@@ -38,6 +38,48 @@ typedef struct CDXLDemuxContext {

     int         audio_stream_index;

 } CDXLDemuxContext;

+static int cdxl_read_probe(AVProbeData *p)

+{

+    int score = AVPROBE_SCORE_MAX / 2 + 10;

+

+    if (p->buf_size < CDXL_HEADER_SIZE)

+        return 0;

+

+    /* reserved bytes should always be set to 0 */

+    if (AV_RN64(&p->buf[24]) || AV_RN16(&p->buf[10]))

+        return 0;

+

+    /* check type */

+    if (p->buf[0] != 1)

+        return 0;

+

+    /* check palette size */

+    if (AV_RB16(&p->buf[20]) > 512)

+        return 0;

+

+    /* check number of planes */

+    if (p->buf[18] || !p->buf[19])

+        return 0;

+

+    /* check widh and height */

+    if (!AV_RN16(&p->buf[14]) || !AV_RN16(&p->buf[16]))

+        return 0;

+

+    /* chunk size */

+    if (AV_RB32(&p->buf[2]) < AV_RB16(&p->buf[22]) + AV_RB16(&p->buf[20]) + CDXL_HEADER_SIZE)

+        return 0;

+

+    /* previous chunk size */

+    if (AV_RN32(&p->buf[6]))

+        score /= 2;

+

+    /* current frame number, usually starts from 1 */

+    if (AV_RB16(&p->buf[12]) != 1)

+        score /= 2;

+

+    return score;

+}

+

 static int cdxl_read_header(AVFormatContext *s)

 {

     CDXLDemuxContext *cdxl = s->priv_data;

@@ -173,6 +215,7 @@ AVInputFormat ff_cdxl_demuxer = {

     .name           = "cdxl",

     .long_name      = NULL_IF_CONFIG_SMALL("Commodore CDXL video"),

     .priv_data_size = sizeof(CDXLDemuxContext),

+    .read_probe     = cdxl_read_probe,

     .read_header    = cdxl_read_header,

     .read_packet    = cdxl_read_packet,

     .extensions     = "cdxl,xl",