diff options
Diffstat (limited to 'libhb/render.c')
| -rw-r--r-- | libhb/render.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/libhb/render.c b/libhb/render.c index a49bdfada..a8abd0e75 100644 --- a/libhb/render.c +++ b/libhb/render.c @@ -34,13 +34,33 @@ hb_work_object_t hb_render = renderClose }; +/* + * getU() & getV() + * + * Utility function that finds where the U is in the YUV sub-picture + * + * The Y data is at the top, followed by U and V, but the U and V + * are half the width of the Y, i.e. each chroma element covers 2x2 + * of the Y's. + */ +static uint8_t *getU(uint8_t *data, int width, int height, int x, int y) +{ + return(&data[(((y/2) * (width/2)) + (x/2)) + (width*height)]); +} + +static uint8_t *getV(uint8_t *data, int width, int height, int x, int y) +{ + return(&data[(((y/2) * (width/2)) + (x/2)) + (width*height) + + (width*height)/4]); +} + static void ApplySub( hb_job_t * job, hb_buffer_t * buf, hb_buffer_t ** _sub ) { hb_buffer_t * sub = *_sub; hb_title_t * title = job->title; int i, j, offset_top, offset_left; - uint8_t * lum, * alpha, * out; + uint8_t * lum, * alpha, * out, * sub_chromaU, * sub_chromaV; if( !sub ) { @@ -73,6 +93,9 @@ static void ApplySub( hb_job_t * job, hb_buffer_t * buf, lum = sub->data; alpha = lum + sub->width * sub->height; + sub_chromaU = alpha + sub->width * sub->height; + sub_chromaV = sub_chromaU + sub->width * sub->height; + out = buf->data + offset_top * title->width + offset_left; for( i = 0; i < sub->height; i++ ) @@ -83,14 +106,40 @@ static void ApplySub( hb_job_t * job, hb_buffer_t * buf, { if( offset_left + j >= 0 && offset_left + j < title->width ) { + uint8_t *chromaU, *chromaV; + + /* + * Merge the luminance and alpha with the picture + */ out[j] = ( (uint16_t) out[j] * ( 16 - (uint16_t) alpha[j] ) + (uint16_t) lum[j] * (uint16_t) alpha[j] ) >> 4; + /* + * Set the chroma (colour) based on whether there is + * any alpha at all. Don't try to blend with the picture. + */ + chromaU = getU(buf->data, title->width, title->height, + offset_left+j, offset_top+i); + + chromaV = getV(buf->data, title->width, title->height, + offset_left+j, offset_top+i); + + if( alpha[j] > 0 ) + { + /* + * Add the chroma from the sub-picture, as this is + * not a transparent element. + */ + *chromaU = sub_chromaU[j]; + *chromaV = sub_chromaV[j]; + } } } } lum += sub->width; alpha += sub->width; + sub_chromaU += sub->width; + sub_chromaV += sub->width; out += title->width; } |