#include "avcodec.h"
#include "libavutil/intreadwrite.h"
#include "bytestream.h"
-#define ALT_BITSTREAM_READER_LE
+#define BITSTREAM_READER_LE
#include "get_bits.h"
// for av_memcpy_backptr
#include "libavutil/lzo.h"
uint8_t *y_buffer;
uint8_t *scratch_buffer;
int buffer_size;
+ GetByteContext gb;
} XanContext;
static av_cold int xan_decode_init(AVCodecContext *avctx)
return 0;
}
-static int xan_unpack_luma(const uint8_t *src, const int src_size,
+static int xan_unpack_luma(XanContext *s,
uint8_t *dst, const int dst_size)
{
- int tree_size, eof;
- const uint8_t *tree;
- int bits, mask;
- int tree_root, node;
- const uint8_t *dst_end = dst + dst_size;
- const uint8_t *src_end = src + src_size;
-
- tree_size = *src++;
- eof = *src++;
- tree = src - eof * 2 - 2;
- tree_root = eof + tree_size;
- src += tree_size * 2;
-
- node = tree_root;
- bits = *src++;
- mask = 0x80;
- for (;;) {
- int bit = !!(bits & mask);
- mask >>= 1;
- node = tree[node*2 + bit];
- if (node == eof)
- break;
- if (node < eof) {
- *dst++ = node;
- if (dst > dst_end)
- break;
- node = tree_root;
- }
- if (!mask) {
- bits = *src++;
- if (src > src_end)
- break;
- mask = 0x80;
- }
- }
- return dst != dst_end;
+ int tree_size, eof;
+ int bits, mask;
+ int tree_root, node;
+ const uint8_t *dst_end = dst + dst_size;
+ GetByteContext tree = s->gb;
+ int start_off = bytestream2_tell(&tree);
+
+ tree_size = bytestream2_get_byte(&s->gb);
+ eof = bytestream2_get_byte(&s->gb);
+ tree_root = eof + tree_size;
+ bytestream2_skip(&s->gb, tree_size * 2);
+
+ node = tree_root;
+ bits = bytestream2_get_byte(&s->gb);
+ mask = 0x80;
+ for (;;) {
+ int bit = !!(bits & mask);
+ mask >>= 1;
+ bytestream2_seek(&tree, start_off + node*2 + bit - eof * 2, SEEK_SET);
+ node = bytestream2_get_byte(&tree);
+ if (node == eof)
+ break;
+ if (node < eof) {
+ *dst++ = node;
+ if (dst > dst_end)
+ break;
+ node = tree_root;
+ }
+ if (!mask) {
+ if (bytestream2_get_bytes_left(&s->gb) <= 0)
+ break;
+ bits = bytestream2_get_byteu(&s->gb);
+ mask = 0x80;
+ }
+ }
+ return dst != dst_end ? AVERROR_INVALIDDATA : 0;
}
/* almost the same as in xan_wc3 decoder */
-static int xan_unpack(uint8_t *dest, const int dest_len,
- const uint8_t *src, const int src_len)
+static int xan_unpack(XanContext *s,
+ uint8_t *dest, const int dest_len)
{
uint8_t opcode;
int size;
uint8_t *orig_dest = dest;
- const uint8_t *src_end = src + src_len;
const uint8_t *dest_end = dest + dest_len;
while (dest < dest_end) {
- opcode = *src++;
+ if (bytestream2_get_bytes_left(&s->gb) <= 0)
+ return AVERROR_INVALIDDATA;
+
+ opcode = bytestream2_get_byteu(&s->gb);
if (opcode < 0xe0) {
int size2, back;
if ((opcode & 0x80) == 0) {
size = opcode & 3;
- back = ((opcode & 0x60) << 3) + *src++ + 1;
+ back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
size2 = ((opcode & 0x1c) >> 2) + 3;
} else if ((opcode & 0x40) == 0) {
- size = *src >> 6;
- back = (bytestream_get_be16(&src) & 0x3fff) + 1;
+ size = bytestream2_peek_byte(&s->gb) >> 6;
+ back = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
size2 = (opcode & 0x3f) + 4;
} else {
size = opcode & 3;
- back = ((opcode & 0x10) << 12) + bytestream_get_be16(&src) + 1;
- size2 = ((opcode & 0x0c) << 6) + *src++ + 5;
+ back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
+ size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&s->gb) + 5;
if (size + size2 > dest_end - dest)
break;
}
- if (src + size > src_end || dest + size + size2 > dest_end)
+ if (dest + size + size2 > dest_end ||
+ dest - orig_dest + size < back)
return -1;
- bytestream_get_buffer(&src, dest, size);
+ bytestream2_get_buffer(&s->gb, dest, size);
dest += size;
av_memcpy_backptr(dest, back, size2);
dest += size2;
int finish = opcode >= 0xfc;
size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
- if (src + size > src_end || dest + size > dest_end)
+ if (dest_end - dest < size)
return -1;
- bytestream_get_buffer(&src, dest, size);
+ bytestream2_get_buffer(&s->gb, dest, size);
dest += size;
if (finish)
break;
return dest - orig_dest;
}
-static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
+static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
{
- const uint8_t *buf = avpkt->data;
XanContext *s = avctx->priv_data;
uint8_t *U, *V;
- unsigned chroma_off;
int val, uval, vval;
int i, j;
const uint8_t *src, *src_end;
const uint8_t *table;
- int mode, offset, dec_size;
+ int mode, offset, dec_size, table_size;
- chroma_off = AV_RL32(buf + 4);
if (!chroma_off)
return 0;
- if (chroma_off + 10 >= avpkt->size) {
+ if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
return -1;
}
- src = avpkt->data + 4 + chroma_off;
- table = src + 2;
- mode = bytestream_get_le16(&src);
- offset = bytestream_get_le16(&src) * 2;
-
- if (src - avpkt->data >= avpkt->size - offset) {
+ bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
+ mode = bytestream2_get_le16(&s->gb);
+ table = s->gb.buffer;
+ table_size = bytestream2_get_le16(&s->gb);
+ offset = table_size * 2;
+ table_size += 1;
+
+ if (offset >= bytestream2_get_bytes_left(&s->gb)) {
av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
return -1;
}
+ bytestream2_skip(&s->gb, offset);
memset(s->scratch_buffer, 0, s->buffer_size);
- dec_size = xan_unpack(s->scratch_buffer, s->buffer_size, src + offset,
- avpkt->size - offset - (src - avpkt->data));
+ dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
if (dec_size < 0) {
av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
return -1;
for (j = 0; j < avctx->height >> 1; j++) {
for (i = 0; i < avctx->width >> 1; i++) {
val = *src++;
- if (val) {
+ if (val && val < table_size) {
val = AV_RL16(table + (val << 1));
uval = (val >> 3) & 0xF8;
vval = (val >> 8) & 0xF8;
for (j = 0; j < avctx->height >> 2; j++) {
for (i = 0; i < avctx->width >> 1; i += 2) {
val = *src++;
- if (val) {
+ if (val && val < table_size) {
val = AV_RL16(table + (val << 1));
uval = (val >> 3) & 0xF8;
vval = (val >> 8) & 0xF8;
return 0;
}
-static int xan_decode_frame_type0(AVCodecContext *avctx, AVPacket *avpkt)
+static int xan_decode_frame_type0(AVCodecContext *avctx)
{
- const uint8_t *buf = avpkt->data;
XanContext *s = avctx->priv_data;
uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
unsigned chroma_off, corr_off;
- int cur, last, size;
+ int cur, last;
int i, j;
int ret;
- corr_off = AV_RL32(buf + 8);
- chroma_off = AV_RL32(buf + 4);
+ chroma_off = bytestream2_get_le32(&s->gb);
+ corr_off = bytestream2_get_le32(&s->gb);
- if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
+ if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
return ret;
- size = avpkt->size - 4;
- if (corr_off >= avpkt->size) {
+ if (corr_off >= (s->gb.buffer_end - s->gb.buffer_start)) {
av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
corr_off = 0;
}
- if (corr_off)
- size = corr_off;
- if (chroma_off)
- size = FFMIN(size, chroma_off);
- ret = xan_unpack_luma(buf + 12, size, src, s->buffer_size >> 1);
+ bytestream2_seek(&s->gb, 12, SEEK_SET);
+ ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
if (ret) {
av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
return ret;
}
if (corr_off) {
- int corr_end, dec_size;
-
- corr_end = avpkt->size;
- if (chroma_off > corr_off)
- corr_end = chroma_off;
- dec_size = xan_unpack(s->scratch_buffer, s->buffer_size,
- avpkt->data + 8 + corr_off,
- corr_end - corr_off);
+ int dec_size;
+
+ bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
+ dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
if (dec_size < 0)
dec_size = 0;
for (i = 0; i < dec_size; i++)
return 0;
}
-static int xan_decode_frame_type1(AVCodecContext *avctx, AVPacket *avpkt)
+static int xan_decode_frame_type1(AVCodecContext *avctx)
{
- const uint8_t *buf = avpkt->data;
XanContext *s = avctx->priv_data;
uint8_t *ybuf, *src = s->scratch_buffer;
int cur, last;
int i, j;
int ret;
- if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
+ if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
return ret;
- ret = xan_unpack_luma(buf + 16, avpkt->size - 16, src,
+ bytestream2_seek(&s->gb, 16, SEEK_SET);
+ ret = xan_unpack_luma(s, src,
s->buffer_size >> 1);
if (ret) {
av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
return ret;
}
- ftype = AV_RL32(avpkt->data);
+ bytestream2_init(&s->gb, avpkt->data, avpkt->size);
+ ftype = bytestream2_get_le32(&s->gb);
switch (ftype) {
case 0:
- ret = xan_decode_frame_type0(avctx, avpkt);
+ ret = xan_decode_frame_type0(avctx);
break;
case 1:
- ret = xan_decode_frame_type1(avctx, avpkt);
+ ret = xan_decode_frame_type1(avctx);
break;
default:
av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
.close = xan_decode_end,
.decode = xan_decode_frame,
.capabilities = CODEC_CAP_DR1,
- .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
+ .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
};
-
projects / ffmpeg / blobdiff