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Add support for qtrle4 (16 colors/gray levels) 

Originally committed as revision 3183 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Roberto Togni 2004-05-31 20:18:08 +00:00
parent e05655fbbd
commit 8b408dbf0f
1 changed files with 92 additions and 0 deletions
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92
libavcodec/qtrle.c
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@ -74,6 +74,92 @@ static void qtrle_decode_2bpp(QtrleContext *s)
static void qtrle_decode_4bpp(QtrleContext *s)
{
int stream_ptr;
int header;
int start_line;
int lines_to_change;
int rle_code;
int row_ptr, pixel_ptr;
int row_inc = s->frame.linesize[0];
unsigned char pi1, pi2, pi3, pi4, pi5, pi6, pi7, pi8; /* 8 palette indices */
unsigned char *rgb = s->frame.data[0];
int pixel_limit = s->frame.linesize[0] * s->avctx->height;
/* check if this frame is even supposed to change */
if (s->size < 8)
return;
/* start after the chunk size */
stream_ptr = 4;
/* fetch the header */
CHECK_STREAM_PTR(2);
header = BE_16(&s->buf[stream_ptr]);
stream_ptr += 2;
/* if a header is present, fetch additional decoding parameters */
if (header & 0x0008) {
CHECK_STREAM_PTR(8);
start_line = BE_16(&s->buf[stream_ptr]);
stream_ptr += 4;
lines_to_change = BE_16(&s->buf[stream_ptr]);
stream_ptr += 4;
} else {
start_line = 0;
lines_to_change = s->avctx->height;
}
row_ptr = row_inc * start_line;
while (lines_to_change--) {
CHECK_STREAM_PTR(2);
pixel_ptr = row_ptr + (8 * (s->buf[stream_ptr++] - 1));
while ((rle_code = (signed char)s->buf[stream_ptr++]) != -1) {
if (rle_code == 0) {
/* there's another skip code in the stream */
CHECK_STREAM_PTR(1);
pixel_ptr += (8 * (s->buf[stream_ptr++] - 1));
} else if (rle_code < 0) {
/* decode the run length code */
rle_code = -rle_code;
/* get the next 4 bytes from the stream, treat them as palette
* indices, and output them rle_code times */
CHECK_STREAM_PTR(4);
pi1 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi2 = (s->buf[stream_ptr++]) & 0x0f;
pi3 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi4 = (s->buf[stream_ptr++]) & 0x0f;
pi5 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi6 = (s->buf[stream_ptr++]) & 0x0f;
pi7 = ((s->buf[stream_ptr]) >> 4) & 0x0f;
pi8 = (s->buf[stream_ptr++]) & 0x0f;
CHECK_PIXEL_PTR(rle_code * 8);
while (rle_code--) {
rgb[pixel_ptr++] = pi1;
rgb[pixel_ptr++] = pi2;
rgb[pixel_ptr++] = pi3;
rgb[pixel_ptr++] = pi4;
rgb[pixel_ptr++] = pi5;
rgb[pixel_ptr++] = pi6;
rgb[pixel_ptr++] = pi7;
rgb[pixel_ptr++] = pi8;
}
} else {
/* copy the same pixel directly to output 4 times */
rle_code *= 4;
CHECK_STREAM_PTR(rle_code);
CHECK_PIXEL_PTR(rle_code*2);
while (rle_code--) {
rgb[pixel_ptr++] = ((s->buf[stream_ptr]) >> 4) & 0x0f;
rgb[pixel_ptr++] = (s->buf[stream_ptr++]) & 0x0f;
}
}
}
row_ptr += row_inc;
}
}
static void qtrle_decode_8bpp(QtrleContext *s)
@ -473,6 +559,12 @@ static int qtrle_decode_frame(AVCodecContext *avctx,
case 4:
case 36:
qtrle_decode_4bpp(s);
/* make the palette available on the way out */
memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
if (s->avctx->palctrl->palette_changed) {
s->frame.palette_has_changed = 1;
s->avctx->palctrl->palette_changed = 0;
}
break;
case 8: