static int estimate_best_b_count(MpegEncContext *s){
    AVCodec *codec= avcodec_find_encoder(s->avctx->codec_id);
    AVCodecContext *c= avcodec_alloc_context();
    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[FF_P_TYPE];
    b_lambda= s->last_lambda_for[FF_B_TYPE];
    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_open(c, codec) < 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.type != FF_BUFFER_TYPE_SHARED && i) {
                pre_input.data[0]+=INPLACE_OFFSET;
                pre_input.data[1]+=INPLACE_OFFSET;
                pre_input.data[2]+=INPLACE_OFFSET;
            }
            s->dsp.shrink[scale](input[i].data[0], input[i].linesize[0], pre_input.data[0], pre_input.linesize[0], c->width, c->height);
            s->dsp.shrink[scale](input[i].data[1], input[i].linesize[1], pre_input.data[1], pre_input.linesize[1], c->width>>1, c->height>>1);
            s->dsp.shrink[scale](input[i].data[2], input[i].linesize[2], pre_input.data[2], pre_input.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= FF_I_TYPE;
        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 ? FF_P_TYPE : FF_B_TYPE;
            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_context();\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[FF_P_TYPE];\n    b_lambda= s->last_lambda_for[FF_B_TYPE];\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_open(c, codec) < 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.type != FF_BUFFER_TYPE_SHARED && i) {\n                pre_input.data[0]+=INPLACE_OFFSET;\n                pre_input.data[1]+=INPLACE_OFFSET;\n                pre_input.data[2]+=INPLACE_OFFSET;\n            }\n            s->dsp.shrink[scale](input[i].data[0], input[i].linesize[0], pre_input.data[0], pre_input.linesize[0], c->width, c->height);\n            s->dsp.shrink[scale](input[i].data[1], input[i].linesize[1], pre_input.data[1], pre_input.linesize[1], c->width>>1, c->height>>1);\n            s->dsp.shrink[scale](input[i].data[2], input[i].linesize[2], pre_input.data[2], pre_input.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= FF_I_TYPE;\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 ? FF_P_TYPE : FF_B_TYPE;\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_context(void){\n    return avcodec_alloc_context2(AVMEDIA_TYPE_UNKNOWN);\n}', 'AVCodecContext *avcodec_alloc_context2(enum AVMediaType codec_type){\n    AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));\n    if(avctx==NULL) return NULL;\n    avcodec_get_context_defaults2(avctx, codec_type);\n    return avctx;\n}', 'void *av_malloc(FF_INTERNAL_MEM_TYPE 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}']