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ffmpeg/libavcodec/msmpeg4enc.c
Andreas Rheinhardt 89a0cec790 avcodec/msmpeg4enc: Combine writing bits 
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-06-20 18:58:38 +02:00

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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>
#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];
/* build the table which associate a (x,y) motion vector to a vlc */
static av_cold void init_mv_table(MVTable *tab, uint16_t table_mv_index[4096])
{
int i, x, y;
tab->table_mv_index = table_mv_index;
/* mark all entries as not used */
for(i=0;i<4096;i++)
tab->table_mv_index[i] = MSMPEG4_MV_TABLES_NB_ELEMS;
for (i = 0; i < MSMPEG4_MV_TABLES_NB_ELEMS; i++) {
x = tab->table_mvx[i];
y = tab->table_mvy[i];
tab->table_mv_index[(x << 6) | y] = i;
}
}
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)
{
static uint16_t mv_index_tables[2][4096];
init_mv_table(&ff_mv_tables[0], mv_index_tables[0]);
init_mv_table(&ff_mv_tables[1], mv_index_tables[1]);
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);
}
}
}
}
}
av_cold void ff_msmpeg4_encode_init(MpegEncContext *s)
{
static AVOnce init_static_once = AV_ONCE_INIT;
ff_msmpeg4_common_init(s);
if (s->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);
}
static void find_best_tables(MSMPEG4EncContext *ms)
{
MpegEncContext *const s = &ms->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->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->pict_type==AV_PICTURE_TYPE_P) chroma_best= best;
memset(ms->ac_stats, 0, sizeof(ms->ac_stats));
s->rl_table_index = best;
s->rl_chroma_table_index= chroma_best;
if(s->pict_type != s->last_non_b_pict_type){
s->rl_table_index= 2;
if(s->pict_type==AV_PICTURE_TYPE_I)
s->rl_chroma_table_index= 1;
else
s->rl_chroma_table_index= 2;
}
}
/* write MSMPEG4 compatible frame header */
void ff_msmpeg4_encode_picture_header(MpegEncContext * s)
{
MSMPEG4EncContext *const ms = (MSMPEG4EncContext*)s;
find_best_tables(ms);
align_put_bits(&s->pb);
put_bits(&s->pb, 2, s->pict_type - 1);
put_bits(&s->pb, 5, s->qscale);
if (s->msmpeg4_version <= MSMP4_V2) {
s->rl_table_index = 2;
s->rl_chroma_table_index = 2;
}
s->dc_table_index = 1;
s->mv_table_index = 1; /* only if P-frame */
s->use_skip_mb_code = 1; /* only if P-frame */
s->per_mb_rl_table = 0;
if (s->msmpeg4_version == MSMP4_WMV1)
s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE && s->pict_type==AV_PICTURE_TYPE_P);
ff_dlog(s, "%d %"PRId64" %d %d %d\n", s->pict_type, s->bit_rate,
s->inter_intra_pred, s->width, s->height);
if (s->pict_type == AV_PICTURE_TYPE_I) {
s->slice_height= s->mb_height/1;
put_bits(&s->pb, 5, 0x16 + s->mb_height/s->slice_height);
if (s->msmpeg4_version == MSMP4_WMV1) {
ff_msmpeg4_encode_ext_header(s);
if(s->bit_rate>MBAC_BITRATE)
put_bits(&s->pb, 1, s->per_mb_rl_table);
}
if (s->msmpeg4_version > MSMP4_V2) {
if(!s->per_mb_rl_table){
ff_msmpeg4_code012(&s->pb, s->rl_chroma_table_index);
ff_msmpeg4_code012(&s->pb, s->rl_table_index);
}
put_bits(&s->pb, 1, s->dc_table_index);
}
} else {
put_bits(&s->pb, 1, s->use_skip_mb_code);
if (s->msmpeg4_version == MSMP4_WMV1 && s->bit_rate > MBAC_BITRATE)
put_bits(&s->pb, 1, s->per_mb_rl_table);
if (s->msmpeg4_version > MSMP4_V2) {
if(!s->per_mb_rl_table)
ff_msmpeg4_code012(&s->pb, s->rl_table_index);
put_bits(&s->pb, 1, s->dc_table_index);
put_bits(&s->pb, 1, s->mv_table_index);
}
}
s->esc3_level_length= 0;
s->esc3_run_length= 0;
}
void ff_msmpeg4_encode_ext_header(MpegEncContext * s)
{
unsigned fps;
if (s->avctx->framerate.num > 0 && s->avctx->framerate.den > 0)
fps = s->avctx->framerate.num / s->avctx->framerate.den;
else {
FF_DISABLE_DEPRECATION_WARNINGS
fps = s->avctx->time_base.den / s->avctx->time_base.num
#if FF_API_TICKS_PER_FRAME
/ FFMAX(s->avctx->ticks_per_frame, 1)
#endif
;
FF_ENABLE_DEPRECATION_WARNINGS
}
put_bits(&s->pb, 5, FFMIN(fps, 31)); //yes 29.97 -> 29
put_bits(&s->pb, 11, FFMIN(s->bit_rate / 1024, 2047));
if (s->msmpeg4_version >= MSMP4_V3)
put_bits(&s->pb, 1, s->flipflop_rounding);
else
av_assert0(!s->flipflop_rounding);
}
void ff_msmpeg4_encode_motion(MpegEncContext * s,
int mx, int my)
{
int code;
MVTable *mv;
/* 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;
mv = &ff_mv_tables[s->mv_table_index];
code = mv->table_mv_index[(mx << 6) | my];
put_bits(&s->pb,
mv->table_mv_bits[code],
mv->table_mv_code[code]);
if (code == MSMPEG4_MV_TABLES_NB_ELEMS) {
/* escape : code literally */
put_bits(&s->pb, 6, mx);
put_bits(&s->pb, 6, my);
}
}
void ff_msmpeg4_handle_slices(MpegEncContext *s){
if (s->mb_x == 0) {
if (s->slice_height && (s->mb_y % s->slice_height) == 0) {
if (s->msmpeg4_version < MSMP4_WMV1) {
ff_mpeg4_clean_buffers(s);
}
s->first_slice_line = 1;
} else {
s->first_slice_line = 0;
}
}
}
static void msmpeg4v2_encode_motion(MpegEncContext * s, int val)
{
int range, bit_size, sign, code, bits;
if (val == 0) {
/* zero vector */
code = 0;
put_bits(&s->pb, ff_mvtab[code][1], ff_mvtab[code][0]);
} 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);
}
}
}
void ff_msmpeg4_encode_mb(MpegEncContext * s,
int16_t block[6][64],
int motion_x, int motion_y)
{
int cbp, coded_cbp, i;
int pred_x, pred_y;
ff_msmpeg4_handle_slices(s);
if (!s->mb_intra) {
/* compute cbp */
cbp = 0;
for (i = 0; i < 6; i++) {
if (s->block_last_index[i] >= 0)
cbp |= 1 << (5 - i);
}
if (s->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 (s->use_skip_mb_code)
put_bits(&s->pb, 1, 0); /* mb coded */
if (s->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, 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, 0, 0, &pred_x, &pred_y);
ff_msmpeg4_encode_motion(s, 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->block_last_index[i] >= 1);
cbp |= val << (5 - i);
}
if (s->msmpeg4_version <= MSMP4_V2) {
if (s->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 (s->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->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, i, &coded_block);
int val = (s->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 (s->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->inter_intra_pred){
s->h263_aic_dir=0;
put_bits(&s->pb, ff_table_inter_intra[s->h263_aic_dir][1], ff_table_inter_intra[s->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(MpegEncContext * s, int level, int n, int *dir_ptr)
{
int sign, code;
int pred;
int16_t *dc_val;
pred = ff_msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
/* update predictor */
if (n < 4) {
*dc_val = level * s->y_dc_scale;
} else {
*dc_val = level * s->c_dc_scale;
}
/* do the prediction */
level -= pred;
if (s->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[s->dc_table_index][n >= 4][code][1],
ff_msmp4_dc_tables[s->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(MpegEncContext * 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->mb_intra) {
msmpeg4_encode_dc(s, block[0], n, &dc_pred_dir);
i = 1;
if (n < 4) {
rl = &ff_rl_table[s->rl_table_index];
} else {
rl = &ff_rl_table[3 + s->rl_chroma_table_index];
}
run_diff = s->msmpeg4_version >= MSMP4_WMV1;
scantable= s->intra_scantable.permutated;
} else {
i = 0;
rl = &ff_rl_table[3 + s->rl_table_index];
run_diff = s->msmpeg4_version > MSMP4_V2;
scantable= s->inter_scantable.permutated;
}
/* recalculate block_last_index for M$ wmv1 */
if (s->msmpeg4_version >= MSMP4_WMV1 && s->block_last_index[n] > 0) {
for(last_index=63; last_index>=0; last_index--){
if(block[scantable[last_index]]) break;
}
s->block_last_index[n]= last_index;
}else
last_index = s->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->mb_intra][n>3][level][run][last]++;
}
ms->ac_stats[s->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->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->msmpeg4_version >= MSMP4_WMV1) {
if(s->esc3_level_length==0){
s->esc3_level_length=8;
s->esc3_run_length= 6;
//ESCLVLSZ + ESCRUNSZ
if(s->qscale<8)
put_bits(&s->pb, 6, 3);
else
put_bits(&s->pb, 8, 3);
}
put_bits(&s->pb, s->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;
}
}
}
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,
.p.pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
.p.priv_class = &ff_mpv_enc_class,
.p.capabilities = 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,
.p.pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
.p.priv_class = &ff_mpv_enc_class,
.p.capabilities = 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,
.p.pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
.p.priv_class = &ff_mpv_enc_class,
.p.capabilities = 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,
};
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