---
libavcodec/4xm.c | 28 +++++++++++++++-------------
libavcodec/bytestream.h | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+), 13 deletions(-)
diff --git a/libavcodec/4xm.c b/libavcodec/4xm.c
index 0ae10d5..ba8bb4a 100644
--- a/libavcodec/4xm.c
+++ b/libavcodec/4xm.c
@@ -132,8 +132,8 @@ typedef struct FourXContext{
AVFrame current_picture, last_picture;
GetBitContext pre_gb; ///< ac/dc prefix
GetBitContext gb;
- const uint8_t *bytestream;
- const uint16_t *wordstream;
+ GetByteContext g;
+ GetByteContext g2;
int mv[256];
VLC pre_vlc;
int last_dc;
@@ -328,7 +328,7 @@ static void decode_p_block(FourXContext *f, uint16_t *dst,
uint16_t *src, int lo
assert(code>=0 && code<=6);
if(code == 0){
- src += f->mv[ *f->bytestream++ ];
+ src += f->mv[bytestream2_get_byte(&f->g)];
if(start > src || src > end){
av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
return;
@@ -345,21 +345,21 @@ static void decode_p_block(FourXContext *f, uint16_t
*dst, uint16_t *src, int lo
}else if(code == 3 && f->version<2){
mcdc(dst, src, log2w, h, stride, 1, 0);
}else if(code == 4){
- src += f->mv[ *f->bytestream++ ];
+ src += f->mv[bytestream2_get_byte(&f->g)];
if(start > src || src > end){
av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
return;
}
- mcdc(dst, src, log2w, h, stride, 1, av_le2ne16(*f->wordstream++));
+ mcdc(dst, src, log2w, h, stride, 1, bytestream2_get_le16(&f->g2));
}else if(code == 5){
- mcdc(dst, src, log2w, h, stride, 0, av_le2ne16(*f->wordstream++));
+ mcdc(dst, src, log2w, h, stride, 0, bytestream2_get_le16(&f->g2));
}else if(code == 6){
if(log2w){
- dst[0] = av_le2ne16(*f->wordstream++);
- dst[1] = av_le2ne16(*f->wordstream++);
+ dst[0] = bytestream2_get_le16(&f->g2);
+ dst[1] = bytestream2_get_le16(&f->g2);
}else{
- dst[0 ] = av_le2ne16(*f->wordstream++);
- dst[stride] = av_le2ne16(*f->wordstream++);
+ dst[0 ] = bytestream2_get_le16(&f->g2);
+ dst[stride] = bytestream2_get_le16(&f->g2);
}
}
}
@@ -371,7 +371,7 @@ static int decode_p_frame(FourXContext *f, const uint8_t
*buf, int length){
uint16_t *src= (uint16_t*)f->last_picture.data[0];
uint16_t *dst= (uint16_t*)f->current_picture.data[0];
const int stride= f->current_picture.linesize[0]>>1;
- unsigned int bitstream_size, bytestream_size, wordstream_size, extra;
+ unsigned int bitstream_size, bytestream_size, wordstream_size, extra,
bytestream_offset, wordstream_offset;
if(f->version>1){
extra=20;
@@ -402,8 +402,10 @@ static int decode_p_frame(FourXContext *f, const uint8_t
*buf, int length){
memset((uint8_t*)f->bitstream_buffer + bitstream_size, 0,
FF_INPUT_BUFFER_PADDING_SIZE);
init_get_bits(&f->gb, f->bitstream_buffer, 8*bitstream_size);
- f->wordstream= (const uint16_t*)(buf + extra + bitstream_size);
- f->bytestream= buf + extra + bitstream_size + wordstream_size;
+ wordstream_offset = extra + bitstream_size;
+ bytestream_offset = extra + bitstream_size + wordstream_size;
+ bytestream2_init(&f->g2, buf + wordstream_offset, length -
wordstream_offset);
+ bytestream2_init(&f->g, buf + bytestream_offset, length -
bytestream_offset);
init_mv(f);
diff --git a/libavcodec/bytestream.h b/libavcodec/bytestream.h
index 98f0087..f60b6c2 100644
--- a/libavcodec/bytestream.h
+++ b/libavcodec/bytestream.h
@@ -26,6 +26,10 @@
#include "libavutil/common.h"
#include "libavutil/intreadwrite.h"
+typedef struct {
+ const uint8_t *buffer, *buffer_end;
+} GetByteContext;
+
#define DEF_T(type, name, bytes, read, write) \
static av_always_inline type bytestream_get_ ## name(const uint8_t **b){\
(*b) += bytes;\
@@ -34,6 +38,12 @@ static av_always_inline type bytestream_get_ ## name(const
uint8_t **b){\
static av_always_inline void bytestream_put_ ##name(uint8_t **b, const type
value){\
write(*b, value);\
(*b) += bytes;\
+}\
+static av_always_inline type bytestream2_get_ ## name(GetByteContext *g)\
+{\
+ if (g->buffer_end - g->buffer < bytes)\
+ return 0;\
+ return bytestream_get_ ## name(&g->buffer);\
}
#define DEF(name, bytes, read, write) \
@@ -55,6 +65,30 @@ DEF (byte, 1, AV_RB8 , AV_WB8 )
#undef DEF64
#undef DEF_T
+static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t
*buf, int buf_size)
+{
+ g->buffer = buf;
+ g->buffer_end = buf + buf_size;
+}
+
+static av_always_inline unsigned int bytestream2_peek_byte(GetByteContext *g)
+{
+ return *g->buffer;
+}
+
+static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext
*g)
+{
+ return g->buffer_end - g->buffer;
+}
+
+static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g
, uint8_t *dst, unsigned int size)
+{
+ int size2 = FFMIN(g->buffer_end - g->buffer, size);
+ memcpy(dst, g->buffer, size2);
+ g->buffer += size2;
+ return size2;
+}
+
static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b,
uint8_t *dst, unsigned int size)
{
memcpy(dst, *b, size);
--
1.7.4.1
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