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One more simplification for ipvideo_decode_block_opcode_0xA 

Originally committed as revision 18282 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Reimar Döffinger 2009-03-31 19:18:13 +00:00
parent bcbd9a149e
commit 49a20ffabc
1 changed files with 22 additions and 49 deletions
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71
libavcodec/interplayvideo.c
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@ -399,23 +399,17 @@ static int ipvideo_decode_block_opcode_0x9(IpvideoContext *s)
static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s)
{
int x, y;
unsigned char P[8];
unsigned char B[16];
unsigned char P[4];
int flags = 0;
int split;
/* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
* either top and bottom or left and right halves */
CHECK_STREAM_PTR(4);
CHECK_STREAM_PTR(24);
memcpy(P, s->stream_ptr, 4);
s->stream_ptr += 4;
if (s->stream_ptr[0] <= s->stream_ptr[1]) {
if (P[0] <= P[1]) {
/* 4-color encoding for each quadrant; need 28 more bytes */
CHECK_STREAM_PTR(28);
s->stream_ptr -= 4;
/* 4-color encoding for each quadrant; need 32 bytes */
CHECK_STREAM_PTR(32);
for (y = 0; y < 16; y++) {
// new values for each 4x4 block
@ -435,50 +429,29 @@ static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s)
}
} else {
// vertical split?
int vert = s->stream_ptr[12] <= s->stream_ptr[13];
uint64_t flags = 0;
/* 4-color encoding for either left and right or top and bottom
* halves; need 20 more bytes */
CHECK_STREAM_PTR(20);
* halves */
memcpy(B, s->stream_ptr, 8);
s->stream_ptr += 8;
memcpy(P + 4, s->stream_ptr, 4);
s->stream_ptr += 4;
memcpy(B + 8, s->stream_ptr, 8);
s->stream_ptr += 8;
if (P[4] <= P[5]) {
/* block is divided into left and right halves */
for (y = 0; y < 8; y++) {
flags = (B[y + 8] << 8) | B[y];
split = 0;
for (x = 0; x < 8; x++, flags >>= 2) {
if (x == 4)
split = 4;
*s->pixel_ptr++ = P[split + (flags & 0x03)];
}
s->pixel_ptr += s->line_inc;
for (y = 0; y < 16; y++) {
// load values for each half
if (!(y & 7)) {
memcpy(P, s->stream_ptr, 4);
s->stream_ptr += 4;
flags = bytestream_get_le64(&s->stream_ptr);
}
} else {
for (x = 0; x < 4; x++, flags >>= 2)
*s->pixel_ptr++ = P[flags & 0x03];
/* block is divided into top and bottom halves */
split = 0;
for (y = 0; y < 8; y++) {
flags = (B[y * 2 + 1] << 8) | B[y * 2];
if (y == 4)
split = 4;
for (x = 0; x < 8; x++, flags >>= 2)
*s->pixel_ptr++ = P[split + (flags & 0x03)];
s->pixel_ptr += s->line_inc;
}
if (vert) {
s->pixel_ptr += s->stride - 4;
// switch to right half
if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
} else if (y & 1) s->pixel_ptr += s->line_inc;
}
}