libavformat/rtsp.c:1663: error: Null Dereference
  pointer `content` last assigned on line 1657 could be null and is dereferenced at line 1663, column 5.

libavformat/rtsp.c:1646:1: start of procedure sdp_read_header()
1644. #define SDP_MAX_SIZE 8192
1645. 
1646. static int sdp_read_header(AVFormatContext *s,
      ^
1647.                            AVFormatParameters *ap)
1648. {

libavformat/rtsp.c:1649:5: 
1647.                            AVFormatParameters *ap)
1648. {
1649.     RTSPState *rt = s->priv_data;
          ^
1650.     RTSPStream *rtsp_st;
1651.     int size, i, err;

libavformat/rtsp.c:1657:5: 
1655.     /* read the whole sdp file */
1656.     /* XXX: better loading */
1657.     content = av_malloc(SDP_MAX_SIZE);
          ^
1658.     size = get_buffer(s->pb, content, SDP_MAX_SIZE - 1);
1659.     if (size <= 0) {

libavutil/mem.c:47:1: start of procedure av_malloc()
  45.    linker will do it automatically. */
  46. 
  47. void *av_malloc(unsigned int size)
      ^
  48. {
  49.     void *ptr = NULL;

libavutil/mem.c:49:5: 
  47. void *av_malloc(unsigned int size)
  48. {
  49.     void *ptr = NULL;
          ^
  50. #if CONFIG_MEMALIGN_HACK
  51.     long diff;

libavutil/mem.c:55:8: Taking false branch
  53. 
  54.     /* let's disallow possible ambiguous cases */
  55.     if(size > (INT_MAX-16) )
             ^
  56.         return NULL;
  57. 

libavutil/mem.c:66:9: Taking true branch
  64.     ((char*)ptr)[-1]= diff;
  65. #elif HAVE_POSIX_MEMALIGN
  66.     if (posix_memalign(&ptr,16,size))
              ^
  67.         ptr = NULL;
  68. #elif HAVE_MEMALIGN

libavutil/mem.c:67:9: 
  65. #elif HAVE_POSIX_MEMALIGN
  66.     if (posix_memalign(&ptr,16,size))
  67.         ptr = NULL;
              ^
  68. #elif HAVE_MEMALIGN
  69.     ptr = memalign(16,size);

libavutil/mem.c:99:5: 
   97.     ptr = malloc(size);
   98. #endif
   99.     return ptr;
           ^
  100. }
  101. 

libavutil/mem.c:100:1: return from a call to av_malloc
   98. #endif
   99.     return ptr;
  100. }
       ^
  101. 
  102. void *av_realloc(void *ptr, unsigned int size)

libavformat/rtsp.c:1658:5: Skipping get_buffer(): empty list of specs
1656.     /* XXX: better loading */
1657.     content = av_malloc(SDP_MAX_SIZE);
1658.     size = get_buffer(s->pb, content, SDP_MAX_SIZE - 1);
          ^
1659.     if (size <= 0) {
1660.         av_free(content);

libavformat/rtsp.c:1659:9: Taking false branch
1657.     content = av_malloc(SDP_MAX_SIZE);
1658.     size = get_buffer(s->pb, content, SDP_MAX_SIZE - 1);
1659.     if (size <= 0) {
              ^
1660.         av_free(content);
1661.         return AVERROR_INVALIDDATA;

libavformat/rtsp.c:1663:5: 
1661.         return AVERROR_INVALIDDATA;
1662.     }
1663.     content[size] ='\0';
          ^
1664. 
1665.     sdp_parse(s, content);

static int sdp_read_header(AVFormatContext *s,
                           AVFormatParameters *ap)
{
    RTSPState *rt = s->priv_data;
    RTSPStream *rtsp_st;
    int size, i, err;
    char *content;
    char url[1024];
    content = av_malloc(SDP_MAX_SIZE);
    size = get_buffer(s->pb, content, SDP_MAX_SIZE - 1);
    if (size <= 0) {
        av_free(content);
        return AVERROR_INVALIDDATA;
    }
    content[size] ='\0';
    sdp_parse(s, content);
    av_free(content);
    for(i=0;i<rt->nb_rtsp_streams;i++) {
        rtsp_st = rt->rtsp_streams[i];
        snprintf(url, sizeof(url), "rtp://%s:%d?localport=%d&ttl=%d",
                 inet_ntoa(rtsp_st->sdp_ip),
                 rtsp_st->sdp_port,
                 rtsp_st->sdp_port,
                 rtsp_st->sdp_ttl);
        if (url_open(&rtsp_st->rtp_handle, url, URL_RDWR) < 0) {
            err = AVERROR_INVALIDDATA;
            goto fail;
        }
        if ((err = rtsp_open_transport_ctx(s, rtsp_st)))
            goto fail;
    }
    return 0;
 fail:
    rtsp_close_streams(rt);
    return err;
}
['static int sdp_read_header(AVFormatContext *s,\n                           AVFormatParameters *ap)\n{\n    RTSPState *rt = s->priv_data;\n    RTSPStream *rtsp_st;\n    int size, i, err;\n    char *content;\n    char url[1024];\n    content = av_malloc(SDP_MAX_SIZE);\n    size = get_buffer(s->pb, content, SDP_MAX_SIZE - 1);\n    if (size <= 0) {\n        av_free(content);\n        return AVERROR_INVALIDDATA;\n    }\n    content[size] =\'\\0\';\n    sdp_parse(s, content);\n    av_free(content);\n    for(i=0;i<rt->nb_rtsp_streams;i++) {\n        rtsp_st = rt->rtsp_streams[i];\n        snprintf(url, sizeof(url), "rtp://%s:%d?localport=%d&ttl=%d",\n                 inet_ntoa(rtsp_st->sdp_ip),\n                 rtsp_st->sdp_port,\n                 rtsp_st->sdp_port,\n                 rtsp_st->sdp_ttl);\n        if (url_open(&rtsp_st->rtp_handle, url, URL_RDWR) < 0) {\n            err = AVERROR_INVALIDDATA;\n            goto fail;\n        }\n        if ((err = rtsp_open_transport_ctx(s, rtsp_st)))\n            goto fail;\n    }\n    return 0;\n fail:\n    rtsp_close_streams(rt);\n    return err;\n}', 'void *av_malloc(unsigned int size)\n{\n    void *ptr = NULL;\n#if CONFIG_MEMALIGN_HACK\n    long diff;\n#endif\n    if(size > (INT_MAX-16) )\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    ptr = malloc(size+16);\n    if(!ptr)\n        return ptr;\n    diff= ((-(long)ptr - 1)&15) + 1;\n    ptr = (char*)ptr + diff;\n    ((char*)ptr)[-1]= diff;\n#elif HAVE_POSIX_MEMALIGN\n    if (posix_memalign(&ptr,16,size))\n        ptr = NULL;\n#elif HAVE_MEMALIGN\n    ptr = memalign(16,size);\n#else\n    ptr = malloc(size);\n#endif\n    return ptr;\n}']