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FFmpeg/libavcodec/dfa.c
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec 
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

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/*
* Chronomaster DFA Video Decoder
* Copyright (c) 2011 Konstantin Shishkov
* based on work by Vladimir "VAG" Gneushev
*
* 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 <inttypes.h>
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "internal.h"
#include "libavutil/avassert.h"
#include "libavutil/imgutils.h"
#include "libavutil/mem.h"
typedef struct DfaContext {
uint32_t pal[256];
uint8_t *frame_buf;
} DfaContext;
static av_cold int dfa_decode_init(AVCodecContext *avctx)
{
DfaContext *s = avctx->priv_data;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
if (!avctx->width || !avctx->height || FFMAX(avctx->width, avctx->height) >= (1<<16))
return AVERROR_INVALIDDATA;
av_assert0(av_image_check_size(avctx->width, avctx->height, 0, avctx) >= 0);
s->frame_buf = av_mallocz(avctx->width * avctx->height);
if (!s->frame_buf)
return AVERROR(ENOMEM);
return 0;
}
static int decode_copy(GetByteContext *gb, uint8_t *frame, int width, int height)
{
const int size = width * height;
if (bytestream2_get_buffer(gb, frame, size) != size)
return AVERROR_INVALIDDATA;
return 0;
}
static int decode_tsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
{
const uint8_t *frame_start = frame;
const uint8_t *frame_end = frame + width * height;
int mask = 0x10000, bitbuf = 0;
int v, count;
unsigned segments;
unsigned offset;
segments = bytestream2_get_le32(gb);
offset = bytestream2_get_le32(gb);
if (segments == 0 && offset == frame_end - frame)
return 0; // skip frame
if (frame_end - frame <= offset)
return AVERROR_INVALIDDATA;
frame += offset;
while (segments--) {
if (bytestream2_get_bytes_left(gb) < 2)
return AVERROR_INVALIDDATA;
if (mask == 0x10000) {
bitbuf = bytestream2_get_le16u(gb);
mask = 1;
}
if (frame_end - frame < 2)
return AVERROR_INVALIDDATA;
if (bitbuf & mask) {
v = bytestream2_get_le16(gb);
offset = (v & 0x1FFF) << 1;
count = ((v >> 13) + 2) << 1;
if (frame - frame_start < offset || frame_end - frame < count)
return AVERROR_INVALIDDATA;
av_memcpy_backptr(frame, offset, count);
frame += count;
} else {
*frame++ = bytestream2_get_byte(gb);
*frame++ = bytestream2_get_byte(gb);
}
mask <<= 1;
}
return 0;
}
static int decode_dsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
{
const uint8_t *frame_start = frame;
const uint8_t *frame_end = frame + width * height;
int mask = 0x10000, bitbuf = 0;
int v, offset, count, segments;
segments = bytestream2_get_le16(gb);
while (segments--) {
if (bytestream2_get_bytes_left(gb) < 2)
return AVERROR_INVALIDDATA;
if (mask == 0x10000) {
bitbuf = bytestream2_get_le16u(gb);
mask = 1;
}
if (frame_end - frame < 2)
return AVERROR_INVALIDDATA;
if (bitbuf & mask) {
v = bytestream2_get_le16(gb);
offset = (v & 0x1FFF) << 1;
count = ((v >> 13) + 2) << 1;
if (frame - frame_start < offset || frame_end - frame < count)
return AVERROR_INVALIDDATA;
av_memcpy_backptr(frame, offset, count);
frame += count;
} else if (bitbuf & (mask << 1)) {
frame += bytestream2_get_le16(gb);
} else {
*frame++ = bytestream2_get_byte(gb);
*frame++ = bytestream2_get_byte(gb);
}
mask <<= 2;
}
return 0;
}
static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height)
{
const uint8_t *frame_start = frame;
const uint8_t *frame_end = frame + width * height;
int mask = 0x10000, bitbuf = 0;
int i, v, offset, count, segments;
if ((width | height) & 1)
return AVERROR_INVALIDDATA;
segments = bytestream2_get_le16(gb);
while (segments--) {
if (bytestream2_get_bytes_left(gb) < 2)
return AVERROR_INVALIDDATA;
if (mask == 0x10000) {
bitbuf = bytestream2_get_le16u(gb);
mask = 1;
}
if (bitbuf & mask) {
v = bytestream2_get_le16(gb);
offset = (v & 0x1FFF) << 2;
count = ((v >> 13) + 2) << 1;
if (frame - frame_start < offset || frame_end - frame < count*2 + width)
return AVERROR_INVALIDDATA;
for (i = 0; i < count; i++) {
frame[0] = frame[1] =
frame[width] = frame[width + 1] = frame[-offset];
frame += 2;
}
} else if (bitbuf & (mask << 1)) {
v = bytestream2_get_le16(gb)*2;
if (frame - frame_end < v)
return AVERROR_INVALIDDATA;
frame += v;
} else {
if (width < 4 || frame_end - frame < width + 4)
return AVERROR_INVALIDDATA;
frame[0] = frame[1] =
frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
frame += 2;
frame[0] = frame[1] =
frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
frame += 2;
}
mask <<= 2;
}
return 0;
}
static int decode_bdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
{
uint8_t *line_ptr;
int count, lines, segments;
count = bytestream2_get_le16(gb);
if (count >= height)
return AVERROR_INVALIDDATA;
frame += width * count;
lines = bytestream2_get_le16(gb);
if (count + lines > height)
return AVERROR_INVALIDDATA;
while (lines--) {
if (bytestream2_get_bytes_left(gb) < 1)
return AVERROR_INVALIDDATA;
line_ptr = frame;
frame += width;
segments = bytestream2_get_byteu(gb);
while (segments--) {
if (frame - line_ptr <= bytestream2_peek_byte(gb))
return AVERROR_INVALIDDATA;
line_ptr += bytestream2_get_byte(gb);
count = (int8_t)bytestream2_get_byte(gb);
if (count >= 0) {
if (frame - line_ptr < count)
return AVERROR_INVALIDDATA;
if (bytestream2_get_buffer(gb, line_ptr, count) != count)
return AVERROR_INVALIDDATA;
} else {
count = -count;
if (frame - line_ptr < count)
return AVERROR_INVALIDDATA;
memset(line_ptr, bytestream2_get_byte(gb), count);
}
line_ptr += count;
}
}
return 0;
}
static int decode_wdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
{
const uint8_t *frame_end = frame + width * height;
uint8_t *line_ptr;
int count, i, v, lines, segments;
int y = 0;
lines = bytestream2_get_le16(gb);
if (lines > height)
return AVERROR_INVALIDDATA;
while (lines--) {
if (bytestream2_get_bytes_left(gb) < 2)
return AVERROR_INVALIDDATA;
segments = bytestream2_get_le16u(gb);
while ((segments & 0xC000) == 0xC000) {
unsigned skip_lines = -(int16_t)segments;
int64_t delta = -((int16_t)segments * (int64_t)width);
if (frame_end - frame <= delta || y + lines + skip_lines > height)
return AVERROR_INVALIDDATA;
frame += delta;
y += skip_lines;
segments = bytestream2_get_le16(gb);
}
if (frame_end <= frame)
return AVERROR_INVALIDDATA;
if (segments & 0x8000) {
frame[width - 1] = segments & 0xFF;
segments = bytestream2_get_le16(gb);
}
line_ptr = frame;
if (frame_end - frame < width)
return AVERROR_INVALIDDATA;
frame += width;
y++;
while (segments--) {
if (frame - line_ptr <= bytestream2_peek_byte(gb))
return AVERROR_INVALIDDATA;
line_ptr += bytestream2_get_byte(gb);
count = (int8_t)bytestream2_get_byte(gb);
if (count >= 0) {
if (frame - line_ptr < count * 2)
return AVERROR_INVALIDDATA;
if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
return AVERROR_INVALIDDATA;
line_ptr += count * 2;
} else {
count = -count;
if (frame - line_ptr < count * 2)
return AVERROR_INVALIDDATA;
v = bytestream2_get_le16(gb);
for (i = 0; i < count; i++)
bytestream_put_le16(&line_ptr, v);
}
}
}
return 0;
}
static int decode_tdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
{
const uint8_t *frame_end = frame + width * height;
uint32_t segments = bytestream2_get_le32(gb);
int skip, copy;
while (segments--) {
if (bytestream2_get_bytes_left(gb) < 2)
return AVERROR_INVALIDDATA;
copy = bytestream2_get_byteu(gb) * 2;
skip = bytestream2_get_byteu(gb) * 2;
if (frame_end - frame < copy + skip ||
bytestream2_get_bytes_left(gb) < copy)
return AVERROR_INVALIDDATA;
frame += skip;
bytestream2_get_buffer(gb, frame, copy);
frame += copy;
}
return 0;
}
static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
{
memset(frame, 0, width * height);
return 0;
}
typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
static const chunk_decoder decoder[8] = {
decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
decode_tdlt, decode_dsw1, decode_blck, decode_dds1,
};
static const char chunk_name[8][5] = {
"COPY", "TSW1", "BDLT", "WDLT", "TDLT", "DSW1", "BLCK", "DDS1"
};
static int dfa_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
AVFrame *frame = data;
DfaContext *s = avctx->priv_data;
GetByteContext gb;
const uint8_t *buf = avpkt->data;
uint32_t chunk_type, chunk_size;
uint8_t *dst;
int ret;
int i, pal_elems;
int version = avctx->extradata_size==2 ? AV_RL16(avctx->extradata) : 0;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
bytestream2_init(&gb, avpkt->data, avpkt->size);
while (bytestream2_get_bytes_left(&gb) > 0) {
if (bytestream2_get_bytes_left(&gb) < 12)
return AVERROR_INVALIDDATA;
bytestream2_skip(&gb, 4);
chunk_size = bytestream2_get_le32(&gb);
chunk_type = bytestream2_get_le32(&gb);
if (!chunk_type)
break;
if (chunk_type == 1) {
pal_elems = FFMIN(chunk_size / 3, 256);
for (i = 0; i < pal_elems; i++) {
s->pal[i] = bytestream2_get_be24(&gb) << 2;
s->pal[i] |= 0xFFU << 24 | (s->pal[i] >> 6) & 0x30303;
}
frame->palette_has_changed = 1;
} else if (chunk_type <= 9) {
if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
chunk_name[chunk_type - 2]);
return AVERROR_INVALIDDATA;
}
} else {
av_log(avctx, AV_LOG_WARNING,
"Ignoring unknown chunk type %"PRIu32"\n",
chunk_type);
}
buf += chunk_size;
}
buf = s->frame_buf;
dst = frame->data[0];
for (i = 0; i < avctx->height; i++) {
if(version == 0x100) {
int j;
const uint8_t *buf1 = buf + (i&3)*(avctx->width/4) + (i/4)*avctx->width;
int stride = (avctx->height/4)*avctx->width;
for(j = 0; j < avctx->width/4; j++) {
dst[4*j+0] = buf1[j + 0*stride];
dst[4*j+1] = buf1[j + 1*stride];
dst[4*j+2] = buf1[j + 2*stride];
dst[4*j+3] = buf1[j + 3*stride];
}
j *= 4;
for(; j < avctx->width; j++) {
dst[j] = buf1[(j/4) + (j&3)*stride];
}
} else {
memcpy(dst, buf, avctx->width);
buf += avctx->width;
}
dst += frame->linesize[0];
}
memcpy(frame->data[1], s->pal, sizeof(s->pal));
*got_frame = 1;
return avpkt->size;
}
static av_cold int dfa_decode_end(AVCodecContext *avctx)
{
DfaContext *s = avctx->priv_data;
av_freep(&s->frame_buf);
return 0;
}
const FFCodec ff_dfa_decoder = {
.p.name = "dfa",
.p.long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_DFA,
.priv_data_size = sizeof(DfaContext),
.init = dfa_decode_init,
.close = dfa_decode_end,
.decode = dfa_decode_frame,
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};
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