From: Bjorn Roche <bj...@xowave.com>
---
libavcodec/gif.c | 131 +++++++++++++++++++++++++++++++++----------------------
1 file changed, 78 insertions(+), 53 deletions(-)
diff --git a/libavcodec/gif.c b/libavcodec/gif.c
index db2193a718..3838aa7592 100644
--- a/libavcodec/gif.c
+++ b/libavcodec/gif.c
@@ -80,7 +80,7 @@ static int is_image_translucent(AVCodecContext *avctx,
const uint8_t *buf, const int linesize)
{
GIFContext *s = avctx->priv_data;
- int trans = s->transparent_index;
+ uint8_t trans = s->transparent_index;
int p;
const int m = avctx->width * avctx->height ;
@@ -88,7 +88,6 @@ static int is_image_translucent(AVCodecContext *avctx,
return 0;
}
- // FIXME: this might be faster with strchr
for( p=0; p<m; ++p ) {
if( buf[p] == trans ) {
return 1;
@@ -254,60 +253,86 @@ static int gif_image_write_translucent(AVCodecContext
*avctx,
AVPacket *pkt)
{
GIFContext *s = avctx->priv_data;
- int len = 0, height = avctx->height, width = avctx->width, x, y;
+ int len = 0, height = avctx->height, width = avctx->width, y;
int x_start = 0, y_start = 0, trans = s->transparent_index;
- int honor_transparency = (s->flags & GF_TRANSDIFF) && s->last_frame &&
!palette;
+ //int honor_transparency = (s->flags & GF_TRANSDIFF) && s->last_frame &&
!palette;
const uint8_t *ptr;
- // /* Crop image */
- // if ((s->flags & GF_OFFSETTING) && s->last_frame && !palette) {
- // const uint8_t *ref = s->last_frame->data[0];
- // const int ref_linesize = s->last_frame->linesize[0];
- // int x_end = avctx->width - 1,
- // y_end = avctx->height - 1;
-
- // /* skip common lines */
- // while (y_start < y_end) {
- // if (memcmp(ref + y_start*ref_linesize, buf + y_start*linesize,
width))
- // break;
- // y_start++;
- // }
- // while (y_end > y_start) {
- // if (memcmp(ref + y_end*ref_linesize, buf + y_end*linesize,
width))
- // break;
- // y_end--;
- // }
- // height = y_end + 1 - y_start;
-
- // /* skip common columns */
- // while (x_start < x_end) {
- // int same_column = 1;
- // for (y = y_start; y <= y_end; y++) {
- // if (ref[y*ref_linesize + x_start] != buf[y*linesize +
x_start]) {
- // same_column = 0;
- // break;
- // }
- // }
- // if (!same_column)
- // break;
- // x_start++;
- // }
- // while (x_end > x_start) {
- // int same_column = 1;
- // for (y = y_start; y <= y_end; y++) {
- // if (ref[y*ref_linesize + x_end] != buf[y*linesize + x_end])
{
- // same_column = 0;
- // break;
- // }
- // }
- // if (!same_column)
- // break;
- // x_end--;
- // }
- // width = x_end + 1 - x_start;
-
- // av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d)
[area:%dx%d]\n",
- // width, height, x_start, y_start, avctx->width,
avctx->height);
+ /* Crop Image */
+ if ( (s->flags & GF_OFFSETTING) && trans >=0 ) {
+ const int w = avctx->width;
+ const int h = avctx->height;
+ int x_end = w - 1,
+ y_end = h - 1;
+
+ // top
+ while (y_start < y_end) {
+ int i;
+ int is_trans = 1;
+ for( i=0; i<w; ++i ) {
+ if( buf[w*y_start+i] != trans ) {
+ is_trans = 0;
+ break;
+ }
+ }
+ if( !is_trans )
+ break;
+ ++y_start;
+ }
+
+ // bottom
+ while (y_end < h) {
+ int i;
+ int is_trans = 1;
+ for( i=0; i<w; ++i ) {
+ if( buf[w*y_end+i] != trans ) {
+ is_trans = 0;
+ break;
+ }
+ }
+ if( !is_trans )
+ break;
+ --y_end;
+ }
+
+ // left
+ while (x_start < x_end) {
+ int i;
+ int is_trans = 1;
+ for( i=y_start; i<y_end; ++i ) {
+ if( buf[w*i+x_start] != trans ) {
+ is_trans = 0;
+ break;
+ }
+ }
+ if( !is_trans )
+ break;
+ ++x_start;
+ }
+
+ // right
+ while (x_end < w) {
+ int i;
+ int is_trans = 1;
+ for( i=y_start; i<y_end; ++i ) {
+ if( buf[w*i+x_end] != trans ) {
+ is_trans = 0;
+ break;
+ }
+ }
+ if( !is_trans )
+ break;
+ --x_end;
+ }
+
+ height = y_end + 1 - y_start;
+ width = x_end + 1 - x_start;
+ av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n",
+ width, height, x_start, y_start, avctx->width, avctx->height);
+ }
+
+ // for( int i=0; i<avctx->width*avctx->height; ++i ) {
+ // ((uint8_t *)buf)[i] = 120;
// }
--
2.14.1
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