From 283531a81eaa934708b07b51aeba1ebdf109a204 Mon Sep 17 00:00:00 2001 From: Reimar Döffinger Date: Tue, 31 Mar 2009 18:35:19 +0000 Subject: Make ipvideo_decode_block_opcode_0x8 a lot simpler by decoding the pixels in a more natural order. Originally committed as revision 18277 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/interplayvideo.c | 95 +++++++++++---------------------------------- 1 file changed, 22 insertions(+), 73 deletions(-) (limited to 'libavcodec/interplayvideo.c') diff --git a/libavcodec/interplayvideo.c b/libavcodec/interplayvideo.c index 8ef365dea6..9bcc9f45e9 100644 --- a/libavcodec/interplayvideo.c +++ b/libavcodec/interplayvideo.c @@ -243,11 +243,8 @@ static int ipvideo_decode_block_opcode_0x7(IpvideoContext *s) static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s) { int x, y; - unsigned char P[8]; - unsigned char B[8]; + unsigned char P[2]; 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 * 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]) { CHECK_STREAM_PTR(14); - B[0] = *s->stream_ptr++; B[1] = *s->stream_ptr++; - 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++) { + s->stream_ptr -= 2; - /* time to reload flags? */ - 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); - 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 (y = 0; y < 16; y++) { + // new values for each 4x4 block + if (!(y & 3)) { + P[0] = *s->stream_ptr++; P[1] = *s->stream_ptr++; + flags = bytestream_get_le16(&s->stream_ptr); } - for (x = 0; x < 8; x++, flags >>= 1) { - /* get the pixel values ready for this quadrant */ - 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; + for (x = 0; x < 4; x++, flags >>= 1) { + *s->pixel_ptr++ = P[flags & 1]; } - 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 { @@ -308,44 +280,21 @@ static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s) if (s->stream_ptr[4] <= s->stream_ptr[5]) { - B[0] = *s->stream_ptr++; B[1] = *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++; + flags = bytestream_get_le32(&s->stream_ptr); /* vertical split; left & right halves are 2-color encoded */ - for (y = 0; y < 8; y++) { - - /* time to reload flags? */ - 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); + for (y = 0; y < 16; y++) { + for (x = 0; x < 4; x++, flags >>= 1) { + *s->pixel_ptr++ = P[flags & 1]; } - - for (x = 0; x < 8; x++, flags >>= 1) { - /* get the pixel values ready for this half */ - if (x == 0) { - P0 = P[0]; - P1 = P[1]; - } else if (x == 4) { - P0 = P[2]; - P1 = P[3]; - } - - *s->pixel_ptr++ = flags & 1 ? P1 : P0; + s->pixel_ptr += s->stride - 4; + // switch to right half + if (y == 7) { + s->pixel_ptr -= 8 * s->stride - 4; + P[0] = *s->stream_ptr++; P[1] = *s->stream_ptr++; + flags = bytestream_get_le32(&s->stream_ptr); } - s->pixel_ptr += s->line_inc; } } else { -- cgit v1.2.3