It addes support PAL8 pixel format for APNG-picture.
The picture is http://littlesvr.ca/apng/samples.html (clock)
It is a qualification task of GSoC 2015 (mentor is Paul B Mahol)
---
libavcodec/pngdec.c | 58 +++++++++++++++++++++++++++++++++--------------------
1 file changed, 36 insertions(+), 22 deletions(-)
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 901abae..7dbf28a 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -877,7 +877,8 @@ static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
return ls;
if (s->blend_op == APNG_BLEND_OP_OVER &&
- avctx->pix_fmt != AV_PIX_FMT_RGBA && avctx->pix_fmt != AV_PIX_FMT_ARGB) {
+ avctx->pix_fmt != AV_PIX_FMT_RGBA && avctx->pix_fmt != AV_PIX_FMT_ARGB &&
+ avctx->pix_fmt != AV_PIX_FMT_PAL8) {
avpriv_request_sample(avctx, "Blending with pixel format %s",
av_get_pix_fmt_name(avctx->pix_fmt));
return AVERROR_PATCHWELCOME;
@@ -897,43 +898,56 @@ static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
uint8_t ri, gi, bi, ai;
pd_last_region += s->y_offset * s->image_linesize;
- if (avctx->pix_fmt == AV_PIX_FMT_RGBA) {
+ switch(avctx->pix_fmt)
+ {
+ case AV_PIX_FMT_RGBA:
ri = 0;
gi = 1;
bi = 2;
ai = 3;
- } else {
+ break;
+ case AV_PIX_FMT_ARGB:
ri = 3;
gi = 2;
bi = 1;
ai = 0;
+ break;
+ case AV_PIX_FMT_PAL8:
+ memcpy(s->palette, p->data[1], 256 * sizeof(uint32_t));
+ break;
}
for (j = s->y_offset; j < s->y_offset + s->cur_h; j++) {
i = s->x_offset * s->bpp;
+
if (i)
memcpy(pd, pd_last, i);
- for (; i < (s->x_offset + s->cur_w) * s->bpp; i += s->bpp) {
- uint8_t alpha = pd[i+ai];
-
- /* output = alpha * foreground + (1-alpha) * background */
- switch (alpha) {
- case 0:
- pd[i+ri] = pd_last_region[i+ri];
- pd[i+gi] = pd_last_region[i+gi];
- pd[i+bi] = pd_last_region[i+bi];
- pd[i+ai] = 0xff;
- break;
- case 255:
- break;
- default:
- pd[i+ri] = FAST_DIV255(alpha * pd[i+ri] + (255 - alpha) * pd_last_region[i+ri]);
- pd[i+gi] = FAST_DIV255(alpha * pd[i+gi] + (255 - alpha) * pd_last_region[i+gi]);
- pd[i+bi] = FAST_DIV255(alpha * pd[i+bi] + (255 - alpha) * pd_last_region[i+bi]);
- pd[i+ai] = 0xff;
- break;
+
+ if (avctx->pix_fmt != AV_PIX_FMT_PAL8) {
+ for (; i < (s->x_offset + s->cur_w) * s->bpp; i += s->bpp) {
+ uint8_t alpha = pd[i+ai];
+ /* output = alpha * foreground + (1-alpha) * background */
+ switch (alpha) {
+ case 0:
+ pd[i+ri] = pd_last_region[i+ri];
+ pd[i+gi] = pd_last_region[i+gi];
+ pd[i+bi] = pd_last_region[i+bi];
+ pd[i+ai] = 0xff;
+ break;
+ case 255:
+ break;
+ default:
+ pd[i+ri] = FAST_DIV255(alpha * pd[i+ri] + (255 - alpha) * pd_last_region[i+ri]);
+ pd[i+gi] = FAST_DIV255(alpha * pd[i+gi] + (255 - alpha) * pd_last_region[i+gi]);
+ pd[i+bi] = FAST_DIV255(alpha * pd[i+bi] + (255 - alpha) * pd_last_region[i+bi]);
+ pd[i+ai] = 0xff;
+ break;
+ }
}
}
+ else
+ i = (s->x_offset + s->cur_w) * s->bpp;
+
if (ls - i)
memcpy(pd+i, pd_last+i, ls - i);
pd += s->image_linesize;
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