Optimize/simplify ebml_read_num.

[ffmpeg] / libavformat / mm.c

diff --git a/libavformat/mm.c b/libavformat/mm.c
index b72c259e143617fdc5fabc38aa22a01fb8662fee..cb0917a7abdbeec8880c662108f52f6ee1c7fd2e 100644 (file)
--- a/libavformat/mm.c
+++ b/libavformat/mm.c
@@ -20,9 +20,9 @@
  */
 
 /**
- * @file libavformat/mm.c
+ * @file
  * American Laser Games MM Format Demuxer
- * by Peter Ross (suxen_drol at hotmail dot com)
+ * by Peter Ross (pross@xvid.org)
  *
  * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
  * including Mad Dog McCree and Crime Patrol.
@@ -56,19 +56,31 @@ typedef struct {
   unsigned int audio_pts, video_pts;
 } MmDemuxContext;
 
-static int mm_probe(AVProbeData *p)
+static int probe(AVProbeData *p)
 {
+    int len, type, fps, w, h;
+    if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
+        return 0;
     /* the first chunk is always the header */
     if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
         return 0;
-    if (AV_RL32(&p->buf[2]) != MM_HEADER_LEN_V && AV_RL32(&p->buf[2]) != MM_HEADER_LEN_AV)
+    len = AV_RL32(&p->buf[2]);
+    if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
+        return 0;
+    fps = AV_RL16(&p->buf[8]);
+    w = AV_RL16(&p->buf[12]);
+    h = AV_RL16(&p->buf[14]);
+    if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
+        return 0;
+    type = AV_RL16(&p->buf[len]);
+    if (!type || type > 0x31)
         return 0;
 
     /* only return half certainty since this check is a bit sketchy */
     return AVPROBE_SCORE_MAX / 2;
 }
 
-static int mm_read_header(AVFormatContext *s,
+static int read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
 {
     MmDemuxContext *mm = s->priv_data;
@@ -96,7 +108,7 @@ static int mm_read_header(AVFormatContext *s,
     st = av_new_stream(s, 0);
     if (!st)
         return AVERROR(ENOMEM);
-    st->codec->codec_type = CODEC_TYPE_VIDEO;
+    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codec->codec_id = CODEC_ID_MMVIDEO;
     st->codec->codec_tag = 0;  /* no fourcc */
     st->codec->width = width;
@@ -108,7 +120,7 @@ static int mm_read_header(AVFormatContext *s,
         st = av_new_stream(s, 0);
         if (!st)
             return AVERROR(ENOMEM);
-        st->codec->codec_type = CODEC_TYPE_AUDIO;
+        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
         st->codec->codec_tag = 0; /* no fourcc */
         st->codec->codec_id = CODEC_ID_PCM_U8;
         st->codec->channels = 1;
@@ -121,7 +133,7 @@ static int mm_read_header(AVFormatContext *s,
     return 0;
 }
 
-static int mm_read_packet(AVFormatContext *s,
+static int read_packet(AVFormatContext *s,
                            AVPacket *pkt)
 {
     MmDemuxContext *mm = s->priv_data;
@@ -168,7 +180,7 @@ static int mm_read_packet(AVFormatContext *s,
             return 0;
 
         default :
-            av_log(NULL, AV_LOG_INFO, "mm: unknown chunk type 0x%x\n", type);
+            av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
             url_fseek(pb, length, SEEK_CUR);
         }
     }
@@ -180,7 +192,7 @@ AVInputFormat mm_demuxer = {
     "mm",
     NULL_IF_CONFIG_SMALL("American Laser Games MM format"),
     sizeof(MmDemuxContext),
-    mm_probe,
-    mm_read_header,
-    mm_read_packet,
+    probe,
+    read_header,
+    read_packet,
 };