libavcodec/mpegvideo_enc.c:984: error: Null Dereference
  pointer `c` last assigned on line 967 could be null and is dereferenced at line 984, column 5.

libavcodec/mpegvideo_enc.c:965:1: start of procedure estimate_best_b_count()
963. }
964. 
965. static int estimate_best_b_count(MpegEncContext *s){
     ^
966.     AVCodec *codec= avcodec_find_encoder(s->avctx->codec_id);
967.     AVCodecContext *c = avcodec_alloc_context3(NULL);

libavcodec/mpegvideo_enc.c:966:5: Skipping avcodec_find_encoder(): empty list of specs
964. 
965. static int estimate_best_b_count(MpegEncContext *s){
966.     AVCodec *codec= avcodec_find_encoder(s->avctx->codec_id);
         ^
967.     AVCodecContext *c = avcodec_alloc_context3(NULL);
968.     AVFrame input[FF_MAX_B_FRAMES+2];

libavcodec/mpegvideo_enc.c:967:5: 
965. static int estimate_best_b_count(MpegEncContext *s){
966.     AVCodec *codec= avcodec_find_encoder(s->avctx->codec_id);
967.     AVCodecContext *c = avcodec_alloc_context3(NULL);
         ^
968.     AVFrame input[FF_MAX_B_FRAMES+2];
969.     const int scale= s->avctx->brd_scale;

libavcodec/options.c:599:1: start of procedure avcodec_alloc_context3()
  597. }
  598. 
  599. AVCodecContext *avcodec_alloc_context3(AVCodec *codec){
       ^
  600.     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
  601. 

libavcodec/options.c:600:5: 
  598. 
  599. AVCodecContext *avcodec_alloc_context3(AVCodec *codec){
  600.     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
           ^
  601. 
  602.     if(avctx==NULL) return NULL;

libavutil/mem.c:64:1: start of procedure av_malloc()
    62.    linker will do it automatically. */
    63. 
    64. void *av_malloc(size_t size)
        ^
    65. {
    66.     void *ptr = NULL;

libavutil/mem.c:66:5: 
    64. void *av_malloc(size_t size)
    65. {
    66.     void *ptr = NULL;
            ^
    67. #if CONFIG_MEMALIGN_HACK
    68.     long diff;

libavutil/mem.c:72:8: Taking false branch
    70. 
    71.     /* let's disallow possible ambiguous cases */
    72.     if(size > (INT_MAX-32) )
               ^
    73.         return NULL;
    74. 

libavutil/mem.c:83:9: Taking false branch
    81.     ((char*)ptr)[-1]= diff;
    82. #elif HAVE_POSIX_MEMALIGN
    83.     if (posix_memalign(&ptr,32,size))
                ^
    84.         ptr = NULL;
    85. #elif HAVE_MEMALIGN

libavutil/mem.c:114:5: 
    112.     ptr = malloc(size);
    113. #endif
    114.     return ptr;
             ^
    115. }
    116. 

libavutil/mem.c:115:1: return from a call to av_malloc
    113. #endif
    114.     return ptr;
    115. }
         ^
    116. 
    117. void *av_realloc(void *ptr, size_t size)

libavcodec/options.c:602:8: Taking true branch
  600.     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
  601. 
  602.     if(avctx==NULL) return NULL;
              ^
  603. 
  604.     if(avcodec_get_context_defaults3(avctx, codec) < 0){

libavcodec/options.c:602:21: 
  600.     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
  601. 
  602.     if(avctx==NULL) return NULL;
                           ^
  603. 
  604.     if(avcodec_get_context_defaults3(avctx, codec) < 0){

libavcodec/options.c:610:1: return from a call to avcodec_alloc_context3
  608. 
  609.     return avctx;
  610. }
       ^
  611. 
  612. #if FF_API_ALLOC_CONTEXT

libavcodec/mpegvideo_enc.c:969:5: 
967.     AVCodecContext *c = avcodec_alloc_context3(NULL);
968.     AVFrame input[FF_MAX_B_FRAMES+2];
969.     const int scale= s->avctx->brd_scale;
         ^
970.     int i, j, out_size, p_lambda, b_lambda, lambda2;
971.     int outbuf_size= s->width * s->height; //FIXME

libavcodec/mpegvideo_enc.c:971:5: 
969.     const int scale= s->avctx->brd_scale;
970.     int i, j, out_size, p_lambda, b_lambda, lambda2;
971.     int outbuf_size= s->width * s->height; //FIXME
         ^
972.     uint8_t *outbuf= av_malloc(outbuf_size);
973.     int64_t best_rd= INT64_MAX;

libavcodec/mpegvideo_enc.c:972:5: 
970.     int i, j, out_size, p_lambda, b_lambda, lambda2;
971.     int outbuf_size= s->width * s->height; //FIXME
972.     uint8_t *outbuf= av_malloc(outbuf_size);
         ^
973.     int64_t best_rd= INT64_MAX;
974.     int best_b_count= -1;

libavutil/mem.c:64:1: start of procedure av_malloc()
  62.    linker will do it automatically. */
  63. 
  64. void *av_malloc(size_t size)
      ^
  65. {
  66.     void *ptr = NULL;

libavutil/mem.c:66:5: 
  64. void *av_malloc(size_t size)
  65. {
  66.     void *ptr = NULL;
          ^
  67. #if CONFIG_MEMALIGN_HACK
  68.     long diff;

libavutil/mem.c:72:8: Taking false branch
  70. 
  71.     /* let's disallow possible ambiguous cases */
  72.     if(size > (INT_MAX-32) )
             ^
  73.         return NULL;
  74. 

libavutil/mem.c:83:9: Taking false branch
  81.     ((char*)ptr)[-1]= diff;
  82. #elif HAVE_POSIX_MEMALIGN
  83.     if (posix_memalign(&ptr,32,size))
              ^
  84.         ptr = NULL;
  85. #elif HAVE_MEMALIGN

libavutil/mem.c:114:5: 
  112.     ptr = malloc(size);
  113. #endif
  114.     return ptr;
           ^
  115. }
  116. 

libavutil/mem.c:115:1: return from a call to av_malloc
  113. #endif
  114.     return ptr;
  115. }
       ^
  116. 
  117. void *av_realloc(void *ptr, size_t size)

libavcodec/mpegvideo_enc.c:973:5: 
971.     int outbuf_size= s->width * s->height; //FIXME
972.     uint8_t *outbuf= av_malloc(outbuf_size);
973.     int64_t best_rd= INT64_MAX;
         ^
974.     int best_b_count= -1;
975. 

libavcodec/mpegvideo_enc.c:974:5: 
972.     uint8_t *outbuf= av_malloc(outbuf_size);
973.     int64_t best_rd= INT64_MAX;
974.     int best_b_count= -1;
         ^
975. 
976.     assert(scale>=0 && scale <=3);

libavcodec/mpegvideo_enc.c:976:5: 
974.     int best_b_count= -1;
975. 
976.     assert(scale>=0 && scale <=3);
         ^
977. 
978. //    emms_c();

libavcodec/mpegvideo_enc.c:979:5: 
977. 
978. //    emms_c();
979.     p_lambda= s->last_lambda_for[AV_PICTURE_TYPE_P]; //s->next_picture_ptr->quality;
         ^
980.     b_lambda= s->last_lambda_for[AV_PICTURE_TYPE_B]; //p_lambda *FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset;
981.     if(!b_lambda) b_lambda= p_lambda; //FIXME we should do this somewhere else

libavcodec/mpegvideo_enc.c:980:5: 
978. //    emms_c();
979.     p_lambda= s->last_lambda_for[AV_PICTURE_TYPE_P]; //s->next_picture_ptr->quality;
980.     b_lambda= s->last_lambda_for[AV_PICTURE_TYPE_B]; //p_lambda *FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset;
         ^
981.     if(!b_lambda) b_lambda= p_lambda; //FIXME we should do this somewhere else
982.     lambda2= (b_lambda*b_lambda + (1<<FF_LAMBDA_SHIFT)/2 ) >> FF_LAMBDA_SHIFT;

libavcodec/mpegvideo_enc.c:981:9: Taking false branch
979.     p_lambda= s->last_lambda_for[AV_PICTURE_TYPE_P]; //s->next_picture_ptr->quality;
980.     b_lambda= s->last_lambda_for[AV_PICTURE_TYPE_B]; //p_lambda *FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset;
981.     if(!b_lambda) b_lambda= p_lambda; //FIXME we should do this somewhere else
             ^
982.     lambda2= (b_lambda*b_lambda + (1<<FF_LAMBDA_SHIFT)/2 ) >> FF_LAMBDA_SHIFT;
983. 

libavcodec/mpegvideo_enc.c:982:5: 
980.     b_lambda= s->last_lambda_for[AV_PICTURE_TYPE_B]; //p_lambda *FFABS(s->avctx->b_quant_factor) + s->avctx->b_quant_offset;
981.     if(!b_lambda) b_lambda= p_lambda; //FIXME we should do this somewhere else
982.     lambda2= (b_lambda*b_lambda + (1<<FF_LAMBDA_SHIFT)/2 ) >> FF_LAMBDA_SHIFT;
         ^
983. 
984.     c->width = s->width >> scale;

libavcodec/mpegvideo_enc.c:984:5: 
982.     lambda2= (b_lambda*b_lambda + (1<<FF_LAMBDA_SHIFT)/2 ) >> FF_LAMBDA_SHIFT;
983. 
984.     c->width = s->width >> scale;
         ^
985.     c->height= s->height>> scale;
986.     c->flags= CODEC_FLAG_QSCALE | CODEC_FLAG_PSNR | CODEC_FLAG_INPUT_PRESERVED /*| CODEC_FLAG_EMU_EDGE*/;

static int estimate_best_b_count(MpegEncContext *s){
    AVCodec *codec= avcodec_find_encoder(s->avctx->codec_id);
    AVCodecContext *c = avcodec_alloc_context3(NULL);
    AVFrame input[FF_MAX_B_FRAMES+2];
    const int scale= s->avctx->brd_scale;
    int i, j, out_size, p_lambda, b_lambda, lambda2;
    int outbuf_size= s->width * s->height;
    uint8_t *outbuf= av_malloc(outbuf_size);
    int64_t best_rd= INT64_MAX;
    int best_b_count= -1;
    assert(scale>=0 && scale <=3);
    p_lambda= s->last_lambda_for[AV_PICTURE_TYPE_P];
    b_lambda= s->last_lambda_for[AV_PICTURE_TYPE_B];
    if(!b_lambda) b_lambda= p_lambda;
    lambda2= (b_lambda*b_lambda + (1<<FF_LAMBDA_SHIFT)/2 ) >> FF_LAMBDA_SHIFT;
    c->width = s->width >> scale;
    c->height= s->height>> scale;
    c->flags= CODEC_FLAG_QSCALE | CODEC_FLAG_PSNR | CODEC_FLAG_INPUT_PRESERVED  ;
    c->flags|= s->avctx->flags & CODEC_FLAG_QPEL;
    c->mb_decision= s->avctx->mb_decision;
    c->me_cmp= s->avctx->me_cmp;
    c->mb_cmp= s->avctx->mb_cmp;
    c->me_sub_cmp= s->avctx->me_sub_cmp;
    c->pix_fmt = PIX_FMT_YUV420P;
    c->time_base= s->avctx->time_base;
    c->max_b_frames= s->max_b_frames;
    if (avcodec_open2(c, codec, NULL) < 0)
        return -1;
    for(i=0; i<s->max_b_frames+2; i++){
        int ysize= c->width*c->height;
        int csize= (c->width/2)*(c->height/2);
        Picture pre_input, *pre_input_ptr= i ? s->input_picture[i-1] : s->next_picture_ptr;
        avcodec_get_frame_defaults(&input[i]);
        input[i].data[0]= av_malloc(ysize + 2*csize);
        input[i].data[1]= input[i].data[0] + ysize;
        input[i].data[2]= input[i].data[1] + csize;
        input[i].linesize[0]= c->width;
        input[i].linesize[1]=
        input[i].linesize[2]= c->width/2;
        if(pre_input_ptr && (!i || s->input_picture[i-1])) {
            pre_input= *pre_input_ptr;
            if (pre_input.f.type != FF_BUFFER_TYPE_SHARED && i) {
                pre_input.f.data[0] += INPLACE_OFFSET;
                pre_input.f.data[1] += INPLACE_OFFSET;
                pre_input.f.data[2] += INPLACE_OFFSET;
            }
            s->dsp.shrink[scale](input[i].data[0], input[i].linesize[0], pre_input.f.data[0], pre_input.f.linesize[0], c->width,      c->height);
            s->dsp.shrink[scale](input[i].data[1], input[i].linesize[1], pre_input.f.data[1], pre_input.f.linesize[1], c->width >> 1, c->height >> 1);
            s->dsp.shrink[scale](input[i].data[2], input[i].linesize[2], pre_input.f.data[2], pre_input.f.linesize[2], c->width >> 1, c->height >> 1);
        }
    }
    for(j=0; j<s->max_b_frames+1; j++){
        int64_t rd=0;
        if(!s->input_picture[j])
            break;
        c->error[0]= c->error[1]= c->error[2]= 0;
        input[0].pict_type= AV_PICTURE_TYPE_I;
        input[0].quality= 1 * FF_QP2LAMBDA;
        out_size = avcodec_encode_video(c, outbuf, outbuf_size, &input[0]);
        for(i=0; i<s->max_b_frames+1; i++){
            int is_p= i % (j+1) == j || i==s->max_b_frames;
            input[i+1].pict_type= is_p ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_B;
            input[i+1].quality= is_p ? p_lambda : b_lambda;
            out_size = avcodec_encode_video(c, outbuf, outbuf_size, &input[i+1]);
            rd += (out_size * lambda2) >> (FF_LAMBDA_SHIFT - 3);
        }
        while(out_size){
            out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
            rd += (out_size * lambda2) >> (FF_LAMBDA_SHIFT - 3);
        }
        rd += c->error[0] + c->error[1] + c->error[2];
        if(rd < best_rd){
            best_rd= rd;
            best_b_count= j;
        }
    }
    av_freep(&outbuf);
    avcodec_close(c);
    av_freep(&c);
    for(i=0; i<s->max_b_frames+2; i++){
        av_freep(&input[i].data[0]);
    }
    return best_b_count;
}
['static int estimate_best_b_count(MpegEncContext *s){\n    AVCodec *codec= avcodec_find_encoder(s->avctx->codec_id);\n    AVCodecContext *c = avcodec_alloc_context3(NULL);\n    AVFrame input[FF_MAX_B_FRAMES+2];\n    const int scale= s->avctx->brd_scale;\n    int i, j, out_size, p_lambda, b_lambda, lambda2;\n    int outbuf_size= s->width * s->height;\n    uint8_t *outbuf= av_malloc(outbuf_size);\n    int64_t best_rd= INT64_MAX;\n    int best_b_count= -1;\n    assert(scale>=0 && scale <=3);\n    p_lambda= s->last_lambda_for[AV_PICTURE_TYPE_P];\n    b_lambda= s->last_lambda_for[AV_PICTURE_TYPE_B];\n    if(!b_lambda) b_lambda= p_lambda;\n    lambda2= (b_lambda*b_lambda + (1<<FF_LAMBDA_SHIFT)/2 ) >> FF_LAMBDA_SHIFT;\n    c->width = s->width >> scale;\n    c->height= s->height>> scale;\n    c->flags= CODEC_FLAG_QSCALE | CODEC_FLAG_PSNR | CODEC_FLAG_INPUT_PRESERVED  ;\n    c->flags|= s->avctx->flags & CODEC_FLAG_QPEL;\n    c->mb_decision= s->avctx->mb_decision;\n    c->me_cmp= s->avctx->me_cmp;\n    c->mb_cmp= s->avctx->mb_cmp;\n    c->me_sub_cmp= s->avctx->me_sub_cmp;\n    c->pix_fmt = PIX_FMT_YUV420P;\n    c->time_base= s->avctx->time_base;\n    c->max_b_frames= s->max_b_frames;\n    if (avcodec_open2(c, codec, NULL) < 0)\n        return -1;\n    for(i=0; i<s->max_b_frames+2; i++){\n        int ysize= c->width*c->height;\n        int csize= (c->width/2)*(c->height/2);\n        Picture pre_input, *pre_input_ptr= i ? s->input_picture[i-1] : s->next_picture_ptr;\n        avcodec_get_frame_defaults(&input[i]);\n        input[i].data[0]= av_malloc(ysize + 2*csize);\n        input[i].data[1]= input[i].data[0] + ysize;\n        input[i].data[2]= input[i].data[1] + csize;\n        input[i].linesize[0]= c->width;\n        input[i].linesize[1]=\n        input[i].linesize[2]= c->width/2;\n        if(pre_input_ptr && (!i || s->input_picture[i-1])) {\n            pre_input= *pre_input_ptr;\n            if (pre_input.f.type != FF_BUFFER_TYPE_SHARED && i) {\n                pre_input.f.data[0] += INPLACE_OFFSET;\n                pre_input.f.data[1] += INPLACE_OFFSET;\n                pre_input.f.data[2] += INPLACE_OFFSET;\n            }\n            s->dsp.shrink[scale](input[i].data[0], input[i].linesize[0], pre_input.f.data[0], pre_input.f.linesize[0], c->width,      c->height);\n            s->dsp.shrink[scale](input[i].data[1], input[i].linesize[1], pre_input.f.data[1], pre_input.f.linesize[1], c->width >> 1, c->height >> 1);\n            s->dsp.shrink[scale](input[i].data[2], input[i].linesize[2], pre_input.f.data[2], pre_input.f.linesize[2], c->width >> 1, c->height >> 1);\n        }\n    }\n    for(j=0; j<s->max_b_frames+1; j++){\n        int64_t rd=0;\n        if(!s->input_picture[j])\n            break;\n        c->error[0]= c->error[1]= c->error[2]= 0;\n        input[0].pict_type= AV_PICTURE_TYPE_I;\n        input[0].quality= 1 * FF_QP2LAMBDA;\n        out_size = avcodec_encode_video(c, outbuf, outbuf_size, &input[0]);\n        for(i=0; i<s->max_b_frames+1; i++){\n            int is_p= i % (j+1) == j || i==s->max_b_frames;\n            input[i+1].pict_type= is_p ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_B;\n            input[i+1].quality= is_p ? p_lambda : b_lambda;\n            out_size = avcodec_encode_video(c, outbuf, outbuf_size, &input[i+1]);\n            rd += (out_size * lambda2) >> (FF_LAMBDA_SHIFT - 3);\n        }\n        while(out_size){\n            out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);\n            rd += (out_size * lambda2) >> (FF_LAMBDA_SHIFT - 3);\n        }\n        rd += c->error[0] + c->error[1] + c->error[2];\n        if(rd < best_rd){\n            best_rd= rd;\n            best_b_count= j;\n        }\n    }\n    av_freep(&outbuf);\n    avcodec_close(c);\n    av_freep(&c);\n    for(i=0; i<s->max_b_frames+2; i++){\n        av_freep(&input[i].data[0]);\n    }\n    return best_b_count;\n}', 'AVCodecContext *avcodec_alloc_context3(AVCodec *codec){\n    AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));\n    if(avctx==NULL) return NULL;\n    if(avcodec_get_context_defaults3(avctx, codec) < 0){\n        av_free(avctx);\n        return NULL;\n    }\n    return avctx;\n}', 'void *av_malloc(size_t size)\n{\n    void *ptr = NULL;\n#if CONFIG_MEMALIGN_HACK\n    long diff;\n#endif\n    if(size > (INT_MAX-32) )\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    ptr = malloc(size+32);\n    if(!ptr)\n        return ptr;\n    diff= ((-(long)ptr - 1)&31) + 1;\n    ptr = (char*)ptr + diff;\n    ((char*)ptr)[-1]= diff;\n#elif HAVE_POSIX_MEMALIGN\n    if (posix_memalign(&ptr,32,size))\n        ptr = NULL;\n#elif HAVE_MEMALIGN\n    ptr = memalign(32,size);\n#else\n    ptr = malloc(size);\n#endif\n    return ptr;\n}']