* Escape 124 Video Decoder
* Copyright (C) 2008 Eli Friedman (eli.friedman@gmail.com)
*
- * This file is part of Libav.
+ * This file is part of FFmpeg.
*
- * Libav is free software; you can redistribute it and/or
+ * 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.
*
- * Libav is distributed in the hope that it will be useful,
+ * 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 Libav; if not, write to the Free Software
+ * 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"
-
#define BITSTREAM_READER_LE
+#include "avcodec.h"
#include "get_bits.h"
+#include "internal.h"
typedef union MacroBlock {
uint16_t pixels[4];
} CodeBook;
typedef struct Escape124Context {
- AVFrame frame;
+ AVFrame *frame;
unsigned num_superblocks;
CodeBook codebooks[3];
} Escape124Context;
-static int can_safely_read(GetBitContext* gb, int bits) {
- return get_bits_left(gb) >= bits;
-}
-
/**
* Initialize the decoder
* @param avctx decoder context
s->num_superblocks = ((unsigned)avctx->width / 8) *
((unsigned)avctx->height / 8);
+ s->frame = av_frame_alloc();
+ if (!s->frame)
+ return AVERROR(ENOMEM);
+
return 0;
}
Escape124Context *s = avctx->priv_data;
for (i = 0; i < 3; i++)
- av_free(s->codebooks[i].blocks);
+ av_freep(&s->codebooks[i].blocks);
- av_frame_unref(&s->frame);
+ av_frame_free(&s->frame);
return 0;
}
unsigned i, j;
CodeBook cb = { 0 };
- if (!can_safely_read(gb, size * 34))
+ if (size >= INT_MAX / 34 || get_bits_left(gb) < size * 34)
return cb;
if (size >= INT_MAX / sizeof(MacroBlock))
unsigned value;
// This function reads a maximum of 23 bits,
// which is within the padding space
- if (!can_safely_read(gb, 1))
+ if (get_bits_left(gb) < 1)
return -1;
value = get_bits1(gb);
if (!value)
// This function reads a maximum of 22 bits; the callers
// guard this function appropriately
unsigned block_index, depth;
-
- if (get_bits1(gb)) {
- static const char transitions[3][2] = { {2, 1}, {0, 2}, {1, 0} };
- *codebook_index = transitions[*codebook_index][get_bits1(gb)];
+ int value = get_bits1(gb);
+ if (value) {
+ static const int8_t transitions[3][2] = { {2, 1}, {0, 2}, {1, 0} };
+ value = get_bits1(gb);
+ *codebook_index = transitions[*codebook_index][value];
}
depth = s->codebooks[*codebook_index].depth;
// depth = 0 means that this shouldn't read any bits;
// in theory, this is the same as get_bits(gb, 0), but
// that doesn't actually work.
- block_index = depth ? get_bits(gb, depth) : 0;
+ block_index = get_bitsz(gb, depth);
if (*codebook_index == 1) {
block_index += superblock_index << s->codebooks[1].depth;
void *data, int *got_frame,
AVPacket *avpkt)
{
- const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
Escape124Context *s = avctx->priv_data;
AVFrame *frame = data;
uint16_t* old_frame_data, *new_frame_data;
unsigned old_stride, new_stride;
+
int ret;
- init_get_bits(&gb, buf, buf_size * 8);
+ if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0)
+ return ret;
// This call also guards the potential depth reads for the
// codebook unpacking.
- if (!can_safely_read(&gb, 64))
+ if (get_bits_left(&gb) < 64)
return -1;
frame_flags = get_bits_long(&gb, 32);
// Leave last frame unchanged
// FIXME: Is this necessary? I haven't seen it in any real samples
if (!(frame_flags & 0x114) || !(frame_flags & 0x7800000)) {
- if (!s->frame.data[0])
+ if (!s->frame->data[0])
return AVERROR_INVALIDDATA;
- av_log(NULL, AV_LOG_DEBUG, "Skipping frame\n");
+ av_log(avctx, AV_LOG_DEBUG, "Skipping frame\n");
*got_frame = 1;
- if ((ret = av_frame_ref(frame, &s->frame)) < 0)
+ if ((ret = av_frame_ref(frame, s->frame)) < 0)
return ret;
return frame_size;
// This codebook can be cut off at places other than
// powers of 2, leaving some of the entries undefined.
cb_size = get_bits_long(&gb, 20);
+ if (!cb_size) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid codebook size 0.\n");
+ return AVERROR_INVALIDDATA;
+ }
cb_depth = av_log2(cb_size - 1) + 1;
} else {
cb_depth = get_bits(&gb, 4);
cb_size = s->num_superblocks << cb_depth;
}
}
- av_free(s->codebooks[i].blocks);
+ if (s->num_superblocks >= INT_MAX >> cb_depth) {
+ av_log(avctx, AV_LOG_ERROR, "Depth or num_superblocks are too large\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ av_freep(&s->codebooks[i].blocks);
s->codebooks[i] = unpack_codebook(&gb, cb_depth, cb_size);
if (!s->codebooks[i].blocks)
return -1;
}
}
- if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
- av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+ if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
return ret;
- }
new_frame_data = (uint16_t*)frame->data[0];
new_stride = frame->linesize[0] / 2;
- old_frame_data = (uint16_t*)s->frame.data[0];
- old_stride = s->frame.linesize[0] / 2;
+ old_frame_data = (uint16_t*)s->frame->data[0];
+ old_stride = s->frame->linesize[0] / 2;
for (superblock_index = 0; superblock_index < s->num_superblocks;
superblock_index++) {
copy_superblock(sb.pixels, 8,
old_frame_data, old_stride);
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
+ while (get_bits_left(&gb) >= 1 && !get_bits1(&gb)) {
unsigned mask;
mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
mask = get_bits(&gb, 16);
}
}
- if (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
+ if (!get_bits1(&gb)) {
unsigned inv_mask = get_bits(&gb, 4);
for (i = 0; i < 4; i++) {
if (inv_mask & (1 << i)) {
for (i = 0; i < 16; i++) {
if (multi_mask & mask_matrix[i]) {
- if (!can_safely_read(&gb, 1))
- break;
mb = decode_macroblock(s, &gb, &cb_index,
superblock_index);
insert_mb_into_sb(&sb, mb, i);
}
}
} else if (frame_flags & (1 << 16)) {
- while (can_safely_read(&gb, 1) && !get_bits1(&gb)) {
+ while (get_bits_left(&gb) >= 1 && !get_bits1(&gb)) {
mb = decode_macroblock(s, &gb, &cb_index, superblock_index);
insert_mb_into_sb(&sb, mb, get_bits(&gb, 4));
}
skip--;
}
- av_log(NULL, AV_LOG_DEBUG,
+ av_log(avctx, AV_LOG_DEBUG,
"Escape sizes: %i, %i, %i\n",
frame_size, buf_size, get_bits_count(&gb) / 8);
- av_frame_unref(&s->frame);
- if ((ret = av_frame_ref(&s->frame, frame)) < 0)
+ av_frame_unref(s->frame);
+ if ((ret = av_frame_ref(s->frame, frame)) < 0)
return ret;
*got_frame = 1;
AVCodec ff_escape124_decoder = {
.name = "escape124",
+ .long_name = NULL_IF_CONFIG_SMALL("Escape 124"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_ESCAPE124,
.priv_data_size = sizeof(Escape124Context),
.init = escape124_decode_init,
.close = escape124_decode_close,
.decode = escape124_decode_frame,
- .capabilities = CODEC_CAP_DR1,
- .long_name = NULL_IF_CONFIG_SMALL("Escape 124"),
+ .capabilities = AV_CODEC_CAP_DR1,
};