check stream existence before assignment, fix #1222

Originally committed as revision 19259 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/mov.c

@@ -244,10 +244,15 @@ static int mov_read_default(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_dref(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     int entries, i, j;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_be32(pb); // version + flags
     entries = get_be32(pb);
     if (entries >= UINT_MAX / sizeof(*sc->drefs))
@@ -390,9 +395,13 @@ static const AVCodecTag mp4_audio_types[] = {
 
 static int mov_read_esds(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
     int tag, len;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+
     get_be32(pb); /* version + flags */
     len = mp4_read_descr(c, pb, &tag);
     if (tag == MP4ESDescrTag) {
@@ -449,7 +458,12 @@ static int mov_read_pasp(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
     const int num = get_be32(pb);
     const int den = get_be32(pb);
-    AVStream * const st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
+
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+
     if (den != 0) {
         if ((st->sample_aspect_ratio.den != 1 || st->sample_aspect_ratio.num) && // default
             (den != st->sample_aspect_ratio.den || num != st->sample_aspect_ratio.num))
@@ -503,12 +517,18 @@ static int mov_read_moof(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_mdhd(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
-    int version = get_byte(pb);
+    int version;
     char language[4] = {0};
     unsigned lang;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
+    version = get_byte(pb);
     if (version > 1)
         return -1; /* unsupported */
 
@@ -570,7 +590,11 @@ static int mov_read_mvhd(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_smi(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
+
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
 
     if((uint64_t)atom.size > (1<<30))
         return -1;
@@ -590,9 +614,14 @@ static int mov_read_smi(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_enda(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    int little_endian = get_be16(pb);
+    int little_endian;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+
+    little_endian = get_be16(pb);
     dprintf(c->fc, "enda %d\n", little_endian);
     if (little_endian == 1) {
         switch (st->codec->codec_id) {
@@ -642,7 +671,11 @@ static int mov_read_extradata(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_wave(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
+
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
 
     if((uint64_t)atom.size > (1<<30))
         return -1;
@@ -669,7 +702,11 @@ static int mov_read_wave(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
  */
 static int mov_read_glbl(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
+
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
 
     if((uint64_t)atom.size > (1<<30))
         return -1;
@@ -685,10 +722,15 @@ static int mov_read_glbl(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_stco(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     unsigned int i, entries;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
 
@@ -751,10 +793,15 @@ static enum CodecID mov_get_lpcm_codec_id(int bps, int flags)
 
 static int mov_read_stsd(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     int j, entries, pseudo_stream_id;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
 
@@ -1078,10 +1125,15 @@ static int mov_read_stsd(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_stsc(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     unsigned int i, entries;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
 
@@ -1135,10 +1187,15 @@ static int mov_read_stps(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_stss(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     unsigned int i, entries;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
 
@@ -1162,12 +1219,17 @@ static int mov_read_stss(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_stsz(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     unsigned int i, entries, sample_size, field_size, num_bytes;
     GetBitContext gb;
     unsigned char* buf;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
 
@@ -1225,12 +1287,17 @@ static int mov_read_stsz(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_stts(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     unsigned int i, entries;
     int64_t duration=0;
     int64_t total_sample_count=0;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
     entries = get_be32(pb);
@@ -1290,10 +1357,15 @@ static int mov_read_cslg(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 
 static int mov_read_ctts(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
 {
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
     unsigned int i, entries;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
     get_byte(pb); /* version */
     get_be24(pb); /* flags */
     entries = get_be32(pb);
@@ -1547,10 +1619,16 @@ static int mov_read_tkhd(MOVContext *c, ByteIOContext *pb, MOVAtom atom)
     int height;
     int64_t disp_transform[2];
     int display_matrix[3][2];
-    AVStream *st = c->fc->streams[c->fc->nb_streams-1];
+    AVStream *st;
-    MOVStreamContext *sc = st->priv_data;
+    MOVStreamContext *sc;
-    int version = get_byte(pb);
+    int version;
 
+    if (c->fc->nb_streams < 1)
+        return 0;
+    st = c->fc->streams[c->fc->nb_streams-1];
+    sc = st->priv_data;
+
+    version = get_byte(pb);
     get_be24(pb); /* flags */
     /*
     MOV_TRACK_ENABLED 0x0001