diff --git a/libavformat/pva.c b/libavformat/pva.c index fda5fc3867..1aad6db29d 100644 --- a/libavformat/pva.c +++ b/libavformat/pva.c @@ -31,13 +31,26 @@ typedef struct { int continue_pes; } PVAContext; +static int pva_check(uint8_t *p) { + int length = AV_RB16(p + 6); + if (AV_RB16(p) != PVA_MAGIC || !p[2] || p[2] > 2 || p[4] != 0x55 || + (p[5] & 0xe0) || length > PVA_MAX_PAYLOAD_LENGTH) + return -1; + return length + 8; +} + static int pva_probe(AVProbeData * pd) { unsigned char *buf = pd->buf; + int len = pva_check(buf); - if (AV_RB16(buf) == PVA_MAGIC && buf[2] && buf[2] < 3 && buf[4] == 0x55) + if (len < 0) + return 0; + + if (pd->buf_size >= len + 8 && + pva_check(buf + len) >= 0) return AVPROBE_SCORE_MAX / 2; - return 0; + return AVPROBE_SCORE_MAX / 4; } static int pva_read_header(AVFormatContext *s, AVFormatParameters *ap) {