diff options
| -rw-r--r-- | libavformat/mpeg.c | 39 | ||||
| -rw-r--r-- | libavformat/raw.c | 29 |
2 files changed, 37 insertions, 31 deletions
diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c index 294c807b07..dcbd8f0457 100644 --- a/libavformat/mpeg.c +++ b/libavformat/mpeg.c @@ -405,28 +405,31 @@ static int mpeg_mux_end(AVFormatContext *ctx) static int mpegps_probe(AVProbeData *p) { - int code, c, i; - code = 0xff; + int code; + const uint8_t *d; /* we search the first start code. If it is a packet start code, then we decide it is mpeg ps. We do not send highest value to give a chance to mpegts */ - for(i=0;i<p->buf_size;i++) { - c = p->buf[i]; - code = (code << 8) | c; - if ((code & 0xffffff00) == 0x100) { - if (code == PACK_START_CODE || - code == SYSTEM_HEADER_START_CODE || - (code >= 0x1e0 && code <= 0x1ef) || - (code >= 0x1c0 && code <= 0x1df) || - code == PRIVATE_STREAM_2 || - code == PROGRAM_STREAM_MAP || - code == PRIVATE_STREAM_1 || - code == PADDING_STREAM) - return AVPROBE_SCORE_MAX - 1; - else - return 0; - } + /* NOTE: the search range was restricted to avoid too many false + detections */ + + if (p->buf_size < 6) + return 0; + d = p->buf; + code = (d[0] << 24) | (d[1] << 16) | (d[2] << 8) | (d[3]); + if ((code & 0xffffff00) == 0x100) { + if (code == PACK_START_CODE || + code == SYSTEM_HEADER_START_CODE || + (code >= 0x1e0 && code <= 0x1ef) || + (code >= 0x1c0 && code <= 0x1df) || + code == PRIVATE_STREAM_2 || + code == PROGRAM_STREAM_MAP || + code == PRIVATE_STREAM_1 || + code == PADDING_STREAM) + return AVPROBE_SCORE_MAX - 1; + else + return 0; } return 0; } diff --git a/libavformat/raw.c b/libavformat/raw.c index 70185f8e42..e5cae2ff67 100644 --- a/libavformat/raw.c +++ b/libavformat/raw.c @@ -153,23 +153,26 @@ static int video_read_header(AVFormatContext *s, /* XXX: improve that by looking at several start codes */ static int mpegvideo_probe(AVProbeData *p) { - int code, c, i; - code = 0xff; + int code; + const uint8_t *d; /* we search the first start code. If it is a sequence, gop or picture start code then we decide it is an mpeg video stream. We do not send highest value to give a chance to mpegts */ - for(i=0;i<p->buf_size;i++) { - c = p->buf[i]; - code = (code << 8) | c; - if ((code & 0xffffff00) == 0x100) { - if (code == SEQ_START_CODE || - code == GOP_START_CODE || - code == PICTURE_START_CODE) - return 50 - 1; - else - return 0; - } + /* NOTE: the search range was restricted to avoid too many false + detections */ + + if (p->buf_size < 6) + return 0; + d = p->buf; + code = (d[0] << 24) | (d[1] << 16) | (d[2] << 8) | (d[3]); + if ((code & 0xffffff00) == 0x100) { + if (code == SEQ_START_CODE || + code == GOP_START_CODE || + code == PICTURE_START_CODE) + return 50 - 1; + else + return 0; } return 0; } |