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FFmpeg/libavcodec/msmpeg4dec.c
Michael Niedermayer 09ec182864 avcodec/msmpeg4dec: Skip frame if its smaller than 1/8 of the minimal size 
Frames that small are not valid and of limited use for error concealment, while
being very computationally intensive to process.

Fixes: Timeout
Fixes: 11318/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MSMPEG4V1_fuzzer-5710884555456512

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2018-12-05 00:50:13 +01:00

952 lines
31 KiB
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/*
* MSMPEG4 backend for encoder and decoder
* Copyright (c) 2001 Fabrice Bellard
* Copyright (c) 2002-2013 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
*/
#include "avcodec.h"
#include "internal.h"
#include "mpegutils.h"
#include "mpegvideo.h"
#include "msmpeg4.h"
#include "libavutil/imgutils.h"
#include "h263.h"
#include "mpeg4video.h"
#include "msmpeg4data.h"
#include "vc1data.h"
#include "wmv2.h"
#define DC_VLC_BITS 9
#define V2_INTRA_CBPC_VLC_BITS 3
#define V2_MB_TYPE_VLC_BITS 7
#define MV_VLC_BITS 9
#define V2_MV_VLC_BITS 9
#define TEX_VLC_BITS 9
#define DEFAULT_INTER_INDEX 3
static inline int msmpeg4v1_pred_dc(MpegEncContext * s, int n,
int32_t **dc_val_ptr)
{
int i;
if (n < 4) {
i= 0;
} else {
i= n-3;
}
*dc_val_ptr= &s->last_dc[i];
return s->last_dc[i];
}
/****************************************/
/* decoding stuff */
VLC ff_mb_non_intra_vlc[4];
static VLC v2_dc_lum_vlc;
static VLC v2_dc_chroma_vlc;
static VLC v2_intra_cbpc_vlc;
static VLC v2_mb_type_vlc;
static VLC v2_mv_vlc;
VLC ff_inter_intra_vlc;
/* This is identical to H.263 except that its range is multiplied by 2. */
static int msmpeg4v2_decode_motion(MpegEncContext * s, int pred, int f_code)
{
int code, val, sign, shift;
code = get_vlc2(&s->gb, v2_mv_vlc.table, V2_MV_VLC_BITS, 2);
ff_dlog(s, "MV code %d at %d %d pred: %d\n", code, s->mb_x,s->mb_y, pred);
if (code < 0)
return 0xffff;
if (code == 0)
return pred;
sign = get_bits1(&s->gb);
shift = f_code - 1;
val = code;
if (shift) {
val = (val - 1) << shift;
val |= get_bits(&s->gb, shift);
val++;
}
if (sign)
val = -val;
val += pred;
if (val <= -64)
val += 64;
else if (val >= 64)
val -= 64;
return val;
}
static int msmpeg4v12_decode_mb(MpegEncContext *s, int16_t block[6][64])
{
int cbp, code, i;
uint32_t * const mb_type_ptr = &s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride];
if (s->pict_type == AV_PICTURE_TYPE_P) {
if (s->use_skip_mb_code) {
if (get_bits1(&s->gb)) {
/* skip mb */
s->mb_intra = 0;
for(i=0;i<6;i++)
s->block_last_index[i] = -1;
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
s->mv[0][0][0] = 0;
s->mv[0][0][1] = 0;
s->mb_skipped = 1;
*mb_type_ptr = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
return 0;
}
}
if(s->msmpeg4_version==2)
code = get_vlc2(&s->gb, v2_mb_type_vlc.table, V2_MB_TYPE_VLC_BITS, 1);
else
code = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
if(code<0 || code>7){
av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", code, s->mb_x, s->mb_y);
return -1;
}
s->mb_intra = code >>2;
cbp = code & 0x3;
} else {
s->mb_intra = 1;
if(s->msmpeg4_version==2)
cbp= get_vlc2(&s->gb, v2_intra_cbpc_vlc.table, V2_INTRA_CBPC_VLC_BITS, 1);
else
cbp= get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
if(cbp<0 || cbp>3){
av_log(s->avctx, AV_LOG_ERROR, "cbpc %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
return -1;
}
}
if (!s->mb_intra) {
int mx, my, cbpy;
cbpy= get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
if(cbpy<0){
av_log(s->avctx, AV_LOG_ERROR, "cbpy %d invalid at %d %d\n", cbp, s->mb_x, s->mb_y);
return -1;
}
cbp|= cbpy<<2;
if(s->msmpeg4_version==1 || (cbp&3) != 3) cbp^= 0x3C;
ff_h263_pred_motion(s, 0, 0, &mx, &my);
mx= msmpeg4v2_decode_motion(s, mx, 1);
my= msmpeg4v2_decode_motion(s, my, 1);
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
s->mv[0][0][0] = mx;
s->mv[0][0][1] = my;
*mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
} else {
int v;
if(s->msmpeg4_version==2){
s->ac_pred = get_bits1(&s->gb);
v = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
if (v < 0) {
av_log(s->avctx, AV_LOG_ERROR, "cbpy vlc invalid\n");
return -1;
}
cbp|= v<<2;
} else{
s->ac_pred = 0;
v = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
if (v < 0) {
av_log(s->avctx, AV_LOG_ERROR, "cbpy vlc invalid\n");
return -1;
}
cbp|= v<<2;
if(s->pict_type==AV_PICTURE_TYPE_P) cbp^=0x3C;
}
*mb_type_ptr = MB_TYPE_INTRA;
}
s->bdsp.clear_blocks(s->block[0]);
for (i = 0; i < 6; i++) {
if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
{
av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
return -1;
}
}
return 0;
}
static int msmpeg4v34_decode_mb(MpegEncContext *s, int16_t block[6][64])
{
int cbp, code, i;
uint8_t *coded_val;
uint32_t * const mb_type_ptr = &s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride];
if (get_bits_left(&s->gb) <= 0)
return AVERROR_INVALIDDATA;
if (s->pict_type == AV_PICTURE_TYPE_P) {
if (s->use_skip_mb_code) {
if (get_bits1(&s->gb)) {
/* skip mb */
s->mb_intra = 0;
for(i=0;i<6;i++)
s->block_last_index[i] = -1;
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
s->mv[0][0][0] = 0;
s->mv[0][0][1] = 0;
s->mb_skipped = 1;
*mb_type_ptr = MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
return 0;
}
}
code = get_vlc2(&s->gb, ff_mb_non_intra_vlc[DEFAULT_INTER_INDEX].table, MB_NON_INTRA_VLC_BITS, 3);
if (code < 0)
return -1;
//s->mb_intra = (code & 0x40) ? 0 : 1;
s->mb_intra = (~code & 0x40) >> 6;
cbp = code & 0x3f;
} else {
s->mb_intra = 1;
code = get_vlc2(&s->gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
if (code < 0)
return -1;
/* predict coded block pattern */
cbp = 0;
for(i=0;i<6;i++) {
int val = ((code >> (5 - i)) & 1);
if (i < 4) {
int pred = ff_msmpeg4_coded_block_pred(s, i, &coded_val);
val = val ^ pred;
*coded_val = val;
}
cbp |= val << (5 - i);
}
}
if (!s->mb_intra) {
int mx, my;
if(s->per_mb_rl_table && cbp){
s->rl_table_index = decode012(&s->gb);
s->rl_chroma_table_index = s->rl_table_index;
}
ff_h263_pred_motion(s, 0, 0, &mx, &my);
if (ff_msmpeg4_decode_motion(s, &mx, &my) < 0)
return -1;
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
s->mv[0][0][0] = mx;
s->mv[0][0][1] = my;
*mb_type_ptr = MB_TYPE_L0 | MB_TYPE_16x16;
} else {
ff_dlog(s, "I at %d %d %d %06X\n", s->mb_x, s->mb_y,
((cbp & 3) ? 1 : 0) +((cbp & 0x3C)? 2 : 0),
show_bits(&s->gb, 24));
s->ac_pred = get_bits1(&s->gb);
*mb_type_ptr = MB_TYPE_INTRA;
if(s->inter_intra_pred){
s->h263_aic_dir= get_vlc2(&s->gb, ff_inter_intra_vlc.table, INTER_INTRA_VLC_BITS, 1);
ff_dlog(s, "%d%d %d %d/",
s->ac_pred, s->h263_aic_dir, s->mb_x, s->mb_y);
}
if(s->per_mb_rl_table && cbp){
s->rl_table_index = decode012(&s->gb);
s->rl_chroma_table_index = s->rl_table_index;
}
}
s->bdsp.clear_blocks(s->block[0]);
for (i = 0; i < 6; i++) {
if (ff_msmpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1, NULL) < 0)
{
av_log(s->avctx, AV_LOG_ERROR, "\nerror while decoding block: %d x %d (%d)\n", s->mb_x, s->mb_y, i);
return -1;
}
}
return 0;
}
/* init all vlc decoding tables */
av_cold int ff_msmpeg4_decode_init(AVCodecContext *avctx)
{
MpegEncContext *s = avctx->priv_data;
static volatile int done = 0;
int i, ret;
MVTable *mv;
if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
return ret;
if (ff_h263_decode_init(avctx) < 0)
return -1;
ff_msmpeg4_common_init(s);
if (!done) {
for(i=0;i<NB_RL_TABLES;i++) {
ff_rl_init(&ff_rl_table[i], ff_static_rl_table_store[i]);
}
INIT_VLC_RL(ff_rl_table[0], 642);
INIT_VLC_RL(ff_rl_table[1], 1104);
INIT_VLC_RL(ff_rl_table[2], 554);
INIT_VLC_RL(ff_rl_table[3], 940);
INIT_VLC_RL(ff_rl_table[4], 962);
INIT_VLC_RL(ff_rl_table[5], 554);
mv = &ff_mv_tables[0];
INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, mv->n + 1,
mv->table_mv_bits, 1, 1,
mv->table_mv_code, 2, 2, 3714);
mv = &ff_mv_tables[1];
INIT_VLC_STATIC(&mv->vlc, MV_VLC_BITS, mv->n + 1,
mv->table_mv_bits, 1, 1,
mv->table_mv_code, 2, 2, 2694);
INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[0], DC_VLC_BITS, 120,
&ff_table0_dc_lum[0][1], 8, 4,
&ff_table0_dc_lum[0][0], 8, 4, 1158);
INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[0], DC_VLC_BITS, 120,
&ff_table0_dc_chroma[0][1], 8, 4,
&ff_table0_dc_chroma[0][0], 8, 4, 1118);
INIT_VLC_STATIC(&ff_msmp4_dc_luma_vlc[1], DC_VLC_BITS, 120,
&ff_table1_dc_lum[0][1], 8, 4,
&ff_table1_dc_lum[0][0], 8, 4, 1476);
INIT_VLC_STATIC(&ff_msmp4_dc_chroma_vlc[1], DC_VLC_BITS, 120,
&ff_table1_dc_chroma[0][1], 8, 4,
&ff_table1_dc_chroma[0][0], 8, 4, 1216);
INIT_VLC_STATIC(&v2_dc_lum_vlc, DC_VLC_BITS, 512,
&ff_v2_dc_lum_table[0][1], 8, 4,
&ff_v2_dc_lum_table[0][0], 8, 4, 1472);
INIT_VLC_STATIC(&v2_dc_chroma_vlc, DC_VLC_BITS, 512,
&ff_v2_dc_chroma_table[0][1], 8, 4,
&ff_v2_dc_chroma_table[0][0], 8, 4, 1506);
INIT_VLC_STATIC(&v2_intra_cbpc_vlc, V2_INTRA_CBPC_VLC_BITS, 4,
&ff_v2_intra_cbpc[0][1], 2, 1,
&ff_v2_intra_cbpc[0][0], 2, 1, 8);
INIT_VLC_STATIC(&v2_mb_type_vlc, V2_MB_TYPE_VLC_BITS, 8,
&ff_v2_mb_type[0][1], 2, 1,
&ff_v2_mb_type[0][0], 2, 1, 128);
INIT_VLC_STATIC(&v2_mv_vlc, V2_MV_VLC_BITS, 33,
&ff_mvtab[0][1], 2, 1,
&ff_mvtab[0][0], 2, 1, 538);
INIT_VLC_STATIC(&ff_mb_non_intra_vlc[0], MB_NON_INTRA_VLC_BITS, 128,
&ff_wmv2_inter_table[0][0][1], 8, 4,
&ff_wmv2_inter_table[0][0][0], 8, 4, 1636);
INIT_VLC_STATIC(&ff_mb_non_intra_vlc[1], MB_NON_INTRA_VLC_BITS, 128,
&ff_wmv2_inter_table[1][0][1], 8, 4,
&ff_wmv2_inter_table[1][0][0], 8, 4, 2648);
INIT_VLC_STATIC(&ff_mb_non_intra_vlc[2], MB_NON_INTRA_VLC_BITS, 128,
&ff_wmv2_inter_table[2][0][1], 8, 4,
&ff_wmv2_inter_table[2][0][0], 8, 4, 1532);
INIT_VLC_STATIC(&ff_mb_non_intra_vlc[3], MB_NON_INTRA_VLC_BITS, 128,
&ff_wmv2_inter_table[3][0][1], 8, 4,
&ff_wmv2_inter_table[3][0][0], 8, 4, 2488);
INIT_VLC_STATIC(&ff_msmp4_mb_i_vlc, MB_INTRA_VLC_BITS, 64,
&ff_msmp4_mb_i_table[0][1], 4, 2,
&ff_msmp4_mb_i_table[0][0], 4, 2, 536);
INIT_VLC_STATIC(&ff_inter_intra_vlc, INTER_INTRA_VLC_BITS, 4,
&ff_table_inter_intra[0][1], 2, 1,
&ff_table_inter_intra[0][0], 2, 1, 8);
done = 1;
}
switch(s->msmpeg4_version){
case 1:
case 2:
s->decode_mb= msmpeg4v12_decode_mb;
break;
case 3:
case 4:
s->decode_mb= msmpeg4v34_decode_mb;
break;
case 5:
if (CONFIG_WMV2_DECODER)
s->decode_mb= ff_wmv2_decode_mb;
case 6:
//FIXME + TODO VC1 decode mb
break;
}
s->slice_height= s->mb_height; //to avoid 1/0 if the first frame is not a keyframe
return 0;
}
int ff_msmpeg4_decode_picture_header(MpegEncContext * s)
{
int code;
// at minimum one bit per macroblock is required at least in a valid frame,
// we discard frames much smaller than this. Frames smaller than 1/8 of the
// smallest "black/skip" frame generally contain not much recoverable content
// while at the same time they have the highest computational requirements
// per byte
if (get_bits_left(&s->gb) * 8LL < (s->width+15)/16 * ((s->height+15)/16))
return AVERROR_INVALIDDATA;
if(s->msmpeg4_version==1){
int start_code = get_bits_long(&s->gb, 32);
if(start_code!=0x00000100){
av_log(s->avctx, AV_LOG_ERROR, "invalid startcode\n");
return -1;
}
skip_bits(&s->gb, 5); // frame number */
}
s->pict_type = get_bits(&s->gb, 2) + 1;
if (s->pict_type != AV_PICTURE_TYPE_I &&
s->pict_type != AV_PICTURE_TYPE_P){
av_log(s->avctx, AV_LOG_ERROR, "invalid picture type\n");
return -1;
}
s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
if(s->qscale==0){
av_log(s->avctx, AV_LOG_ERROR, "invalid qscale\n");
return -1;
}
if (s->pict_type == AV_PICTURE_TYPE_I) {
code = get_bits(&s->gb, 5);
if(s->msmpeg4_version==1){
if(code==0 || code>s->mb_height){
av_log(s->avctx, AV_LOG_ERROR, "invalid slice height %d\n", code);
return -1;
}
s->slice_height = code;
}else{
/* 0x17: one slice, 0x18: two slices, ... */
if (code < 0x17){
av_log(s->avctx, AV_LOG_ERROR, "error, slice code was %X\n", code);
return -1;
}
s->slice_height = s->mb_height / (code - 0x16);
}
switch(s->msmpeg4_version){
case 1:
case 2:
s->rl_chroma_table_index = 2;
s->rl_table_index = 2;
s->dc_table_index = 0; //not used
break;
case 3:
s->rl_chroma_table_index = decode012(&s->gb);
s->rl_table_index = decode012(&s->gb);
s->dc_table_index = get_bits1(&s->gb);
break;
case 4:
ff_msmpeg4_decode_ext_header(s, (2+5+5+17+7)/8);
if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
else s->per_mb_rl_table= 0;
if(!s->per_mb_rl_table){
s->rl_chroma_table_index = decode012(&s->gb);
s->rl_table_index = decode012(&s->gb);
}
s->dc_table_index = get_bits1(&s->gb);
s->inter_intra_pred= 0;
break;
}
s->no_rounding = 1;
if(s->avctx->debug&FF_DEBUG_PICT_INFO)
av_log(s->avctx, AV_LOG_DEBUG, "qscale:%d rlc:%d rl:%d dc:%d mbrl:%d slice:%d \n",
s->qscale,
s->rl_chroma_table_index,
s->rl_table_index,
s->dc_table_index,
s->per_mb_rl_table,
s->slice_height);
} else {
switch(s->msmpeg4_version){
case 1:
case 2:
if(s->msmpeg4_version==1)
s->use_skip_mb_code = 1;
else
s->use_skip_mb_code = get_bits1(&s->gb);
s->rl_table_index = 2;
s->rl_chroma_table_index = s->rl_table_index;
s->dc_table_index = 0; //not used
s->mv_table_index = 0;
break;
case 3:
s->use_skip_mb_code = get_bits1(&s->gb);
s->rl_table_index = decode012(&s->gb);
s->rl_chroma_table_index = s->rl_table_index;
s->dc_table_index = get_bits1(&s->gb);
s->mv_table_index = get_bits1(&s->gb);
break;
case 4:
s->use_skip_mb_code = get_bits1(&s->gb);
if(s->bit_rate > MBAC_BITRATE) s->per_mb_rl_table= get_bits1(&s->gb);
else s->per_mb_rl_table= 0;
if(!s->per_mb_rl_table){
s->rl_table_index = decode012(&s->gb);
s->rl_chroma_table_index = s->rl_table_index;
}
s->dc_table_index = get_bits1(&s->gb);
s->mv_table_index = get_bits1(&s->gb);
s->inter_intra_pred= (s->width*s->height < 320*240 && s->bit_rate<=II_BITRATE);
break;
}
if(s->avctx->debug&FF_DEBUG_PICT_INFO)
av_log(s->avctx, AV_LOG_DEBUG, "skip:%d rl:%d rlc:%d dc:%d mv:%d mbrl:%d qp:%d \n",
s->use_skip_mb_code,
s->rl_table_index,
s->rl_chroma_table_index,
s->dc_table_index,
s->mv_table_index,
s->per_mb_rl_table,
s->qscale);
if(s->flipflop_rounding){
s->no_rounding ^= 1;
}else{
s->no_rounding = 0;
}
}
ff_dlog(s->avctx, "%d %"PRId64" %d %d %d\n", s->pict_type, s->bit_rate,
s->inter_intra_pred, s->width, s->height);
s->esc3_level_length= 0;
s->esc3_run_length= 0;
return 0;
}
int ff_msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size)
{
int left= buf_size*8 - get_bits_count(&s->gb);
int length= s->msmpeg4_version>=3 ? 17 : 16;
/* the alt_bitstream reader could read over the end so we need to check it */
if(left>=length && left<length+8)
{
skip_bits(&s->gb, 5); /* fps */
s->bit_rate= get_bits(&s->gb, 11)*1024;
if(s->msmpeg4_version>=3)
s->flipflop_rounding= get_bits1(&s->gb);
else
s->flipflop_rounding= 0;
}
else if(left<length+8)
{
s->flipflop_rounding= 0;
if(s->msmpeg4_version != 2)
av_log(s->avctx, AV_LOG_ERROR, "ext header missing, %d left\n", left);
}
else
{
av_log(s->avctx, AV_LOG_ERROR, "I-frame too long, ignoring ext header\n");
}
return 0;
}
static int msmpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
{
int level, pred;
if(s->msmpeg4_version<=2){
if (n < 4) {
level = get_vlc2(&s->gb, v2_dc_lum_vlc.table, DC_VLC_BITS, 3);
} else {
level = get_vlc2(&s->gb, v2_dc_chroma_vlc.table, DC_VLC_BITS, 3);
}
if (level < 0) {
av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
*dir_ptr = 0;
return -1;
}
level-=256;
}else{ //FIXME optimize use unified tables & index
if (n < 4) {
level = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
} else {
level = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
}
if (level < 0){
av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
*dir_ptr = 0;
return -1;
}
if (level == DC_MAX) {
level = get_bits(&s->gb, 8);
if (get_bits1(&s->gb))
level = -level;
} else if (level != 0) {
if (get_bits1(&s->gb))
level = -level;
}
}
if(s->msmpeg4_version==1){
int32_t *dc_val;
pred = msmpeg4v1_pred_dc(s, n, &dc_val);
level += pred;
/* update predictor */
*dc_val= level;
}else{
int16_t *dc_val;
pred = ff_msmpeg4_pred_dc(s, n, &dc_val, dir_ptr);
level += pred;
/* update predictor */
if (n < 4) {
*dc_val = level * s->y_dc_scale;
} else {
*dc_val = level * s->c_dc_scale;
}
}
return level;
}
int ff_msmpeg4_decode_block(MpegEncContext * s, int16_t * block,
int n, int coded, const uint8_t *scan_table)
{
int level, i, last, run, run_diff;
int av_uninit(dc_pred_dir);
RLTable *rl;
RL_VLC_ELEM *rl_vlc;
int qmul, qadd;
if (s->mb_intra) {
qmul=1;
qadd=0;
/* DC coef */
level = msmpeg4_decode_dc(s, n, &dc_pred_dir);
if (level < 0){
av_log(s->avctx, AV_LOG_ERROR, "dc overflow- block: %d qscale: %d//\n", n, s->qscale);
if(s->inter_intra_pred) level=0;
}
if (n < 4) {
rl = &ff_rl_table[s->rl_table_index];
if(level > 256*s->y_dc_scale){
av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ L qscale: %d//\n", s->qscale);
if(!s->inter_intra_pred) return -1;
}
} else {
rl = &ff_rl_table[3 + s->rl_chroma_table_index];
if(level > 256*s->c_dc_scale){
av_log(s->avctx, AV_LOG_ERROR, "dc overflow+ C qscale: %d//\n", s->qscale);
if(!s->inter_intra_pred) return -1;
}
}
block[0] = level;
run_diff = s->msmpeg4_version >= 4;
i = 0;
if (!coded) {
goto not_coded;
}
if (s->ac_pred) {
if (dc_pred_dir == 0)
scan_table = s->intra_v_scantable.permutated; /* left */
else
scan_table = s->intra_h_scantable.permutated; /* top */
} else {
scan_table = s->intra_scantable.permutated;
}
rl_vlc= rl->rl_vlc[0];
} else {
qmul = s->qscale << 1;
qadd = (s->qscale - 1) | 1;
i = -1;
rl = &ff_rl_table[3 + s->rl_table_index];
if(s->msmpeg4_version==2)
run_diff = 0;
else
run_diff = 1;
if (!coded) {
s->block_last_index[n] = i;
return 0;
}
if(!scan_table)
scan_table = s->inter_scantable.permutated;
rl_vlc= rl->rl_vlc[s->qscale];
}
{
OPEN_READER(re, &s->gb);
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
if (level==0) {
int cache;
cache= GET_CACHE(re, &s->gb);
/* escape */
if (s->msmpeg4_version==1 || (cache&0x80000000)==0) {
if (s->msmpeg4_version==1 || (cache&0x40000000)==0) {
/* third escape */
if(s->msmpeg4_version!=1) LAST_SKIP_BITS(re, &s->gb, 2);
UPDATE_CACHE(re, &s->gb);
if(s->msmpeg4_version<=3){
last= SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
run= SHOW_UBITS(re, &s->gb, 6); SKIP_CACHE(re, &s->gb, 6);
level= SHOW_SBITS(re, &s->gb, 8);
SKIP_COUNTER(re, &s->gb, 1+6+8);
}else{
int sign;
last= SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
if(!s->esc3_level_length){
int ll;
ff_dlog(s->avctx, "ESC-3 %X at %d %d\n",
show_bits(&s->gb, 24), s->mb_x, s->mb_y);
if(s->qscale<8){
ll= SHOW_UBITS(re, &s->gb, 3); SKIP_BITS(re, &s->gb, 3);
if(ll==0){
ll= 8+SHOW_UBITS(re, &s->gb, 1); SKIP_BITS(re, &s->gb, 1);
}
}else{
ll=2;
while(ll<8 && SHOW_UBITS(re, &s->gb, 1)==0){
ll++;
SKIP_BITS(re, &s->gb, 1);
}
if(ll<8) SKIP_BITS(re, &s->gb, 1);
}
s->esc3_level_length= ll;
s->esc3_run_length= SHOW_UBITS(re, &s->gb, 2) + 3; SKIP_BITS(re, &s->gb, 2);
UPDATE_CACHE(re, &s->gb);
}
run= SHOW_UBITS(re, &s->gb, s->esc3_run_length);
SKIP_BITS(re, &s->gb, s->esc3_run_length);
sign= SHOW_UBITS(re, &s->gb, 1);
SKIP_BITS(re, &s->gb, 1);
level= SHOW_UBITS(re, &s->gb, s->esc3_level_length);
SKIP_BITS(re, &s->gb, s->esc3_level_length);
if(sign) level= -level;
}
//level = level * qmul + (level>0) * qadd - (level<=0) * qadd ;
if (level>0) level= level * qmul + qadd;
else level= level * qmul - qadd;
i+= run + 1;
if(last) i+=192;
} else {
/* second escape */
SKIP_BITS(re, &s->gb, 2);
GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
i+= run + rl->max_run[run>>7][level/qmul] + run_diff; //FIXME opt indexing
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
}
} else {
/* first escape */
SKIP_BITS(re, &s->gb, 1);
GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
i+= run;
level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
}
} else {
i+= run;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
}
if (i > 62){
i-= 192;
if(i&(~63)){
const int left= get_bits_left(&s->gb);
if (((i + 192 == 64 && level / qmul == -1) ||
!(s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))) &&
left >= 0) {
av_log(s->avctx, AV_LOG_ERROR, "ignoring overflow at %d %d\n", s->mb_x, s->mb_y);
i = 63;
break;
}else{
av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
}
block[scan_table[i]] = level;
break;
}
block[scan_table[i]] = level;
}
CLOSE_READER(re, &s->gb);
}
not_coded:
if (s->mb_intra) {
ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
if (s->ac_pred) {
i = 63; /* XXX: not optimal */
}
}
if(s->msmpeg4_version>=4 && i>0) i=63; //FIXME/XXX optimize
s->block_last_index[n] = i;
return 0;
}
int ff_msmpeg4_decode_motion(MpegEncContext * s,
int *mx_ptr, int *my_ptr)
{
MVTable *mv;
int code, mx, my;
mv = &ff_mv_tables[s->mv_table_index];
code = get_vlc2(&s->gb, mv->vlc.table, MV_VLC_BITS, 2);
if (code < 0){
av_log(s->avctx, AV_LOG_ERROR, "illegal MV code at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
if (code == mv->n) {
mx = get_bits(&s->gb, 6);
my = get_bits(&s->gb, 6);
} else {
mx = mv->table_mvx[code];
my = mv->table_mvy[code];
}
mx += *mx_ptr - 32;
my += *my_ptr - 32;
/* WARNING : they do not do exactly modulo encoding */
if (mx <= -64)
mx += 64;
else if (mx >= 64)
mx -= 64;
if (my <= -64)
my += 64;
else if (my >= 64)
my -= 64;
*mx_ptr = mx;
*my_ptr = my;
return 0;
}
AVCodec ff_msmpeg4v1_decoder = {
.name = "msmpeg4v1",
.long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MSMPEG4V1,
.priv_data_size = sizeof(MpegEncContext),
.init = ff_msmpeg4_decode_init,
.close = ff_h263_decode_end,
.decode = ff_h263_decode_frame,
.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
.max_lowres = 3,
.pix_fmts = (const enum AVPixelFormat[]) {
AV_PIX_FMT_YUV420P,
AV_PIX_FMT_NONE
},
};
AVCodec ff_msmpeg4v2_decoder = {
.name = "msmpeg4v2",
.long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MSMPEG4V2,
.priv_data_size = sizeof(MpegEncContext),
.init = ff_msmpeg4_decode_init,
.close = ff_h263_decode_end,
.decode = ff_h263_decode_frame,
.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
.max_lowres = 3,
.pix_fmts = (const enum AVPixelFormat[]) {
AV_PIX_FMT_YUV420P,
AV_PIX_FMT_NONE
},
};
AVCodec ff_msmpeg4v3_decoder = {
.name = "msmpeg4",
.long_name = NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MSMPEG4V3,
.priv_data_size = sizeof(MpegEncContext),
.init = ff_msmpeg4_decode_init,
.close = ff_h263_decode_end,
.decode = ff_h263_decode_frame,
.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
.max_lowres = 3,
.pix_fmts = (const enum AVPixelFormat[]) {
AV_PIX_FMT_YUV420P,
AV_PIX_FMT_NONE
},
};
AVCodec ff_wmv1_decoder = {
.name = "wmv1",
.long_name = NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_WMV1,
.priv_data_size = sizeof(MpegEncContext),
.init = ff_msmpeg4_decode_init,
.close = ff_h263_decode_end,
.decode = ff_h263_decode_frame,
.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
.max_lowres = 3,
.pix_fmts = (const enum AVPixelFormat[]) {
AV_PIX_FMT_YUV420P,
AV_PIX_FMT_NONE
},
};
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