har0ke/FFmpeg
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
FFmpeg/libavcodec/fmvc.c
Michael Niedermayer 96c1162545
avcodec/fmvc: remove dead assignment 
Fixes: CID1529220 Unused value

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2024-05-13 03:40:17 +02:00

649 lines
22 KiB
C
Raw Blame History

/*
* FM Screen Capture Codec decoder
*
* Copyright (c) 2017 Paul B Mahol
*
* 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 <stdio.h>
#include <string.h>
#include "libavutil/mem.h"
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#define BLOCK_HEIGHT 112u
#define BLOCK_WIDTH 84u
typedef struct InterBlock {
int w, h;
int size;
int xor;
} InterBlock;
typedef struct FMVCContext {
GetByteContext gb;
PutByteContext pb;
uint8_t *buffer;
size_t buffer_size;
uint8_t *pbuffer;
size_t pbuffer_size;
ptrdiff_t stride;
int bpp;
int yb, xb;
InterBlock *blocks;
unsigned nb_blocks;
} FMVCContext;
static int decode_type2(GetByteContext *gb, PutByteContext *pb)
{
unsigned repeat = 0, first = 1, opcode = 0;
int i, len, pos;
while (bytestream2_get_bytes_left(gb) > 0) {
GetByteContext gbc;
while (bytestream2_get_bytes_left(gb) > 0) {
if (first) {
first = 0;
if (bytestream2_peek_byte(gb) > 17) {
len = bytestream2_get_byte(gb) - 17;
if (len < 4) {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
continue;
} else {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
if (opcode < 0x10) {
bytestream2_skip(gb, 1);
pos = - (opcode >> 2) - 4 * bytestream2_get_byte(gb) - 2049;
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
len = opcode & 3;
if (!len) {
repeat = 1;
} else {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
}
continue;
}
}
}
repeat = 1;
}
if (repeat) {
repeat = 0;
opcode = bytestream2_peek_byte(gb);
if (opcode < 0x10) {
bytestream2_skip(gb, 1);
if (!opcode) {
if (!bytestream2_peek_byte(gb)) {
do {
bytestream2_skip(gb, 1);
opcode += 255;
} while (!bytestream2_peek_byte(gb) && bytestream2_get_bytes_left(gb) > 0);
}
opcode += bytestream2_get_byte(gb) + 15;
}
bytestream2_put_le32(pb, bytestream2_get_le32(gb));
for (i = opcode - 1; i > 0; --i)
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
opcode = bytestream2_peek_byte(gb);
if (opcode < 0x10) {
bytestream2_skip(gb, 1);
pos = - (opcode >> 2) - 4 * bytestream2_get_byte(gb) - 2049;
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
len = opcode & 3;
if (!len) {
repeat = 1;
} else {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
}
continue;
}
}
}
if (opcode >= 0x40) {
bytestream2_skip(gb, 1);
pos = - ((opcode >> 2) & 7) - 1 - 8 * bytestream2_get_byte(gb);
len = (opcode >> 5) - 1;
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
do {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
--len;
} while (len);
len = opcode & 3;
if (!len) {
repeat = 1;
} else {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
}
continue;
} else if (opcode < 0x20) {
break;
}
len = opcode & 0x1F;
bytestream2_skip(gb, 1);
if (!len) {
if (!bytestream2_peek_byte(gb)) {
do {
bytestream2_skip(gb, 1);
len += 255;
} while (!bytestream2_peek_byte(gb) && bytestream2_get_bytes_left(gb) > 0);
}
len += bytestream2_get_byte(gb) + 31;
}
i = bytestream2_get_le16(gb);
pos = - (i >> 2) - 1;
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
if (len < 6 || bytestream2_tell_p(pb) - bytestream2_tell(&gbc) < 4) {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
do {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
--len;
} while (len);
} else {
bytestream2_put_le32(pb, bytestream2_get_le32(&gbc));
for (len = len - 2; len; --len)
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
}
len = i & 3;
if (!len) {
repeat = 1;
} else {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
}
}
bytestream2_skip(gb, 1);
if (opcode < 0x10) {
pos = -(opcode >> 2) - 1 - 4 * bytestream2_get_byte(gb);
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
len = opcode & 3;
if (!len) {
repeat = 1;
} else {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
}
continue;
}
len = opcode & 7;
if (!len) {
if (!bytestream2_peek_byte(gb)) {
do {
bytestream2_skip(gb, 1);
len += 255;
} while (!bytestream2_peek_byte(gb) && bytestream2_get_bytes_left(gb) > 0);
}
len += bytestream2_get_byte(gb) + 7;
}
i = bytestream2_get_le16(gb);
pos = bytestream2_tell_p(pb) - 2048 * (opcode & 8);
pos = pos - (i >> 2);
if (pos == bytestream2_tell_p(pb))
break;
pos = pos - 0x4000;
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
bytestream2_seek(&gbc, pos, SEEK_SET);
if (len < 6 || bytestream2_tell_p(pb) - bytestream2_tell(&gbc) < 4) {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
do {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
--len;
} while (len);
} else {
bytestream2_put_le32(pb, bytestream2_get_le32(&gbc));
for (len = len - 2; len; --len)
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
}
len = i & 3;
if (!len) {
repeat = 1;
} else {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--len;
} while (len);
opcode = bytestream2_peek_byte(gb);
}
}
return 0;
}
static int decode_type1(GetByteContext *gb, PutByteContext *pb)
{
unsigned opcode = 0, len;
int high = 0;
int i, pos;
while (bytestream2_get_bytes_left(gb) > 0) {
GetByteContext gbc;
while (bytestream2_get_bytes_left(gb) > 0) {
while (bytestream2_get_bytes_left(gb) > 0) {
opcode = bytestream2_get_byte(gb);
high = opcode >= 0x20;
if (high)
break;
if (opcode)
break;
opcode = bytestream2_get_byte(gb);
if (opcode < 0xF8) {
opcode += 32;
break;
}
i = opcode - 0xF8;
if (i) {
len = 256;
do {
len *= 2;
--i;
} while (i);
} else {
len = 280;
}
do {
bytestream2_put_le32(pb, bytestream2_get_le32(gb));
bytestream2_put_le32(pb, bytestream2_get_le32(gb));
len -= 8;
} while (len && bytestream2_get_bytes_left(gb) > 0);
}
if (!high) {
do {
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
--opcode;
} while (opcode && bytestream2_get_bytes_left(gb) > 0);
while (bytestream2_get_bytes_left(gb) > 0) {
GetByteContext gbc;
opcode = bytestream2_get_byte(gb);
if (opcode >= 0x20)
break;
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
pos = -(opcode | 32 * bytestream2_get_byte(gb)) - 1;
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(gb));
}
}
high = 0;
if (opcode < 0x40)
break;
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
pos = (-((opcode & 0x1F) | 32 * bytestream2_get_byte(gb)) - 1);
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos, SEEK_SET);
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
len = (opcode >> 5) - 1;
do {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
--len;
} while (len && bytestream2_get_bytes_left(&gbc) > 0);
}
len = opcode & 0x1F;
if (!len) {
if (!bytestream2_peek_byte(gb)) {
do {
bytestream2_skip(gb, 1);
len += 255;
} while (!bytestream2_peek_byte(gb) && bytestream2_get_bytes_left(gb) > 0);
}
len += bytestream2_get_byte(gb) + 31;
}
pos = -bytestream2_get_byte(gb);
bytestream2_init(&gbc, pb->buffer_start, pb->buffer_end - pb->buffer_start);
bytestream2_seek(&gbc, bytestream2_tell_p(pb) + pos - (bytestream2_get_byte(gb) << 8), SEEK_SET);
if (bytestream2_tell_p(pb) == bytestream2_tell(&gbc))
break;
if (len < 5 || bytestream2_tell_p(pb) - bytestream2_tell(&gbc) < 4) {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
} else {
bytestream2_put_le32(pb, bytestream2_get_le32(&gbc));
len--;
}
do {
bytestream2_put_byte(pb, bytestream2_get_byte(&gbc));
len--;
} while (len && bytestream2_get_bytes_left(&gbc) > 0);
}
return 0;
}
static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame, AVPacket *avpkt)
{
FMVCContext *s = avctx->priv_data;
GetByteContext *gb = &s->gb;
PutByteContext *pb = &s->pb;
int ret, y, x;
int key_frame;
if (avpkt->size < 8)
return AVERROR_INVALIDDATA;
bytestream2_init(gb, avpkt->data, avpkt->size);
bytestream2_skip(gb, 2);
key_frame = !!bytestream2_get_le16(gb);
if (key_frame) {
const uint8_t *src;
unsigned type, size;
uint8_t *dst;
type = bytestream2_get_le16(gb);
size = bytestream2_get_le16(gb);
if (size > bytestream2_get_bytes_left(gb))
return AVERROR_INVALIDDATA;
bytestream2_init_writer(pb, s->buffer, s->buffer_size);
if (type == 1) {
decode_type1(gb, pb);
} else if (type == 2){
decode_type2(gb, pb);
} else {
avpriv_report_missing_feature(avctx, "Compression type %d", type);
return AVERROR_PATCHWELCOME;
}
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
frame->flags |= AV_FRAME_FLAG_KEY;
frame->pict_type = AV_PICTURE_TYPE_I;
src = s->buffer;
dst = frame->data[0] + (avctx->height - 1) * frame->linesize[0];
for (y = 0; y < avctx->height; y++) {
memcpy(dst, src, avctx->width * s->bpp);
dst -= frame->linesize[0];
src += s->stride * 4;
if (bytestream2_tell_p(pb) < y*s->stride * 4)
break;
}
} else {
unsigned block, nb_blocks;
int type, k, l;
uint8_t *ssrc, *ddst;
const uint32_t *src;
uint32_t *dst;
for (block = 0; block < s->nb_blocks; block++)
s->blocks[block].xor = 0;
nb_blocks = bytestream2_get_le16(gb);
if (nb_blocks > s->nb_blocks)
return AVERROR_INVALIDDATA;
bytestream2_init_writer(pb, s->pbuffer, s->pbuffer_size);
type = bytestream2_get_le16(gb);
for (block = 0; block < nb_blocks; block++) {
unsigned size, offset;
int start = 0;
offset = bytestream2_get_le16(gb);
if (offset >= s->nb_blocks)
return AVERROR_INVALIDDATA;
size = bytestream2_get_le16(gb);
if (size > bytestream2_get_bytes_left(gb))
return AVERROR_INVALIDDATA;
start = bytestream2_tell_p(pb);
if (type == 1) {
decode_type1(gb, pb);
} else if (type == 2){
decode_type2(gb, pb);
} else {
avpriv_report_missing_feature(avctx, "Compression type %d", type);
return AVERROR_PATCHWELCOME;
}
if (s->blocks[offset].size * 4 != bytestream2_tell_p(pb) - start)
return AVERROR_INVALIDDATA;
s->blocks[offset].xor = 1;
}
src = (const uint32_t *)s->pbuffer;
dst = (uint32_t *)s->buffer;
for (block = 0, y = 0; y < s->yb; y++) {
int block_h = s->blocks[block].h;
uint32_t *rect = dst;
for (x = 0; x < s->xb; x++) {
int block_w = s->blocks[block].w;
uint32_t *row = dst;
block_h = s->blocks[block].h;
if (s->blocks[block].xor) {
for (k = 0; k < block_h; k++) {
uint32_t *column = dst;
for (l = 0; l < block_w; l++)
*dst++ ^= *src++;
dst = &column[s->stride];
}
}
dst = &row[block_w];
++block;
}
dst = &rect[block_h * s->stride];
}
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
frame->flags &= ~AV_FRAME_FLAG_KEY;
frame->pict_type = AV_PICTURE_TYPE_P;
ssrc = s->buffer;
ddst = frame->data[0] + (avctx->height - 1) * frame->linesize[0];
for (y = 0; y < avctx->height; y++) {
memcpy(ddst, ssrc, avctx->width * s->bpp);
ddst -= frame->linesize[0];
ssrc += s->stride * 4;
}
}
*got_frame = 1;
return avpkt->size;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
FMVCContext *s = avctx->priv_data;
int i, j, m, block = 0, h = BLOCK_HEIGHT, w = BLOCK_WIDTH;
switch (avctx->bits_per_coded_sample) {
case 16:
avctx->pix_fmt = AV_PIX_FMT_RGB555LE;
break;
case 24:
avctx->pix_fmt = AV_PIX_FMT_BGR24;
break;
case 32:
avctx->pix_fmt = AV_PIX_FMT_BGRA;
break;
default:
av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n",
avctx->bits_per_coded_sample);
return AVERROR_INVALIDDATA;
}
s->stride = (avctx->width * avctx->bits_per_coded_sample + 31) / 32;
s->xb = s->stride / BLOCK_WIDTH;
m = s->stride % BLOCK_WIDTH;
if (m) {
if (m < 37) {
w = m + BLOCK_WIDTH;
} else {
w = m;
s->xb++;
}
}
s->yb = avctx->height / BLOCK_HEIGHT;
m = avctx->height % BLOCK_HEIGHT;
if (m) {
if (m < 49) {
h = m + BLOCK_HEIGHT;
} else {
h = m;
s->yb++;
}
}
s->nb_blocks = s->xb * s->yb;
if (!s->nb_blocks)
return AVERROR_INVALIDDATA;
s->blocks = av_calloc(s->nb_blocks, sizeof(*s->blocks));
if (!s->blocks)
return AVERROR(ENOMEM);
for (i = 0; i < s->yb; i++) {
for (j = 0; j < s->xb; j++) {
if (i != (s->yb - 1) || j != (s->xb - 1)) {
if (i == s->yb - 1) {
s->blocks[block].w = BLOCK_WIDTH;
s->blocks[block].h = h;
s->blocks[block].size = BLOCK_WIDTH * h;
} else if (j == s->xb - 1) {
s->blocks[block].w = w;
s->blocks[block].h = BLOCK_HEIGHT;
s->blocks[block].size = BLOCK_HEIGHT * w;
} else {
s->blocks[block].w = BLOCK_WIDTH;
s->blocks[block].h = BLOCK_HEIGHT;
s->blocks[block].size = BLOCK_WIDTH * BLOCK_HEIGHT;
}
} else {
s->blocks[block].w = w;
s->blocks[block].h = h;
s->blocks[block].size = w * h;
}
block++;
}
}
s->bpp = avctx->bits_per_coded_sample >> 3;
s->buffer_size = avctx->width * avctx->height * 4;
s->pbuffer_size = avctx->width * avctx->height * 4;
s->buffer = av_mallocz(s->buffer_size);
s->pbuffer = av_mallocz(s->pbuffer_size);
if (!s->buffer || !s->pbuffer)
return AVERROR(ENOMEM);
return 0;
}
static av_cold int decode_close(AVCodecContext *avctx)
{
FMVCContext *s = avctx->priv_data;
av_freep(&s->buffer);
av_freep(&s->pbuffer);
av_freep(&s->blocks);
return 0;
}
const FFCodec ff_fmvc_decoder = {
.p.name = "fmvc",
CODEC_LONG_NAME("FM Screen Capture Codec"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_FMVC,
.priv_data_size = sizeof(FMVCContext),
.init = decode_init,
.close = decode_close,
FF_CODEC_DECODE_CB(decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};
Reference in New Issue View Git Blame Copy Permalink