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avcodec/magicyuv: Don't use GetBit API for byte-aligned reads

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Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2020-09-23 06:42:24 +02:00
parent 3c172a2fb9
commit bf31b45155
1 changed files with 22 additions and 23 deletions
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45
libavcodec/magicyuv.c
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@ -270,27 +270,26 @@ static int magy_decode_slice(AVCodecContext *avctx, void *tdata,
int sheight = AV_CEIL_RSHIFT(s->slice_height, s->vshift[i]);
ptrdiff_t fake_stride = p->linesize[i] * (1 + interlaced);
ptrdiff_t stride = p->linesize[i];
const uint8_t *slice = s->buf + s->slices[i][j].start;
int flags, pred;
int ret = init_get_bits8(&gb, s->buf + s->slices[i][j].start,
s->slices[i][j].size);
if (ret < 0)
return ret;
flags = get_bits(&gb, 8);
pred = get_bits(&gb, 8);
flags = bytestream_get_byte(&slice);
pred = bytestream_get_byte(&slice);
dst = p->data[i] + j * sheight * stride;
if (flags & 1) {
if (get_bits_left(&gb) < 8* width * height)
if (s->slices[i][j].size - 2 < width * height)
return AVERROR_INVALIDDATA;
for (k = 0; k < height; k++) {
for (x = 0; x < width; x++)
dst[x] = get_bits(&gb, 8);
bytestream_get_buffer(&slice, dst, width);
dst += stride;
}
} else {
int ret = init_get_bits8(&gb, slice, s->slices[i][j].size - 2);
if (ret < 0)
return ret;
for (k = 0; k < height; k++) {
for (x = 0; x < width; x++) {
int pix;
@ -385,21 +384,25 @@ static int magy_decode_slice(AVCodecContext *avctx, void *tdata,
return 0;
}
static int build_huffman(AVCodecContext *avctx, GetBitContext *gbit, int max)
static int build_huffman(AVCodecContext *avctx, const uint8_t *table,
int table_size, int max)
{
MagicYUVContext *s = avctx->priv_data;
GetByteContext gb;
HuffEntry he[4096];
int i = 0, j = 0, k;
while (get_bits_left(gbit) >= 8) {
int b = get_bits(gbit, 1);
int x = get_bits(gbit, 7);
bytestream2_init(&gb, table, table_size);
while (bytestream2_get_bytes_left(&gb) > 0) {
int b = bytestream2_peek_byteu(&gb) & 0x80;
int x = bytestream2_get_byteu(&gb) & ~0x80;
int l = 1;
if (b) {
if (get_bits_left(gbit) < 8)
if (bytestream2_get_bytes_left(&gb) <= 0)
break;
l += get_bits(gbit, 8);
l += bytestream2_get_byteu(&gb);
}
k = j + l;
if (k > max || x == 0 || x > 32) {
@ -440,7 +443,6 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
ThreadFrame frame = { .f = data };
AVFrame *p = data;
GetByteContext gbyte;
GetBitContext gbit;
uint32_t first_offset, offset, next_offset, header_size, slice_width;
int width, height, format, version, table_size;
int ret, i, j;
@ -632,11 +634,8 @@ static int magy_decode_frame(AVCodecContext *avctx, void *data,
if (table_size < 2)
return AVERROR_INVALIDDATA;
ret = init_get_bits8(&gbit, avpkt->data + bytestream2_tell(&gbyte), table_size);
if (ret < 0)
return ret;
ret = build_huffman(avctx, &gbit, s->max);
ret = build_huffman(avctx, avpkt->data + bytestream2_tell(&gbyte),
table_size, s->max);
if (ret < 0)
return ret;