diff options
| -rw-r--r-- | libavcodec/gif.h | 2 | ||||
| -rw-r--r-- | libavformat/gifdec.c | 24 |
2 files changed, 25 insertions, 1 deletions
diff --git a/libavcodec/gif.h b/libavcodec/gif.h index b5575344ac..b4cf66546c 100644 --- a/libavcodec/gif.h +++ b/libavcodec/gif.h @@ -43,5 +43,7 @@ static const uint8_t gif89a_sig[6] = "GIF89a"; #define GIF_EXTENSION_INTRODUCER 0x21 #define GIF_IMAGE_SEPARATOR 0x2c #define GIF_GCE_EXT_LABEL 0xf9 +#define GIF_APP_EXT_LABEL 0xff +#define NETSCAPE_EXT_STR "NETSCAPE2.0" #endif /* AVCODEC_GIFDEFS_H */ diff --git a/libavformat/gifdec.c b/libavformat/gifdec.c index 1122849abd..e05dc419c7 100644 --- a/libavformat/gifdec.c +++ b/libavformat/gifdec.c @@ -44,6 +44,13 @@ typedef struct GIFDemuxContext { */ int min_delay; int default_delay; + + /** + * loop options + */ + int total_iter; + int iter_count; + int ignore_loop; } GIFDemuxContext; /** @@ -156,6 +163,17 @@ static int gif_read_ext(AVFormatContext *s) /* skip the rest of the Graphic Control Extension block */ if ((ret = avio_skip(pb, sb_size - 3)) < 0 ) return ret; + } else if (ext_label == GIF_APP_EXT_LABEL) { + uint8_t netscape_ext[sizeof(NETSCAPE_EXT_STR)-1 + 2]; + + if ((sb_size = avio_r8(pb)) != strlen(NETSCAPE_EXT_STR)) + return 0; + ret = avio_read(pb, netscape_ext, sizeof(netscape_ext)); + if (ret < sizeof(netscape_ext)) + return ret; + gdc->total_iter = avio_rl16(pb); + if (gdc->total_iter == 0) + gdc->total_iter = -1; } if ((ret = gif_skip_subblocks(pb)) < 0) @@ -268,9 +286,12 @@ resync: } } - if (ret >= 0 && !frame_parsed) { + if ((ret >= 0 && !frame_parsed) || ret == AVERROR_EOF) { /* This might happen when there is no image block * between extension blocks and GIF_TRAILER or EOF */ + if (!gdc->ignore_loop && (block_label == GIF_TRAILER || url_feof(pb)) + && (gdc->total_iter < 0 || ++gdc->iter_count < gdc->total_iter)) + return avio_seek(pb, 0, SEEK_SET); return AVERROR_EOF; } else return ret; @@ -279,6 +300,7 @@ resync: static const AVOption options[] = { { "min_delay" , "minimum valid delay between frames (in hundredths of second)", offsetof(GIFDemuxContext, min_delay) , AV_OPT_TYPE_INT, {.i64 = GIF_MIN_DELAY} , 0, 100 * 60, AV_OPT_FLAG_DECODING_PARAM }, { "default_delay", "default delay between frames (in hundredths of second)" , offsetof(GIFDemuxContext, default_delay), AV_OPT_TYPE_INT, {.i64 = GIF_DEFAULT_DELAY}, 0, 100 * 60, AV_OPT_FLAG_DECODING_PARAM }, + { "ignore_loop" , "ignore loop setting (netscape extension)" , offsetof(GIFDemuxContext, ignore_loop) , AV_OPT_TYPE_INT, {.i64 = 1} , 0, 1, AV_OPT_FLAG_DECODING_PARAM }, { NULL }, }; |