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Make ipvideo_decode_block_opcode_0x8 a lot simpler by decoding the pixels

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in a more natural order.

Originally committed as revision 18277 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Reimar Döffinger 2009-03-31 18:35:19 +00:00
parent 4472ad2cc4
commit 283531a81e
1 changed files with 22 additions and 73 deletions

95
libavcodec/interplayvideo.c
View File

@ -243,11 +243,8 @@ static int ipvideo_decode_block_opcode_0x7(IpvideoContext *s)
static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s) static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
{ {
int x, y; int x, y;
unsigned char P[8]; unsigned char P[2];
unsigned char B[8];
unsigned int flags = 0; unsigned int flags = 0;
unsigned char P0 = 0, P1 = 0;
int lower_half = 0;
/* 2-color encoding for each 4x4 quadrant, or 2-color encoding on /* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
* either top and bottom or left and right halves */ * either top and bottom or left and right halves */
@ -259,46 +256,21 @@ static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
if (P[0] <= P[1]) { if (P[0] <= P[1]) {
CHECK_STREAM_PTR(14); CHECK_STREAM_PTR(14);
B[0] = *s->stream_ptr++; B[1] = *s->stream_ptr++; s->stream_ptr -= 2;
P[2] = *s->stream_ptr++; P[3] = *s->stream_ptr++;
B[2] = *s->stream_ptr++; B[3] = *s->stream_ptr++;
P[4] = *s->stream_ptr++; P[5] = *s->stream_ptr++;
B[4] = *s->stream_ptr++; B[5] = *s->stream_ptr++;
P[6] = *s->stream_ptr++; P[7] = *s->stream_ptr++;
B[6] = *s->stream_ptr++; B[7] = *s->stream_ptr++;
for (y = 0; y < 8; y++) { for (y = 0; y < 16; y++) {
// new values for each 4x4 block
/* time to reload flags? */ if (!(y & 3)) {
if (y == 0) { P[0] = *s->stream_ptr++; P[1] = *s->stream_ptr++;
flags = flags = bytestream_get_le16(&s->stream_ptr);
((B[0] & 0xF0) << 4) | ((B[4] & 0xF0) << 8) |
((B[0] & 0x0F) ) | ((B[4] & 0x0F) << 4) |
((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
lower_half = 0; /* still on top half */
} else if (y == 4) {
flags =
((B[2] & 0xF0) << 4) | ((B[6] & 0xF0) << 8) |
((B[2] & 0x0F) ) | ((B[6] & 0x0F) << 4) |
((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
lower_half = 2;
} }
for (x = 0; x < 8; x++, flags >>= 1) { for (x = 0; x < 4; x++, flags >>= 1) {
/* get the pixel values ready for this quadrant */ *s->pixel_ptr++ = P[flags & 1];
if (x == 0) {
P0 = P[lower_half + 0];
P1 = P[lower_half + 1];
} else if (x == 4) {
P0 = P[lower_half + 4];
P1 = P[lower_half + 5];
}
*s->pixel_ptr++ = flags & 1 ? P1 : P0;
} }
s->pixel_ptr += s->line_inc; s->pixel_ptr += s->stride - 4;
// switch to right half
if (y == 7) s->pixel_ptr -= 8 * s->stride - 4;
} }
} else { } else {
@ -308,44 +280,21 @@ static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
if (s->stream_ptr[4] <= s->stream_ptr[5]) { if (s->stream_ptr[4] <= s->stream_ptr[5]) {
B[0] = *s->stream_ptr++; B[1] = *s->stream_ptr++; flags = bytestream_get_le32(&s->stream_ptr);
B[2] = *s->stream_ptr++; B[3] = *s->stream_ptr++;
P[2] = *s->stream_ptr++; P[3] = *s->stream_ptr++;
B[4] = *s->stream_ptr++; B[5] = *s->stream_ptr++;
B[6] = *s->stream_ptr++; B[7] = *s->stream_ptr++;
/* vertical split; left & right halves are 2-color encoded */ /* vertical split; left & right halves are 2-color encoded */
for (y = 0; y < 8; y++) { for (y = 0; y < 16; y++) {
for (x = 0; x < 4; x++, flags >>= 1) {
/* time to reload flags? */ *s->pixel_ptr++ = P[flags & 1];
if (y == 0) {
flags =
((B[0] & 0xF0) << 4) | ((B[4] & 0xF0) << 8) |
((B[0] & 0x0F) ) | ((B[4] & 0x0F) << 4) |
((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
} else if (y == 4) {
flags =
((B[2] & 0xF0) << 4) | ((B[6] & 0xF0) << 8) |
((B[2] & 0x0F) ) | ((B[6] & 0x0F) << 4) |
((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
} }
s->pixel_ptr += s->stride - 4;
for (x = 0; x < 8; x++, flags >>= 1) { // switch to right half
/* get the pixel values ready for this half */ if (y == 7) {
if (x == 0) { s->pixel_ptr -= 8 * s->stride - 4;
P0 = P[0]; P[0] = *s->stream_ptr++; P[1] = *s->stream_ptr++;
P1 = P[1]; flags = bytestream_get_le32(&s->stream_ptr);
} else if (x == 4) {
P0 = P[2];
P1 = P[3];
}
*s->pixel_ptr++ = flags & 1 ? P1 : P0;
} }
s->pixel_ptr += s->line_inc;
} }
} else { } else {