msmpeg4enc.c

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/*
 * MSMPEG4 encoder backend
 * Copyright (c) 2001 Fabrice Bellard
 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
 *
 * msmpeg4v1 & v2 stuff by 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
 */
 
/**
 * @file
 * MSMPEG4 encoder backend
 */
 
#include <stdint.h>
#include <string.h>
 
#define NO_SLICE_THREADING_HERE
 
#include "libavutil/attributes.h"
#include "libavutil/avutil.h"
#include "libavutil/thread.h"
#include "codec_internal.h"
#include "mpegvideo.h"
#include "mpegvideoenc.h"
#include "h263.h"
#include "h263data.h"
#include "mpeg4video.h"
#include "msmpeg4.h"
#include "msmpeg4data.h"
#include "msmpeg4_vc1_data.h"
#include "msmpeg4enc.h"
#include "put_bits.h"
#include "rl.h"
 
static uint8_t rl_length[NB_RL_TABLES][MAX_LEVEL+1][MAX_RUN+1][2];
 
// The lowest 8 bits of each entry are length, the other bits are the code.
// The index of the (mx, my) entry is (mx * 64) + my.
static uint32_t mv_vector_tables[2][4096];
 
/* build the table which associate a (x,y) motion vector to a vlc */
static av_cold void init_mv_table(const uint16_t mv_table[], const uint8_t mv_table_lens[],
                                  uint32_t mv_vector_table[4096],
                                  unsigned escape_code, int escape_length)
{
    for (int i = 0; i < 4096; i++) {
        // Initialize to the table to "escaped". This code is equivalent to
        // the following double loop (with x and y ranging over 0..63):
        // tab[x * 64 + y] = (esc_code << 20) | (x << 14) | (y << 8) | esc_length
        mv_vector_table[i] = (escape_code << 20) | (i << 8) | escape_length;
    }
 
    for (uint32_t i = 0, code = 0; i < MSMPEG4_MV_TABLES_NB_ELEMS; i++) {
        int sym = mv_table[i];
        int len = mv_table_lens[i];
        int x = sym >> 8;
        int y = sym & 0xFF;
        // We ignore the escape value here and restore it after the loop.
        mv_vector_table[(x << 6) | y] = (code >> (24 - len)) | len;
        code += 1U << (32 - len);
    }
    mv_vector_table[0] = (escape_code << 20) | escape_length;
}
 
void ff_msmpeg4_code012(PutBitContext *pb, int n)
{
    if (n == 0) {
        put_bits(pb, 1, 0);
    } else {
        put_bits(pb, 2, 2 | (n >= 2));
    }
}
 
static int get_size_of_code(const RLTable *rl, int last, int run,
                            int level, int intra)
{
    int size=0;
    int code;
    int run_diff= intra ? 0 : 1;
 
    code = get_rl_index(rl, last, run, level);
    size+= rl->table_vlc[code][1];
    if (code == rl->n) {
        int level1, run1;
 
        level1 = level - rl->max_level[last][run];
        if (level1 < 1)
            goto esc2;
        code = get_rl_index(rl, last, run, level1);
        if (code == rl->n) {
            esc2:
            size++;
            if (level > MAX_LEVEL)
                goto esc3;
            run1 = run - rl->max_run[last][level] - run_diff;
            if (run1 < 0)
                goto esc3;
            code = get_rl_index(rl, last, run1, level);
            if (code == rl->n) {
            esc3:
                /* third escape */
                size+=1+1+6+8;
            } else {
                /* second escape */
                size+= 1+1+ rl->table_vlc[code][1];
            }
        } else {
            /* first escape */
            size+= 1+1+ rl->table_vlc[code][1];
        }
    } else {
        size++;
    }
    return size;
}
 
static av_cold void msmpeg4_encode_init_static(void)
{
    init_mv_table(ff_msmp4_mv_table0, ff_msmp4_mv_table0_lens,
                  mv_vector_tables[0], 0x0000, 8 + 12);
    init_mv_table(ff_msmp4_mv_table1, ff_msmp4_mv_table1_lens,
                  mv_vector_tables[1], 0x000b, 4 + 12);
 
    for (int i = 0; i < NB_RL_TABLES; i++) {
        for (int level = 1; level <= MAX_LEVEL; level++) {
            for (int run = 0; run <= MAX_RUN; run++) {
                for (int last = 0; last < 2; last++) {
                    rl_length[i][level][run][last] = get_size_of_code(&ff_rl_table[i], last, run, level, 0);
                }
            }
        }
    }
}
 
static void find_best_tables(MSMPEG4EncContext *ms)
{
    MPVEncContext *const s = &ms->m.s;
    int i;
    int best        = 0, best_size        = INT_MAX;
    int chroma_best = 0, best_chroma_size = INT_MAX;
 
    for(i=0; i<3; i++){
        int level;
        int chroma_size=0;
        int size=0;
 
        if(i>0){// ;)
            size++;
            chroma_size++;
        }
        for(level=0; level<=MAX_LEVEL; level++){
            int run;
            for(run=0; run<=MAX_RUN; run++){
                int last;
                const int last_size= size + chroma_size;
                for(last=0; last<2; last++){
                    int inter_count       = ms->ac_stats[0][0][level][run][last] + ms->ac_stats[0][1][level][run][last];
                    int intra_luma_count  = ms->ac_stats[1][0][level][run][last];
                    int intra_chroma_count= ms->ac_stats[1][1][level][run][last];
 
                    if (s->c.pict_type == AV_PICTURE_TYPE_I) {
                        size       += intra_luma_count  *rl_length[i  ][level][run][last];
                        chroma_size+= intra_chroma_count*rl_length[i+3][level][run][last];
                    }else{
                        size+=        intra_luma_count  *rl_length[i  ][level][run][last]
                                     +intra_chroma_count*rl_length[i+3][level][run][last]
                                     +inter_count       *rl_length[i+3][level][run][last];
                    }
                }
                if(last_size == size+chroma_size) break;
            }
        }
        if(size<best_size){
            best_size= size;
            best= i;
        }
        if(chroma_size<best_chroma_size){
            best_chroma_size= chroma_size;
            chroma_best= i;
        }
    }
 
    if (s->c.pict_type == AV_PICTURE_TYPE_P) chroma_best = best;
 
    memset(ms->ac_stats, 0, sizeof(ms->ac_stats));
 
    ms->rl_table_index        =        best;
    ms->rl_chroma_table_index = chroma_best;
 
    if (s->c.pict_type != ms->m.last_non_b_pict_type) {
        ms->rl_table_index= 2;
        if (s->c.pict_type == AV_PICTURE_TYPE_I)
            ms->rl_chroma_table_index = 1;
        else
            ms->rl_chroma_table_index = 2;
    }
 
}
 
/* write MSMPEG4 compatible frame header */
static int msmpeg4_encode_picture_header(MPVMainEncContext *const m)
{
    MSMPEG4EncContext *const ms = (MSMPEG4EncContext*)m;
    MPVEncContext *const s = &m->s;
 
    find_best_tables(ms);
 
    put_bits_assume_flushed(&s->pb);
 
    put_bits(&s->pb, 2, s->c.pict_type - 1);
 
    put_bits(&s->pb, 5, s->c.qscale);
    if (s->c.msmpeg4_version <= MSMP4_V2) {
        ms->rl_table_index = 2;
        ms->rl_chroma_table_index = 2;
    }
 
    ms->dc_table_index   = 1;
    ms->mv_table_index   = 1; /* only if P-frame */
    ms->use_skip_mb_code = 1; /* only if P-frame */
    ms->per_mb_rl_table  = 0;
    if (s->c.msmpeg4_version == MSMP4_WMV1)
        s->c.inter_intra_pred = s->c.width * s->c.height < 320*240 &&
                              m->bit_rate  <= II_BITRATE     &&
                              s->c.pict_type == AV_PICTURE_TYPE_P;
    ff_dlog(s->c.avctx, "%d %"PRId64" %d %d %d\n", s->c.pict_type, m->bit_rate,
            s->c.inter_intra_pred, s->c.width, s->c.height);
 
    if (s->c.pict_type == AV_PICTURE_TYPE_I) {
        s->slice_height = s->c.mb_height/1;
        put_bits(&s->pb, 5, 0x16 + s->c.mb_height / s->slice_height);
 
        if (s->c.msmpeg4_version == MSMP4_WMV1) {
            ff_msmpeg4_encode_ext_header(s);
            if (m->bit_rate > MBAC_BITRATE)
                put_bits(&s->pb, 1, ms->per_mb_rl_table);
        }
 
        if (s->c.msmpeg4_version > MSMP4_V2) {
            if (!ms->per_mb_rl_table){
                ff_msmpeg4_code012(&s->pb, ms->rl_chroma_table_index);
                ff_msmpeg4_code012(&s->pb, ms->rl_table_index);
            }
 
            put_bits(&s->pb, 1, ms->dc_table_index);
        }
    } else {
        put_bits(&s->pb, 1, ms->use_skip_mb_code);
 
        if (s->c.msmpeg4_version == MSMP4_WMV1 && m->bit_rate > MBAC_BITRATE)
            put_bits(&s->pb, 1, ms->per_mb_rl_table);
 
        if (s->c.msmpeg4_version > MSMP4_V2) {
            if (!ms->per_mb_rl_table)
                ff_msmpeg4_code012(&s->pb, ms->rl_table_index);
 
            put_bits(&s->pb, 1, ms->dc_table_index);
 
            put_bits(&s->pb, 1, ms->mv_table_index);
        }
    }
 
    s->esc3_level_length = 0;
    ms->esc3_run_length  = 0;
 
    return 0;
}
 
void ff_msmpeg4_encode_ext_header(MPVEncContext *const s)
{
    const MPVMainEncContext *const m = slice_to_mainenc(s);
    unsigned fps;
 
    if (s->c.avctx->framerate.num > 0 && s->c.avctx->framerate.den > 0)
        fps = s->c.avctx->framerate.num / s->c.avctx->framerate.den;
    else {
        fps = s->c.avctx->time_base.den / s->c.avctx->time_base.num;
    }
 
    put_bits(&s->pb, 5, FFMIN(fps, 31)); //yes 29.97 -> 29
 
    put_bits(&s->pb, 11, FFMIN(m->bit_rate / 1024, 2047));
 
    if (s->c.msmpeg4_version >= MSMP4_V3)
        put_bits(&s->pb, 1, s->flipflop_rounding);
    else
        av_assert0(!s->flipflop_rounding);
}
 
void ff_msmpeg4_encode_motion(MSMPEG4EncContext *const ms,
                                  int mx, int my)
{
    MPVEncContext *const s = &ms->m.s;
    const uint32_t *const mv_vector_table = mv_vector_tables[ms->mv_table_index];
    uint32_t code;
 
    /* modulo encoding */
    /* WARNING : you cannot reach all the MVs even with the modulo
       encoding. This is a somewhat strange compromise they took !!!  */
    if (mx <= -64)
        mx += 64;
    else if (mx >= 64)
        mx -= 64;
    if (my <= -64)
        my += 64;
    else if (my >= 64)
        my -= 64;
 
    mx += 32;
    my += 32;
 
    code = mv_vector_table[(mx << 6) | my];
    put_bits(&s->pb, code & 0xff, code >> 8);
}
 
void ff_msmpeg4_handle_slices(MPVEncContext *const s)
{
    if (s->c.mb_x == 0) {
        if (s->slice_height && (s->c.mb_y % s->slice_height) == 0) {
            if (s->c.msmpeg4_version < MSMP4_WMV1)
                ff_mpeg4_clean_buffers(&s->c);
            s->c.first_slice_line = 1;
        } else {
            s->c.first_slice_line = 0;
        }
    }
}
 
static void msmpeg4v2_encode_motion(MPVEncContext *const s, int val)
{
    int range, bit_size, sign, code, bits;
 
    if (val == 0) {
        /* zero vector; corresponds to ff_mvtab[0] */
        put_bits(&s->pb, 1, 0x1);
    } else {
        bit_size = s->f_code - 1;
        range = 1 << bit_size;
        if (val <= -64)
            val += 64;
        else if (val >= 64)
            val -= 64;
 
        if (val >= 0) {
            sign = 0;
        } else {
            val = -val;
            sign = 1;
        }
        val--;
        code = (val >> bit_size) + 1;
        bits = val & (range - 1);
 
        put_bits(&s->pb, ff_mvtab[code][1] + 1, (ff_mvtab[code][0] << 1) | sign);
        if (bit_size > 0) {
            put_bits(&s->pb, bit_size, bits);
        }
    }
}
 
static void msmpeg4_encode_mb(MPVEncContext *const s,
                              int16_t block[][64],
                              int motion_x, int motion_y)
{
    MSMPEG4EncContext *const ms = mpv_to_msmpeg4(s);
    int cbp, coded_cbp, i;
    int pred_x, pred_y;
 
    ff_msmpeg4_handle_slices(s);
 
    if (!s->c.mb_intra) {
        /* compute cbp */
        cbp = 0;
        for (i = 0; i < 6; i++) {
            if (s->c.block_last_index[i] >= 0)
                cbp |= 1 << (5 - i);
        }
        if (ms->use_skip_mb_code && (cbp | motion_x | motion_y) == 0) {
            /* skip macroblock */
            put_bits(&s->pb, 1, 1);
            s->last_bits++;
            s->misc_bits++;
 
            return;
        }
        if (ms->use_skip_mb_code)
            put_bits(&s->pb, 1, 0);     /* mb coded */
 
        if (s->c.msmpeg4_version <= MSMP4_V2) {
            put_bits(&s->pb,
                     ff_v2_mb_type[cbp&3][1],
                     ff_v2_mb_type[cbp&3][0]);
            if((cbp&3) != 3) coded_cbp= cbp ^ 0x3C;
            else             coded_cbp= cbp;
 
            put_bits(&s->pb,
                     ff_h263_cbpy_tab[coded_cbp>>2][1],
                     ff_h263_cbpy_tab[coded_cbp>>2][0]);
 
            s->misc_bits += get_bits_diff(s);
 
            ff_h263_pred_motion(&s->c, 0, 0, &pred_x, &pred_y);
            msmpeg4v2_encode_motion(s, motion_x - pred_x);
            msmpeg4v2_encode_motion(s, motion_y - pred_y);
        }else{
            put_bits(&s->pb,
                     ff_table_mb_non_intra[cbp + 64][1],
                     ff_table_mb_non_intra[cbp + 64][0]);
 
            s->misc_bits += get_bits_diff(s);
 
            /* motion vector */
            ff_h263_pred_motion(&s->c, 0, 0, &pred_x, &pred_y);
            ff_msmpeg4_encode_motion(ms, motion_x - pred_x,
                                     motion_y - pred_y);
        }
 
        s->mv_bits += get_bits_diff(s);
 
        for (i = 0; i < 6; i++) {
            ff_msmpeg4_encode_block(s, block[i], i);
        }
        s->p_tex_bits += get_bits_diff(s);
    } else {
        /* compute cbp */
        cbp = 0;
        for (int i = 0; i < 6; i++) {
            int val = (s->c.block_last_index[i] >= 1);
            cbp |= val << (5 - i);
        }
        if (s->c.msmpeg4_version <= MSMP4_V2) {
            if (s->c.pict_type == AV_PICTURE_TYPE_I) {
                put_bits(&s->pb,
                         ff_v2_intra_cbpc[cbp&3][1], ff_v2_intra_cbpc[cbp&3][0]);
            } else {
                if (ms->use_skip_mb_code)
                    put_bits(&s->pb, 1, 0);     /* mb coded */
                put_bits(&s->pb,
                         ff_v2_mb_type[(cbp&3) + 4][1],
                         ff_v2_mb_type[(cbp&3) + 4][0]);
            }
            put_bits(&s->pb, 1, 0);             /* no AC prediction yet */
            put_bits(&s->pb,
                     ff_h263_cbpy_tab[cbp>>2][1],
                     ff_h263_cbpy_tab[cbp>>2][0]);
        }else{
            if (s->c.pict_type == AV_PICTURE_TYPE_I) {
                /* compute coded_cbp; the 0x3 corresponds to chroma cbp;
                 * luma coded_cbp are set in the loop below */
                coded_cbp = cbp & 0x3;
                for (int i = 0; i < 4; i++) {
                    uint8_t *coded_block;
                    int pred = ff_msmpeg4_coded_block_pred(&s->c, i, &coded_block);
                    int val = (s->c.block_last_index[i] >= 1);
                    *coded_block = val;
                    val ^= pred;
                    coded_cbp |= val << (5 - i);
                }
 
                put_bits(&s->pb,
                         ff_msmp4_mb_i_table[coded_cbp][1], ff_msmp4_mb_i_table[coded_cbp][0]);
            } else {
                if (ms->use_skip_mb_code)
                    put_bits(&s->pb, 1, 0);     /* mb coded */
                put_bits(&s->pb,
                         ff_table_mb_non_intra[cbp][1],
                         ff_table_mb_non_intra[cbp][0]);
            }
            put_bits(&s->pb, 1, 0);             /* no AC prediction yet */
            if (s->c.inter_intra_pred) {
                s->c.h263_aic_dir = 0;
                put_bits(&s->pb, ff_table_inter_intra[s->c.h263_aic_dir][1],
                                 ff_table_inter_intra[s->c.h263_aic_dir][0]);
            }
        }
        s->misc_bits += get_bits_diff(s);
 
        for (i = 0; i < 6; i++) {
            ff_msmpeg4_encode_block(s, block[i], i);
        }
        s->i_tex_bits += get_bits_diff(s);
        s->i_count++;
    }
}
 
static void msmpeg4_encode_dc(MSMPEG4EncContext *const ms, int level, int n, int *dir_ptr)
{
    MPVEncContext *const s = &ms->m.s;
    int sign, code;
    int pred;
 
    int16_t *dc_val;
    pred = ff_msmpeg4_pred_dc(&s->c, n, &dc_val, dir_ptr);
 
    /* update predictor */
    if (n < 4) {
        *dc_val = level * s->c.y_dc_scale;
    } else {
        *dc_val = level * s->c.c_dc_scale;
    }
 
    /* do the prediction */
    level -= pred;
 
    if (s->c.msmpeg4_version <= MSMP4_V2) {
        if (n < 4) {
            put_bits(&s->pb,
                     ff_v2_dc_lum_table[level + 256][1],
                     ff_v2_dc_lum_table[level + 256][0]);
        }else{
            put_bits(&s->pb,
                     ff_v2_dc_chroma_table[level + 256][1],
                     ff_v2_dc_chroma_table[level + 256][0]);
        }
    }else{
        sign = 0;
        if (level < 0) {
            level = -level;
            sign = 1;
        }
        code = level;
        if (code > DC_MAX)
            code = DC_MAX;
 
        put_bits(&s->pb, ff_msmp4_dc_tables[ms->dc_table_index][n >= 4][code][1],
                         ff_msmp4_dc_tables[ms->dc_table_index][n >= 4][code][0]);
 
        if (code == DC_MAX)
            put_bits(&s->pb, 8, level);
 
        if (level != 0) {
            put_bits(&s->pb, 1, sign);
        }
    }
}
 
/* Encoding of a block; very similar to MPEG-4 except for a different
 * escape coding (same as H.263) and more VLC tables. */
void ff_msmpeg4_encode_block(MPVEncContext *const s, int16_t * block, int n)
{
    MSMPEG4EncContext *const ms = (MSMPEG4EncContext*)s;
    int level, run, last, i, j, last_index;
    int last_non_zero, sign, slevel;
    int code, run_diff, dc_pred_dir;
    const RLTable *rl;
    const uint8_t *scantable;
 
    if (s->c.mb_intra) {
        msmpeg4_encode_dc(ms, block[0], n, &dc_pred_dir);
        i = 1;
        if (n < 4) {
            rl = &ff_rl_table[ms->rl_table_index];
        } else {
            rl = &ff_rl_table[3 + ms->rl_chroma_table_index];
        }
        run_diff  = s->c.msmpeg4_version >= MSMP4_WMV1;
        scantable = s->c.intra_scantable.permutated;
    } else {
        i = 0;
        rl = &ff_rl_table[3 + ms->rl_table_index];
        run_diff  = s->c.msmpeg4_version > MSMP4_V2;
        scantable = s->c.inter_scantable.permutated;
    }
 
    /* recalculate block_last_index for M$ wmv1 */
    if (s->c.msmpeg4_version >= MSMP4_WMV1 && s->c.block_last_index[n] > 0) {
        for(last_index=63; last_index>=0; last_index--){
            if(block[scantable[last_index]]) break;
        }
        s->c.block_last_index[n] = last_index;
    }else
        last_index = s->c.block_last_index[n];
    /* AC coefs */
    last_non_zero = i - 1;
    for (; i <= last_index; i++) {
        j = scantable[i];
        level = block[j];
        if (level) {
            run = i - last_non_zero - 1;
            last = (i == last_index);
            sign = 0;
            slevel = level;
            if (level < 0) {
                sign = 1;
                level = -level;
            }
 
            if(level<=MAX_LEVEL && run<=MAX_RUN){
                ms->ac_stats[s->c.mb_intra][n>3][level][run][last]++;
            }
 
            ms->ac_stats[s->c.mb_intra][n > 3][40][63][0]++; //esc3 like
 
            code = get_rl_index(rl, last, run, level);
            put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
            if (code == rl->n) {
                int level1, run1;
 
                level1 = level - rl->max_level[last][run];
                if (level1 < 1)
                    goto esc2;
                code = get_rl_index(rl, last, run, level1);
                if (code == rl->n) {
                esc2:
                    put_bits(&s->pb, 1, 0);
                    if (level > MAX_LEVEL)
                        goto esc3;
                    run1 = run - rl->max_run[last][level] - run_diff;
                    if (run1 < 0)
                        goto esc3;
                    code = get_rl_index(rl, last, run1+1, level);
                    if (s->c.msmpeg4_version == MSMP4_WMV1 && code == rl->n)
                        goto esc3;
                    code = get_rl_index(rl, last, run1, level);
                    if (code == rl->n) {
                    esc3:
                        /* third escape */
                        put_bits(&s->pb, 1, 0);
                        put_bits(&s->pb, 1, last);
                        if (s->c.msmpeg4_version >= MSMP4_WMV1) {
                            if (s->esc3_level_length == 0) {
                                s->esc3_level_length = 8;
                                ms->esc3_run_length  = 6;
                                //ESCLVLSZ + ESCRUNSZ
                                if (s->c.qscale < 8)
                                    put_bits(&s->pb, 6, 3);
                                else
                                    put_bits(&s->pb, 8, 3);
                            }
                            put_bits(&s->pb, ms->esc3_run_length, run);
                            put_bits(&s->pb, 1, sign);
                            put_bits(&s->pb, s->esc3_level_length, level);
                        }else{
                            put_bits(&s->pb, 6, run);
                            put_sbits(&s->pb, 8, slevel);
                        }
                    } else {
                        /* second escape */
                        put_bits(&s->pb, 1, 1);
                        put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
                        put_bits(&s->pb, 1, sign);
                    }
                } else {
                    /* first escape */
                    put_bits(&s->pb, 1, 1);
                    put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
                    put_bits(&s->pb, 1, sign);
                }
            } else {
                put_bits(&s->pb, 1, sign);
            }
            last_non_zero = i;
        }
    }
}
 
av_cold void ff_msmpeg4_encode_init(MPVMainEncContext *const m)
{
    MPVEncContext *const s = &m->s;
    static AVOnce init_static_once = AV_ONCE_INIT;
 
    ff_msmpeg4_common_init(&s->c);
 
    if (s->c.msmpeg4_version <= MSMP4_WMV1) {
        m->encode_picture_header = msmpeg4_encode_picture_header;
        s->encode_mb             = msmpeg4_encode_mb;
    }
 
    if (s->c.msmpeg4_version >= MSMP4_WMV1) {
        s->min_qcoeff = -255;
        s->max_qcoeff =  255;
    }
 
    /* init various encoding tables */
    ff_thread_once(&init_static_once, msmpeg4_encode_init_static);
}
 
const FFCodec ff_msmpeg4v2_encoder = {
    .p.name         = "msmpeg4v2",
    CODEC_LONG_NAME("MPEG-4 part 2 Microsoft variant version 2"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_MSMPEG4V2,
    CODEC_PIXFMTS(AV_PIX_FMT_YUV420P),
    .color_ranges   = AVCOL_RANGE_MPEG,
    .p.priv_class   = &ff_mpv_enc_class,
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
    .priv_data_size = sizeof(MSMPEG4EncContext),
    .init           = ff_mpv_encode_init,
    FF_CODEC_ENCODE_CB(ff_mpv_encode_picture),
    .close          = ff_mpv_encode_end,
};
 
const FFCodec ff_msmpeg4v3_encoder = {
    .p.name         = "msmpeg4",
    CODEC_LONG_NAME("MPEG-4 part 2 Microsoft variant version 3"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_MSMPEG4V3,
    CODEC_PIXFMTS(AV_PIX_FMT_YUV420P),
    .color_ranges   = AVCOL_RANGE_MPEG,
    .p.priv_class   = &ff_mpv_enc_class,
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
    .priv_data_size = sizeof(MSMPEG4EncContext),
    .init           = ff_mpv_encode_init,
    FF_CODEC_ENCODE_CB(ff_mpv_encode_picture),
    .close          = ff_mpv_encode_end,
};
 
const FFCodec ff_wmv1_encoder = {
    .p.name         = "wmv1",
    CODEC_LONG_NAME("Windows Media Video 7"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_WMV1,
    CODEC_PIXFMTS(AV_PIX_FMT_YUV420P),
    .color_ranges   = AVCOL_RANGE_MPEG,
    .p.priv_class   = &ff_mpv_enc_class,
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
    .priv_data_size = sizeof(MSMPEG4EncContext),
    .init           = ff_mpv_encode_init,
    FF_CODEC_ENCODE_CB(ff_mpv_encode_picture),
    .close          = ff_mpv_encode_end,
};