diff options
-rw-r--r-- | libavcodec/pngdec.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c index a70a7f599b..fa69c87732 100644 --- a/libavcodec/pngdec.c +++ b/libavcodec/pngdec.c @@ -58,6 +58,7 @@ typedef struct PNGDecContext { int channels; int bits_per_pixel; int bpp; + int has_trns; uint8_t *image_buf; int image_linesize; @@ -732,6 +733,8 @@ static int decode_trns_chunk(AVCodecContext *avctx, PNGDecContext *s, } bytestream2_skip(&s->gb, 4); /* crc */ + s->has_trns = 1; + return 0; } @@ -848,6 +851,18 @@ static int decode_fctl_chunk(AVCodecContext *avctx, PNGDecContext *s, s->dispose_op = APNG_DISPOSE_OP_BACKGROUND; } + if (s->dispose_op == APNG_BLEND_OP_OVER && !s->has_trns && ( + avctx->pix_fmt == AV_PIX_FMT_RGB24 || + avctx->pix_fmt == AV_PIX_FMT_RGB48BE || + avctx->pix_fmt == AV_PIX_FMT_PAL8 || + avctx->pix_fmt == AV_PIX_FMT_GRAY8 || + avctx->pix_fmt == AV_PIX_FMT_GRAY16BE || + avctx->pix_fmt == AV_PIX_FMT_MONOBLACK + )) { + // APNG_DISPOSE_OP_OVER is the same as APNG_DISPOSE_OP_SOURCE when there is no alpha channel + s->dispose_op = APNG_BLEND_OP_SOURCE; + } + return 0; } |