* These are the sample quantization tables given in JPEG spec section K.1.
 * The spec says that the values given produce "good" quality, and
 * when divided by 2, "very good" quality.
 */
static const unsigned char std_luminance_quant_tbl[64] = {
    16,  11,  10,  16,  24,  40,  51,  61,
    12,  12,  14,  19,  26,  58,  60,  55,
    14,  13,  16,  24,  40,  57,  69,  56,
    14,  17,  22,  29,  51,  87,  80,  62,
    18,  22,  37,  56,  68, 109, 103,  77,
    24,  35,  55,  64,  81, 104, 113,  92,
    49,  64,  78,  87, 103, 121, 120, 101,
    72,  92,  95,  98, 112, 100, 103,  99
};
static const unsigned char std_chrominance_quant_tbl[64] = {
    17,  18,  24,  47,  99,  99,  99,  99,
    18,  21,  26,  66,  99,  99,  99,  99,
    24,  26,  56,  99,  99,  99,  99,  99,
    47,  66,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99,
    99,  99,  99,  99,  99,  99,  99,  99
};
#endif

/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
/* IMPORTANT: these are only valid for 8-bit data precision! */
static const UINT8 bits_dc_luminance[17] =
{ /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
static const UINT8 val_dc_luminance[] =
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };

static const UINT8 bits_dc_chrominance[17] =
{ /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
static const UINT8 val_dc_chrominance[] =
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };

static const UINT8 bits_ac_luminance[17] =
{ /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
static const UINT8 val_ac_luminance[] =
{ 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
  0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
  0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
  0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
  0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
  0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
  0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
  0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
  0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
  0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
  0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
  0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
  0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
  0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
  0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
  0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
  0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
  0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
  0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
  0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  0xf9, 0xfa 
};

static const UINT8 bits_ac_chrominance[17] =
{ /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };

static const UINT8 val_ac_chrominance[] =
{ 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
  0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
  0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
  0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
  0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
  0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
  0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
  0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
  0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
  0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
  0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
  0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
  0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
  0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
  0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
  0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
  0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
  0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
  0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
  0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
  0xf9, 0xfa 
};


/* isn't this function nicer than the one in the libjpeg ? */
static void build_huffman_codes(UINT8 *huff_size, UINT16 *huff_code,
                                const UINT8 *bits_table, const UINT8 *val_table)
{
    int i, j, k,nb, code, sym;

    code = 0;
    k = 0;
    for(i=1;i<=16;i++) {
        nb = bits_table[i];
        for(j=0;j<nb;j++) {
            sym = val_table[k++];
            huff_size[sym] = i;
            huff_code[sym] = code;
            code++;
        }
        code <<= 1;
    }
}

int mjpeg_init(MpegEncContext *s)
{
    MJpegContext *m;
    
    m = malloc(sizeof(MJpegContext));
    if (!m)
        return -1;

    /* build all the huffman tables */
    build_huffman_codes(m->huff_size_dc_luminance,
                        m->huff_code_dc_luminance,
                        bits_dc_luminance,
                        val_dc_luminance);
    build_huffman_codes(m->huff_size_dc_chrominance,
                        m->huff_code_dc_chrominance,
                        bits_dc_chrominance,
                        val_dc_chrominance);
    build_huffman_codes(m->huff_size_ac_luminance,
                        m->huff_code_ac_luminance,
                        bits_ac_luminance,
                        val_ac_luminance);
    build_huffman_codes(m->huff_size_ac_chrominance,
                        m->huff_code_ac_chrominance,
                        bits_ac_chrominance,
                        val_ac_chrominance);
    
    s->mjpeg_ctx = m;
    return 0;
}

void mjpeg_close(MpegEncContext *s)
{
    free(s->mjpeg_ctx);
}

static inline void put_marker(PutBitContext *p, int code)
{
    put_bits(p, 8, 0xff);
    put_bits(p, 8, code);
}

/* table_class: 0 = DC coef, 1 = AC coefs */
static int put_huffman_table(MpegEncContext *s, int table_class, int table_id,
                             const UINT8 *bits_table, const UINT8 *value_table)
{
    PutBitContext *p = &s->pb;
    int n, i;

    put_bits(p, 4, table_class);
    put_bits(p, 4, table_id);

    n = 0;
    for(i=1;i<=16;i++) {
        n += bits_table[i];
        put_bits(p, 8, bits_table[i]);
    }

    for(i=0;i<n;i++)
        put_bits(p, 8, value_table[i]);

    return n + 17;
}

static void jpeg_table_header(MpegEncContext *s)
{
    PutBitContext *p = &s->pb;
    int i, size;
    UINT8 *ptr;

    /* quant matrixes */
    put_marker(p, DQT);
    put_bits(p, 16, 2 + 1 * (1 + 64));
    put_bits(p, 4, 0); /* 8 bit precision */
    put_bits(p, 4, 0); /* table 0 */
    for(i=0;i<64;i++) {
        put_bits(p, 8, s->intra_matrix[i]);
    }
#if 0
    put_bits(p, 4, 0); /* 8 bit precision */
    put_bits(p, 4, 1); /* table 1 */
    for(i=0;i<64;i++) {
        put_bits(p, 8, s->chroma_intra_matrix[i]);
    }
#endif

    /* huffman table */
    put_marker(p, DHT);
    flush_put_bits(p);
    ptr = p->buf_ptr;
    put_bits(p, 16, 0); /* patched later */
    size = 2;
    size += put_huffman_table(s, 0, 0, bits_dc_luminance, val_dc_luminance);
    size += put_huffman_table(s, 0, 1, bits_dc_chrominance, val_dc_chrominance);
    
    size += put_huffman_table(s, 1, 0, bits_ac_luminance, val_ac_luminance);
    size += put_huffman_table(s, 1, 1, bits_ac_chrominance, val_ac_chrominance);
    ptr[0] = size >> 8;
    ptr[1] = size;
}

void mjpeg_picture_header(MpegEncContext *s)
{
    put_marker(&s->pb, SOI);

    jpeg_table_header(s);

    put_marker(&s->pb, SOF0);

    put_bits(&s->pb, 16, 17);
    put_bits(&s->pb, 8, 8); /* 8 bits/component */
    put_bits(&s->pb, 16, s->height);
    put_bits(&s->pb, 16, s->width);
    put_bits(&s->pb, 8, 3); /* 3 components */
    
    /* Y component */
    put_bits(&s->pb, 8, 1); /* component number */
    put_bits(&s->pb, 4, 2); /* H factor */
    put_bits(&s->pb, 4, 2); /* V factor */
    put_bits(&s->pb, 8, 0); /* select matrix */
    
    /* Cb component */
    put_bits(&s->pb, 8, 2); /* component number */
    put_bits(&s->pb, 4, 1); /* H factor */
    put_bits(&s->pb, 4, 1); /* V factor */
    put_bits(&s->pb, 8, 0); /* select matrix */

    /* Cr component */
    put_bits(&s->pb, 8, 3); /* component number */
    put_bits(&s->pb, 4, 1); /* H factor */
    put_bits(&s->pb, 4, 1); /* V factor */
    put_bits(&s->pb, 8, 0); /* select matrix */

    /* scan header */
    put_marker(&s->pb, SOS);
    put_bits(&s->pb, 16, 12); /* length */
    put_bits(&s->pb, 8, 3); /* 3 components */
    
    /* Y component */
    put_bits(&s->pb, 8, 1); /* index */
    put_bits(&s->pb, 4, 0); /* DC huffman table index */
    put_bits(&s->pb, 4, 0); /* AC huffman table index */
    
    /* Cb component */
    put_bits(&s->pb, 8, 2); /* index */
    put_bits(&s->pb, 4, 1); /* DC huffman table index */
    put_bits(&s->pb, 4, 1); /* AC huffman table index */
    
    /* Cr component */
    put_bits(&s->pb, 8, 3); /* index */
    put_bits(&s->pb, 4, 1); /* DC huffman table index */
    put_bits(&s->pb, 4, 1); /* AC huffman table index */

    put_bits(&s->pb, 8, 0); /* Ss (not used) */
    put_bits(&s->pb, 8, 63); /* Se (not used) */
    put_bits(&s->pb, 8, 0); /* (not used) */
}

void mjpeg_picture_trailer(MpegEncContext *s)
{
    jflush_put_bits(&s->pb);
    put_marker(&s->pb, EOI);
}

static inline void encode_dc(MpegEncContext *s, int val, 
                             UINT8 *huff_size, UINT16 *huff_code)
{
    int mant, nbits;

    if (val == 0) {
        jput_bits(&s->pb, huff_size[0], huff_code[0]);
    } else {
        mant = val;
        if (val < 0) {
            val = -val;
            mant--;
        }
        
        /* compute the log (XXX: optimize) */
        nbits = 0;
        while (val != 0) {
            val = val >> 1;
            nbits++;
        }
            
        jput_bits(&s->pb, huff_size[nbits], huff_code[nbits]);
        
        jput_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
    }
}

static void encode_block(MpegEncContext *s, DCTELEM *block, int n)
{
    int mant, nbits, code, i, j;
    int component, dc, run, last_index, val;
    MJpegContext *m = s->mjpeg_ctx;
    UINT8 *huff_size_ac;
    UINT16 *huff_code_ac;
    
    /* DC coef */
    component = (n <= 3 ? 0 : n - 4 + 1);
    dc = block[0]; /* overflow is impossible */
    val = dc - s->last_dc[component];
    if (n < 4) {
        encode_dc(s, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance);
        huff_size_ac = m->huff_size_ac_luminance;
        huff_code_ac = m->huff_code_ac_luminance;
    } else {
        encode_dc(s, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
        huff_size_ac = m->huff_size_ac_chrominance;
        huff_code_ac = m->huff_code_ac_chrominance;
    }
    s->last_dc[component] = dc;
    
    /* AC coefs */
    
    run = 0;
    last_index = s->block_last_index[n];
    for(i=1;i<=last_index;i++) {
        j = zigzag_direct[i];
        val = block[j];
        if (val == 0) {
            run++;
        } else {
            while (run >= 16) {
                jput_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);
                run -= 16;
            }
            mant = val;
            if (val < 0) {
                val = -val;
                mant--;
            }
            
            /* compute the log (XXX: optimize) */
            nbits = 0;
            while (val != 0) {
                val = val >> 1;
                nbits++;
            }
            code = (run << 4) | nbits;

            jput_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);
        
            jput_bits(&s->pb, nbits, mant & ((1 << nbits) - 1));
            run = 0;
        }
    }

    /* output EOB only if not already 64 values */
    if (last_index < 63 || run != 0)
        jput_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
}

void mjpeg_encode_mb(MpegEncContext *s, 
                     DCTELEM block[6][64])
{
    int i;
    for(i=0;i<6;i++) {
        encode_block(s, block[i], i);
    }
}