ffmpeg-bb/libavcodec/wmv2dec.c
Andreas Rheinhardt fadadb56e6 avcodec/mpegvideo_dec: Avoid implicit NULL + offset
Happens since 4fc874ef08
when this code is called via error resilience.
Also do the same for wmv2dec.c.
Fixes the vsynth_{1,2,3,_lena}-mpeg4-error and wmv2-drm-dec FATE-tests.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2025-07-11 15:14:36 +02:00

609 lines
20 KiB
C

/*
* Copyright (c) 2002 The FFmpeg Project
*
* 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 "libavutil/mem_internal.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "h263dec.h"
#include "intrax8.h"
#include "mathops.h"
#include "mpegutils.h"
#include "mpegvideo.h"
#include "mpegvideodec.h"
#include "msmpeg4.h"
#include "msmpeg4_vc1_data.h"
#include "msmpeg4dec.h"
#include "simple_idct.h"
#include "wmv2.h"
#include "wmv2data.h"
#include "wmv2dec.h"
typedef struct WMV2DecContext {
MSMP4DecContext ms;
WMV2Context common;
IntraX8Context x8;
int j_type_bit;
int j_type;
int abt_flag;
int abt_type;
int abt_type_table[6];
int per_mb_abt;
int per_block_abt;
int mspel_bit;
int cbp_table_index;
int top_left_mv_flag;
int per_mb_rl_bit;
int skip_type;
DECLARE_ALIGNED(32, int16_t, abt_block2)[6][64];
} WMV2DecContext;
static void wmv2_add_block(WMV2DecContext *w, int16_t blocks1[][64],
uint8_t *dst, int stride, int n)
{
H263DecContext *const h = &w->ms.h;
if (h->c.block_last_index[n] >= 0) {
int16_t *block1 = blocks1[n];
switch (w->abt_type_table[n]) {
case 0:
w->common.wdsp.idct_add(dst, stride, block1);
break;
case 1:
ff_simple_idct84_add(dst, stride, block1);
ff_simple_idct84_add(dst + 4 * stride, stride, w->abt_block2[n]);
h->c.bdsp.clear_block(w->abt_block2[n]);
break;
case 2:
ff_simple_idct48_add(dst, stride, block1);
ff_simple_idct48_add(dst + 4, stride, w->abt_block2[n]);
h->c.bdsp.clear_block(w->abt_block2[n]);
break;
default:
av_log(h->c.avctx, AV_LOG_ERROR, "internal error in WMV2 abt\n");
}
}
}
void ff_wmv2_add_mb(MpegEncContext *s, int16_t block1[6][64],
uint8_t *dest_y, uint8_t *dest_cb, uint8_t *dest_cr)
{
WMV2DecContext *const w = (WMV2DecContext *) s;
wmv2_add_block(w, block1, dest_y, s->linesize, 0);
wmv2_add_block(w, block1, dest_y + 8, s->linesize, 1);
wmv2_add_block(w, block1, dest_y + 8 * s->linesize, s->linesize, 2);
wmv2_add_block(w, block1, dest_y + 8 + 8 * s->linesize, s->linesize, 3);
if (s->avctx->flags & AV_CODEC_FLAG_GRAY)
return;
wmv2_add_block(w, block1, dest_cb, s->uvlinesize, 4);
wmv2_add_block(w, block1, dest_cr, s->uvlinesize, 5);
}
static int parse_mb_skip(WMV2DecContext *w)
{
H263DecContext *const h = &w->ms.h;
int coded_mb_count = 0;
uint32_t *const mb_type = h->c.cur_pic.mb_type;
w->skip_type = get_bits(&h->gb, 2);
switch (w->skip_type) {
case SKIP_TYPE_NONE:
for (int mb_y = 0; mb_y < h->c.mb_height; mb_y++)
for (int mb_x = 0; mb_x < h->c.mb_width; mb_x++)
mb_type[mb_y * h->c.mb_stride + mb_x] =
MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
break;
case SKIP_TYPE_MPEG:
if (get_bits_left(&h->gb) < h->c.mb_height * h->c.mb_width)
return AVERROR_INVALIDDATA;
for (int mb_y = 0; mb_y < h->c.mb_height; mb_y++)
for (int mb_x = 0; mb_x < h->c.mb_width; mb_x++)
mb_type[mb_y * h->c.mb_stride + mb_x] =
(get_bits1(&h->gb) ? MB_TYPE_SKIP : 0) | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
break;
case SKIP_TYPE_ROW:
for (int mb_y = 0; mb_y < h->c.mb_height; mb_y++) {
if (get_bits_left(&h->gb) < 1)
return AVERROR_INVALIDDATA;
if (get_bits1(&h->gb)) {
for (int mb_x = 0; mb_x < h->c.mb_width; mb_x++)
mb_type[mb_y * h->c.mb_stride + mb_x] =
MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
} else {
for (int mb_x = 0; mb_x < h->c.mb_width; mb_x++)
mb_type[mb_y * h->c.mb_stride + mb_x] =
(get_bits1(&h->gb) ? MB_TYPE_SKIP : 0) | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
}
}
break;
case SKIP_TYPE_COL:
for (int mb_x = 0; mb_x < h->c.mb_width; mb_x++) {
if (get_bits_left(&h->gb) < 1)
return AVERROR_INVALIDDATA;
if (get_bits1(&h->gb)) {
for (int mb_y = 0; mb_y < h->c.mb_height; mb_y++)
mb_type[mb_y * h->c.mb_stride + mb_x] =
MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
} else {
for (int mb_y = 0; mb_y < h->c.mb_height; mb_y++)
mb_type[mb_y * h->c.mb_stride + mb_x] =
(get_bits1(&h->gb) ? MB_TYPE_SKIP : 0) | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
}
}
break;
}
for (int mb_y = 0; mb_y < h->c.mb_height; mb_y++)
for (int mb_x = 0; mb_x < h->c.mb_width; mb_x++)
coded_mb_count += !IS_SKIP(mb_type[mb_y * h->c.mb_stride + mb_x]);
if (coded_mb_count > get_bits_left(&h->gb))
return AVERROR_INVALIDDATA;
return 0;
}
static int decode_ext_header(WMV2DecContext *w)
{
H263DecContext *const h = &w->ms.h;
GetBitContext gb;
int fps;
int code;
if (h->c.avctx->extradata_size < 4)
return AVERROR_INVALIDDATA;
init_get_bits(&gb, h->c.avctx->extradata, 32);
fps = get_bits(&gb, 5);
w->ms.bit_rate = get_bits(&gb, 11) * 1024;
w->mspel_bit = get_bits1(&gb);
h->loop_filter = get_bits1(&gb);
w->abt_flag = get_bits1(&gb);
w->j_type_bit = get_bits1(&gb);
w->top_left_mv_flag = get_bits1(&gb);
w->per_mb_rl_bit = get_bits1(&gb);
code = get_bits(&gb, 3);
if (code == 0)
return AVERROR_INVALIDDATA;
h->slice_height = h->c.mb_height / code;
if (h->c.avctx->debug & FF_DEBUG_PICT_INFO)
av_log(h->c.avctx, AV_LOG_DEBUG,
"fps:%d, br:%d, qpbit:%d, abt_flag:%d, j_type_bit:%d, "
"tl_mv_flag:%d, mbrl_bit:%d, code:%d, loop_filter:%d, "
"slices:%d\n",
fps, w->ms.bit_rate, w->mspel_bit, w->abt_flag, w->j_type_bit,
w->top_left_mv_flag, w->per_mb_rl_bit, code, h->loop_filter,
code);
return 0;
}
static int wmv2_decode_picture_header(H263DecContext *const h)
{
int code;
h->c.pict_type = get_bits1(&h->gb) + 1;
if (h->c.pict_type == AV_PICTURE_TYPE_I) {
code = get_bits(&h->gb, 7);
av_log(h->c.avctx, AV_LOG_DEBUG, "I7:%X/\n", code);
}
h->c.chroma_qscale = h->c.qscale = get_bits(&h->gb, 5);
if (h->c.qscale <= 0)
return AVERROR_INVALIDDATA;
if (h->c.pict_type != AV_PICTURE_TYPE_I && show_bits(&h->gb, 1)) {
GetBitContext gb = h->gb;
int skip_type = get_bits(&gb, 2);
int run = skip_type == SKIP_TYPE_COL ? h->c.mb_width : h->c.mb_height;
while (run > 0) {
int block = FFMIN(run, 25);
if (get_bits(&gb, block) + 1 != 1<<block)
break;
run -= block;
}
if (!run)
return FRAME_SKIPPED;
}
return 0;
}
int ff_wmv2_decode_secondary_picture_header(H263DecContext *const h)
{
WMV2DecContext *const w = (WMV2DecContext *)h;
if (h->c.pict_type == AV_PICTURE_TYPE_I) {
/* Is filling with zeroes really the right thing to do? */
memset(h->c.cur_pic.mb_type, 0,
sizeof(*h->c.cur_pic.mb_type) * h->c.mb_height * h->c.mb_stride);
if (w->j_type_bit)
w->j_type = get_bits1(&h->gb);
else
w->j_type = 0; // FIXME check
if (!w->j_type) {
if (w->per_mb_rl_bit)
w->ms.per_mb_rl_table = get_bits1(&h->gb);
else
w->ms.per_mb_rl_table = 0;
if (!w->ms.per_mb_rl_table) {
w->ms.rl_chroma_table_index = decode012(&h->gb);
w->ms.rl_table_index = decode012(&h->gb);
}
w->ms.dc_table_index = get_bits1(&h->gb);
// 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(&h->gb) * 8LL < (h->c.width+15)/16 * ((h->c.height+15)/16))
return AVERROR_INVALIDDATA;
}
h->c.inter_intra_pred = 0;
h->c.no_rounding = 1;
if (h->c.avctx->debug & FF_DEBUG_PICT_INFO) {
av_log(h->c.avctx, AV_LOG_DEBUG,
"qscale:%d rlc:%d rl:%d dc:%d mbrl:%d j_type:%d \n",
h->c.qscale, w->ms.rl_chroma_table_index, w->ms.rl_table_index,
w->ms.dc_table_index, w->ms.per_mb_rl_table, w->j_type);
}
} else {
int cbp_index;
int ret;
w->j_type = 0;
ret = parse_mb_skip(w);
if (ret < 0)
return ret;
cbp_index = decode012(&h->gb);
w->cbp_table_index = wmv2_get_cbp_table_index(h->c.qscale, cbp_index);
if (w->mspel_bit)
h->c.mspel = get_bits1(&h->gb);
else
h->c.mspel = 0; // FIXME check
if (w->abt_flag) {
w->per_mb_abt = get_bits1(&h->gb) ^ 1;
if (!w->per_mb_abt)
w->abt_type = decode012(&h->gb);
}
if (w->per_mb_rl_bit)
w->ms.per_mb_rl_table = get_bits1(&h->gb);
else
w->ms.per_mb_rl_table = 0;
if (!w->ms.per_mb_rl_table) {
w->ms.rl_table_index = decode012(&h->gb);
w->ms.rl_chroma_table_index = w->ms.rl_table_index;
}
if (get_bits_left(&h->gb) < 2)
return AVERROR_INVALIDDATA;
w->ms.dc_table_index = get_bits1(&h->gb);
w->ms.mv_table_index = get_bits1(&h->gb);
h->c.inter_intra_pred = 0; // (h->c.width * h->c.height < 320 * 240 && w->ms.bit_rate <= II_BITRATE);
h->c.no_rounding ^= 1;
if (h->c.avctx->debug & FF_DEBUG_PICT_INFO) {
av_log(h->c.avctx, AV_LOG_DEBUG,
"rl:%d rlc:%d dc:%d mv:%d mbrl:%d qp:%d mspel:%d "
"per_mb_abt:%d abt_type:%d cbp:%d ii:%d\n",
w->ms.rl_table_index, w->ms.rl_chroma_table_index,
w->ms.dc_table_index, w->ms.mv_table_index,
w->ms.per_mb_rl_table, h->c.qscale, h->c.mspel,
w->per_mb_abt, w->abt_type, w->cbp_table_index,
h->c.inter_intra_pred);
}
}
w->ms.esc3_level_length = 0;
w->ms.esc3_run_length = 0;
if (w->j_type) {
ff_intrax8_decode_picture(&w->x8, h->c.cur_pic.ptr,
&h->gb, &h->c.mb_x, &h->c.mb_y,
2 * h->c.qscale, (h->c.qscale - 1) | 1,
h->loop_filter, h->c.low_delay);
ff_er_add_slice(&h->c.er, 0, 0,
(h->c.mb_x >> 1) - 1, (h->c.mb_y >> 1) - 1,
ER_MB_END);
return 1;
}
return 0;
}
static inline void wmv2_decode_motion(WMV2DecContext *w, int *mx_ptr, int *my_ptr)
{
H263DecContext *const h = &w->ms.h;
ff_msmpeg4_decode_motion(&w->ms, mx_ptr, my_ptr);
if ((((*mx_ptr) | (*my_ptr)) & 1) && h->c.mspel)
w->common.hshift = get_bits1(&h->gb);
else
w->common.hshift = 0;
}
static int16_t *wmv2_pred_motion(WMV2DecContext *w, int *px, int *py)
{
H263DecContext *const h = &w->ms.h;
int diff, type;
int wrap = h->c.b8_stride;
int xy = h->c.block_index[0];
int16_t *mot_val = h->c.cur_pic.motion_val[0][xy];
const int16_t *A = h->c.cur_pic.motion_val[0][xy - 1];
const int16_t *B = h->c.cur_pic.motion_val[0][xy - wrap];
const int16_t *C = h->c.cur_pic.motion_val[0][xy + 2 - wrap];
if (h->c.mb_x && !h->c.first_slice_line && !h->c.mspel && w->top_left_mv_flag)
diff = FFMAX(FFABS(A[0] - B[0]), FFABS(A[1] - B[1]));
else
diff = 0;
if (diff >= 8)
type = get_bits1(&h->gb);
else
type = 2;
if (type == 0) {
*px = A[0];
*py = A[1];
} else if (type == 1) {
*px = B[0];
*py = B[1];
} else {
/* special case for first (slice) line */
if (h->c.first_slice_line) {
*px = A[0];
*py = A[1];
} else {
*px = mid_pred(A[0], B[0], C[0]);
*py = mid_pred(A[1], B[1], C[1]);
}
}
return mot_val;
}
static inline int wmv2_decode_inter_block(WMV2DecContext *w, int16_t *block,
int n, int cbp)
{
H263DecContext *const h = &w->ms.h;
static const int sub_cbp_table[3] = { 2, 3, 1 };
int sub_cbp, ret;
if (!cbp) {
h->c.block_last_index[n] = -1;
return 0;
}
if (w->per_block_abt)
w->abt_type = decode012(&h->gb);
w->abt_type_table[n] = w->abt_type;
if (w->abt_type) {
const uint8_t *scantable = w->abt_type == 1 ? ff_wmv2_scantableA : ff_wmv2_scantableB;
sub_cbp = sub_cbp_table[decode012(&h->gb)];
if (sub_cbp & 1) {
ret = ff_msmpeg4_decode_block(&w->ms, block, n, 1, scantable);
if (ret < 0)
return ret;
}
if (sub_cbp & 2) {
ret = ff_msmpeg4_decode_block(&w->ms, w->abt_block2[n], n, 1, scantable);
if (ret < 0)
return ret;
}
h->c.block_last_index[n] = 63;
return 0;
} else {
return ff_msmpeg4_decode_block(&w->ms, block, n, 1,
h->c.inter_scantable.permutated);
}
}
static int wmv2_decode_mb(H263DecContext *const h)
{
/* The following is only allowed because this decoder
* does not use slice threading. */
WMV2DecContext *const w = (WMV2DecContext *) h;
MSMP4DecContext *const ms = &w->ms;
int cbp, code, i, ret;
uint8_t *coded_val;
if (w->j_type)
return 0;
if (h->c.pict_type == AV_PICTURE_TYPE_P) {
if (IS_SKIP(h->c.cur_pic.mb_type[h->c.mb_y * h->c.mb_stride + h->c.mb_x])) {
/* skip mb */
h->c.mb_intra = 0;
for (i = 0; i < 6; i++)
h->c.block_last_index[i] = -1;
h->c.mv_dir = MV_DIR_FORWARD;
h->c.mv_type = MV_TYPE_16X16;
h->c.mv[0][0][0] = 0;
h->c.mv[0][0][1] = 0;
h->c.mb_skipped = 1;
w->common.hshift = 0;
return 0;
}
if (get_bits_left(&h->gb) <= 0)
return AVERROR_INVALIDDATA;
code = get_vlc2(&h->gb, ff_mb_non_intra_vlc[w->cbp_table_index],
MB_NON_INTRA_VLC_BITS, 3);
h->c.mb_intra = (~code & 0x40) >> 6;
cbp = code & 0x3f;
} else {
h->c.mb_intra = 1;
if (get_bits_left(&h->gb) <= 0)
return AVERROR_INVALIDDATA;
code = get_vlc2(&h->gb, ff_msmp4_mb_i_vlc,
MSMP4_MB_INTRA_VLC_BITS, 2);
/* 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(&h->c, i, &coded_val);
val = val ^ pred;
*coded_val = val;
}
cbp |= val << (5 - i);
}
}
if (!h->c.mb_intra) {
int mx, my;
wmv2_pred_motion(w, &mx, &my);
if (cbp) {
h->c.bdsp.clear_blocks(h->block[0]);
if (ms->per_mb_rl_table) {
ms->rl_table_index = decode012(&h->gb);
ms->rl_chroma_table_index = ms->rl_table_index;
}
if (w->abt_flag && w->per_mb_abt) {
w->per_block_abt = get_bits1(&h->gb);
if (!w->per_block_abt)
w->abt_type = decode012(&h->gb);
} else
w->per_block_abt = 0;
}
wmv2_decode_motion(w, &mx, &my);
h->c.mv_dir = MV_DIR_FORWARD;
h->c.mv_type = MV_TYPE_16X16;
h->c.mv[0][0][0] = mx;
h->c.mv[0][0][1] = my;
for (i = 0; i < 6; i++) {
if ((ret = wmv2_decode_inter_block(w, h->block[i], i, (cbp >> (5 - i)) & 1)) < 0) {
av_log(h->c.avctx, AV_LOG_ERROR,
"\nerror while decoding inter block: %d x %d (%d)\n",
h->c.mb_x, h->c.mb_y, i);
return ret;
}
}
} else {
if (h->c.pict_type == AV_PICTURE_TYPE_P)
ff_dlog(h->c.avctx, "%d%d ", h->c.inter_intra_pred, cbp);
ff_dlog(h->c.avctx, "I at %d %d %d %06X\n", h->c.mb_x, h->c.mb_y,
((cbp & 3) ? 1 : 0) + ((cbp & 0x3C) ? 2 : 0),
show_bits(&h->gb, 24));
h->c.ac_pred = get_bits1(&h->gb);
if (h->c.inter_intra_pred) {
h->c.h263_aic_dir = get_vlc2(&h->gb, ff_inter_intra_vlc,
INTER_INTRA_VLC_BITS, 1);
ff_dlog(h->c.avctx, "%d%d %d %d/",
h->c.ac_pred, h->c.h263_aic_dir, h->c.mb_x, h->c.mb_y);
}
if (ms->per_mb_rl_table && cbp) {
ms->rl_table_index = decode012(&h->gb);
ms->rl_chroma_table_index = ms->rl_table_index;
}
h->c.bdsp.clear_blocks(h->block[0]);
for (i = 0; i < 6; i++) {
ret = ff_msmpeg4_decode_block(ms, h->block[i], i, (cbp >> (5 - i)) & 1, NULL);
if (ret < 0) {
av_log(h->c.avctx, AV_LOG_ERROR,
"\nerror while decoding intra block: %d x %d (%d)\n",
h->c.mb_x, h->c.mb_y, i);
return ret;
}
}
}
return 0;
}
static av_cold int wmv2_decode_init(AVCodecContext *avctx)
{
WMV2DecContext *const w = avctx->priv_data;
H263DecContext *const h = &w->ms.h;
MpegEncContext *const s = &h->c;
int ret;
s->private_ctx = &w->common;
if ((ret = ff_msmpeg4_decode_init(avctx)) < 0)
return ret;
h->decode_header = wmv2_decode_picture_header;
h->decode_mb = wmv2_decode_mb;
ff_wmv2_common_init(s);
decode_ext_header(w);
return ff_intrax8_common_init(avctx, &w->x8, h->block[0],
s->mb_width, s->mb_height);
}
static av_cold int wmv2_decode_end(AVCodecContext *avctx)
{
WMV2DecContext *const w = avctx->priv_data;
ff_intrax8_common_end(&w->x8);
return ff_mpv_decode_close(avctx);
}
const FFCodec ff_wmv2_decoder = {
.p.name = "wmv2",
CODEC_LONG_NAME("Windows Media Video 8"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_WMV2,
.priv_data_size = sizeof(WMV2DecContext),
.init = wmv2_decode_init,
.close = wmv2_decode_end,
FF_CODEC_DECODE_CB(ff_h263_decode_frame),
.p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};