Commit 0469baf1 authored by Fabrice Bellard's avatar Fabrice Bellard

added img_get_alpha_info()

Originally committed as revision 1809 to svn://svn.ffmpeg.org/ffmpeg/trunk
parent a059da12
......@@ -15,8 +15,8 @@ extern "C" {
#define LIBAVCODEC_VERSION_INT 0x000406
#define LIBAVCODEC_VERSION "0.4.6"
#define LIBAVCODEC_BUILD 4665
#define LIBAVCODEC_BUILD_STR "4665"
#define LIBAVCODEC_BUILD 4666
#define LIBAVCODEC_BUILD_STR "4666"
#define LIBAVCODEC_IDENT "FFmpeg" LIBAVCODEC_VERSION "b" LIBAVCODEC_BUILD_STR
......@@ -1276,6 +1276,10 @@ int avcodec_get_pix_fmt_loss(int dst_pix_fmt, int src_pix_fmt,
int avcodec_find_best_pix_fmt(int pix_fmt_mask, int src_pix_fmt,
int has_alpha, int *loss_ptr);
#define FF_ALPHA_TRANSP 0x0001 /* image has some totally transparent pixels */
#define FF_ALPHA_SEMI_TRANSP 0x0002 /* image has some transparent pixels */
int img_get_alpha_info(AVPicture *src, int pix_fmt, int width, int height);
/* convert among pixel formats */
int img_convert(AVPicture *dst, int dst_pix_fmt,
AVPicture *src, int pix_fmt,
......
......@@ -475,7 +475,9 @@ static void img_copy_plane(uint8_t *dst, int dst_wrap,
}
}
/* copy image 'src' to 'dst' */
/**
* Copy image 'src' to 'dst'.
*/
void img_copy(AVPicture *dst, AVPicture *src,
int pix_fmt, int width, int height)
{
......@@ -1808,6 +1810,62 @@ int img_convert(AVPicture *dst, int dst_pix_fmt,
return ret;
}
/* NOTE: we scan all the pixels to have an exact information */
static int get_alpha_info_pal8(AVPicture *src, int width, int height)
{
const unsigned char *p;
int src_wrap, ret, x, y;
unsigned int a;
uint32_t *palette = (uint32_t *)src->data[1];
p = src->data[0];
src_wrap = src->linesize[0] - width;
ret = 0;
for(y=0;y<height;y++) {
for(x=0;x<width;x++) {
a = palette[p[0]] >> 24;
if (a == 0x00) {
ret |= FF_ALPHA_TRANSP;
} else if (a != 0xff) {
ret |= FF_ALPHA_SEMI_TRANSP;
}
p++;
}
p += src_wrap;
}
return ret;
}
/**
* Tell if an image really has transparent alpha values.
* @return ored mask of FF_ALPHA_xxx constants
*/
int img_get_alpha_info(AVPicture *src, int pix_fmt, int width, int height)
{
PixFmtInfo *pf = &pix_fmt_info[pix_fmt];
int ret;
pf = &pix_fmt_info[pix_fmt];
/* no alpha can be represented in format */
if (!pf->is_alpha)
return 0;
switch(pix_fmt) {
case PIX_FMT_RGBA32:
ret = get_alpha_info_rgba32(src, width, height);
break;
case PIX_FMT_RGB555:
ret = get_alpha_info_rgb555(src, width, height);
break;
case PIX_FMT_PAL8:
ret = get_alpha_info_pal8(src, width, height);
break;
default:
/* we do not know, so everything is indicated */
ret = FF_ALPHA_TRANSP | FF_ALPHA_SEMI_TRANSP;
break;
}
return ret;
}
#ifdef HAVE_MMX
#define DEINT_INPLACE_LINE_LUM \
......
......@@ -814,6 +814,34 @@ static void glue(RGB_NAME, _to_pal8)(AVPicture *dst, AVPicture *src,
#endif /* defined(FMT_RGB24) || defined(FMT_RGBA32) */
#ifdef RGBA_IN
static int glue(get_alpha_info_, RGB_NAME)(AVPicture *src, int width, int height)
{
const unsigned char *p;
int src_wrap, ret, x, y;
unsigned int r, g, b, a;
p = src->data[0];
src_wrap = src->linesize[0] - BPP * width;
ret = 0;
for(y=0;y<height;y++) {
for(x=0;x<width;x++) {
RGBA_IN(r, g, b, a, p);
if (a == 0x00) {
ret |= FF_ALPHA_TRANSP;
} else if (a != 0xff) {
ret |= FF_ALPHA_SEMI_TRANSP;
}
p += BPP;
}
p += src_wrap;
}
return ret;
}
#endif /* RGBA_IN */
#undef RGB_IN
#undef RGBA_IN
#undef RGB_OUT
......
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